SASless: I have flown the 105 and 117 and once we turned the Transfer Pumps ON....they stayed ON until the Shutdown Procedure after landing.
Are there any real reason that could not be the policy for the 135?
Depends if you view the AFM as real reason
(p. 3 - 26):
.F PUMP FWD
(MISC)
Conditions/Indications
Failure of forward fuel transfer pump, or dry run.
Procedure
1. Fuel level in the main tank – Check
If main tank fuel quantity is sufficient to keep both fuel pumps wet:
2. FUEL PUMP XFER-F sw – Check ON
3. XFER-F PUMP circuit breaker – Check in
If F PUMP FWD indication remains on:
4. FUEL PUMP XFER-F sw – OFF
If main tank fuel quantity is low:
2. FUEL PUMP XFER-F sw OFF
NOTE Each fuel transfer pump is capable of feeding more fuel than both engines will
consume. In forward flight conditions the unusable fuel can be up to 59 kg. The quantity
of unusable fuel can be reduced to 3.6 kg when flying with 80 KIAS or less.
Firend of mine is flying HEMS in EC135 and confirmend that one has to switch between XFER-F ON and XFER-A ON between cruise and hover, IF you did not gass her up fully, because you were anticipating you have to climb to high places to rescue someone.
I accept there might be additional wear on the Pumps over time but as they do have OverTemp protection....is there any absolute need to shut them off?
Had those Pumps been turned on at Engine Start and left on until the After Landing/Shut Down procedure....would that have had any effect upon the outcome of this accident?
If they were oscillating between "hover" attitude (< XX kts) and cruise flight maybe the run dry lamp would not have come on...
IIRC the was a statement in the report that them pumps can survive 20min of running dry. Didn't sound as if ignoring dry running were a professional/safe thing to do.
edit: I've got to talk to said friend, as he is FI on BO105, too.