Search Results

This SAE Aerospace Recommended Practice (ARP) recommends a methodology to be used for the design, analysis and test evaluation of modern helicopter gas turbine propulsion system stability and transient response characteristics. This methodology utilizes the computational power of modern digital computers to more thoroughly analyze, simulate and bench-test the helicopter engine/rotor system speed control loop over the flight envelope. This up-front work results in significantly less effort expended during flight test and delivers a more effective system into service. The methodology presented herein is recommended for modern digital electronic propulsion control systems and also for traditional analog and hydromechanical systems.

(This document supersedes and cancels AIR 12) 'Ground resonance' is a term which originated in the early days of autogiro development in this country. It is a somewhat ambiguous term as the conditions it describes usually occur at the ground but do not have any association with the common expression 'ground effect'. However, the troubles usually associated with 'ground resonance' do occur when the ship is on or near the ground.

This document is reissued for application to helicopters.

Turbine engines installed in helicopters require a highly sophisticated oil system to fulfill two tasks: a Cooling/oil supply b Lubrication While lubrication is an engine internal procedure, cooling and oil supply require more or less design activity on the aircraft side of the engine/airframe interface for proper engine function, depending on the engine type. The necessity for engine cooling and oil supply provisions on the airframe can lead to interface problems because the helicopter manufacturer can influence engine related functions due to the design of corresponding oil system components. This SAE Aerospace Information Report (AIR) deals with integration of engine oil systems with the airframe and gives information for both helicopter and engine manufacturers for a better understanding of interface requirements.

Turbine engines installed in helicopters require a highly sophisticated oil system to fulfill two tasks: a. Cooling/oil supply b. Lubrication. While lubrication is an engine internal procedure, cooling and oil supply require more or less design activity on the aircraft side of the engine/airframe interface for proper engine function, depending on the engine type. The necessity for engine cooling and oil supply provisions on the airframe can lead to interface problems because the helicopter manufacturer can influence engine related functions due to the design of corresponding oil system components. This SAE Aerospace Information Report (AIR) deals with integration of engine oil systems with the airframe and gives information for both helicopter and engine manufacturers for a better understanding of interface requirements.

Turbine engines installed in rotorcraft have an exhaust system that is designed and produced by the aircraft manufacturer. The primary function of the exhaust system is to direct hot exhaust gases away from the airframe. The exhaust system may consist of a tailpipe, which is attached to the engine, and an exhaust fairing, which is part of the rotorcraft. The engine manufacturer specifies a baseline "referee" tailpipe design, and guaranteed engine performance is based upon the use of the referee tailpipe and tailpipe exit diameter. The configuration used on the rotocraft may differ from the referee tailpipe, but it is intended to minimize additional losses attributed to the installation. This Aerospace Recommended Practice (ARP) describes the physical, functional, and performance interfaces to be considered in the design of the aircraft exhaust system.

The purpose of this recommended practice is to establish a standard format for the presentation of helicopter mission data, which will provide data required to establish airframe and/or engine component life.

The purpose of this recommended practice is to establish a standard format for the presentation of helicopter mission data, which will provide data required to establish airframe and/or engine component life.

This SAE Aerospace Information Report (AIR) outlines a recommended procedure for evaluation of the vibration environment to which the gas turbine engine powerplant is subjected in the helicopter installation. This analysis of engine vibration is normally demonstrated on a one-time basis upon initial certification, or after a major modification, of an engine/helicopter configuration. This AIR deals with linear vibration as measured on the basic case structure of the engine and not, for example, torsional vibration in drive shafting or vibration of a component within the engine such as a compressor or turbine airfoil. In summary, this AIR discusses the engine manufacturer’s "Installation Test Code" aspects of engine vibration and proposes an appropriate measurement method.

This document is reissued for application to helicopters. It is primarily intended to apply to the engine or engines, but it shall also apply to fire protection of lines, tanks, combustion heaters, and auxiliary powerplants (APU). Post-crash fire protection is also discussed.

This SAE Aerospace Information Report (AIR) defines helicopter turboshaft engine power assurance theory and methods. Several inflight power assurance example procedures are presented. These procedures vary from a very simple method used on some normal category civil helicopters, to the more complex methods involving trend monitoring and rolling average techniques. The latter method can be used by small operators but is generally better suited to the larger operator with computerized maintenance record capability.

This SAE Aerospace Information Report (AIR) describes the different aspects of corrosion on helicopter powerplants, on the components that are affected, and the subsequent consequences on the helicopter, engine durability, performance, and dependability. Guidelines that minimize corrosion during the design stage and during service operation are also discussed.

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.

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 SAE Aerospace Recommended Practice (ARP) identifies and defines a method of measuring those factors affecting installed power available for helicopter power plants. These factors are installation losses, accessory power extraction, and operation effects. Accurate determination of these factors is vital in the calculation of helicopter performance as described in the flight manual. It is intended that the methods herein prescribe and define each factor as well as an approach to measuring said factor. Only standard installations of turboshaft engines in helicopters are considered. Special arrangements leading to high installation losses, such as the fitting of an infrared suppressor may require individual techniques for the determination and definition of engine installation losses.

This SAE Aerospace Recommended Practice (ARP) identifies and defines a method of measuring those factors affecting installed power available for helicopter powerplants. These factors are installation losses, accessory power extraction, and operational effects. Accurate determination of these factors is vital in the calculation of helicopter performance as described in the RFM. It is intended that the methods presented herein prescribe and define each factor as well as an approach to measuring said factor. Only basic installations of turboshaft engines in helicopters are considered. Although the methods described may apply in principle to other configurations that lead to more complex installation losses, such as an inlet particle separator, inlet barrier filter (with or without a bypass system), or infrared suppressor, specialized or individual techniques may be required in these cases for the determination and definition of engine installation losses.

This SAE Aerospace Recommended Practice (ARP) provides a guide for the preparation of a Helicopter Engine/Airframe Interface Document and Checklist. This document and checklist is intended to provide complete relevant information on the characteristics, performance, and engine interfaces. Of most importance is the identification of the data and the location of data to assure that the engine manufacturer and the airframe manufacturer supply information that can be easily located by either manufacturer.

This SAE Aerospace Recommended Practice (ARP) provides a guide for the preparation of a helicopter engine/airframe interface document and checklist. This document and checklist should identify the information needed by the engine manufacturer and the aircraft manufacturer to integrate the engine design with the aircraft design and either provide this information or give reference to where this information is located. The intent is to assure that the engine manufacturer and the airframe manufacturer identify and make provision for this information so it can be easily accessible to either manufacturer as needed in the development stages of an engine-airframe integration project.