rysponycar

The plane has been flying non-stop so I havent had a chance to mess with it. The aircrew has been starting #4 first until we get a fix on her. My plan is to deffinately bump the fuel up and get the start temps on the high side and then go from there. Will post the result when I get it. Thanks to all for the help EC Jammers!!

Started all four engines at 102F individually off the GTC. See attachment for #'s. All the manifold drops were good (drop to 25 then sustained at 31), the bleed down was 13 seconds with a 37PSI GTC. Surprising enough, the other 3 engines all started much much faster. Looked at the start ducting on #3 and no leaks or blow outs. The starter control valve is brand new. The starter looks a little old as its a Bendix self lubricated QD. Thinking about swapping it with a Parker Hannifin.

As soon as we get the chance to run it again, I will definately check the manifold pressure. This time start each engine individually off the GTC and document the times as well. Also, the aircraft is a modified "E" model. So we have -15 motors and dont have the horsecollar regulating valves. So they are just open/close valves.

Yes, #3 engine is the first one started. The ATM is NOT on. The GTC is pressurizing the manifold to about 36-39PSI. I know.... If I had an APU, we wouldnt have this problem. In this heat, thats all the GTC will put out and thats the same on our other planes. I agree, the hot air and elevation is the name of the game... Its just too bad the T.O's dont says that. Dont know how to fix it?

We have some #3 engines on different aircrafts that start slow. At a 83F temp, the GTC will start the #3 and come on speed (72%RPM) in 65 seconds. At 102F it will start and come on speed in 76 seconds. The engines are pulling 99% max power efficiency and have known new starters and control valves. The GTC's are putting out from 36 to 39PSI. The blade angles are all set to the low side and are all having 800TIT starts. The problem has been pointing towards the heat here in Arizona and a 2700 ft elevation. Does anyone have an idea how to get the starts down below 70 seconds?

I believe the cause of on an over pressurized atmospheric sump is the pitchloch regulator. I have had prop lip seal leak one after another so I took out the pitchlock regulator and disassembled it. Found the all the cups to be pretty blocked. Cleaned each individual one and put her back together. Installed and hasnt leaked from the lip again. I hope this helped?