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A general method for the preliminary design of a single, straight-sided, low subsonic ejector is presented. The method is based on the information presented in References 1, 2, 3, and 4, and utilizes analytical and empirical data for the sizing of the ejector mixing duct diameter and flow length. The low subsonic restriction applies because compressibility effects were not included in the development of the basic design equations. The equations are restricted to applications where Mach numbers within the ejector primary or secondary flow paths are equal to or less than 0.3.

The purpose of this AIR (Aerospace Information Report) is to provide aircraft and engine designers with a better understanding of helicopter turboshaft engine idle power characteristics and objectives to be considered in the design process. Idle is the lowest steady state power setting. At this setting, the engine typically does not produce enough power to obtain governed output shaft speed (i.e. the shaft speed is determined by the load imposed by the aircraft). In the aircraft, the engine is typically stabilized at this power setting after starting, prior to taxi and for some period of time after rotor shutdown for cool down prior to engine shutoff. Traditionally, the aircraft designer wants idle power scheduled as low as possible and of course, does not want any resulting aircraft operational difficulties such as overcoming the rotor brake. The engine designer, however, desires a higher scheduled power because of the reduced probability of engine operational problems.

The purpose of this SAE Aerospace Information Report (AIR) is to disseminate qualitative information regarding foreign object debris (FOD) damage to the gas path of rotorcraft gas turbine engines and to discuss methods of FOD prevention. Although turbine-powered fixed-wing aircraft are also subject to FOD, the unique ability of the rotorcraft to hover above, takeoff from, and land on unprepared surfaces creates a special need for a separate treatment of this subject.

This document presents Flight Test Techniques, Data Analysis Methods, and Reporting examples related to installed turbine Power Available and Power Assurance demonstrations as required by CFR Title 14 Part 29.45(c) and (f).

This SAE Aerospace Recommended Practice (ARP) identifies and defines methods of compliance with power available and inlet distortion requirements for rotorcraft with inlet barrier filter (IBF) installations. The material developed herein is intended to provide industry-recommended methods of compliance with civil airworthiness regulations. It is intended to serve as a basis for new or revised FAA advisory material describing acceptable methods for determining power assurance, establishing power available, and for substantiating acceptable engine inlet distortion for IBF installations. The ARP does not address other types of inlet protection systems such as inertial separator, electrostatic precipitators, or foreign object debris (FOD) screens.

The purpose of this SAE Aerospace Information Report (AIR) is to illustrate the effect of installation power losses on the performance of a helicopter. Installation power losses result from a variety of sources, some associated directly with the basic engine installation, and some coming from the installation of specific items of aircraft mission specific equipment. Close attention must be paid to the accurate measurement of these losses so that the correct aircraft performance is calculated. Installation power losses inevitably result in a reduction in the overall performance of the aircraft. In some cases, careful attention to detail will allow specific elements of the overall loss to be reduced with immediate benefit for the mission performance of the aircraft. When considering items of equipment that affect the engine, it is important to understand the effect these will have on overall aircraft performance to ensure that mission capability is not unduly compromised.

This ARP applies to turbine engines that are to be used in helicopters. It provides the engine designer guide lines in achieving a satisfactory turbine engine drive shaft connection.

The purpose of this document is to define the power spectrum during normal and emergency operations of a twin engine helicopter and thereby to postulate suitable power plant rating structures. The document does not address the power requirements for single engine helicopters or those with more than two engines.

This SAE Aerospace Information Report (AIR) defines the power spectrum during normal and emergency operations of a twin engine helicopter and thereby postulates suitable power plant rating structures. This document does not address the power requirements for single engine helicopters or those with more than two engines.