Development of A Visual Aid to 

Indicate Temporary Runway _ ? 

Closure 

a!m 

January 1987 

Document is on file at the Technical Center 

Library, Atlantic City Airport, N.J. 08405 

 N J. 08405 
NOTICE 

This document is under the 

the Department of Transportation in the interest of 

information exchange. The United Government 

of 

assumes no liability for the contents or use thereof. 

The United States Government does not endorse products 

or manufacturers. Trade or names appear 

herein solely because they are eoneidered to 

the object of this report. 
Technical Report Documentation Page 

1. Report No. ‘2. Government Accessron No. 3. No. , 

4. and 5. Report Date 

January 

 OF A VISUAL AID TO INDICATE TEMPORARY 6. Code 

 CLOSURE 

7. Author’s) 

8. Report No. 

 Aviation Administration 

Technical Center 

 City Jersey 08405 

of Transportation 

Aviation Administration 

15. s Notes 

, 

, 

16. Abstract 

 prototype visual aid to advise pilots that a runway is temporarily closed was 

leveloped at the Federal Aviation Administration (FAA) Technical Center. Subject 

 were asked to provide comments as to the effectiveness of the system. Results 

 the evaluation indicate that the device provides an intuitive indication of a 

 runway in adequate time for a pilot to execute a safe missed approach. 

17. Key words Statement 

 Lighting Document is on file at the Technical 

 Runway Center Library, Atlantic City Airport, 

 Aids New Jersey 08405 

19. (of report) 20. (of page) 21. No. of Page. 22. 

Form DOT F 1700.7 

1987 
ACKNOWLEDGEMENT 

The author would like to express appreciation to the personnel at San 

Francisco International Airport, and particularly to Mr. Phil Meginness, 

Operations Superintendent, for their timely assistance and cooperation in 

the development of this visual aid. . 
TABLE OF CONTENTS 

EXECUTIVE SUMMARY , 

INTRODUCTION 

Purpose 

DISCUSSION 

Preliminary Evaluation 

Final Evaluation 

RESULTS 

CONCLUSIONS 

RECOMMENDATIONS 
 OF ILLUSTRATIONS

Figure

Variable Configuration Device 

2 Ultimate Lighting Configuration 

3 Summary of Questionnaire Responses 

4 Summary of Pilot Comments 

5 Aerial Views of Lighting Array 
EXECUTIVE 

The purpose of this project was to develop a prototype visual aid to advise

* pilots that a runway is temporarily closed during visual meteorological 

conditions for both day and night operations as recommended by Task Group 

3-1.6 of the National Airspace Review. 

Several prototype systems were constructed and subjected to preliminary

evaluation. An array of nine spotlights in the shape of the letter was

selected for final evaluation. Subject pilots were asked to provide

 as to the effectiveness of the system.

Results of the evaluation indicated that the device provides an intuitive

Indication of a closed runway in adequate time for a pilot to execute a safe

missed approach. The signal is effective during both straight-in and

circling approaches.

vii 

-
INTRODUCTION

PURPOSE.

The purpose of this project was to develop and test a prototype visual aid to

advise pilots that a runway is temporarily closed during visual meteorological

conditions. The project was undertaken in response to a request from the Office

of Airport Standards, submitted through the Program Engineering and

Maintenance Service, APM-1. The development of a lighted visual aid for this

purpose was recommended by Task Group 3-1.6 of the National Airspace Review. The

work was accomplished under Technical Center Project No. Airport

Lighting and Marking. The Technical Project Manager was Rick ACT-310.

DISCUSSION

There have been instances of aircraft landing on runways temporarily closed for

maintenance or snow clearing operations. The problem becomes particularly acute

at night when runway edge lights must be on for electrical maintenance or for

avoidance by snow plow operators. The solution was determined by Task Group 3-

1.6 of the National Review to be the development of a lighted visual aid

to provide the closed runway warning. The performance criteria specified by the

Federal Aviation Administration (FAA) Office of Airport Standards for evaluation

of the visual aid were as follows:

1. The visual aid shall be conspicuous when viewed from the air and readily

distinguishable from other visual devices used on airports. The runway

edge lights and other visual aids may be on while the runway-closed light is

operating.

2. It shall be visible from any point mile from the runway threshold and

shall have a vertical coverage adequate for both circling guidance and final

approach areas.

3. It shall be suitable for night operations down to a visibility of 3 miles.

4. It shall be capable of being quickly set up and turned on.

These criteria were supplemented by the Technical Center Visual Guidance Section

in that it was felt the visual aid should have the following characteristics:

5. The message presented by the aid should be intuitively understood.

6. The aid should be readily constructed using "off-the-shelf" components. 

would allow it to be built and used at small airports , where lack of a control 

tower would make it especially desirable. 

1
PRELIMINARY EVALUATION. 

 no. 2 suggests an omnidirectional visual aid. Red lighting was 

selected as intuitively suggesting prohibition. Several versions of 

point red light sources were selected for preliminary evaluation, but all failed 

criterium no. 1, in that they were not sufficiently conspicuous and/or could be 

confused with other visual aids (e.g. VASI, PLASI). In fact, a very bright 

light source , color-coded Runway End Identifier Lights was evaluated 

1983 as a closed-runway indicator and was to be confusing to pilots at best 

(FAA Technical Note No. 

A message can also be conveyed through lighting by the configuration of a 

point light source. The configuration chosen for preliminary evaluation was that 

of the letter pilot will recognize as an indication of a closed 

runway when it is laid out the pavement. To meet criterium no. 4, the was 

formed upright to project the signal into the approach area and mounted on a 

trailer (figure 1). This configuration would not be omnidirectional, but should 

still provide sufficient horizontal coverage to be effective. Obviously, the 

larger the device, the more effective it would be. Fourteen-foot arms were 

chosen as the longest still meeting portability requirements. 

Several combinations of clear and yellow spotlights or fluorescent lights were 

evaluated, along with a strobe-lighted developed for San Francisco International Airport in a parallel effort. Having too many lights was found to be as 

detrimental as having too few. Pulsing lights were found to be far superior to 

steady-burning lights for early acquisition. Pulse rates were varied for 

selection of the optimum cycle. The configuration selected for final evaluation 

was an evenly spaced set of nine clear spotlights (figure 2) pulsing at a 

rate of three seconds "on" and one second "off". 

FINAL EVALUATION. 

The unit was set up on the runway numbers, with the runway edge lights turned on. 

Subjects ranged in experience from low-time private pilots to Technical Center 

test pilots trained in evaluation of visual aids. They were not informed of the 

nature of the evaluation, other than that a lighting system was being tested. 

They were asked to indicate to an observor when the system was noticed, when a 

message was conveyed, and what the message was. Straight-in and circling 

approaches were made, in no particular order. The pilots were then asked if they 

had time to execute appropriate maneuvers during both types of approaches, as it 

was felt that recognition at mile might not provide sufficient reaction time. 

Five types of aircraft-were used , ranging from single-engine to a Boeing 727-

100. 

A summary of pilot responses to specific questions is shown in figure 3. Pilot 

comments are summarized in figure 4. 
RESULTS 

At night, the unit was initially found to be too bright in that, even though 

was extremely noticeable, "blooming" of the individual lights obscured the 

configuration. Reducing the voltage to one-third (40V) at night resulted in the 

* best compromise of acquisition and recognition. Results were then very

consistent.

- During both high-brightness day and full dark night testing, the unit was -

acquired as "something on the runway" at from five to eight miles distance during

a straight-in approach. A bright pulsing light in the runway touchdown zone

should cause any pilot to question the advisability of landing, but without

exception, each pilot recognized the signal as an while at least miles

from threshold, and received a definite "Do not land" signal in plenty of

time to execute a safe missed approach (figure 5). The pulsing feature was noted

by several pilots as effective in drawing attention to the device. As the white

lights were quite visible against the background of a concrete runway, colored

filters served only to decrease intensity, with no noticeable improvement in

recognition.

Although a limited number of approaches were made with high-performance aircraft,

subsequent sharing of information with personnel at San Francisco International

Airport, where a similar is in operational use, has reinforced results

obtained at the Technical Center.

The device meets all criteria set forth, except criterium no. 2, that is, that it

be visible, omnidirectionally, from any point mile from the runway threshold.

It was found that the required peak intensity could not be obtained from an

omnidirectional source, and that rotation of a large system of lights is not

practical. Since all of the subject pilots found the device to be adequate

during a circling approach, it is felt that this requirement is not critical.

The device was not tested at the lowest limits of conditions, but as the lamp

used is the same one used in the Medium Intensity Approach Lighting System, it is

felt that its visibility would be similar.

CONCLUSIONS

From the results of this effort, it is concluded that the performance standards

for a temporarily-closed-runway visual aid should be as follows:

1. The device should be a lighted signal in the shape of the letter 

2. The device should be capable of being acquired at a range of least 5

nautical miles both day and night.

3. The signal should be recognizable as a letter from at least 

nautical miles both day and night.
4. The signal should provide horizontal coverage to at least 15 degrees on 

each side of runway centerline , and provide vertical coverage from 0 

degrees to 10 degrees above horizontal, both day and night, at a range of 

1 nautical miles. 

5. The signal should pulse at a rate of three seconds "on' and one second 

"Off". 

If an FAA standard for a temporarily closed runway indicator is issued, it is 

recommended that the lighting configuration developed in the performance of 

this project be specified. The salient features of the device suggested for 

adoption as meeting the performance standards developed in this report are 

as follows: 

1. Lamps shall be clear PAR-38 spotlights. 

2. Lamps shall be arranged in the shape of the letter on arms of 

fourteen-foot minimum crossed at ninety degrees. 

3. Lamps shall be placed on 3-foot B-inch centers. 

4. Lamps shall be operated at 120V during daylight hours, and at 40V at 

night. 

5. The device shall be energized by a portable power source. 

6. The device shall be controlled by a timer causing the signal to pulse 

at an approximate rate of three seconds "on" and one second "off". 

7. The vertical aiming of the array shall be adjustable to allow tilting 

to an optimum aiming angle of five degrees from vertical. 

150 V PAR - 38 CLEAR SPOTLIGHT �

FIGURE 2. ULTIMATE LIGHTING CONFIGURATION

E 

6 
‘ 

PILOT 15 Total

AIRCRAFT

TIME OF DAY

CONDITIONS

DURING STRAIGHT-IN APPROACH, AT WHAT POINT DID YOU THE 

LIGHTING CONFIGURATION UNDER EVALUATION? 5.5 nm 

AT WHAT POINT WAS A MESSAGE, IF ANY, CONVEYED TO 5 - 2.3 NM 

WHAT WAS THE MESSAGE? Ik not 15 (100%) ’ 

WAS THE MESSAGE CONVEYED IN TIME TO EXECUTE APPROPRIATE MANEUVERS?

PLEASE_ SPECIFY "BARELY ADEQUATE, ADEQUATE, MORE THAN ADEQUATE", ETC.

STRAIGHT-IN APPROACH Adequate - 14, more adequate - 1 

PATTERN APPROACH Adequate - 15 

PLEASE PROVIDE ANY ADDITIONAL COMMENTS:

FIGURE SUMMARY OF QUESTIONNAIRE RESPONSES

7
Subject pilot comments, as recorded by the pilots on their post-flight 

questionaire forms, are shown below. The excerpts, while not necessarily direct 

quotes of individual pilots reflect the general nature of the comments. 

1. The pulsing feature of the device is important in drawing the pilot's 

attention. (3 pilots) 

2. A different color might be better - red or amber. 

3. intuitive for indicating a closed runway. '(1 pilot) 

4. Pilot education would be necessary. pilot) 

Since the device is an obstruction; it should only be used when other 

equipment is on a temporarily closed runway. (1 pilot) 

FIGURE 4. SUMMARY OF PILOT COMMENTS 

8