MTU F-16 - F-100 - Overview
A few days have passed since we joined the MTU.
The next chapters, presented by Adj Knaepen are enabling us to get to the heart of the matter, the study of the Pratt & Whitney F-100-PW-200 engine.
The development of the Pratt & Whitney F100 starts in 1967 when the United States Navy and United States Air Force join together into an engine program called the IEDP (Initial Engine Development Program) aiming to develop an engine for the F-14 Tomcat and the F-15 Eagle.
The IEDP was created to be a competitive engine design/demonstration phase followed by a development program of the winning engine.
General Electric and Pratt & Whitney were placed on contract for an approximately 18-month program with goals to improve thrust and reduce weight to achieve a thrust-to-weight ratio of 8.
In 1970, the Air Force award Pratt & Whitney to develop and produce F-100-PW-100 (USAF) and F401-PW-400 (USN) engines. The Navy will cut back and later cancel its order, choosing to continue to use the Pratt & Whitney TF30 engine from the F-111 in its F-14.
The F100-PW-100 first flew in an F-15 Eagle in 1972 with a thrust of 23.930 lbs.
A F100-PW-200 version is developed for the F-16 and includes modifications some of which being associated with the fact that contrary to the F-15, the F-16 is a single engine aircraft. A back-up fuel control called (BUC) is joined to the main fuel control system and is to be used in case of emergency.
The engine is initially certified with a thrust of 23.770 Lbs.
The two prototypes ( #721567 et #721568) fly in 1974 equipped with a F100-PW-100 engine.
The first production F-16A and F-16B aircraft (Block 1) will be fitted with the F100-PW-200.
We begin with the engine general information’s which, at that time, includes the latest technological improvements.
The F100 is an axial flow two-spool turbofan engine having a bypass ratio of 0.36 and an overall pressure ratio of 32:1. It is fitted with a variable exhaust nozzle system containing an afterburner.
- In a turbofan engine, the compressor is divided in two successive parts, a low-pressure part (called Fan) and a high-pressure part (called Core). The two compressors are driven by a dedicated turbine, a low-pressure turbine for the Fan and a high-pressure turbine for the Core.
- The bypass ratio is the ratio between the mass flow produced by the Fan and the mass flow entering the Core. In this case 26% of the mass flow generated by the Fan is ducted outside the core engine to the afterburner system when 74% enters the core engine.
- The overall pressure ratio is the ratio of the static pressure between the front and the rear of the two compressors. The Fan includes three compression stages while the Core contains ten of them for a total of thirteen stages.
The fan’s three stage compress the air at a rate of 4:1 while the core compress it at 8:1, so a overall pressure rate of 32:1. - The afterburning system or afterburner consist to inject additional fuel into the jet pipe downstream of the last turbine. The fuel/air mixture ignited by a dedicated sparking plug cause a significant raise of the exhaust gas pressure and subsequent exhaust gas velocity.
The additional thrust generated by the afterburner on the F100 is around 7000 lbs. (+ 40%)
The Fan compressor and turbine assembly called N1, is supported by three dedicated roller/ball bearings (Nr.1 – Nr.2 – Nr.5) while the high-pressure compressor and turbine assembly is called N2, and is supported by two dedicated roller/ball bearing. (Nr.3 & Nr.4)
A HD view is available via this link : F100-PW-200 Hires
The F100 includes the following characteristics:
- The engine is built in a modular concept enabling the quick replacement of big sub-assemblies. This concept increases the reliability rate of the aircraft as an unserviceable engine can be released back to service more quickly by replacing the affected module rather than fixing the module itself.
The engine comprises 5 distinct modules: Inlet Fan Module – Core Engine Module - Fan Drive Turbine Module – Augmentor & Nozzle Module – Gearbox Module.
The main Fuel Control System is composed of a hydromechanical fuel control unit called UFC (Unified Fuel Control) supervised by an engine electronic controller called EEC (Engine Electronic Control)
The EEC supervises and adjust the basic UFC settings in order to optimize the engine operation while keeping the higher thrust available.
The F100-PW-200 provides an alternate fuel regulation system called Back-up Control or BUC.
- Engine length: 4.85 m
- Engine diameter: 1.20 m
- Engine weight: +/- 1400 kg.
