NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

0201-20-2301 3900

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

October 1 to December 31, 1954

for

Bureau of Aeronautics Projects

TED No. NBS-AE- 10002

TED No. MBS-AE- 10006

TED No. NBS-AE- 10008

TED No. NBS-AE- 10011

If. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication,

unless permisslo

25, D, C. Such |

cal ly prepared I

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015

or In part, Is prohibited

Standards, Washington

i report has been specifir report for its own use.

Development, Testing, and Evaluation of

Visual Landing Aids

October 1 to December 31, 1954

I. REPORTS ISSUED

ReDort No.

21P-11/54. Photometric Tests of a Model Light for Night Field

Carrier Landing Practice.

2 IP- 12/54 Photometric, Life, and Thermal Shock Tests of Ten

Approach Light Lamps.

21P-18c/53 Qualification Tests of Seven TEE and Three Fused

Connectors.

3789 Photometric Tests of 36 Retroreflective Samples.

(2 IP- 16/54)

3741 Development, Testing, and Evaluation of Visual Landing Aids, Consolidated Progress Report for the

Period July 1 to September 30, 1954.

II. TED No. NBS-AE-10002. GENERAL RESEARCH, LABORATORY AND CONSULTATION SERVICES IN CONNECTION WITH SPECIALIZED LIGHTING

PROBLEMS, VISIBILITY AND FOG MODIFICATION

a. Visibility Meters and Slant Visibility

Transmissometers : Assistance to the Aerology Section in the

technical phases of their transmissoraeter procurement program has continued. A two-day provisioning conference at the plant of the contractor was attended. The editing and revising of the transmissometer instruction manual to include changes in circuitry and procedure made

since the manual was originally issued has been completed and the manual

is now ready for rerunning.

Circuit diagrams of the instruments and auxiliary instruments designed and constructed at the Bureau have been completed in final form.

Slant Visibility Meter : The electrical controls of the slant visibility meter have been designed, installed, and tested. Several modifications of the receiver circuit recommended by the Weather Bureau have

been incorporated into the equipment. Considerable difficulty has been

encountered with a high noise level in the receiver. The primary source
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of this noise was traced to an intermittently defective capacitor.

Defective cabling and connections in the receiver as received from

the manufacturer were also sources of noise. After these were

corrected, there was still, on occasion, somewhat more noise than was desired. This was traced to radio-frequency pickup from a local

T-V station. When this noise was eliminated by suitable bypassing,

it was possible to complete the tests of sensitivity and of the noise

produced by the scanning mechanism. These tests indicate that the

operation of the receiver is satisfactory.

d. Night Field Carrier Landing Practice Lights

A report describing photometric teLSts of a model light for

night field carrier landing practice and incorporating the results

of these tests and of field tests made at NATC to determine the

optimum intensity into a specification has been released (NBS Test

Report 21P-11/54). This completes the development work on this task.

e. General Laboratory and Consultive Services

Several conferences have been held with engineers of the con- tractor and of the Bureau of Aeronautics. An early model of the preproduction detector was demonstrated at one of these conferences.

The preproduction set has been shipped to the Bureau for test. Tests

will be expedited since there is urgent need for this instrument.

Characteristics of Retroreflectors : A report describing the

method of test and giving the results of specific intensity measurements of 36 colorless retroreflectors, representative of all types

produced in this country, has been released (NBS Report No. 3789).

A report giving the specific intensity measurements of 21 colored

retroreflectors is being prepared.

Connectors ; Test results of seven TEE and three fused connectors

have been reported in NBS Test Report 2lP-18c/53.

III. TED NO. NBS-AE- 10006. DEVELOPMENT OF AN AIRFIELD LIGHTING INTENSITY CONTROL SYSTEM.

No time was devoted to this task during this period.

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 continued. The results of tests of ten approach-light lamps

given in NBS Test Report 21P-12/54 complete the laboratory measurements

for this task.
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V. TED NO. NBS-AE-lOOl 1. FIELD SERVICE OPERATIONS

a. Airfield Lighting

Approach Beacons : Additional flight test data have been obtained.

The pilot comments continue to indicate general satisfaction with the

flash duration and frequency and that the system is very easy to interpret by pilots unfamiliar with the system. The beacons on two

occasions provided needed assistance to visiting pilots who were having difficulty in orienting themselves with the runway. The elevation of the beams of beacons has been increased to provide better

vertical coverage. Threshold lights of higher intensity have been

installed. Eighteen-inch course lights were obtained from the CAA

for this purpose. Some programmed flight testing is now required in

order to explore fully the possibilities and performance of these

units.

c. Research on Visibility Measurements and Visibility Meters

Transmissometers : The touchdown area transmissometer was relocated because of the possibility of interference with the new ILS

glidepath transmitter. The baseline was extended to 750 feet during

the move.

Equivalent Intensity of Flashing Lights ("Strobeacon”) and

Groups of Lights (Slopeline fixtures). ; During recent tests in fogs

emphasis was placed upon obtaining equivalent intensity data of the

"Strobeacon" and a 6- and 10-light slopeline unit. The fogs were

of densities which permitted the obtaining of data which filled the

gaps in the previous data. A report giving the results of the tests

on the slopeline unit has been drafted and is being edited. A

report describing the tests of the "Strobeacon" is being prepared.

d. Electrical Engineering.

Maintenance Manual : The step-by-step trouble-shooting procedure

for airfield series lighting systems has been completed and edited.

A discussion of the variations in the operation of different regulators has been prepared and other material to supplement the stepby-step procedure is being prepared. A description of the proposed

trouble-shooting manual was presented at the October meeting of the

Lighting and Marking Panel.
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General

During much of this quarter and of the last quarter, there have

been two vacancies in the field. One of these vacancies has been

filled and the other is in the process of being filled.

The recent earthquakes in Northern California caused no damage

to any of the facilities of the operation.