ENGINE STARTING

Either of two sources of pneumatic power can be utilized for the initial engine start:

1. An external ground cart gas turbine compressor or other low pressure air source connects to the main manifold at a point in the lower leading edge fillet area of the right wing. As a customer option, an additional connector is furnished under the fuselage aft of the rear cabin door.

2. An integral air bottle starting system entirely contained within the airplane is also offered as an option. The air bottles are normally recharged during flight. However, recharging may be accomplished on the ground by a 3, 000 psi ground source or by the use of the airplane hydraulic power when an AC ground source is connected to the external electrical receptacle. The ground recharging procedure requires approximately 55 minutes.

When one engine has been started by the use of either of these pneumatic sources the remaining three engines can be started by the use of engine bleed air. Engines may be started in any desired order but only one can be started at a time.

The starting system requirements for air flow rate and minimum pressure are detailed on the following page. This chart may be used to determine the general suitability of any ground air source which has a relatively constant supply pressure and temperature during the starting cycle. Experience with turbojet engines indicates susceptibility to foreign object ingestion due to the suction of the intake starting vortex. Although the propjet engine on the Electra is a turbine powerplant the possibility of foreign objects entering the intake is reduced to a minimum by the high position of the intake and the additional influence of the propeller.