Loss of all electrical power 1976 PA 32R

Beeler

On IFR approach recently descended through a cloud layer with Peto heat on as i set up for landing, dropped my gear, then lost all electric displays. Didn’t know if gear was down or not? Made couple of circles then dropped the gear manually. Landed safely still no electrical components of any kind with power. Has anybody else experienced the situation? As I was taxing to the ramp, all electric displays came back up?

thanks, C

jacobsja

Will let better experts help with troubleshooting specifics.

Unless I am missing something, it is possible that a number of holes in the Swiss cheese are lining-up for this scenario and multiple items are feeding into the event. Or perhaps a singular item of the Master switch going bad?

Just curious, what avionics are in the panel? All glass? Any analog gauges?

Related, was the plane still in clouds when the power dropped? If so, by chance was it possible to determine whether the landing lights and strobes (presuming they were not turned off during the cloud transition) were still functional?

griff390

https://piperowner.org/talk/discussion/157531/loss-of-all-electrical-power-1976-pa-32r

Beeler:

First: that's a scary situation, and I think I speak for everyone when I say great job handling the problem and getting safely on the ground.

Second: intermittent problems are the toughest to troubleshoot because when everything is working, there's nothing to diagnose.

I'll reiterate jacobsja's question: When you lost your instrument displays, was there power to anything else e.g. interior lights, panel lights, strobes, etc.? If yes, that may narrow it down to the instrument/avionics bus.

Some suggestions in no particular order: Check for a charging problem (battery, wiring, alternator, voltage regulator, overvoltage relay). If the voltage is below the minimum avionics threshold, the avionics may shut down. If the voltage is too high, the OV relay will shut down the electrical system. Check that there are no intermittent connections between the busses. It's also possible that the avionics themselves hiccuped. Did I mention that intermittent problems are difficult to trace?

Do everything you can to reproduce the problem on the ground. If there was a complete power loss, I would begin tracing the fault from the battery. Turn the master on. Wiggle all the power wires, lightly tap the master switch, master relay, etc. If the power drops out (for instance) when you wiggle the power cable going from the battery to the master solenoid, narrow your search to the battery, wire and the solenoid, but check everything else anyway. Your electrical system may have more than 1 problem, and sometimes one problem can mask others.

More suggestions: Check for loose connections, an intermittent master switch (as jacobsja mentioned), a bad or intermittent master relay/solenoid, etc. Continue to work forward into the aircraft's electrical system. Check the voltage on all the busses with the engine off and running.

I'd be very leary about flying until the problem is identified, and definitely no iFR!

Seneca38173

Yes, have experienced before.

What is the avionics configuration in your Lance?

Bob

robertthoyer

When u lower ldg gr created a high draw on elec system and the voltage reg possibly could not handle the draw and shut off , but battery should still provide power for a period of time unless it has bad cells. When was last time battery replaced? Meaning volts check good but amps don't . For the gear after the dim light issue in daylight I had to come up with a backup mirror to actually see the gear. Using new reg based on safety from EAA I fashioned a two foot long two inch wide aluminum angle iron and attached a 4" mirror to flat side at one end epoxy glue. And fit under the left wing tip using four of the existing screws hold wing tip on . U have to attach to the flat part and add spacer washers where underside starts to curve up so the shaft is perfectly aligned strait with bottom of wing. Very little fwd surface area drag is negligible .was tested to Vne. Great way to see all three gear down and over center locked. Going on 5 years.

robertthoyer

This is FAR I used and my IA agreed.  21.303 (b)(2). There is nothing like being able to actually see u gear is down and locked. Depending on the age of nose gear spring you really have to slow the aircraft down 80 to 75kts to get it to pull nose gear over enter locked. With The mirror u can actually see the brace support is straight and not bent slightly!

planewrench

While Roberts creativity is certainly commendable, My customer Jim went one step further and mounted a small remote camera on the bottom of the Saratoga. Absolutely awesome being able to see all three gear come down the same time. He has it tied into the Garmin G3 system so you can just pull it up when you need it. Giveen the advent of all of our electronic cockpit gizmos it's almost easier to just put a camera on each part of the wing much like a backup camera on your car. These can be installed basically under the NORSEE policy. The options in applications are almost endless when you start to think about it.

Carl

robertthoyer

I had a camera at first but it blew off and lost it, so decided on KISS principle and mounted the mirror no electricity needed.

planewrench

Lol. Carl

jacobsja

One of these mirrors?

https://www.etsy.com/listing/1549945702/piper-wing-mirror-landing-gear-mirror

I like the seller's honesty: "This is not an FAA approved part but is easily removable by hand." Like in the case of gaining attention from the atypical component as the Gov't rep walks by? 😀