Aircraft Engine Nacelles

Nacelles or pods are streamlined enclosures used on multi-engine aircraft primarily to house the engines. They are located below, or at the leading edge of the wing or on the tail of the aircraft.

An engine nacelle or pod consists of skin, cowling, structural members, a fire-wall, and engine mounts. Skins and cowlings cover the outside of the nacelle. Both are usually made of sheet aluminum alloy, stainless steel, or titanium. Regardless of the material used, the skin is usually attached to the framework by rivets.

The framework can consist of structural members similar to those are of the fuselage. The framework would include length ways members, such as longerons and stringers, and width ways/vertical members, such as bulkheads, rings, and formers.

A nacelle or pod also contains a firewall, which separates the engine compartment from the rest of the aircraft. This bulkhead is usually made of stainless steel, or titanium sheet metal.

Aircraft Marshaling

When aircraft are moving under their own power the view from the cockpit may be restricted or the pilot may find extreme difficulty in judging the clearances between other aircraft or obstructions especially when trying to park in a parking area. To do this in a safe way a method of aircraft marshaling is utilized.

• Aircraft Marshaller should wear a distinctive bright high visibility surcoat or vest to be easily identified.
• When an aircraft lands, the marshaller concerned must first identify himself to the pilot by extending his arms above his head, with palms or bats facing forwards.
• Once identified, the marshaller should then stand where he can be clearly seen by the pilot and all of the marshaller signals are clearly observed.
• During start-up the marshaller should always stand in a set position, which is usually, slightly ahead of the aircraft between the left wingtip and the cockpit.
• At night marshaling signals are given using wand torches.

Pilot`s singnals to the marshaller on ground  are as follows.

Raised arm with clenched fist.	Brakes 'On'
Raised arm with fingers extended.	Brakes ‘Off’
Arms extended palms facing outwards thumbs extended, move hands inwards to cross in front of face.	Insert chocks
Arms extended palms facing inwards thumbs extended, move hands outwards from in front of face.	Remove chocks
Raise the number of fingers on one hand indicating the number of the engine to be started.  For this purpose the aircraft engines are numbered as follows: No 1 engine should be the port outer engine. No 2 engine should be the port inner engine. No 3 engine should be starboard inner engine. No 4 engine should be the starboard outer engine.	Ready to start engine