Originally Posted by 'Chuffer' Dandridge
Opencirrus 619,
That Vac Pump looks $hagged!
Originally Posted by OpenCirrus619
P.S. Yes I do realise this is a rather poorly example
I couldn't find a photo of a good one.
Actually, from what I've read in various places, there seems to be a lot of debate on the question of whether rotating vacuum pumps backwards is really likely to cause problems.
Firstly if you have a wet pump then its no problem which way you turn it.
If you have a dry pump (as above) then there are 2 variants - one which has the vanes arranged radially and the other at a slant (as above). It seems pretty well everyone is agreed that roatating a pump with radially arranged vanes backwards will not cause a problem.
So, the only type likely to cause a problem iif turned backwards is one with the slanted vanes. I would put my vote in the "
It won't cause a problem unless the vanes are so worn they are almost out of the slots in the central rotor, or there is another problem with the pump already" camp. Since, in either case the pump should either have already been changed, or is about to fail anyway, I'm not going to get excited (at least as far as the vacuum pump goes) seeing someone turning a propellor backwards.
Should I admit here that nothing I fly regularly has a vacuum pump fitted?
OC619
P.S. If you're going to turn propellors learn how. Join a
club where part of the checkout is hand-swinging - if you don't have a starter how else are you going to start it?