Representative Engine Power Data for Army Helicopters.
Abstract
With rapid engine torque pressure changes as the factor of prime interest, some 700 hours of multichannel oscillogram data recorded on AH-1G and UH-1H helicopters while they operated in Southeast Asia and Alaska were reviewed with 5.4 hours selected and processed to obtain engine power data suitable for the development of criteria for future low-cycle fatigue testing of advanced helicopter engines. After short and medium flight lengths were determined, a representative flight was selected for each of seven categories of aircraft type, geographical location, mission type (utility, combat assault, and combat support), and flight length. Four parameters in the seven flights were processed: engine torque pressure, main rotor speed, outside air temperature (OAT), and pressure altitude. The intermediate rated power (IRP) limit was computed as a function of OAT and altitude and the engine shaft horsepower was derived from the rotor speed and torque pressure to yield the percent IRP. Data presentations include histograms of the flight length frequency distributions; time histories of the percent IRP, altitude, and OAT; histograms of the percentage of time in percent IRP ranges; and a tabular summary of the 13 torque excursions in the seven flights and related data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1976
- Accession Number
- ADA022254
Entities
People
- Terry L. Cox