NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT MBS REPORT

0201-20-2304 October 1, 1954 3748

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 September 30, 1954

for

Bureau of Aeronautics Projects

TED No. NBS-AE-10001

TED No. NBS-AE-10003

TED No. NBS-AE-10004

TED No. NBS-AE-10005

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U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, re

unless permission ts

25, D. C. Such per

cal ly prepared If tl

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015

In part, is prohibited

andards, Washington

port has been specifieport for its own use,

Development, Testing, and Evaluation of Visual Landing Aids

Quarter Ending September 30, 1954

Laboratory Tests

Test No. Requested

Study of the life characteristics of 36 seadromelight batteries.

In conference 2-12-54

Letter dated 3-16-54

Status: Final life test has been completed and report is in

preparation.

21A-3/54

Photometric and colorimetric characteristics

of two approach-angle lights.

21A-5/54 In conference 3-31-54

Status: Test completed, report in preparation.

21A-9/54

Status:

Performance tests on airfield lighting control panel.

Letter dated 5-29-53

Notified 8-4-54 that panel was ready for inspection

Factory inspection completed and delivery accepted,

laboratory tests in progress.

Consultation Services

Sea„drome Light Development - Assistance has been furnished in the

preparation of drafts for discussion by a symposium on requirements for

seadrome lights. The symposium formulated technical requirements for

seadrome lights and brought out the fundamental difference between the

seadrome lighting problem and the airfield lighting problem.

Specification for Colors of Lights - A draft for converting

Specification AN-C-56, "Colors, Aeronautical Lights and Lighting

Equipment", into a military specification has been prepared within the

Defense Services. At the request of the Bureau of Aeronautics, this

-2-

draft has been reviewed and it was found that numerous errors had been introduced in the conversion process. These have been brought to the attention

of the Bureau of Aeronautics and it is understood that a revised draft is in

preparation. The military specification is intended to serve the needs of

the Defense Services until the proposed U. S. Standard has been adopted.

Approach-angle lights

An experimental model of an improved approach-angle indicator has been

constructed and subjected to visibility tests on a 900-foot range. The

new light was found to be superior in intensity and sharpness of color

transition to either of the approach-angle indicators which had been

submitted to this Bureau for tests. A duplicate of the model has been

furnished to the Marine Corps for flight testing.

Kinorama research

During the previous quarter attempts to validate Hie kinorama had

encountered difficulties due to extraneous cues which enabled Hie pilot

to give a better performance than could be accounted for by the lights

visible to him. Preliminary tests indicate Hia,t these cues can be eliminated

through Hie use of dyed tracing cloth or dark-colored rubber for the belt.

The use of tracing cloHi had to be given up when it was found Hiat such

cloHi warped during Hie humid weaHier and in consequence it wrinkled on the

kinorama table. Although the wrinkling was slight, neverHieless since 0.01"

of belt represents 1.0* of approach, even a slight wrinkle is undesirable.

Experiments have been made using a rubber belt attached to a tow bar which

is held at right angles to the direction of motion by two sprocket-driven

towr chains, one on each side of the belt. These were found to give the

required restraint to the forward end of Hie belt but the central portion

of Hie belt continued to drift to Hie side causing a bowing of the light

configuration. This difficulty has been overcome by cementing zipper strips

to the sides of the belt and parsing these Hirough guides just ahead of one of the cylinders. By this means satisfactory operation has been obtained

with a single belt but it was found that Hie use of two belts, one as a towr belt and the oHier carrying the configuration of lights, again introduced

wrinkling. It is believed this can be avoided by inproving the equipment

for handling and installing belts on the kinorama table so that it will

not be necessary to use a separate tow belt.

Seadrome lights

Progress with Hie life-testing the seadrome-light batteries has been

described under Tests . The symposium described \mder Consultation

Services has resulted in the drafting of technical requirements for Hiese

lights.

Airfield lighting control panel

The airfield lighting control panel built by the Federal Electric Co*

was inspected on 18 August 1954 . The panel was found to be in accordance

with the contract except for some minor deficiencies which were corrected

during the course of inspection . The panel has been shipped to this

Bureau and the contract approved for payment . Tests here indicate that

the system for dimming the panel illumination is not satisfactory because

the control rheostat overheats under some conditions . It was impossible

to specify a definite lighting system for the panel until the experimental

panel had been made, hence the contract could not be specific on this item.

The problem will be studied to determine first the wattage of the lamps

necessary to produce satisfactory illumination and then it will be possible

to select a transformer and rheostat for controlling the lights without

overheating. Another difficulty has arisen in the breakage of the plastic

buttons in the switch actuators. These were made in accordance with the

sketch but some modification appears desirable.
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