Narrative:

I had taken a passenger (also a pilot) on a flight. We turned around due to fog not lifting at the destination.there were equipment issues in the rental aircraft; a t-tail piper PA32 lance. The first thing noticed was that the intercom didn't work. I could talk to the passenger but he couldn't talk to me.the #2 radio would not transmit when selected and the #1 unit was scratchy and often not clear on reception.there was no panel mounted GPS database at all so I used my portable garmin 496 for navigation.the landing gear unsafe light was on all the time; but went out when the gear came down. There was a standby vacuum warning light on and off but the vacuum pump gauge showed no malfunction. The amp gauge had no pointer; but for voltage check; the 496 portable GPS has a voltage indication; which was fine.other things seemed to work ok; but I made the mistake of trusting the autopilot too much.upon commencing the ILS approach to runway xy; I had all the parameters set up correctly on the radios; HSI; and #2 CDI. When selecting the localizer function on the autopilot the airplane flew into an unusual attitude and the GPS terrain warning came on. The airplane rolled into a steep bank and the nose dropped.ATC was talking to me; telling of the warning. I told them I would abandon the approach but mostly I was busy disconnecting the autopilot; correcting the wings to level and initiating a climb.the approach controller talked too much while I had things to do to straighten out the aircraft; but I'm sure that's their function. I tried to ignore audio in my headset until the aircraft was in a normal attitude.eventually I said to them; I have the wings level; I'm climbing and proceeding to the 180 degrees heading you assigned me.I hand flew the second approach.first I told the tower I wanted to land straight in on runway xy because I didn't want to circle due to the high accident rate of circling approaches. But when I descended out of the clouds; I saw I was traveling too fast; so told the tower I wanted to land on the other end; runway xx; due to the strong winds.after circling the field; the landing was uneventful. Upon returning the plane to the FBO; I told maintenance of the issues reported here.

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Original NASA ASRS Text

Title: PA32 pilot reported a malfunctioning autopilot put the aircraft into an unusual attitude and triggered a terrain warning on approach.

Narrative: I had taken a passenger (also a pilot) on a flight. We turned around due to fog not lifting at the destination.There were equipment issues in the rental aircraft; a T-Tail Piper PA32 Lance. The first thing noticed was that the intercom didn't work. I could talk to the passenger but he couldn't talk to me.The #2 radio would not transmit when selected and the #1 unit was scratchy and often not clear on reception.There was no panel mounted GPS database at all so I used my portable Garmin 496 for navigation.The landing gear unsafe light was on all the time; but went out when the gear came down. There was a standby vacuum warning light on and off but the vacuum pump gauge showed no malfunction. The amp gauge had no pointer; but for voltage check; the 496 portable GPS has a voltage indication; which was fine.Other things seemed to work OK; but I made the mistake of trusting the autopilot too much.Upon commencing the ILS approach to Runway XY; I had all the parameters set up correctly on the radios; HSI; and #2 CDI. When selecting the LOC function on the autopilot the airplane flew into an unusual attitude and the GPS terrain warning came on. The airplane rolled into a steep bank and the nose dropped.ATC was talking to me; telling of the warning. I told them I would abandon the approach but mostly I was busy disconnecting the autopilot; correcting the wings to level and initiating a climb.The approach controller talked too much while I had things to do to straighten out the aircraft; but I'm sure that's their function. I tried to ignore audio in my headset until the aircraft was in a normal attitude.Eventually I said to them; I have the wings level; I'm climbing and proceeding to the 180 degrees heading you assigned me.I hand flew the second approach.First I told the tower I wanted to land straight in on Runway XY because I didn't want to circle due to the high accident rate of circling approaches. But when I descended out of the clouds; I saw I was traveling too fast; so told the tower I wanted to land on the other end; Runway XX; due to the strong winds.After circling the field; the landing was uneventful. Upon returning the plane to the FBO; I told maintenance of the issues reported here.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.