N AT S O N A L BUREAU OF STANDARDS REPORT

ms PROJECT ms REPORT

0201-20-2301 October 18, 195*+ 3741

0201-20-2327

Development, Testing, and Evaluation of

Visual Landing Aids

Consolidated Progress Report

to the

Airborne Equipment Division

Bureau of Aeronautics

Department of the Navy

For the Period

July 1 to Sept. 30, 1954

for

Bureau of Aeronautics Projects

TED No. NBS-AS- 10002

TED No. NBS-AE-lOOOo

TED No. NBS-AE- 10008

TED No. NBS-AE -10011

0. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, r Approved for public release by the

unless permission Director of the National Institute of

25, d, c. Such p< Standards and Technology (NIST)

caiiy prepared if on October 9, 2015

ir In part, is prohibited

Standards, Washington

eport has been speclfireport for its own use,

Development, Testing, and Evaluation of

Visual Landing Aids

July 1 to September 30? 195^

I. A" JETS ISSUED

Report No.

77 Development, Testing, and Evaluation of

Visual Landing Aids, Consolidated Progress

Report for the Period April 1 to June 30,

19 ^+

TED NO. NBS-AS- 10002. GENERAL RESEARCH, LABORATORY

AND CONSULTATION SERVICES IN CONNECTION WITH SPECIALIZED LIGHTING PROBLEMS, VISIBILITY AND FOG MODIFICATION

a. Visibility Meters and Slant Visibility

Assistance has been given the Aerology Section

in the technical phases of their procurement of ten

transmissometers . The instruction manual has been

edited to include changes in circuitry and procedure

made since it was originally prepared preparatory to

the reproduction of additional copies.

The electrical controls of the scanning drive

of the slant visibility meter have been designed,

installed, and are now being tested. Difficulties

with a high noise level in the receiver amplifier

have been traced to an intermittently defective

capacitor and corrected. This correction permits

completion of the tests of the scanning drive.

d. Night Field Carrier Landing Practice Lights

A group of special light boxes were taken to the

Naval Air Test Center where they were used in field

tests to determine the optimum intensity for night

field carrier landing practice lights. Data from

this test. and photometric data obtained last quarter have been used In preparing a specification. A

report giving the results of the tests and including the specju. ication requirements has been completed and is being prepared for reproduction.

e. General Laboratory and Consultive Services

Tests of fused and TEE connectors manufactured

by Pacific Electricord have been completed and a report has been prepared. Because of the relatively
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low insulation resistance of these connectors^

the tests of insulation' resistance were much

more extensive than had been anticipated.

A report describing the method of testing

retroref lectors and giving the results of measurements of a group of retroref lectors has been

prepared. Release of the report has been delayed

so that measurements of some additional reflectors

can be included.

III. TED NO. NBS-AE-10006 . DEVELOPMENT OF AN AIRFIELD

LIGHTING INTENSITY CONTROL SYSTEM.

Schematic and block diagrams of the automatic intensity control system used at the Naval

Air Test Center have been completed. Two milliammeters with a logarithmic response have been

obtained. These meters will be specially calibrated to indicate directly the proper approachor runway-light intensity in the control tower

at NATC and will be connected into the regular

transmissometer circuit.

IV. TED NO. NBS-AE-10008. DEVELOPMENT AND TEST

OF SEALED-REFLECTOR APPROACH-LIGHT LAMPS.

Preparation of a report and a specification

covering this work has been started.

V. TED NO. NBS-AE- 10011 FIELD SERVICE OPERATIONS.

a. Airfield Lighting

Some flight test data have been obtained on

the performance of the approach beacons. Pilot

comments indicate general satisfaction with the

flash frequency and the horizontal beam spread and

that the eleT a-tion of the beams may need to be increased. Threshold lights of higher intensity

are indicated. The 18-inch course lights requested

from the CAA for this purpose have been received

and will be installed shortly. Some programmed

flight testing is now required in order to fully

explore the possibilities and performance of these

units

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b. Runway and Taxiway Markings.

In an effort to obtain a more satisfactory

pqint for blacktop runway and taxiway markings,

the Areata Airport management has applied small

test sections of uNalcrete n at several locations

on the runway and roads of the station. Thess

have been checked visually from time to time. The

appearance of these samples indicates this finish

is superior to the usual traffic paints. In view

of this, the stripes and ma^Vs on the taxiway

needed for visibility tests (which were in need of

repainting) have been finished with ^Nalcrete'5 in

order to obtain more comprehensive data on reflectance and durability.

The airport management has also refinished

the runway with this finish and has modified the

threshold and distance markers somewhat. The

1500-foot marker has been removed and the touchdown and 2000-foot markers have been increased in

size. Some pilot comment indicates that the larger

markers are more ‘satisfactory.

c. Research on Visibility Measurements and

Visibility Meters.

Transmis some ter s; Checks are being made of

the time required to maintain the five instruments

at the Field Laboratory. For the month of August

the daily checks required 15 hours and the preventive maintenance checks 23 hours. Since these

instruments are being used for special tests, the

require more attention than those used routinely,

and since these laboratory-type instruments are less

easily rervlcod than production instruments, these

times4 are considered to be about the maximum times

which will be required by qualified personnel.

100$ Setting Calibrator : Field checks indicate that the deviations from linearity of the

photocells is limiting the accuracy of the calibrator

producing errors of about ±2%, A calibration procedure which will correct for these diviations has

been developed.
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Brightness Measurements : Analysis of the data

obtained to date has continued.

Equivalent intensity of flashing lights (“Stro- beacon**) and of groups of lights ( Sl ope-line

fixture.") : The comparison larnps~~useB in the

determination of equivalent intensity have been

recalibrated in Washington. These calibrations

will be used in the completion of the analysis

of the equivalent intensity data obtained in the

field. The field data indicate that the direct

light of the slope-line unit is generally visible

at distances one and two-thirds to twice the

“reported 11 visibility and that the maximum distance at which the " Strobe aconM and the approach

beacon are visible i'S somewhat less.

d. Electrical Engineering.

The step-by-step trouble shooting procedure

for the Maintenance Manual has been organized.

Most of the material for this section has been

drafted and is now being edited. First drafts

of the Preventive Maintenance and Routine Maintenance Sections have been completed.

General

A visit to the field laboratory was made by

the Project Leader in July.

Resignations of two of the four people

assigned to the laboratory during the last four

months has delayed completion of some of the

tests in progress. One part-time replacement

has been obtained and efforts are being made to

obtain a replacement Electrical Engineer.

Tests in Fog . The fog frequency has been

unusually low this fog season. However, during

the period September 25-30 several very stable

fogs occurred during which tests were conducted.
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