EPR impulse at beginning of engine start

[Hardy Heinlin]

Good evening,

we know this is a common effect on the RB211.

Can somebody confirm whether this is common also on the PW4000 series? Aircraft model doesn't matter.


Thanks,

|-|ardy



P.S.: On the RR there is a delay of ca. 8 sec (4 sec on PW) until EPR is indicated on the EICAS after the fuel control switch has been set to RUN, or after the starter switch has been pulled. If autostart is off and you start manually, you won't see the initial impulse because the EICAS blanks the EPR bar in the first 8 seconds. -- Well, you can see it during manual start if you put that switch to RUN early enough, but then you will get a hot start ...

P.P.S.: I don't know how many of those 8 seconds are EEC power-up time and how many are EICAS display timing stuff; or maybe all 8 seconds are just EEC power-up time -- if that is true, the starter should probably begin to rotate only when the EEC power-up is completed.