Piper arrow gear prob

[mtrhedap]

1971 Piper Arrow PA-28R-200

Ok here is the deal. Pilots reported gear would not extend during flight. After going through checklists they manually (emergency) extended gear and landed. They reported In-transit light being lit with gear down selected but no extension.

Upon intial inspection on jacks the gear retracted normally. While extending the In-transit light was on, the hyd. pump was running but did not extend gear. No outside visual leaks found, pump fluid full. The gear will retract and extend normally most of the time. Other times while selecting gear down the pump will run, In-transit light will be on but gear does not extend. While retracting gear it will operate normally until almost all the way up and then the hyd. pump will kick on and off until gear is all the way up. Emergency extension always works fine.

It works on a reversible motor driven pump. It has a pressure switch that opens circuit to pump at 1400 psi and closes at 1100 psi. Automatic gear extension system has been disabled.

So basically I know the gear control circuit is operating correctly because I can hear the solenoids closing and the pump will operate either direction. That leaves me to believe that it has to be a hydraulic issue. It must be the pump motor, pump, pressure switches or something.

Anyone with any information to share about this issue please do. I would really like the help as I am not too familiar with this system. Thanks

[Andrew_VT]

I cant offer much advice...although i should be an expert on arrow gear systems by now considering all the problems I've had with them. The gear in transit light on the arrow i fly now routinely comes on randomly for periods of time...mechanics cant figure out why (no leaks).

My worst experience with the arrow gear system was one of the supporting bars to the nosewheel sheering right off. "Why is the transit light still on...why arnt the green lights on yet...whats that grinding sound?" followed by "SLAM" ...

lets just say it was a good thing i made a smooth landing, 1" diameter bars of metal arnt supposed to crack down the middle and break in two.

Oh...but the advice i CAN offer is that you're problem could get very expensive! And if they're in there working on the gear system, have them rip that automatic gear deployment crap right out of there.

[Dugie8]

I can't remember, but is there a shuttle valve that directs which way the fluid flows? I remember the pump is two way, but since it sounds like there is no leak and the gear goes up and stays up the, upside of the plumbing is getting pressure, but the downside is getting blocked. If you have an ARROW POH there should be a good diagram of the landing gear system in there. I think there are a few ball check valves that could be stopping the down flow??