/

NASA Technical Memorandum 4727

Pilot Evaluations of Runway Status Light

System

Steven D. Young, Robert W. Wills, and R. Marshall Smith

October 1996

NASA Technical Memorandum 4727

Pilot Evaluations of Runway Status Light

System

Steven D. Young, Robert W. Wills, and R. Marshall Smith

Langley Research Center • Hampton, Virginia

National Aeronautics and Space Administration

Langley Research Center • Hampton, Virginia 23681-0001

October 1996
The use of trademarks or names of manufacturers in this report is for

accurate reporting and does not constitute an official endorsement,

either expressed or implied, of such products or manufacturers by the

National Aeronautics and Space Administration.

Acknowledgments

The authors would like to thank Vern Edwards of the Federal Aviation Administration, Robert Rudis of the Volpe National Transportation Systems Center, Jerry Wright of the Air Line Pilots Association,

and the LaRC flight simulation laboratory staff for their help in this

investigation. Without their efforts, this project could not have been

completed.

Available electronically at the following URL address: http://techreports.larc.nasa.gov/Itrs/ltrs.html

Printed copies available from the following:

NASA Center for AeroSpace Information

800 Elkridge Landing Road

Linthicum Heights, MD 21090-2934

(301) 621-0390

National Technical Information Service (NTIS)

5285 Port Royal Road

Springfield, VA 22161-2171

(703) 487-4650
Contents

Abbreviations ...................................................................... v

Abstract ........................................................................... 1

1. Introduction ..................................................................... 1

2. Runway Status Light System ........................................................ 1

3. Simulation Environment ............................................................ 2

3.1. Simulation Facility ............................................................. 2

3.2. RWSL Implementation ......................................................... 2

3.3. Experiment Design ............................................................. 2

4. Pilot Responses ................................................................... 3

4.1. General Comments ............................................................. 3

4.1.1. Viability .................................................................. 3

4.1.2. Workload ................................................................. 3

4.1.3. Situational awareness ........................................................ 3

4.1.4. Clutter ................................................................... 3

4.1.5. Confusion ................................................................. 3

4.1.6. Integration with taxiway lighting system ......................................... 4

4.1.7. Runway incursion experiences ................................................ 4

4.2. Specific Design Issues .......................................................... 4

4.2.1. Conflicting information ...................................................... 4

4.2.2. In-pavement lights .......................................................... 4

4.2.3. Acute angle intersections ..................................................... 4

4.2.4. Cockpit display of runway status ............................................... 4

4.3. Suggested Improvements ........................................................ 5

4.3.1. THL conspicuousness ....................................................... 5

4.3.2. Series of THL's ............................................................ 5

4.3.3. Maintaining capacity ........................................................ 5

4.3.4. RWSL operational status ..................................................... 5

4.3.5. THL height ................................................................ 5

4.3.6. REL's .................................................................... 5

5. Observation ...................................................................... 6

6. Concluding Remarks .............................................................. 6

Appendix A--Simulated Flight Scenarios ................................................ 7

Appendix B--Pilot Questionnaires ..................................................... 8

Appendix C--Tabulated Pilot Responses ................................................ 9

Appendix D--Pilot Responses to Questionnaires ......................................... 10

References ....................................................................... 24

Figures .......................................................................... 25

ooo

I11

Abbreviations

a/c

ALPA

AMASS

AOPA

fliT.

ASMA

ASTA

ATC

ATIDS

ATIS

ATP

CAMAC

CGI

C/O

CRDS

dep.

DGPS

EADI

EHSI

FAA

F/E

aircraft

Air Line Pilot's Association

Airport Movement Area Safety System

Aircraft Owners and Pilots Association

arrival

airport surface movement area

Airport Surface Traffic Automation

air traffic control

Aircraft Tagging and Identifier System

Automatic Terminal Information System

airline transport pilot

Computer Automated Measurement and

Control

computer-generated image

Commanding Officer

calligraphic raster display system

departure

Differential Global Positioning System

electronic attitude display indicator

electronic horizontal situation indicator

Federal Aviation Administration

Flight Engineer

F/O

IFR

ILS

LaRC

ops

PAPI

REL

RVR

RWSL

sim.

SMA

SMEL

SMGCS

TAP

TCAS

THL

TSRV

VASI

VFR

VIOP

vis.

VMC

First Officer

instrument flight rules

Instrument Landing System

Langley Research Center

operations

precision approach path indicator

runway entrance lights

runway visual range

Runway Status Light System

simulator

Surface Movement Advisor

single and muitiengine license

Surface Movement Guidance Control

System

Terminal Area Productivity

Traffic Alert and Collision-Avoidance

System

takeoff hold lights

Transport Systems Research Vehicle

visual approach slope indicator

visual flight rules

VME Input/Output Processor

visibility

visual met conditions

Abstract

This study focuses on use of the Transport Systems Research Vehicle (TSRV) Simulator at the Langley Research Center to obtain pilot opinion and input on the Federal Aviation Administration's Runway Status Light System (RWSL) prior to

installation in an operational airport environment. The RWSL has been designed to

reduce the likelihood of runway incursions by visually alerting pilots when a runway

is occupied. Demonstrations of the RWSL in the TSRV Simulator allowed pilots to

evaluate the system in a realistic cockpit environment.

1. Introduction

Air traffic is expected to increase significantly in the

21st century. With geographical, environmental, and

zoning restrictions placed on most major U.S. airports,

expansion is severely constrained. Therefore, action must

be taken to increase the capacity and safety of existing

airport facilities. One area of focus is the airport surface

movement area (ASMA). The Federal Aviation Administration (FAA) has established Airport Surface Traffic

Automation (ASTA) programs to enhance safety and to

optimize the flow of traffic on the airport surface. These

programs include the Surface Movement Advisor

(SMA), the Airport Movement Area Safety System

(AMASS), the Aircraft Tagging and Identifier System

(ATIDS), and the Runway Status Light System (RWSL).

These programs address the various ASTA issues by

providing air traffic controllers, airline personnel, and

airfield management with positive identification of surface targets on the movement area; providing pilots with

airfield safety alerts; providing controllers with automated warnings of potential and actual runway incursions; providing a surface traffic planning capability; and

providing an automated method of sending instructions

(e.g., taxi route clearances) to aircraft.

Similarly, the National Aeronautics and Space

Administration (NASA) Terminal Area Productivity

(TAP) program is focused on providing technology and

operating procedures for safely achieving clear-weather

capacities in instrument-weather conditions. In cooperation with the FAA, NASA's approach is to develop and

demonstrate airborne and ground technology and procedures to safely reduce aircraft spacing in the terminal

area, enhance air traffic management, reduce controller

workload, improve low-visibility landing and surface

operations, and integrate aircraft and air traffic systems.

Because of LaRC's history of high-fidelity flight

simulation tests (refs. 1-3), realistic cockpit environments, and common interests in safely improving terminal area productivity under the TAP program, the FAA

and the Volpe National Transportation Systems Center

(Volpe Center) requested that LaRC conduct a flight simulation study that would implement a conceptual prototype and also allow for pilot evaluations of the RWSL.

This paper describes the simulation effort conducted as

part of the FAA's RWSL program and the NASA LaRC

TAP program.

The primary goal of the study was to obtain pilot

opinion of the potential usefulness of this lighting system

for reducing the likelihood of runway incursions on the

airport surface. To accomplish this, several incursion situations were introduced, as well as normal operational

situations, to allow pilots to observe the behavior of the

system under various conditions. No attempt was made

to acquire statistical data that would quantify the effectiveness of the RWSL.

Secondary goals were to (1) determine the impact of

the system in a realistic cockpit environment (e.g., Is the

system confusing? Does it add to pilot workload?);

(2) provide suggestions on design issues such as light

size, directionality, and location; and (3) acquire suggestions for operational procedures and areas of

improvement.

2. Runway Status Light System

The Runway Status Light System (RWSL) has been

developed by the FAA in cooperation with MIT Lincoln

Laboratory. (See ref. 4.) As described in reference 4, the

objective of the RWSL is to improve airport safety by

preventing runway incursions by both aircraft and

ground vehicles. Most runway incursions are caused by

human error usually brought about by a lack of situational awareness, failure to communicate properly, and

navigational errors. The RWSL is intended to minimize

the effect of human errors by providing an independent

source of information for pilots about the status of a runway. Currently, pilots obtain information about the status

of the runway from visual scans or from air traffic

control (ATC).

The RWSL operates by conveying the status of individual runways indicating whether or not runways are

unsafe to occupy. The RWSL is not intended to convey

clearance to proceed onto a runway or down a runway.

The RWSL is intended for use at all times of the day or

night.
Functionally, the RWSL is a system of lights automatically controlled through use of surface radar data.

Two types of lights make up the RWSL. (See fig. 1.)

Takeoff hold lights (THL's) are positioned to warn pilots

who are ready to take off that the runway is presently not

clear or that other aircraft are projected to enter the runway in front of the takeoff. The THL's are positioned on

either side of a runway ahead of the takeoff hold position. Runway entrance lights (REL's) are designed to

inform pilots (or ground vehicle operators) when a runway is unsafe to enter. The REL's are positioned on

either side of taxiways just prior to the intersection of the

taxiway and the runway. Both THL's and REL's are

bright red when "on."

A prototype of the RWSL was installed at the Boston

Logan International Airport by the Volpe Center in the

summer of 1995. This prototype system is being used for

extensive trials so that the RWSL can be fine-tuned in an

operational airport environment. Prior to this set of trials,

the FAA and the Volpe Center determined the need to

allow pilots to evaluate a prototype of the RWSL concept

in a simulated environment. Feedback from the pilot

community during the early stages of system development could provide support, not only for the trial system

in Boston, but also for an eventual operational implementation of the system that would evolve from the

Boston Logan prototype.

3. Simulation Environment

3.1. Simulation Facility

Initial pilot opinion of the proposed RWSL has been

obtained through a series of flight simulations performed

with the Transport Systems Research Vehicle (TSRV)

Simulator at the Langley Research Center. The TSRV

Simulator consists of a modified Boeing 737 cockpit that

contains an "all-glass" instrument panel, dual sidearm

controllers, Boeing 737 throttle quadrant and center aisle

stand, and a four-window display configuration that provides crew members with a 150 ° field of view of the outthe-window scene. (See ref. 5.) A block diagram of the

simulator (fig. 2) shows several systems that are required

to operate the simulation. Control inputs to the simulation are made through dual McFadden sidearm control

loaders, rudder pedals, and a tiller for nose wheel steering. The input is read at 32 Hz and sent over a fiber-optic

highway to a Convex minisupercomputer. (See ref. 6.)

The Boeing 737 simulation executed on the Convex

accurately simulates the flight dynamics experienced

during all phases of flight and taxi. The pilot receives aircraft state information from the instrument panel and outthe-window scenes from the computer-generated image

(CGI) system. The CGI used in the study was an Evans

and Sutherland CT6, which is a high-performance

system capable of rendering day and night scenes with

complex environmental special effects (e.g., fog, storms,

and clouds). The CGI-generated visual scenes accurately

depicted a three-dimensional view of the Denver,

Colorado, area (200 n.mi x 200 n.mi) from a Denver

database. The Denver Stapleton International Airport

(fig. 3) is modeled at the center of the database. The

lights, which made up the RWSL system, were included

in the database used by the CT6 to generate the out-thewindow scenes at the Denver Stapleton International

Airport. (See fig. 3.) The real-time system emulates

Boeing 737 flight dynamics during all phases of flight.

Further, the CT6 image generator can simulate other aircraft and show their movement in the fields of view of

the test subjects. The pilot receives instrumentation

information from the monitors mounted in the cockpit

panel. The calligraphic raster display system (CRDS)

provides an electronic attitude display indicator (EADI),

an electronic horizontal situation indicator (EHSI), and

other required information on the eight monitors

mounted in the cockpit.

3.2. RWSL Implementation

To perform the evaluations described previously,

REL and THL fixtures had to be depicted in the computer-generated image (CGI) of the Denver Stapleton airport (Denver database). The lights that make up the

RWSL were constructed in the Denver database.

Because of the limitation of the number of lights that can

reside in the CGI database, lights were located only on

runways 26L/8R and 26R/8L and the associated taxiways

leading to and from the terminal building. These are the

two parallel runways on the south side of the Denver

Stapleton airport. (See fig. 3.) The light fixtures were

specified as 12- by 24-in. rectangular boxes placed on the

surface. In areas where acute angles occur between the

taxiway and the runway, multiple lights were modeled in

multiple locations. This permits movement of lights to

determine the best locations so that pilots will be able to

see the lights. Each of these figures could be turned on

and off independently by the host computer. Each fixture

contained two circular lights 6 in. in diameter and centered in the box. The lights were red and the box enclosing them was black. Side and top fins were added to

allow the host computer to set the necessary directionality and beam width. These variables were added to the

specific on-field light fixture because the on-line operational characteristics were still to be determined during

the suitability assessment demonstration.

3.3. Experiment Design

Pilots were briefed on the purpose and limitations of

the RWSL-simulated demonstrations and were given the

opportunity to become familiar with the flight simulator

2
environment. Thepilotswerethenaskedto operatethe

simulatedaircraftduringtendifferentscenarios. Thescenariosincludedarrivalsanddeparturesthatpermitted

taxiingto andfromrunways.(SeeappendixA.) These

testsallowedthepilotstoevaluatetheRWSLundervariousoperational andsituationalconditions.Pilotswere

askedto answerseveralquestionsbothbeforeandafter

thesimulationsessions. Thequestionnaires arelistedin

appendixB.Theresponseshavebeenaccumulatedand

arepresentedin appendixesCandD.Theresultsof this

studywerebasedontheseresponsesaswellasoncommentsmadebythepilotsduringtheirvisits.

Departurescenariosstartedafterpushback, on the

initialtaxiway,inthecontrolledarea,andendedjustafter

takeoff.Arrivalscenariosstartedonfinalapproachand

endedattheramp.Crewswereaskedtoperformnormal

operational activitiesduringeachscenario(e.g.,checklistsandradiocommunications). Severalofthescenarios

placedpilotsin incursionsituationsthroughcontroller

misdirections.

An airtrafficcontroller(actingasboththeground

controllerandthetowercontroller)wassituatedat a

remotelocationandhadreal-timedisplaysof thetraffic

beingsimulated. Thiscontrollernotonlycommunicated

withthetestsubjectsduringthescenarios, butalsoemulatedvoicetrafficof otheraircraftin thefieldof viewof

thetestsubjects.

CockpitimefortheRWSLdemonstrationscenarios

was2hrforeachcrew.All cockpitaudioandvideowere

recordedaswellasatop-levelanimatedviewof theairportactivity.Theserecordingsallowedfor playbackof

anytest,if necessary.

Twenty-onepilotsparticipatedinthesimulationtest

andcompletedtheevaluationof theRWSLasdemonstratedin theTSRVsimulator.Thesepilotsrepresented

commercialairline pilots from USAir, United,and

AmericaWestAirlines,aswellaspilotsfromNASAand

thegeneralaviationcommunity.Of the16commercial

airlinepilots,12werecaptains,and4 werefirstofficers,

of which13weremembersof theAir LinePilot'sAssociation.Averagepilotexperiencewasnearly10000hrof

flighttime.

4. Pilot Responses

Subjects were asked to evaluate the RWSL in

the following three categories: (1) general comments,

(2) specific design issues, and (3) suggested improvements. Responses to each of these categories are presented in the following discussion. Tabulated data, along

with all questionnaire responses, are included in appendixes C and D.

4.1. General Comments

4.1.1. Viability. Responses reveal that test subjects

unanimously support the concept of the Runway Status

Light System. Further, they feel the status lights will, in

fact, reduce the likelihood of runway incursions on the

airport surface movement area. Test subjects frequently

referred to the system independence as being the most

attractive characteristic. By having a passive, independent source of status information to support the information pilots get from controllers and visual scans, little

doubt will exist about the situation with respect to active

runways. On the other hand, if they receive conflicting

information about the runway status, this independent

source can be used as a backup to prevent possibly proceeding into an incursion situation.

4.1.2. Workload. Seventy-six percent of the subjects

felt that the RWSL would not add to pilot workload in an

operational environment. This is based on the comment

that inclusion of one more item in your visual scan is not

a noticeable increase. However, the remaining 24 percent

did point out that the system will increase workload initially because of unfamiliarity and insufficient training.

Until the system becomes commonplace (i.e., part of the

user's habit) in the airport environment, additional work

will be required to understand this new system. Pilots felt

that, once the habit is formed, additional workload would

be negligible.

4.1.3. Situational awareness. Seventy-six percent

of subjects felt the RWSL would improve their situational awareness to a degree. The remaining 24 percent

felt it would not. The difference in opinion here can be

attributed to different definitions of situational awareness. Some of the 24-percent group are referring to positional awareness (e.g., "The RWSL will not help me

determine my location."). The 76-percent group is referring to the fact that the RWSL will improve their awareness of the other activity currently taking place on the

active runways which, in a manner, improves their

awareness of the situation.

4.1.4. Clutter. All subjects felt that the RWSL would

not add an unreasonable amount of clutter to their visual

scene at airports assuming the lights are hooded and

pointed correctly.

4.1.5. Confusion. Ninety percent of the test subjects

felt that the RWSL would not be confusing to pilots once

it is fully operational. Confusion may occur in three situations: (1) during the training period for new users,

(2) during any conflict between information received

(e.g., between the controller and the lights), and (3) during the time that the RWSL is not working properly.
Eachof thesesituationsmustbeaddressedtominimize

theconfusionthatmayoccur.

4.1.6.Integration with taxiway lighting system.

Ninety-five percent of the test subjects were comfortable

with the appearance of the RWSL in conjunction with the

Surface Movement Guidance Control System (SMGCS)

lights. One subject felt that these two systems could be

integrated functionally. Conceptually, the green taxiway

centerline lights that guide pilots onto the runway would

be triggered by the information received from the RWSL

logic as well as from the controller. These lights would

be driven by a logical "And" between the controller and

radar information indicating the status of the runway.

The lights would only be off (or green) if both the controller has given clearance and the RWSL determines

that the runway is safe to enter. This concept would eliminate the cost of additional light fixtures necessary for the

status lights.

4.1.7. Runway incursion experiences. Eighty-one

percent of the test subjects were aware of incursions that

could have been prevented with the RWSL in place.

Most often mentioned were the accident in the Canary

Islands (Tenerife) in the late 1970's (ref. 7) and the accident in Detroit in 1990 (refs. 8 and 9).

Also of note is the fact that the vast majority of test

subjects felt the RWSL would help them feel safer if an

incursion situation became likely. An incursion could

become more likely if a pilot questioned or doubted the

aircraft location or a taxi instruction. Subjects felt that

the RWSL would decrease the likelihood of an incursion

in these situations.

4.2. Specific Design Issues

Because of the nature of flight simulation environments, several design-implementation issues could not

be adequately addressed. Examples of these issues

include light intensity, glow effects, and beam widths.

These system attributes can only be effectively specified

based on real-world observations. However, a few

specific questions regarding the RWSL design were

answered by pilots who observed the RWSL in the simulated environment.

4.2.1. Conflicting information. With respect to operations, 81 percent of the subjects felt that, whenever

conflicting information is received in the cockpit (e.g.,

the controller says "go" and the lights say "stop"), pilots

should always hold their position and verify with the

tower how to proceed. Fourteen percent explicitly stated

that you should never cross a red light. The remaining

5 percent represents the opinion of the pilot who suggested the integration of SMGCS and the RWSL, which

would conceivably eliminate the possibility of receiving

conflicting information. Of importance with respect to

discrepancies, note that this is only pilots' opinion. The

design must also consider the controller's opinion on this

issue. Adequate consideration of this issue is critical to

the success of the RWSL.

4.2.2. In-pavement lights. Subjects were divided

with respect to installation of RWSL's in rows of inpavement lights. Of the test subjects, 33 percent liked the

idea, 49 percent did not, and 9 percent suggested having

both in-pavement lights and peripheral lights. The

remaining 9 percent did not have any opinions. All

candidates agreed that the cost may make in-pavement

lights prohibitive, but certainly situations exist where inpavement lights become necessary (e.g., extremely wide

taxiway intersections).

4.2.3. Acute angle intersections. Taxiways (as well

as runways) that intersect runways at acute angles

present a unique problem. The REL on the opposite side

of the taxiway (the obtuse angle side) may be much farther from the pilot's eye reference point than the REL on

the acute angle side. Conceivably, by the time a pilot

sees the distant REL, the aircraft may have already

incurred the runway or may not be stopped in time.

When asked about this situation, 76 percent of the subjects suggested placement of the distant REL closer to

the hold line along a line perpendicular to the taxiway

centerline and in line with the opposite REL. Further,

pilots suggested that there be three REL's at this type of

intersection; the first two should be at the normal location and the third at the point closer to the hold line. (See

fig. 4.) Lastly, one pilot who had suggested the integration approach mentioned earlier also noted that this problem would be eliminated if the same lights were used for

the RWSL that are used for the SMGCS, which are

already located in the centerline.

4.2.4. Cockpit display of runway status. When

asked if a status information display in the cockpit would

be preferred to lights on the airfield, 43 percent

responded positively, but 33 percent responded that a

cockpit display of status should only be used as a backup

or in low-visibility situations. In low-visibility situations,

the lights may not be visible until a runway incursion

becomes inevitable. The remaining 24 percent said a

cockpit display would not be preferred. The trade-off

here seems to be protection versus cost. A cockpit display of status could reduce much of the cost of the system; however, many vehicles would not be protected

from runway incursions because of lack of equipage

(e.g., ground vehicles). Also, the question of increased

heads-down time arose, which could lead to additional
incursions.Cockpitdisplayof statusinformationwould

seemmostusefulinlow-visibilitysituations.

4.3.SuggestedImprovements

Pilot concerns with the Runway Status Light System

have focused on the type and location of the status lights.

Future deployment of these lights on airport surfaces

must ensure that they are sufficiently conspicuous to

catch pilots' attention in all weather conditions. Several

suggestions to improve the light system have been made

by the test subjects.

4.3.1. THL conspicuousness. The most frequent

suggestions were related to the conspicuousness of the

takeoff hold lights (THL's). As pilots begin their takeoff

roll, they tend to get tunnel vision. Their visual scan

includes their instruments, but the focus of their attention

is directly down the centerline of the runway. They may

not even notice peripheral activity. Activation of THL's

must be conspicuous enough to get their attention so that

they can avoid a potential incursion. Most subjects suggested a flashing light fixture for the THL's. Some even

suggested this for the REL' s, although this would not be

as important. Pilots had no problems monitoring the state

of the REL's because pilots are more apt to do an outthe-window scan in all directions during taxi.

Another frequent suggestion for improving the conspicuousness of the THL's was to add an in-pavement

light near the centerline of the runway in line with the

two THL's on either side of the runway. This would

allow pilots to continue to focus on the centerline during

takeoff roll and still observe activation of the status light.

4.3.2. Series of THL's. To give pilots every opportunity to avoid an incursion while on takeoff roll, subjects

suggested a series of THL pairs located every 500 ft

down the runway where possible. This configuration

would cover two incursion situations not covered by the

current design: (1) the first THL pair has been activated

after the aircraft on takeoff roll has passed them and

(2) the pilot did not see the first THL pair even though

they were on. This added coverage is not necessary if

users always see and obey the lights, but it would protect

against someone inadvertently "running" a red light.

4.3.3. Maintaining capacity. Subjects felt that the

algorithm that activates the THL's based on the traffic

sequencing at specific airports also needs modification.

In the simulation, THL's came on when the nose of an

aircraft got within 50 ft of the runway edge, and the

THL's went off after the tail of the aircraft crossed a line

50 ft on the other side of the runway. Pilots suggest that

this could potentially impede the flow of traffic at some

airports. Often, if an aircraft is crossing the runway at a

long distance from the takeoff hold point, the departing

aircraft will be cleared to take off prior to the taxiing aircraft clearing the runway. Obviously, if the departing aircraft has to wait for the THL to go off, a delay of

possibly several seconds could occur.

Pilots have suggested two options for resolving this

problem: (1) move the trigger point so that the THL's go

off before the taxiing aircraft is actually clear of the runway (projecting that it will be clear soon) or (2) have the

controllers acknowledge the light state in their instructions (e.g., "NASA515, runway 8R, fly runway heading,

cleared for takeoff pending status lights.").

4.3.4. RWSL operational status. Some pilots suggested the need for an indication that the RWSL is working. This could be part of the Automatic Terminal

Information System (ATIS) services, but pilots would

prefer an indication on the light itself. Another suggestion was to have the status lights be either red or yellow,

but never off (unless they've failed or are being serviced). The yellow indication would relate "proceed with

caution," whereas the red indication would be the same

"stop." If the RWSL' s are down for any reason, the users

must be aware of this. Eventually, pilots may come to

depend on these lights to keep them out of trouble on the

airfield surface. Note, pilots stated that a "green" light

indication would not be effective because a pilot may

assume that it is an indication of clearance to go.

4.3.5. THL height. Pilots suggested raising THL's

2-3 ft off the ground. The light fixtures used in the simulation sat on the ground and were occasionally occluded

by runway edge lights, which also sit on the ground. This

occlusion only occurs from some viewing angles, but a

raised THL would correct this problem.

4.3.6. REL's. Only two suggestions were made with

respect to improving the REL's. The first is for situations

where wide areas of pavement intersect a runway. At

these locations, a number of in-pavement lights should

be installed between the side REL's that also denote runway status. Because of locations where aircraft await

clearance while sitting side by side on a taxiway, crews

may not be able to see the REL pair at the intersection.

Secondly, the use of the SMGCS taxiway centerline

light fixtures to denote runway status (in place of the

REL fixtures) could significantly reduce the cost of this

system at airports where SMGCS lights are operational.

Pilots have suggested that the centerline lights proceeding from a hold line out onto a runway could be forced to

turn "red" if either (1) they are not cleared onto the runway or (2) the RWSL logic declares the runway unsafe to

enter.
5. Observation

One observation with respect to the incursion scenarios that the test subjects were put through should be

noted as follows. Nearly all crews (either one- or twoman) passed an illuminated THL pair after being cleared

incorrectly to take off. In these situations, an aircraft was

crossing the runway somewhere down the runway in

front of the takeoff position (but hidden because of low

visibilities) thus illuminating the THL's. Crews, not

expecting an ATC misdirection, focused their attention

on takeoff duties and did not observe the THL activation.

After they had passed the THL's, ATC would issue an

abort for the takeoff to avoid a collision.

Most subjects remarked that because their attention

is mainly focused on the centerline at a point down the

runway during takeoff, they normally do not look peripherally. This caused pilots to suggest that THL's be more

conspicuous either by including an in-pavement THL

near the centerline or flashing THL's that would catch

the attention of pilots.

6. Concluding Remarks

The RWSL demonstrations performed at LaRC have

produced data from a unique perspective--the pilot' s. As

the most frequent users of the RWSL, pilots must support

its implementation. Further, the pilot community's inputs

should be seriously considered when implementing the

RWSL in an operational airport environment. Several

pilots were enthusiastic about this system because of the

fact that they (the pilot community) were being involved

in the design process prior to implementation. Subjects

suggested that if their input had been solicited for other

developmental systems, more effective systems could

have resulted.

Keep in mind that the opinions expressed in this

document are solely those of the test subjects who participated. Their opinions are based on a simulated demonstration of the RWSL. The authors recognized that

several specific questions about the RWSL could not be

answered in a simulated environment with present day

technology. These include issues such as required light

intensity, luminescence, and beam width. These questions can only be answered at an actual airport facility

busy with aircraft and ground activity where image resolution is no longer limited to a fixed number of pixels.

These demonstrations have shown that these pilots

unanimously support the concept of the Runway Status

Light System. Further, they feel that the RWSL will

reduce the likelihood of runway incursions on the airport

surface. Subjects were concerned with some of the specifications of the light fixtures--they must catch your

attention, light locations for some specific types of intersections (wide areas and acute angles), and timing of the

light state changes with respect to maintaining airport

capacity.

The authors believe that the most important aspect to

address beyond implementation is pilot training. Users

must understand precisely how the system works, and its

operation must become part of the culture in the airport

environment. Part of this training must ensure that users

will not become totally dependent on the RWSL to protect them. The system must also ensure that users will not

misinterpret the state of the lights to denote clearance.

The previous factors could prove fatal to the RWSL

effectiveness and conceivably cause additional incursion

situations.

NASA Langley Research Center

Hampton, VA 23681-0001

July 18, 1996
Appendix A

Simulated Flight Scenarios

The simulated flight scenarios are given in the following table:

No. Conditions Type Taxi route Traffic movement

1 VFR-day Dep.-8L B4-B-B3-C3-8L

a5

VFR-day

VFR-night

RVR = 600 ft

RVR = 800 fi

Dep.-8R

Dep.-26L

Dep.-8R

Dep.-8R

C4-C-CI-8R

C6-C-C12-26L

B4-B-B1-8R

C4-C-C1-8R

1. Arr.-8R

2. Dep.-8.

3. Arr.-8L

4. Taxi along B4 to ramp

1. Arr.-8L

2. Dep.-8R

3. Arr.-8R

4. Taxi along B4 to ramp

1. Arr.-26R

2. Dep.-26L

3. Arr.-26L

4. Taxi along B4 to ramp

1. Dep.-8R

2. Arr.-8R

3. Taxi along B4 to ramp

1. Arr.-8L

2. Dep.-8R

3. Arr.-8R

4. Taxi along B4 to ramp

b6 RVR = 600 ft Dep.-8R C4-B4-B-B I-8R 1. Arr.-8R

7 VFR-night Dep.-26R 1. Arr.-26L

2. Dep.-26R

3. Arr.-26R

4. Taxi along B4 to ramp

c8 RVR = 1200 ft Dep.-26L C6-up 26L-C9- 1. Dep.-26L

C-C12-26L 2. Backtaxi up 26L

o9 VFR-night Arr.-26L 26L-C6-ramp 1. Arr.-26R

dl0 RVR = 600 ft Arr.-26L 26L-C8-C- 1. Arr.-26R

a Pilot is misdirected by ATC to take off while there is an a/c taxiing across 8R. Crew cannot see this a/c because of reduced visibility.

b Pilot is misdirected to cross runway 8R as an a/c is landing on 8R. REL's illuminate prior to own ship incurring the runway but after the

hold line. Crew cannot see the arriving a/c because of reduced visibility.

c Similar to Tenerife accident. Pilot misdirected to take off on 26L while another a/c is backtaxiing up 26L toward him. Crew cannot see

backtaxiing a/c because of reduced visibility.

d Pilot misdirected to expedite across 26R to ramp while a/c lands on 26R. REL's illuminate prior to own ship incurring 26R but after own

ship has crossed the hold line.
Appendix B

Pilot Questionnaires

Preflight Questionnaire

1. Name

2. Date

3. Affiliation:

a. Air Line Pilot's Association (ALPA)

b. Aircraft Owners and Pilots Association

(AOPA)

4. Employer

5. Job title

6. Flight ratings

7. Approximate flight hours experience

8. Approximate flight hours in glass cock pits

9. Have you flown approaches/takeoffs in Category

III conditions? Where?

10. Experience with similar flight simulators (yes/

no)? Where?

11. Were you familiar with the FAA's ASTA program prior to today?

12. Were you familiar with the Runway Status Light

System prior to today?

13. Were you familiar with the Surface Movement

Guidance Control System (SMGCS) light system before

today?

Postflight Questionnaire

1. Do you feel that the Runway Status Light System

is a viable concept?

2. Do you feel that the Runway Status Light System

will reduce the likelihood of runway incursion?

3. Do you feel the Runway Status Light System will

add to pilot workload?

4. Do you feel that the Runway Status Light System

will improve your situational awareness?

5. Do the runway status lights add an unreasonable

amount of clutter to your visual scene during taxi operations (day/night)?

6. Do you feel the runway status lights will be confusing to pilots?

7. In low-visibility situations, were you comfortable

with the integration of the runway status lights and the

Surface Movement Guidance Control System (SMGCS)

lights (wigwags and stop bars)?

8. How would you improve the Runway Status

Light System?

9. How would you resolve a situation where the controller and the status lights disagree?

10. Would you prefer that the runway entrance lights

be an in-pavement row of lights? How about the takeoff

hold lights?

11. Positioning runway entrance lights on taxiways

that intersect runways at acute angles still has to be determined. Where would you suggest they be located at these

types of intersections? Closer to the runway or closer to

the hold line?

12. Would you prefer to have runway status displayed

in the cockpit in an electronic format (e.g., on an electronic taxi-map display)? Would this be useful to you?

13. Are you aware of any runway incursions that

could have been avoided if the Runway Status Light System had been in place?

14. (Optional) Have you ever questioned (or doubted)

a taxi clearance given to you? If so, would the Runway

Status Light System have helped you feel safe?

15. (Optional) Have you ever questioned (or doubted)

your location at an airport? If so, would the Runway Status Light System have helped you feel safe?

16. Any other general comments, criticisms, or support for the Runway Status Light System?

17. Finally, do you feel the TSRV simulator facility

provides adequate realism to evaluate the Runway Status

Light System concept?

8
Appendix C

Tabulated Pilot Responses

The numbers in this appendix correspond to the

question numbers in the postflight questionnaire in

appendix B. Two questions were omitted because the

answers were not easily tabulated, but those answers are

included in the responses in appendix D.

General Questions

Y/N

21/0

1. Do you feel that the RWSL is a viable

concept?

2. Do you feel that the RWSL will reduce

the likelihood of runway incursions? 21/0

3. Do you feel the RWSL will add to pilot

workload ? 5/16

4. Do you feel that the RWSL will improve

your situational awareness? 16/5

5. Does the RWSL add an unreasonable

amount of clutter to your visual scene? 0/21

6. Do you feel the RWSL will be confusing

to pilots? 2119

7. In low-visibility situations, were you

comfortable with the integration of the RWSL

and the Surface Movement Guidance Control

System (SMGCS) lights? 20/1

13. Are you aware of any runway incursions

that could have been avoided if the RWSL had

been in place? 17/4

14. Have you ever questioned (or doubted) a

taxi clearance given to you? 19/2

If so, would the RWSL have helped you

feel safe? 1714

15. Have you ever questioned (or doubted)

your location at an airport? 20/1

If so, would the RWSL have helped you

feel safe? 15/6

Specific Questions

9. How would you resolve a situation where the controller and the status lights disagree?

Verify with controller: 17

Never cross a red light: 3

Integrate with SMGCS: 1

10. Would you prefer that the REL's be an inpavement row of lights? THL' s?

Yes: 7

No: 10

Both: 2

Don't know: 2

11. Positioning REL' s on taxiways that intersect runways at acute angles has yet to be determined. Where

would you suggest they be located at these types of intersections? Closer to the runway or closer to the hold line?

Hold line: 16

Runway: 2

Both: 1

Integrate with SMGCS: 1

Don't know: 1

12. Would you prefer to have runway status displayed in the cockpit in an electronic format?

Yes: 9

No: 5

As backup for low vis.: 7

17. Do you feel that the TRSV simulator facility provides adequate realism to evaluate the RWSL concept?

Yes: 21

No: 0
Appendix D

Pilot Responses to Questionnaires

This appendix contains the written responses provided by the test pilots. The pilots have been assigned

identification letters a-u, and their responses to each

question are listed together.

Preflight Questionnaire Responses

5. Job title:

a. Pilot

b. Captain

c. Research Pilot

d. Pilot

e. - .....

. ......

g. Captain, Boeing 737-200

h. Captain

i. Check Airman-Captain

j. First Officer

k. Captain

1. Captain Boeing 737-3001400

m. F/O

n. Electronic Engineer (Private Pilot)

o. Aviation Safety Inspector

p. First Officer

q. Captain

r. Captain

s. First Officer

t. C/O

u. Lead Engineer

6. Flight ratings:

a. Boeing 737, 757, 767; DC-9; IA-JE7

b. ATP (airline transport pilot)

c. SMEL, glider, rotorcraft

d. ATP

e. DC-9; FK-28; Boeing 737, 757, 767

f. Boeing 737

g. ATP Boeing 757, 767, 737

h. ATP

i. F28; F100; Lear jet; Boeing 737, 727

j. ATP G-IV type

k. ATP-LRJET, Boeing 737-AMEL-COMM ASEL;

CFI-ASE, instrument; F/E-turbojet

1. FIC-28; DC-9; Boeing 737, 757, 767

m. DC-9

n. Private

o. ATP-Boeing 727; Citation

p. ATP-F/E Boeing 737; EC-9; Boeing 757, 767

q. ATP-Boeing 737; DC-9; F/E, COMM/INST R/W

r. Boeing 767, 757, 737; F-28; F-100

s. Boeing 727, 767, 757

t. F-100; Boeing 737; DC-9

u. Airplane single and multiengine commercial

license with instrument, commercial helicopter

7. Approximate flight hours experience:

a. 10000

b. 12000

c. 6500

d. 9500

e. 12750

f. 1100

g. 8 000

h. 17000

i. 4500

j. 5 300

k. 12000+

1. 1200

m. 12 000

n. 100

o. 5000

p. 9000

q. 11600

r. 9400

s. 6000

t. 9000

u. 1 700

8. Approximate flight hours in glass cockpits:

a. 3000

b. 0

c. 20 in flight (NASA C-402 in mid-1980's--part of

the single-pilot IFR program).

d. 50

e. 1200

f. 100

g. 800

h. 3000

i. 1000

j. 275

k. 0

1. 1000

m.0

n. Not applicable

o. 0

p. 1500

q. 0

r. 500

s. 2000

t. 100

u. 0

9. Have you flown approaches/takeoffs in Category III

conditions? Where?

a. Yes. CLT, LAX, LGW, FRA

b. Yes. Various places.

10
c. No.

d.Yes.BOS,PIT,ATL,BWI

e.Yes.PIT,CLT,LAX,SEA

f. Yes.TSRVsim.

g.Yes.CLT,BOS

h.No.

i. Yes.ORD,PIT,BOS,IND,CLT,andothers

j. Yes.Pittsburgh, Charlotte

k. Yes,formerlyPiedmont. I flewtheBoeing737-300

atCategory IIIA.

1. Yes. USAir--Domestic and International

(London, Gatwick, Paris, Orly)

m.No.

n. No.

o. Yes. Oklahoma City, FAA sim.

p. Yes. BWI, LGW, PHL

q. No.

r. Yes. USAir

s. Yes. Germany, France, England, Seattle

t. Yes. BOS

u. No.

10. Experience with similar flight simulators (yes/no)?

Where?

a. Yes. NASA, USAir, Piedmont

b. Yes. USAir

c. Yes. HL-20 in TSRV and a few other brief programs in TSRV.

d. Yes. USAir, PIT, CLT

e. Yes. SEA, Boeing 767-300

CLT, USAir Boeing 737-300/200

PIT, USAir Boeing 737-300/200, 757

TPA, Reflection; USAir FK-28

f. NASA Langley

g. Yes. USAir, Piedmont, Boeing

h. Yes. PHX

i. Yes. USAir Check Airman Simulator Instructor

F28, F100

j. Yes. USAir sim.,NASA

k. Yes. Airline

1. USAir Flight Operations

m. USAir sim.,Flight Safety St. Louis

n. No

o. Yes. FAA and Military (Navy)

p. Yes. USAir PIT, CLT, INT; Boeing SEA; Am

West PHX; Southwest DAL

q. Yes. Airline to USAir

r. Yes. NASA, Navy, USAir

s. Yes. Denver training

t. Yes. USAir

u. Yes, at Mitre.

11. Were you familiar with the FAA's ASTA program

prior to today?

a. No.

b. No.

c. Vaguely.

d. Yes, somewhat.

e. No.

f. Yes, somewhat.

g. No.

h. Yes.

i. No.

j. Somewhat.

k. No.

1. Yes.

m. Vaguely.

n. Yes.

o. Yes.

p. Somewhat.

q. No.

r. No.

s. No.

t. No.

u. Yes.

12. Were you familiar with the Runway Status Light System prior to today?

a. No.

b. No.

c. No.

d. No.

e. No.

f. No.

g. No.

h. Yes.

i. No.

j. No.

k. No.

1. No.

m. Vaguely.

n. Yes.

o. Yes.

p. No.

q. No.

r. No.

s. No.

t. Yes.

u. Yes.

13. Were you familiar with the Surface Movement Guidance Control System (SMGCS) light system before

today?

a. Yes.

b. No.

c. No.

d. Somewhat.

e. Yes.

f. No.

g. Somewhat.

11
h.Yes.

i. No.

j. No.

k. Yes.

1. Yes.

m. No.

n. Yes.

o. Yes.

p. Yes.

q. No.

r. Yes.

s. Yes.

t. Yes.

u. Yes.

Postflight Questionnaire Responses

1. Do you feel that the Runway Status Light System

is a viable concept?

a. Yes.

b. Yes.

c. Absolutely, the primary challenge, I think, is to

find good locations on the airfield for them.

d. Yes.

e. Yes.

f. Yes, I especially like independence from the

controller.

g. Yes.

h. Yes.

i. Yes.

j. Extremely viable because it is passively tied to

the ground surface radar and does not require human

activation. See comments on question 6.

k. Absolutely ! !

1. Yes. It does have a potential to enhance safety.

It does need refinement.

m. Viable concept yes. Needs improvement in the

type of warning lights.

n. Yes.

o. Yes.

p. Yes. As I mentioned earlier, though, I wonder

about reliability. However, if it had some sort of monitor

and this whole system could be shut down manually for

"glitches" or failures, I suppose it would be okay.

q. Yes, definitely.

12

r. Yes. It would be a definite aid in avoiding runway incursions.

s. Yes.

t. Yes.

u. Yes, if some of the physical characteristics of

the lights can be worked out.

2. Do you feel that the Runway Status Light System

will reduce the likelihood of runway incursions?

a. Yes.

b. Yes; however, at busy airports where aJc's are

cleared onto the runway while a landing a/c is still rolling

out, I see a potential problem where pilots could become

accustomed to ignoring the lights.

c. Yes. But it's essential that a habit of checking

and interpreting them be acquired by flight crews. In

effect this action should become part of the taxi and takeoff checklists

d.

e.

if there

aircraft.

f. Yes.

g. Yes.

h. Yes.

i. Yes. This system creates better situational

awareness for the pilot as well as the controllers and that

equates to a safer operation.

j. Yes! They will definitely increase pilot's situational awareness and act as a good backup system for

controller errors.

k. Yes. This is a great idea, long over due. I especially like it because the system operates independently

of controller-pilot actions.

1. Yes. It was helpful, but I had to take the caution

and resist depending on the system too much. My normal

pattern of scanning for traffic and incursions was slightly

affected when I relied on this technology.

m. Yes. If properly interpreted by the pilot. The

"THL" lights could be missed on low-vis, takeoffs.

n. Yes.

o. Yes.

p. Yes. I hope the current system is "good

enough" but feel as if the RWSL will provide an independent backup. I do wonder about how much of an

incremental reduction in runway incursions the system

Yes.

Yes. This will allow pilots to have a backup

is aircraft movement in the vicinity of their
will provideandhowthatreductionwill beaffectedby

systemreliability,i.e.,will abreakdownof thesystem

possiblycausesomeotherproblemthrougha chain

reaction.

q.Yes,definitely.

r. Yes!!To doso,however,it wouldneedto be

incorporatedintotrainingprograms. Tobeeffective,the

pilotswouldneedtobeawareofthelightsuntiltheyand

wepassthem.

s.Yes.

t.Yes.

u.Yes.It's anotherstepaddedto thechainof

eventsthatworktostoprunwayincursions.

3.DoyoufeeltheRunwayStatusLightSystemwill

addtopilotworkload?

a.No,providedpilotsunderstandthesystemand

aren'tconfusedbythisdisplaywhenit isseenagainstall

otherairportrunwaylight displays,suchasICShold

signs,in-groundtaxilightsystems, etc.

b.Notatall.

c.No.Theyareeasilyinterpretableandareeither

off or red.It isimportantthattheirpositioningbestandardsothatpilotsknowwheretolookforthemanddon't

missaredlightbylookinginthewrongplace.

d.No.Redor redflashinglightsduring"headsup"operationwouldbeeasilyrespondedto.

e. No.Not overall.Duringtheinitial stagesof

acclimationtothenewsystemtheremaybeanincrease

(slight)in workloadbutonlyuntilthesystembecomes

secondnaturetothepilot'sexternalscan.

f. No.Pilotworkloadisnotnecessarilyhighduringtaxi.Mightdecreaseworkloadbyinsuringsafertaxi

ops.

g.No.

h.No.

i. No.Thelightsshouldaidthepilotandactually

lessentheworkloadbyallowingforasaferoperation.

j. No.Theywill initiallytakepilotssomegetting

usedtolookingforthembutwouldquicklybecomepart

ofhishabitpattern.

k.Initially,yes,toasmallextent.However,once

thesystemisinstalledatmost-all airports and it becomes

standard, the pilots will treat this the same as any other

lighting system. And it will become second nature. Once

everybody is used to the system, I don't feel there will be

any increase in workload.

1.No.

m. Not a concern with me. In the simulator, I used

the additional input to make decisions about runway and

taxiway traffic.

n. Very little. It adds one more thing to watch for,

although the alternative is to completely trust the controller. In low visibility it added a tremendous amount of

comfort.

o. Somewhat. Another set of lights to watch for.

p. Yes. I think the additional workload is rather

small, but I do feel it is there. Maybe it is because I knew

what this test was for, but I found myself consciously

looking for the lights and trying to anticipate potential

conflicts that the lights would illuminate for. Whereas

the anticipation of conflicts would not be there day to

day, I feel as if the "looking for the lights" would be

there.

As an aside I reread this and feel I need to explain

that pilots try to "anticipate conflicts" always. I just felt

as though I were looking harder at this today (in the context of this study).

q. It will add very slightly to the workload. Pilots

will develop the habit of looking for the lights, but it will

be well worth it.

r. If one considers glancing at a light an increase

in workload, then yes. If it will save my behind, then no.

Basically, no.

s. No.

t. No.

u. Yes and no. It's another detail to look for in airport operations, but it's fairly easy to spot once accustomed to their presence. However, wide taxiways

connecting to a runway may present a problem.

4. Do you feel that the Runway Status Light System

will improve your situational awareness?

a. Yes. It will improve my situational awareness

in relation to areas where an incursion could occur but

not to overall airport awareness.

b. Yes.

c. Yes, in a gross sense. At least runway incursions should be less likely.

d. I don't think so. Only in the area of avoiding

wrongful incursions onto a taxiway or runway in the

immediate area. Would not help in determining your

position on the airport.

e. Yes. It will allow backup information from the

controller that there is no crossing traffic downfleid.

13
f. Notreally.Notanymorethanastoplightdoes

onthehighway.

g.Yes.

h.Yes.

i.Yes.Seeresponsetoquestion1.

j. Definitely,aslongasthereliabilityandvisibility remainsuseful.

k.Probablynot.Underthepresentsystemoftaxiway-runwaymarkingsandlights,apilothasmanycues

relativeto situational awareness. TheREL-THL'sreally

don'tprovide,per se, information that the pilot didn't

already have regarding aircraft location. They do provide

"conflict" information, however.

!. Yes. It also seems to provide another safety net

in areas of high-density operations. However, one can

not be sure what the obstruction really is.

m. We know that somethings there, but we don't

know what (e.g., aircraft, truck, etc.) or where (e.g.,

which taxiway).

n. Yes.

o. Yes.

p. Yes. I don't think it will improve my positional

awareness, but I do feel it will improve my awareness of

situation (e.g., low visibility, aircraft on approach). The

situation I describe may be impossible to detect from the

cockpit because we usually taxi with the Traffic Alert

and Collision-Avoidance System (TCAS) off. In good

weather you can look up and see the approaching aircraft. This is frequently not possible in foggy conditions.

q. No, it will not really help me to locate myself.

r. Yes, especially in low-visibility situation and at

night.

s. Yes.

t. Yes.

u. Yes. It should be as much of a benefit in visual

met conditions (VMC) as in low-vis, conditions, especially, because operations are usually pushed a little

tighter in VMC a lot of times.

5. Do the runway status lights add an unreasonable

amount of clutter to your visual scene during taxi operations (day-night)?

a. No, but possibility of confusion where runway

signs might exist.

b. No. However, there were times (during the sim.

session) where I could only see one light or saw both

lights but one brighter then the other. Ex.: one scenario

involved a high-speed turnoff which then crossed an

active runway. I noticed the right "REL" but could not

see the left one (it was farther away and initially blocked

by a taxi light). I think the REL's would stand out more if

they were perpendicular to the taxi centerline (may be

connected by a printed line). This would eliminate the

possibility of seeing one light and not the other.

c. No, either day or night. However, the status

lights should not be closely surrounded by a mass of

other ground lights.

d. No.

e. No.

f. No. Visual, day/night scene is not normally

cluttered on an airport. In fact, sometimes one has to look

for signage to help find one's way.

g. No.

h. No.

i. No. During night ops the lights might possibly

be a little harder to discern if not placed correctly or in a

location where they will not be confused with other lights

on the surface.

j. Not at all. There are already a lot of lights on the

airfield but having these lights lets the pilot know exactly

what the status is of the runway the pilot may be crossing

or taking off from.

k. No. If anything, they need to be more eyecatching.

1. No. However, depending on the pilot's eye

position in the cockpit, I did not like the picture I saw

when the red RWSL was blocked by the white runway

edge identifier lights.

m. Didn't seem to in the simulator.

n. No (for day or night).

o. If their physical positioning to other lights or

features is complicated, then the status lights would be

more difficult to discern.

p. No. There is probably some clutter at night

(particularly if the lights were very bright), but I did not

feel as though there was any "clutter" in the day visuals.

Also any clutter in the night scene was definitely

acceptable.

q. They don't add much to clutter. The real issue

is: will they stand out from the clutter when illuminated?

(See no. 8.)

r. No, for daytime. Yes, to some degree, at night

when there are many other lights out there, all having a

meaning.

14
s.No.

t.Day,no.Night,no.

u. Not asdepictedin thesimulation(question

remainsof visibilityfromallaircraftypes).

6.Doyoufeeltherunwaystatuslightswill beconfusingtopilots?

a.Notaslongaspilotsunderstandtheblanksign

meansclear(andnotbroken)anddonotconfuselights

withverbalclearancegivenbycontroller.

b. No.Exceptasnotedbyquestion4.Also,how

will you addresslarge "run-upblocks,"e.g.,TPA

runway18.

c.No.Theyconveyasimplemessage. Anysubtypesof meaningorreasonsfortheirilluminationwould

havetobeclarifiedbytalkingtothecontroller.

d.No.

e.No,notoncethepilothasbecomeconditioned

totheirmeaning.TheonlyproblemI canforeseeisthat

thepilot maysubconsciouslyinterprethelight being

turnedoff as"clearancefortakeoff."

f. No,shouldbenaturalsituation,i.e.,redmeans

stop.

g.No.

h.No.

i. No.

j. No.I'm sure90percentof thetimetheywill be

off, especiallytheintersectionlights.At manyairports

(e.g.,Philadelphia), takeoffsandlandingsinvolvecrossinganactiverunwayonbothevents.Theselightswould

beveryvaluableatthoseairports.

k.No,notif they'recoloredredandplainlyvisible.Thecolor"red"tellsit all.

1.Yes.Asstatedinquestion4.Also,I takecautionforI thinkatwo-barvisualapproachslopeindicator

(VASI)systemmaybeconfusedwiththeselights.Round

VASIprecisionapproachpathindicator(PAPI)lights

wouldnotbeconfusedwiththisconcept.

m.ThesteadyredlightscouldbemissedonIowvis.taxiconditions.Perhapsblinkinglightscouldreduce

theconfusion.

n. Pilotswhoareeducatedon theiroperation

shouldnotfindthemconfusing.AlthoughI didnotfind

themconfusing,I canseepotentialfor confusion,especiallyinconjunctionwithstopbarsandwigwags.

o. Not if adequatetrainingto all pilots is

conducted.

p.No.I likethesimplicity.I havetwosmallchildrenandveryearlyontheyknew"GreenforGo,Redfor

Stop."Thissystemisevensimplerbecausewecandelete

the"Green."

q.No.(Seeno.8.)

r.No.

s.No.

t.No,butaprioritymustbethatstatuslightsare

firstandATCclearancesecond.

u.No.However,theymightmakepilotsquestion

thecontrollersmore(hopefullyonlywhenneeded).

7.In low-visibilitysituations,wereyoucomfortable

withtheintegrationof therunwaystatuslightsandthe

SurfaceMovementGuidanceControlSystem(SMGCS)

lights(wigwagsandstopbars)?

a.Verycomfortable, butisthisoverkill?Perhaps

toomuchinformation.Wouldbeniceif systemswere

combinedsomehowto eliminateanyconfusionfromso

manylights.

b.Noproblem.

c.Notfamiliartome.

d. I'm sureI wouldbe comfortablewith this

system.

e.Yes.I feelthisisamust.I foundtheEuropean

Systemat London'sGatwickfor taxiingto bequite

helpful.

f. Yes.Wigwagsarenecessaryto precludemissingtheredlights.

g.Yes.

h.Yes.

i. Yes.Considerationneedsto begiventoplacementof thelightsatthemostoptimumpointaswellas

theheightofthelightsabovetheground.Flashinglights

wouldalsobemorereadilyvisibletothepilots.

j. Yes.Althoughredundantintheirintent,I liked

theconceptthattheRWSLwasnotcontrolleractivated

because,if thesamecontrollerclearsyouto crossin

error,thecontrollerwill alsoturnoff theSMGCSin

error,but the RWSLshouldoverridean erroneous

clearance.

k.Yes.I foundthatto bea muchbettersystem

integratedasit was.

1.I wasverycomfortablewiththissystem.When

in use,theselightsoffera protectivemeasureof safety

thatisunquestionable.

15
m.Yes.

n. Becauseof my previousknowledgeof both

subjects, I didnotfindthecombinationconfusing;otherwise,I probablywouldhave.I didnotethatI waspaying

farmoreattentiontotheRWSLthantothestopbar.

o.Yes.

p.Yes.I felt asif theywerecomplementary. In

rethinkingthescenarios,I knowthatI waitedfor the

SMGCSlightstogooutatleastduringonescenariobut

donotknowif I taxiedoveranyilluminatedSMGCS

lights.I maynothave.I justdon'trememberwhetherI

didornot.

q. No.

These need to

r. Yes.

I thought there was lightbulb overload.

be better integrated.

s. Yes.

t. Yes.

u. Yes. As depicted, they were different enough

not to be a problem.

8. How would you improve the Runway Status Light

System?

a. (1) Large displays.

(2) Distance from hold short line to display

bars might be difficult to see in extremely low vis., i.e.,

0-0.

(3) Include some indication that system is

working when blank.

b. As noted in question 4. Also, the REL's would

be more effective if they blinked in the scenario with the

SMGCS; I think it would be more effective to have the

yellow SMGCS warning lights steady (less important)

and the red REL's blinking (more important).

c. See following comments.

d. Study and implement this system in the already

established centerline system.

e. Make the light boxes bigger. Might even consider placing another set of red lights about 1000 ft

beyond the first set to allow pilots a "secondary view" in

case an aircraft or truck began crossing the runway

downfield after brake release and takeoff roll had been

initiated. Must be careful not to confuse them with VASI

lights.

f. Need to see them in real life to see brightness,

size, etc. Might need to be brighter. Especially in bright

daylight conditions.

g. Wide taxiways need more indicators. Burbank

airport has an unusually wide paved area. Would prefer

flashing lights. Modify on/off time for THL's. The

THL's must catch your attention. Perhaps a series of

them.

h. Flashing lights, at least in daytime. Need to

modify the on/off timing of the THL's to ensure that

capacity is not affected.

i. (1) Flashing lights versus steady lights.

(2) Raising the height of the lights to make

them more visible.

(3) Making sure the lights will not be confused

with any other surface lights.

j. I would raise them 2 1/2-3 ft above the ground.

This elevation would give a better line of sight from most

cockpits because they would be well above any taxiwayrunway lights. Also, in winter this elevation will limit

effects of snow accumulation which might otherwise

obscure visibility of the lights. I would also make the

THL flashing instead of steady. Pilot workload at power

up for takeoff is higher than during taxi and flashing

THL would get their attention better.

k. The REL lights should be placed (perhaps in

conjunction with existing REL lights) along the hold

short line. Perhaps in the concrete.

1. I would alternately blink these lights, in the

same manner as the SMGCS. There would be little confusion on their purpose. Most of the lights we see burn

steady. Blinking lights would be a definitive cue of a runway incursion.

m. Perhaps a blinking red light would be more

distinguishable than a simple steady red light. At present

we have many steady red lights on the airport: red nav.

lights, red VASI lights, and red approach lights. A red

light in the middle of the runway may improve interpretation of the THL lights.

n. ----

o. (1) Initial intensity of lights should be sufficiently conspicuous to pilots and vehicle operators.

(2) Time to turn on and turn off should be

slightly greater. A landing aircraft generates a quick on,

then off, indication. Pilots may want to know of landing

aircraft situations a little sooner.

(3) After crossing the hold short line and about

to enter a runway, the lights could be triggered to come

so abruptly that an average pilot may not be able to stop

his aircraft soon enough without entering a part of the

runway. See question 11.

16
p. Lightplacementseemsokay.Theyaresortof

marginallybrightcurrentlyaspointedoutinthebriefing.

I wouldbecarefulof makingthemsobrightastointerferewithvisiondowntherunwayortaxiway.Thisparticularlyappliestonightoperations.

q. I wouldmakethemmoreconspicuousand

moreunique:thatis,housethemin auniquecabinetor

useanarrayof lightswhichmakesthemmoredistinguishablefromotherlights.I wouldconsiderhaving

lightsbothatholdlinesandattherunwayedgestogive

advancewarningin low-vis,conditionsandthenlastditchwarningwhenpastheholdline.

r. Largerlights.Blinkinglights.Movelights

downtherunway.Thesystemneedstobeableto"reach

outandgrabyou"to getyourattention.A systemthat

mayormaynotgetyourattentionwouldbenogood.

s.Noimprovement thatI canthinkof now.Appears

to beanexcellentideaandprobablyshouldhavebeen

incorporatedyearsago!

t.Fortakeoffandlanding,I donotlikethelightson

thesideof therunway.A barin thecenterwouldwork

fine.

u.Isthereanywaytoknowthedifferencebetweena

brokenlight(orcablerun)andonethatisoff?

9.Howwouldyouresolveasituationwherethecontrollerandthestatuslightsdisagree?

a.Pilotmustcallcontrollerforverificationof situation.Thisis currentlydonein Europewhentaxiing

usinggroundtaxilightsystems.

b.Themostrestrictiveshouldapplyuntilclarified

byverbalcommunication.

c. Followthe mostconservativeconsequence

whilecallingground/tower forclarification.

d. I wouldlike to seestatuslightsincorporated

withcenterlinelightingintaxiwaysandrunways.Changing from green to red would be very effective and

recognizable.

e. Obey the status lights unless the pilot in command can obey controller instructions or if the pilot has

the conflicting traffic in sight and believes it poses no

threat or hazard.

f. Until it could be proven that lights were faulty,

they must be honored. Controller may not have all the

necessary info.

g. Verify with ATC.

h. Verify with ATC.

i. The pilot and a/c should hold position until both

lights and controller agree no conflict exists.

j. Pilots are taught early on to query the controller

if there is any doubt on their clearance. If there is still a

disagreement and the pilots have seen strong reliability

with the RWSL, they should believe the lights first and

question the controller again.

k. The procedure should be to adhere to the lights

while checking with the controller and informing him of

the status of the REL's or THL's.

1. Stop the aircraft and obtain qualification of

instructions. At the same time (from a pilot's point of

view), never place the aircraft in a position of ambiguity

or harm.

m. Utilization of airport ground radar to confirm a

disagreement.

n. Exactly as we did during the simulation:

(1) stop, (2) inform controller of illuminated runway

status lights, and (3) await further instructions.

o. Turn off the system. Pilot should not taxi past

any illumination red lights, such as the case with stop

bars.

p. I suppose I alluded to this earlier with my comment about a manual shutoff. As a pilot, I would not

enter a runway with red lights or take off with red take

hold lights without a substantial discussion with a controller. This presumes very low visibility. Obviously, if I

can also see no traffic, I would probably go with the controller even if the RWSL did disagree. If the controller

knows she/he is right and the status lights are wrong, the

RWSL should be shut down.

q. Pilots should be trained to stop for a light until

getting a verbal confirmation from a controller to

proceed.

r. Status lights rule until an actual condition is

confirmed by other V's.

s. Talk to ground-tower about disparity.

t. Status lights must be controlling.

u. Pilot asks the controller for clarification. After

confirmation that everything is ok with the controller and

visually verifying the area to the best of his/her ability,

then the pilot can proceed. Shutdown rules and criteria

should be established.

10. Would you prefer that runway entrance lights be

an in-pavement row of lights? How about takeoff hold

lights?

a. Runway entrance lights and takeoff hold lights

could both be in the ground. This would allow a pilot

17
duringextremelylow-vis,conditionsto beableto look

out of cockpitwindowsdirectlydownandseelights,

becauseforwardvisibilityissometimeslimitedbycockpitheight,e.g.,Boeing747,767,andDC-10.

b. TheREL'sin thepavementwouldbemore

noticeablebutI don'tthinktheaddedcostis necessary.

However,connectingthetwoedgelightswithapainted

line(perhapsa redbrokenline)wouldbeaneffective

substitute. AsfortheTHL'sontakeoff,theflying pilot is

initially focused on the runway centerline thereby making it possible to overlook the edge lights.

c. The main consideration is making the lights

easy to see. This means that they should be visible from

positions away from runway lights. Also, they should be

visible from positions some distance and angle off the

normal entrance and/or hold positions. These factors may

or may not favor in-pavement lights.

d. Yes. Takeoff hold lights would almost eliminate unauthorized taxiing onto an active runway.

e. No. Because during snowy or icy conditions,

the lights will be covered over and not visible to the

cockpit. Be placed only in pavement as change backup.

f. Runway entrance lights with wigwag okay.

Takeoff hold lights may need some more work. A row of

lights might be good at night, maybe not so good in

daytime.

g. No, because of snow problem. Perhaps could

integrate with SMGCS.

h. No, because of snow problem.

i. I feel the runway entrance lights could actually

use both systems. When the taxiways or airport surfaces

are contaminated, the in-pavement lights could be covered up. The takeoff hold lights are fine the way I tested

them considering that, possibly, they should be elevated

and should flash.

j. During winter ops, the in-pavement row of

lights might have some limitations. Under normal taxi

conditions, the in-pavement lights are very effective. I

would not prefer in-pavement for THL because most

people look downfield for takeoff roll not down in front

on the pavement.

k. Ref. REL's; yes. (See question 8.)

Ref. THL's; I'm not sure yet, how to do that. The

present TIlL display is not optimal and needs to be modified but at this point, I'm not sure exactly how to handle

that.

1. I would suggest that these lights be left as they

are except for the following recommendations:

(1) Place a third round red light in the centerline of the taxiway.

(2) Wigwag these lights to get the pilot's

attention.

m. Yes, for both.

n. For most of the intersection, the elevated lights

worked fine. The wide throats and places where a pilot

approaches the lights from an angle probably needs inset

lights. At times during the simulation (physically), I

could not see the runway status lights. The THL's should

be enhanced in some way. Insets may have some problem with bumps on runways.

600-ft

Below

tion to

o. In all cases but very low visibility (less than

RVR), the above-ground version is acceptable.

600-ft RVR operations, require that all informathe pilot be on or near the taxiway center line.

p. The REL's might be better this way. That

might help with the next question. I don't feel it is necessary for the THL's, but it might make them harder to

miss. If they were installed, I feel it would become

almost automatic to look for them though. (You would

be unlikely to miss them.)

q. No. Snow, ice, or even heavy rain contamination could render them ineffective.

r. In the pavement would be nice, but weather

phenomenon (e.g., snow, ice, sand) would probably

make it unrealistic.

s. No. The two lights on the side of the taxiway

are certainly sufficient. The in-pavement row of lights

would also do the job. Regarding the THL's, once we

were used to them, they were also very sufficient.

t. I would like to see all the lights in the pavement.

u. These are the physical characteristics of the

lights that need to be resolved. If they are in the pavement, what happens with a little snow? Will pilots in all

heights of cockpits be able to see them? How are they

kept from shining all over the airport?

11. Position of runway entrance lights on taxiways

that intersect runways at acute angles still has to be determined. Where would you suggest they be located at these

types of intersections? Closer to the runway or closer to

the hold line?

a. Closer to the hold line. Currently pilots look for

hold short lines in an effort to determine position relative

to runway, this light should probably be close to the lines

to stop further incursions toward the runway in an effort

to see REL system in low-vis, conditions.

18
b. Closeto therunwaybutperpendicular to the

taxicenterline.Seequestion4.

c.Closetotheholdline.Rationale:thisinformationismostimportantto youwhenyouareat thehold

lineandshouldbemosteasilyinterpretablethere.

d. Hereagain,centerlineplacementsolvesthis

problem.Greento redactivationof theselightscould

takeplaceatanytimeandatalongerdistance.

e.Closertotheholdline.Maybeplacetwosetsof

lights:oneattheholdlineandoneattherunway.

. .....

g. Closer to hold line.

h. Not sure.

i. Closer to the hold line and also in the pavement.

j. Close to the hold line especially on the captain's

side (left); closer to the hold line is where you expect to

stop so. If the red lights are where you are looking,

chances are better that you'll see them.

k. I'm a proponent of having the REL's at the

hold line with the REL's at the runway, possibly, as a

backup.

i. At intersections, they could be installed flush

with the ground. In winter, the heat from the lights would

more than likely warm any precipitation falling on them.

Closer to the hold line.

m. Closer to the hold short line or in the pavement

at the hold short line.

n. The REL's were more conspicuous when both

could be seen at the same time. They should probably be

on a line perpendicular to the taxiway.

o. Closer to the hold line, which gives the pilot

more time to react.

p. Lights beside the taxiway should probably be

by the hold line. Lights in the pavement should probably

form a "do not cross line" parallel to the runway

centerline.

q. Both. Closer to the runway to give pilots a "last

chance" to stop and at the hold line for advance warning.

r. Closer to the runway for last-ditch opportunity

to prevent an incursion.

s. Closer to the hold line so they can be easily

detected and observed in low-vis, situations.

t. The hold line.

u. Intuitively, I'd say closer to the runway. If the

aircraft is positioned right at the hold line, the aircraft

crew may have difficulty seeing lights at the hold line.

12. Would you prefer to have runway status displayed in the cockpit in an electronic format (e.g., on an

electronic taxi-map display)? Would this be useful to

you?

a. Yes, it would be useful, but I would be concerned with the possibility of an aircraft system failure so

I would probably want this only as a backup to the

ground system.

b. Based on today's a/c configuration, outside

lights are the way to go.

c. This would be good supplemental information

but not a primary source. Because the airplane is taxied

by looking outside the cockpit, having the lights outside

makes sense. The electronic display might have some

utility in depicting the runway status before you could

see it from the cockpit.

d. I dont think so. The flight crew could use an

airport taxi map in the cockpit incorporated with glass

cockpit displays. The flight crew must be "outside" during critical taxi phases of operation. Airport taxi-map

displays in the cockpit should be used for situational or

positional reference only.

e. Yes. Unfortunately, if this equipment broke, the

company would certainly defer repair. I believe fixtures

on the airport environment to be our best bet.

f. Yes, would preclude getting "lost", taking

wrong route, missing a turn, etc. Electronic taxi map is

highly desirable.

g. Yes, as long as it doesn't increase workload in

the cockpit.

h. My preference depends on how the equipment

is integrated.

i. Absolutely. Any input given to the flight crews

to increase situational awareness and increase the level of

operating safety would be of great use.

j. I'm not sure if that would be cost-effective

because very little time is spent looking inside during

taxi out. It might be a good backup under extremely lowvis. ground ops especially if the copilot was instructed to

monitor the n/c progress on the map display.

k. This would be great ..... but how far down the

road this technology would be and how expensive are the

main factors to consider. You have to remember, that

unless revenue is enhanced, airlines are typically reluctant to buy new gadgets. Quite frankly money is the primary consideration among airline executives today.

19
Also,if adisplayweretobeputinthecockpit,it needsto

bevisiblebyall pilotsin thecockpitandnotjustbythe

Captain.So,you'dneedascreenthatall canseeormore

thanonescreen.

1.Notreally.Tokeeponschedule, ourworkload

wouldbeincreasedandcauseuspossiblytomissother

importantitems.To apilot,theseitems(outsideof the

cockpit)aremoreusefulintheirplaceoutsidethaninour

scaninsidethecockpit.

m.No.Wealreadyhaveourheadsandeyesinthe

cockpitoomuchnow.Weneedtobelookingoutsideto

uselogicandthinkingskills.

n.I preferthemtobelightsontheairfield;howeverif amovingmapis installed,theRWSLindication

shouldprobablybeduplicatedonthemap.

o. No. Taxiing procedures call for good external

visual scanning, not focused in one area.

p. No. I think 99 percent of the time this would

not be that helpful. During that other fractional percentage, it would probably be very helpful. This question gets

me thinking about reliability of the equipment again.

With another layer of data link or whatever, what are we

setting ourselves up for when it does break down. Also it

brings up the vision of taxiing with your "head down" in

the cockpit. I was thinking about a ground radar system

"broadcasting" to the cockpit. If the system was more of

a TCAS-type system, it might take away some of my

objections, but I still think I would not like it.

q. I would prefer it in addition to outside lights, as

long as only the lights appropriate to my position on the

taxi map came on. Otherwise, such lights could sucker

me into believing I were somewhere else.

r. I would not prefer this. I believe that the more

pilots can be outside the cockpit, the safer the operation

will be.

IS.

b. Personally, no, but obviously DTW and Canary

c. Not personally familiar.

d. Yes.

e. Perhaps the Northwest flights in Detroit,

PanAm and KLM in the Canary Islands, Delta and Flying Tigers in Chicago, and Delta and North Central Convair 580 in Chicago. These are the immediate ones that

come to mind.

f. Not really.

g. Yes, Detroit and Tenerife.

h. Detroit and Tenerife.

i. Yes. Two incursions come to mind right away.

Detroit and the accident several years ago in the Canary

Islands (Tenerife). Also I had a situation of my own in

LGA a couple of years ago; we were cleared for takeoff

when another a/c was cleared for takeoff on an intersecting runway.

j. I'm sure that the Tenerife and Detroit accidents

would have been prevented. That would have saved

about 500 lives right there. It's definitely worth the cost.

k. Yes! You have to remember that pilots have

been known to take off or land on a runway other than

the one that they were cleared for. This is another reason

why the idea of this system is so great!

1. Possibly the Northwest Orient incursion at

DTW. Possibly the KLM-PanAm accident in Tenerife.

m. Detroit. Could the L.A. accident have been

avoided? Where an a/c was on the runway and another

a/c was cleared to land on the same runway.

n. Detroit 1990 for the aircraft taking off.

o. Yes

s. Yes. Any additional tool would be helpful,

especially while taxiing at busy airports (e.g., O'Hare).

t. Yes. A electronic taxi-map display would be

useful.

p. Yes. Tenerife, Detroit.

q. I am aware of a near-runway incursion which

would have been stopped sooner if such a system had

been installed.

u. Yes, I believe it would, especially once taxi

clearances are given and displayed electronically causing

more heads-down time in the cockpit anyway. This

would potentially offset the heads-down time. However,

a continual outside scan is still going to be of vital

importance.

13. Are you aware of any runway incursions that

could have been avoided if the Runway Status Light System had been in place?

a. Yes.

r. Personally, no.

s. Sure. Detroit accident with Northwest Airlines.

Also, Tenerife!

t. ----

u. Yes, if they would have been visible. Detroit

accident.

14. (Optional) Have you ever questioned (or

doubted) a taxi clearance given to you? If so, would the

Runway Status Light System have helped you feel safe?

2O
a.Yes.Yes.It wouldhavevalidatedthecontroller

or caused me to question his instruction.

b. Yes. Yes.

c. Yes; yes, in the short term, but I would clear up

any uncertainty by asking the ground controller.

d. Yes. Red "do not continue warning lights"

would have been helpful.

e. Yes. Yes.

f. Rarely do controllers make errors, e.g., taxi

clearances. When I am in doubt when at a strange airport,

I ask for "progressive taxi", which means the controller

will call all turns.

g. Yes and yes.

h. Yes and yes.

i. Yes. If the clearance were to cross an intersecting runway, I would feel much more comfortable crossing that runway if this system were in place.

j. I always question myself before crossing an

active runway. If I have the slightest doubt, I query the

controller. I do the same thing on takeoff clearance versus position and hold. I've caught a couple of errors in

my 20 years of flying military and civilian.

k. Yes, I have doubted-questioned a clearance.

Safety and legality are two factors. The REL system

(also THL) would help me feel safer, but a query to the

controller makes me feel legal.

1. Yes, many times. Would an animal trigger these

lights? Feel safe? No. Just because the lights are off does

not mean there is no danger.

m. Yes. The system would allow me to resolve

the disagreement with the controller.

n. Yes. I have been told to hold position after

crossing the hold line. The REL's would have helped if

the controller didn' t catch the mistake.

o. No. The status system would seem to be very

useful in those areas of low visibility.

p. I have questioned or doubted a clearance.

Whereas the light system would help, I think I would still

have to query the controller to "sort it all out."

q. Yes I have. Such a system definitely would

have helped me feel safer.

r. Yes for both questions.

s. Yes. If I were truly in doubt, I would stop and

talk to ground/tower regarding the clearance-position on

the field.

t. Yes. I have questioned many taxi clearances,

but the status lights will not replace asking the controller

the clearance one more time.

u. Yes I have. Well, I'm not sure they'd make me

feel safe, but at least they would make for an easy intro

for me to talk with the controller about it.

15. (Optional) Have you ever questioned (or

doubted) your location at an airport? If so, would the

Runway Status Light System have helped you feel safe?

a. Yes, yes, but only in the sense that I might be

safe from taxiing onto the active runway, not necessarily

safe on the airport as a whole.

b. Yes. Yes.

c. Yes. The Runway Status Light System would

be of some help in preventing runway incursions. But

position uncertainty should be cleared up by stopping

taxi and determining position before proceeding.

d. Yes. Yes.

e. Yes. No. It was temporary disorientations due

to snow and fog. We had missed a taxiway sign obscured

by a snow drift.

f. Absolutely. No. RWSL would give me assurance that runway incursions are not going to occur, but

RSS will not tell me anything about location.

g. No, but yes.

h. No, but yes.

i. Yes. I feel most, if not all, pilots at some point

and time have felt uncomfortable with their position.

This system would certainly help remove any doubts as

to whether or not you are cleared to cross a runway or

cleared onto a runway.

j. Some airports are definitely confusing to taxi

around. The RWSL would make anyone feel safer.

k. Yes, absolutely.

1. Yes. The RWSL would not make me feel safe,

but maybe feel better. Painted letters on the taxiway

would give me a cue as to my location.

m. Feel safe? NO. Feel better? YES. Reliance on

lights for safety without using one's brain creates complacency. One could be lulled into not observing the surroundings.

n. Yes. Critical cases are double parallels on the

same side of a runway and a parallel sandwiched

between runways.

o. Yes. It would help if I have accidentally

entered an active runway.

21
po ----

q. Yes, I have doubted my position. The runway

status system would have helped me feel safe in a lastditch sense.

r. Yes for both.

s. Yes. Landing at some European fields in

Category-III conditions (fortunately, a "follow me" van

provides some help).

t. Yes. I have questioned my location at an airport,

but I do not think the runway status lights would help me

feel safe. I would stop the aircraft and ask the controller.

u. Yes. Again, I'm not sure about making me feel

safe, but they might keep me from making a bigger mistake! Best help for location on the airport might be a Differential Global Positioning System (DGPS) with a

moving map.

16. Any other general comments, criticisms, or support for the Runway Status Light System?

a. Good system, provided human factors (pilots)

can be integrated successfully into this system and training is adequate.

b. I think it is a worthwhile program.

c. The light intensity for the RWSL components is

good as it is. Too bright a light can cause too much glare,

decreasing visibility at night through a scratched window; also, an annoyingly bright light can cause a pilot to

"tune it out" to pursue other cockpit tasks. For the

present size and brightness, it is important for the pilot to

know just where to look to find the lights

d. A good idea. I would suggest that this system

be used in conjunction with the already established centerline lighting system (even added to or additional centerline lighting would be good.)

e. I feel that it is a great system that is long overdue. The pilots must be made aware that the extinguishing of the light does not provide clearance for crossing or

for takeoff unless the controller states so (i.e., "after

landing Northwest DC-9 and the extinguishing of the status light, you are cleared to cross RWY 26L," which is

similar terminology to European clearances).

f. Would like to see it in real life to check brightness, ease of seeing, etc.

go ----

h° ----

i. None other than those listed previously and the

fact that we as pilots all would have this type of system

22

installed yesterday to increase the safety factor of our

operating environment!

j. I think it's a great idea-system if it proves reliable. At first, pilots will not trust the RWSL system, but

if it is consistently correct, pilots will quickly learn to

believe and trust the lights. I would make the TIlL flashing and elevate all of the light boxes above the taxiwayrunway light level. Make sure it stays passive (not tied to

controller input).

k. This system, along with the new taxiwaymarking system, should eliminate 90 percent or more of

the current runway incursion problems.

1. The concept is good and useful. I would support

this system with pilot input and reforms.

m. I like the concept. I don't believe we have the

final product. We need (1) light improvements and

(2) light position improvement.

n. ----

o. See question 17 also. Based on recent requirements-improvements to airports such as signs, markings,

lighting, SMGCS procedures, etc., this system may be

too expensive if goals-tasks are too complicated to

achieve.

p. I think it is an excellent idea. I like the fact that

it requires no input from the controller and therefore acts

as a backup system to him-her. I also like its very simplicity from a user standpoint.

q. I believe it is worth pursuing at airports with

ground radar.

r. ----

s. Great idea! Let's install them to make the airports safer!

t. A good system and would be a great asset.

u. Installation costs will be high. In the actual

implementation, you might want to talk with controllers

before the final steps are taken. Also, given the timing

that the controllers may want for lights to come on, does

this leave enough time for reaction in a highly dynamic

situation?

17. Finally, do you feel the TSRV simulator facility

provides adequate realism to evaluate the Runway Status

Light System concept?

a. Yes.

b. Yes.

c. Yes, with the exception that the "frame" separating the front windshield panel and the side panel can,

in the real airplane, easily be looked around by small
pilot headpositionchanges;thesepositionchangesdo

notworkaswellinthesimulator.

d.Yes,I do.

e.Yes.ThisisthebestsimulatorvisualthatI have

experiencedincluding:

- USAirMD-80inPittsburgh

- PiedmontBoeing737-300/200in WinstonSalemandCharlotte,NC

- Boeing767-300inSeattle

- RepublicDC-9inMinneapolis

- FederalFalcon10,DC-10inMemphis.

f. Yes,it's agoodevaluationofprocedure, probablyasclosetotherealthingascanget.

g.Yes.

h.Yes.

i. Yes.

j. Yes,exceptin the26Lholdline,thecaptain's

RWSLwasnotvisiblebecauseofabreakinthescreen.

k.Yes,actually,overall,I likethesim.It's anice

sim.!!!

1.Yes!!

m.Yes,verymuchso.

n. Forthemostpart.Backsof signsshouldbe

black.Backsof RWSL'sshouldbeyellow.Location

signsweremissing.Poorresolutionmadereadingsigns

fromadistancedifficult.

o.Yes.It couldusemoreexternalclutterto the

testprogram.Ex.communicationfromotheraircraft,aircrafttaxiingontheairportsurface,etc.Thetestisspringloadedfor theevaluatorto "lookfor" thelights.Normally,a pilot maybebusyelsewhereonthecockpit.

Needto interfacewith normaltraffic flow using

departures/arrivals fromATC.

. ----

q. Yes. Actually, I was pleased with the fidelity of

the simulator visuals. Of course, evaluation of real hardware with real aircraft needs to be done.

r. Yes.

s. Yes, very adequate. Excellent visual by the

way!

t. Yes.

u. Concept, yes. Actual lights, no.

23
References

1. Middelton, David B.; Srivatsan, Raghavachari; and Person,

Lee H., Jr.: Simulator Evaluation of Takeoff Performance

Monitoring System Displays. A Collection of Technical

Papers--AIAA Flight Simulation Technologies Conference,

Sept. 1988, pp. 206-214. (Available as AIAA-88-461 I-CP.)

2. Hinton, David A.: Flight Guidance Research for Recovery

From Microburst Wind Shear. Airborne Wind Shear Detection

and Warning Systems--Second Combined Manufacturers' and

Technologists' Conference, Part 2, Amos A. Spady, Jr.,

Roland L Bowles, and Herbert Schlickenmaier, compilers,

NASA CP-10050, 1990, pp. 395-416.

3. Scanion, Charles H.: Cockpit Weather Information Needs.

Proceedings of Techfest 18, Wichita State Univ., Jan. 1992.

4. Lyon, Ervin E: Airport Surface Traffic Automation. Lincoln

Lab. J., vol. 4, 1991, pp. 151-188.

5. Langley Aerospace Test Highlights--1990. NASA

TM- 104090, 1991.

Cleveland, Jeff I., II; Sudik, Steven J.; and Grove, Randall D.:

High Performance Flight Simulation at NASA Langley. AIAA/

AHS Flight Simulation Technologies Conference, Aug. 1992,

pp. 313-319.

7. Spaniards Analyze Tenerife Accident. Aviat. Week & Space

Technol.,Nov. 20, 1978, pp. 113, 115, 117, 119, and 121.

8. Aircraft Accident Report--Northwest Airlines, Inc., Flights

1482 and 299. Runway Incursion and Collision, Detroit Metropolitan/Wayne County Airport, Romulus, Michigan, December 3, 1990. NTSB-AAR-91-05, National Transportation

Safety Board, June 1991. (Available from NTIS as PB91 910

405.)

9. Fotos, Christopher E: NTSB Hearing Indicates Fog Played

Role in Detroit Crash. Aviat. Week & Space Technol., Mar. 25,

199 I, pp. 30-31, 34.

24
THL

_-, --

m n i

I

.... .._____

I

._ - ___-_- _-

V'_ EL

/

hold short lines

Figure 1. Runway Status Light System (RWSL).

Eaglecrates_, _

IE1 IE2 I

CRDS

CAMAC fiber-optic highway

_ __]_TSRVcrates

i

4

displays

c . 8

'_1 I!U. _$[[__Un

el I CDU1 _ CDU2

| i

TSRV cockpit

I I

m

P 2

..... a

t displays

c

h 2

P

a

n

e

I

I Serial highway driver _1 / I_:_

IPI '

Convex 3840

vehicle dynamics

CAMAC fiber-optic highway

crates

CGI system

Figure 2. Transport Systems Research Vehicle (TSRV) Simulator at Langley Research Center.

25
AIRPORT DIAGRAM

ATI5 ARR 125.6 ._,9°'*'9'e_'_ DEP 124.45

DENVER TOWER ._

118.3 119.5 257.B

GND CON .._

121.9 257.8

CLNC DEL

127.6 257.8

ELEV

\

5245

ELEV

5251

78

AL-114 (FAA)

400 X 200 ILL

X 150

DENVER/STAPLETONINTL(DEN)

D_N_R.COLORADO

_237

JANUARY 1990

ANNUAL RATE OF CHANGE

\, o,.w 

)

Rwy 8L Idg 6696'

Rwy 36 Idg 6500 _ _

RWY _\ | 7L.35R

$I00, 1"250, ST175, TTS00, DD'r750

RWY 171_*_L

SlO0, T250, 5T175, I"1"500,DDI"750

RWY 8R-26L

SI50, T250, $T175, TrS00, DDT750

RWY 8L-26R

5120, T150, 5T175, I"1"260,DDTT00

ELEV

5273

400 X 200 3-

BLACK

HOLDLINE FIRESTATION- I

\

TOWER

5491

AIRPORT

PARKING

104o)A"CV

DIAGRAM

ELEV

5316 ELEV

X150

1000 x 150

AVIATION _O&_52

PARKING

CAUTION: BE ALERT TO RUNWAY

CROSSING CLEARANCES.

READE,ACK OF ALL RUNWAY HOLDIN(_

INSTRUCTIONS IS REQUIRED,

DENVER, COLORADO

DENVER/STAPLETON INTL (DEN)

Figure 3. Denver Stapleton International Airport.

26
Runway

It

J Acute-angle taxiway • Runway entrance light

Figure 4. Suggested acute-angle runway entrance light configuration.

27
REPORT DOCUMENTATION PAGE Fo,,._,d

OMB No. 0704-0188

Public rel_-_t;.g burden for this COlleCtion of information is (intimated 1o average 1 hour per response, including the time for reviewing tnaiructioqls, searching existing date sources

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coflec_on of information, tndudlng suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Informatk0n Opare_ons and Reports, 1215 Jeffarsof

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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

October 1996 Technical Memorandum

4. TITLE AND SU_IiI-E

Pilot Evaluation of Runway Status Light System

6. AUTHOR(S)

Steven D. Young, Robert W. Wills, and R. Marshall Smith

7. PERFORMINGORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center

Hampton, VA 23681-0001

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

11. SUPPLEMENTARY NOTES

5. FUNDING NUMBERS

WU 538-04-13-02

8. PERFORMING ORGANIZATION

REPORT NUMBER

L-17496

10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

NASA TM-4727

12a. DIS i HIBUTION/AVAILABILITY STATEMENT

Unclassified-Unlimited

Subject Category 62

Availability: NASA CASI (301) 621-0390

12b. DISTRIBUTION CODE

13. AB_/HACT (Maximum 200 words)

This study focuses on use of the Transport Systems Research Vehicle (TSRV) Simulator at the Langley Research

Center to obtain pilot opinion and input on the Federal Aviation Administration's Runway Status Light System

(RWSL) prior to installation in an operational airport environment. The RWSL has been designed to reduce the

likelihood of runway incursions by visually alerting pilots when a runway is occupied. Demonstrations of the =

RWSL in the TSRV Simulator allowed pilots to evaluate the system in a realistic cockpit environment.

14. SUBJECT TERMS

Runway status lights; Incursions; Flight simulation

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

18. SECURITY CLASSIFICATION

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Unclassified

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19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

15. NUMBER OF PAGES

32

16. PRICE CODE

A03

20. UMITATION

OF ABSTRACT

Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. Z39-18

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