LF 507

Overview

The LF 507 is an improved derivative of the ALF 502 turbofan, developed by AlliedSignal (now Honeywell) to address performance shortfalls identified in service on the BAe 146 regional jet. While retaining the ALF 502's fundamental architecture — including its distinctive geared fan design — the LF 507 incorporates a higher overall pressure ratio, revised hot-section components, and a new FADEC system that together deliver meaningfully better performance in demanding hot-and-high operating conditions. The engine entered service in 1993 on later BAe 146 variants and continued on the Avro RJ family that succeeded it.

With approximately 200 units delivered, the LF 507 occupies a narrower production footprint than its predecessor but represents an important step in extracting sustained commercial value from the BAe 146 platform. The improved fuel consumption — 0.37 versus 0.38 lb/lbf/hr for the ALF 502 — and better high-altitude performance helped extend the 146/RJ family's operational competitiveness through the late 1990s and 2000s.

Technical Specifications

Variants

The LF 507-1F is the primary production variant, rated at 31.1 kN (7,000 lbf) and certified for operation on the BAe 146-300 and Avro RJ85/RJ100. AlliedSignal explored uprated versions capable of higher thrust to improve field performance, but the market for the BAe 146 platform did not justify further significant development investment. The engine family was effectively closed when BAE Systems ceased Avro RJ production in 2003.

Aircraft Applications

The LF 507 powered later production variants of the BAe 146 — primarily the 146-300 — and the entire Avro RJ family comprising the RJ70, RJ85, and RJ100. The Avro RJ series was essentially a re-engined and avionics-updated BAe 146, sold under the Avro brand from 1993 onward. A small number of operators subsequently retrofitted LF 507 engines to existing ALF 502-powered aircraft to obtain the improved hot-and-high performance, particularly for operations in mountainous regions and high-elevation airports in South America and Africa.

Development History

The LF 507 programme was initiated by AlliedSignal in the late 1980s in response to BAe and operator requests for improved engine performance on the 146 platform. Hot-and-high limitations of the ALF 502 had constrained the aircraft's utility at airports including Mexico City, Bogota, and Johannesburg, reducing its competitive position against twin-engine jets with more powerful core engines. The development cycle was relatively short given the evolutionary nature of the design change: first run was achieved in 1989, with FAA and JAA certification and entry into service following in 1993. The engine represents one of the more focused incremental improvement programmes in recent regional aviation history — delivering meaningful gains within a tightly constrained development budget by maximising reuse of the existing certified architecture.