Q8: Synchronise for noise abatement??

[GoneWest]

Light piston twin, rotate, positive rate of climb, undercarriage up.

Maybe, say, 200 feet agl....little tweak with one finger on a prop lever - synchronise props for noise quieter operation - noise abatement for both passengers and ground dwellers (possible letter writing Nimby's).

...or leave props fully forward until 500 feet - or whatever.

Comments for and against??

[Guido]

For what it's worth, the RAF C130 fleet leave it until above 1000' on take off and take it out in the Landing checks. However I'm sure the system is different since the props are electrically synched and a power loss on the selected master prop would be transmitted to the other 3. Therefore it is selected off/out for safety.
Safety always should come first. Unless the noise is unbearable for passengers, I don't think the distraction of operating engine levers in what could be a busy phase in the flight is worth it. Leave it until safe to do so, especially for single pilot operation.

[Tinstaafl]

I sync. as soon as workload allows. It depends on how out of sync. the max. RPM positions are.

[BlueLine]

Surely the purpose of synchronisation is to reduce low frequency vibration, the noise issue is secondary.

[Chuck Ellsworth]

If I hear an out of sync at takeoff power on the runway I check for an overspeed, if the higest RPM indication is not over max allowable RPM and the engine that is indicating low is within a reasonable RPM I immediately sync the engines by reducing RPM on the engine that is at the higher RPM.

This of course is predicated on Manifold pressure not exceeding the max allowable for the new RPM. If the manifold pressure is excessive I reduce it to correspond with the new RPM setting.

If the power being developed is not sufficient to safely complete the takeoff I reject and taxi back and get it rectified.

If the power being produced is within safe limits to operate the airplane I snag the low RPM engine when I return to base and have the Governor reset.

Nothing drives me more nuts than an out of sync engine...

Hey its so easy to do, that what those levers are for. :D :D :D

Cat Driver:

[Tinstaafl]

Yeah, me too Chuck! Bloody hate those installations that won't stay in sync...

It's easy enough to tweak a bit, even during take-off.