Hi all,
(This question is for the Lance or Saratoga drivers out there who are either mechanics or technically savvy on the landing gear system.)
I've lurked a bit here and there, but this is my first post as I recently purchased a 1976 Lance. As seems to be the case with buying any 40+ year old airplane, I'm in the process of teasing out all the gremlins. Flew it back to New York (7 hours or so) from Florida without incident, other than having the alternator randomly trip offline a couple times. Resetting the field switch took care of it and it would be fine for another hour or more before it did it again. Couldn't correlate it with anything in particular, just boring along in cruise flight and it would trip.
First flight with the family (me, my wife and 3 young kids) went great, took a mid seat out so the kids could take turns crawling up to the right seat. Came back to the airport after about an hour, getting slowed down and into the pattern and dropped the gear. 2 greens for the mains, no nose green and a steady unsafe light :shock:. Gear would go up, but couldn't get the nose green and could tell the pump was still running. Long story short, after a bunch of emergency extension tries and fiddling around, gear ended up being down and locked and we landed uneventfully.
Put it on jacks after that and found it was just the nose gear down lock switch tab had broken. Replaced the switch and cycled the gear a few times to adjust the switch properly. No problem. Came back to it a few days later and cycled again, and now the pump continues to try to run when the gear is fully retracted and the unsafe light is out. I suspect this may have been the cause of the alternator tripping. Gear breaker never popped though. Anybody ever experienced this? In retrospect, the ammeter seemed to show a high draw, but since the plane was new to me I figured that was just where it normally ran. Now I'm thinking the pump motor had been trying to run all that time. But I'm surprised it didn't pop the gear breaker or burn up the motor. Thoughts?
Not sure why it didn't do this initially when I cycled it on jacks. In preliminary troubleshooting there doesn't appear to be internal or external fluid leaks (gear stays up when I let it rest for a while with the master off). The high pressure cutoff switch is where I suspect the problem is, as it had power on both wires when the gear was up and the motor was still trying to run.
So here's my question: I'm looking at the Service Manual and the IPC and according to the IPC, the high pressure switch is the correct part number and the Piper p/n for the power pack cross-references to the HYC5005. But the Service Manual states in a schematic of the hydraulic system that there were 2 different power packs, a 105476A and the HYC5005. The pressure switch for the first one is to cut off at 1800 psi and for the HYC5005 the switch is supposed to cut off at 1400 psi. My plane has the HYC5005, but has the 1800 psi switch. I'm wondering if this could be the issue, as I've looked back in the logs and found that the pump was replaced 3 times within the last 10 years. Was there a supersedure of the 105476A pump with the HYC5005 pump that required replacement of the switch? I searched for any service bulletins from Piper that addressed this, but couldn't come up with anything. I have yet to put a gauge in the system to see what the pressure is actually building to, but either way I'm pretty confident it needs a new switch. And yes, I know those switches are ridiculously expensive.....
Just wanted to see if anyone has run across this before?
Sorry to be long-winded. Thanks for any info!
Luke
(This question is for the Lance or Saratoga drivers out there who are either mechanics or technically savvy on the landing gear system.)
I've lurked a bit here and there, but this is my first post as I recently purchased a 1976 Lance. As seems to be the case with buying any 40+ year old airplane, I'm in the process of teasing out all the gremlins. Flew it back to New York (7 hours or so) from Florida without incident, other than having the alternator randomly trip offline a couple times. Resetting the field switch took care of it and it would be fine for another hour or more before it did it again. Couldn't correlate it with anything in particular, just boring along in cruise flight and it would trip.
First flight with the family (me, my wife and 3 young kids) went great, took a mid seat out so the kids could take turns crawling up to the right seat. Came back to the airport after about an hour, getting slowed down and into the pattern and dropped the gear. 2 greens for the mains, no nose green and a steady unsafe light :shock:. Gear would go up, but couldn't get the nose green and could tell the pump was still running. Long story short, after a bunch of emergency extension tries and fiddling around, gear ended up being down and locked and we landed uneventfully.
Put it on jacks after that and found it was just the nose gear down lock switch tab had broken. Replaced the switch and cycled the gear a few times to adjust the switch properly. No problem. Came back to it a few days later and cycled again, and now the pump continues to try to run when the gear is fully retracted and the unsafe light is out. I suspect this may have been the cause of the alternator tripping. Gear breaker never popped though. Anybody ever experienced this? In retrospect, the ammeter seemed to show a high draw, but since the plane was new to me I figured that was just where it normally ran. Now I'm thinking the pump motor had been trying to run all that time. But I'm surprised it didn't pop the gear breaker or burn up the motor. Thoughts?
Not sure why it didn't do this initially when I cycled it on jacks. In preliminary troubleshooting there doesn't appear to be internal or external fluid leaks (gear stays up when I let it rest for a while with the master off). The high pressure cutoff switch is where I suspect the problem is, as it had power on both wires when the gear was up and the motor was still trying to run.
So here's my question: I'm looking at the Service Manual and the IPC and according to the IPC, the high pressure switch is the correct part number and the Piper p/n for the power pack cross-references to the HYC5005. But the Service Manual states in a schematic of the hydraulic system that there were 2 different power packs, a 105476A and the HYC5005. The pressure switch for the first one is to cut off at 1800 psi and for the HYC5005 the switch is supposed to cut off at 1400 psi. My plane has the HYC5005, but has the 1800 psi switch. I'm wondering if this could be the issue, as I've looked back in the logs and found that the pump was replaced 3 times within the last 10 years. Was there a supersedure of the 105476A pump with the HYC5005 pump that required replacement of the switch? I searched for any service bulletins from Piper that addressed this, but couldn't come up with anything. I have yet to put a gauge in the system to see what the pressure is actually building to, but either way I'm pretty confident it needs a new switch. And yes, I know those switches are ridiculously expensive.....
Just wanted to see if anyone has run across this before?
Sorry to be long-winded. Thanks for any info!
Luke
