Summary report of the turboprop test chamber acceptance tests conducted on 27 April to 8 May 1964
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Authors
Hardy, H.D.
McConnell, R.E.
Bell, R.W.
Subjects
Advisors
Date of Issue
1964
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Acceptance testing of the Turboprop Test Chamber was conducted during the weeks of 27 April and 4
May 1964. The tests were conducted by personnel from the Overhaul and Repair Department, Alameda Naval Air Station, from the Bureau of Naval Weapons Fleet Readiness Representative, Pacific and from the USNPGS Department of Aeronautics. The power plant utilized for correlating purposes for a T-56-lOW turboprop engine, recently overhauled at NAS Alameda while the propeller was the Hamilton
Standard model required for this engine.
The test data reveal satisfactory correlation of the engine performance data with the Alameda test results. The discrepancies that do appear are the result of errors in the instrumentation system and do not present a major problem. All of the major facility systems function satisfactorily except the oil supply system and the chamber lighting fixtures. Engine starting and control systems were adequate although somewhat different from the designs utilized in the NAVWEPS specifications for this engine.
The engine support stand and thrust measuring assembly were found to be structurally sound and
functioned satisfactorily. The propeller orifice assembly did not induce prohibitive vibrational
stresses as was anticipated. However, the vibrational loads did cause the majority of the orifice
retaining bolts to loosen during the test sequence. Three bolts were found beneath the test stand;
these could have caused object damage to the engine.
The major areas of discrepancy are the engine oil supply system and the test chamber lighting
fixtures. The engine oil system as designed could not satisfy the requirements for the T-56 series engine.
It was necessary to re-route the oil by-pass system, to obtain a more precise control of the engine
oil supply and pressure, and to provide a method to heat the oil for operation of the engine at high power settings. The system as temporarily modified, did function adequately during the test period.
The lighting fixtures mounted on swivel joint bases oscillated violently when operating the
engine at Idle power. One fixture above the engine broke loose during this short period and was
blown clear of the engine stand by the propeller air stream. All ceiling-mounted light fixtures
were removed from the chamber before further engine operation.
The acoustic survey revealed that the acoustic paneling in the in let and the exhaust passages
functioned satisfactorily. However, the Sound Pressure Level reduction across the chamber front
double-doors did not meet the specified limits.
Corrective action is required to (1) provide adequate and safe lighting in the test chamber, (2)
re-design and install an oil supply system compatible for operation with the T-56 engine, and
(3) provide positive locking devices on all bolted fixtures in the test chambers.
Type
Report
Description
Series/Report No
Department
Aeronautics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
44 p.
Citation
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.