Page 163 - The Jet Engine

14: Fire protection

Contents Page

Introduction 153
Prevention of engine fire

ignition 153

External cooling and ventilation
Fire detection 154
Fire containment 156

Fire extinguishing 157
Engine overheat detection 157

fireproof bulkhead from the combustion, turbine and
jet pipe area, or 'hot' zone. The zones may be
ventilated, as described in para 8, to prevent the
accumulation of flammable vapours.

4. All pipes that carry fuel, oil or hydraulic fluid, are
made fire resistant/proof to comply with fire
INTRODUCTION
regulations, and all electrical components and
1. All gas turbine engines and their associated connections are made explosion-proof. Sparking
installation systems incorporate features that caused by discharge of static electricity is prevented
minimize the possibility of an engine fire. It is by bonding all aircraft and engine components. This
gives electrical continuity between all the
essential, however, that if a failure does take place
and results in a fire, there is provision for the components and makes them incapable of igniting
flammable vapour.
immediate detection and rapid extinction of the fire,
and for the prevention of it spreading. The detection 5. On some engines, tubes carrying flammable
and extinguishing systems must add as little weight fluids in 'hot areas' of the engine are constructed with
to the installation as possible. a double skin. Should a fracture of the main fluid
carrying tube occur the outer skin will contain any
PREVENTION OF ENGINE FIRE IGNITION leakage, so preventing any possible fire ignition.
2. An engine/powerplant is designed to ensure that 6. The power plant cowlings are provided with an
the prevention of engine fire ignition is achieved as adequate drainage system to remove flammable
far as possible. In most instances a dual failure is fluids from the nacelle, bay, or pod, and all seal
necessary before a fire can occur. leakages from components are drained overboard at
a position such that fluid cannot re-enter the pod and
3. Most of the potential sources of flammable fluids create a fire hazard.
are isolated from the 'hot end' of the engine. External
fuel and oil system components and their associated 7. Spontaneous ignition can be minimized on
pipes are usually located around the compressor aircraft flying at high Mach numbers by ducting
casings, in a 'cool' zone, and are separated by a boundary layer bleed air around the engine.

153