NG Engine start restrictions

[Pin Head]

Hi

Please can someone advise what is Extended Engine Motoring? Why is it different from the normal starter duty cycle?

Many thanks

Pin

[Chesty Morgan]

It is a longer than normal start cycle motoring limit.

The only difference is that it is longer and requires a longer cooling period between cycles.

[Pin Head]

ok, when would it be used? i ve never heard of it. Is it an engineering function?

[Chesty Morgan]

High altitude airport engine starting.

[Capt Quentin McHale]

Pin Head,


Extended engine motoring is used for several functions e.g.


1... cooling engine and lowering egt after a hot or hung start before restart attempt.


2... maintenance motorimg for leak checking various systems e.g. after a fuel,oil or hydraulic filter or component change etc etc.


McHale.

[STBYRUD]

And ensuring EGT margin during (by maximising N2 as well as N1) during tailwind starts!