EC120 Startup/ fuel pump

[as350nut]

Manual says 50% release starter, then straight up to full power <40% tq. Instructor says stop at 60% FLI engaged and for 1 minute and do Hyd checks here turn off fuel pump/ clear the panel and then wind up till gov has it and twist grip light is off then go fly. Which is correct.
Also anyone know why fuel pump is on in flight in AS350 and OFF in 120 after start?

[HillerBee]

The manual is always correct.

[Maff]

Ive been taught to let go of starter button at 50%, if needed wind on a bit for FLI to come up, then do hyd checks etc, switch off prime pump and then when ready wind up to flight setting and governor does the rest.

Prime pumps are switched off as the 120 has siphon suction once started and doesnt need pump to self sustain. Manual says to switch on prime pumps in flight if you get a low fuel pressure caption. When I was at the factory I was told that this was so that if you had a crash fuel would not continue to be pumped if electrics were still on. May well be something to do with the crash resistant fuel system/tanks in the EC120. I believe the EC130 is the same which also has crash resistant fuel system as standard.

[CRAZYBROADSWORD]

Follow the FM the 1 min after start up thing is from Allison engines typically also don't believe anyone who tells you to wait more than 30 seconds at idle during the shut down ether , waiting longer actually raises the oil temp ! Just follow the manual

[as350nut]

Thanks for the advice guys I'll wind er up from now on

[wmy]

Also anyone know why fuel pump is on in flight in AS350 and OFF in 120 after start?

This depends on the AS350 variant. On the B3 Pump is on for Engine start only, remains off during the flight.

As said before, the FM is always right, however check that you have the latest revision of the FM (On the AS350, they came up with a revision about doing the Hyd-checks on idle instead of flt position. Don't know about the 120 though...).

[John R81]

On the EC120 - I don't see the advantage of winding her to flight before you run the hydraulics check, set radio frequencies, cage the AH, etc. The engine at flight idle with prime pump-off is self-sustaining so the difference I see between the two states is how fast the blades are turning / how much fuel you burn.

I use flight idle in a couple of other circumstances - rotor-running refuel, held on the ground for traffic, etc. I have not seen any limitation in the POH for how long you can or should sit at flight idle, other than during shut-down procedure.

I would be interested to hear from an engineer whether there is any difference, other than in the shut-down procedure.

[feathering tickles]

Terminology is important here. Sounds like there's confusion with "flight idle" for starters (pun noted).

[as350nut]

sorted

Confusion exists because early POH and the factory course said to go to pre take off power prior to doing checks the latest manual says to go to flight idle 63 to 65 ng to do them ; then run it up; much more pleasant 1 min cool down all similar to as350
Pilots should check rigging on the throttle; flight idle should be 25% on the card on the engine
Also the trap I fell in to today rotor rpm can only be checked, in flight itself , if the engineer runs it up to say 405 on the ground it will be 420+ in the air and close to max +
If second start and its over 150 don't set it at the white line; start at off position run up to 10% and the go up just like BA as350

[John R81]

I have always carried out hot-starts like AS350 says.

It fascinates me how different 2 machines can start, though. I am familiar with 2x 120's both maintained by the same team. For first start of the day, one is a very rapid, hot starting machine. The other grinds its way into life. Always have been this way.

[mrwhirlwind]

start pump

the EC 120 and EC130 series are JAR/FAR 27 compliant. without getting into how they do it, the certification requires that the boost pumps do not run during flight as a safety precaution. The Boost pump requirement is only for the start.