PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 15; Flight Crew Total 1035; Flight Crew Type 800
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification; General Declared Emergency
Weather; Aircraft
While on Final Approach on the ILS 36; we suffered a partial power failure and total comm failure - the Garmin 430 Nav/Com; King Comm Radio (secondary comm radio); and Mode C transponder went out. The secondary nav; KNS 80 RNAV unit continued to function; as well as other electric devices (engine analyzer; lights; and gauges). We had just broken out of the clouds (about 3 miles from the airport) when the failure occurred. The missed approach instructions were to climb straight ahead to 3000; but as we had the airport in site and we were now VMC we continued the approach and sidestepped left to enter the pattern in order to land (Traffic was landing to the south). We entered the pattern on the left downwind and looked for a light signal from the tower. We tried squawking 7600 but the Mode C transponder appeared to be dead. We did not see any other aircraft in the pattern but saw two aircraft on the ground waiting to take off while we were on the downwind. We continued flying the pattern downwind to base and base to final but did not receive any light signals. We flew over the runway at 300 feet and rocked our wings trying to get the tower to acknowledge us with light signals but we didn't receive any. While upwind I remembered that I had my portable radio in my flight bag so I dug it out and was able to contact the tower explaining that we had an electrical failure and we received clearance to land; number 2. We were not able to see the aircraft on short final; called the tower again; and were cleared to land. On final we advised tower that we needed to taxi to the west side FBO and they provided taxi clearance. We again called tower once we were down to say thank you and they requested we call them on the land line when able to get more information on our electrical failure. It was very difficult to hear with the portable radio so we tried to keep transmissions to a minimum.
While shooting the ILS 36 approach; just after crossing FAF inbound; Garmin 430 went black. Number two radio and transponder also appeared offline. KNS 80 continued to work as well as primary instruments. Flying pilot continue to fly approach we were cleared for. We troubleshoot; amp meter showed power; no circuit breakers popped; and put 7600 in transponder and very shortly broke out of clouds. With no comms; now KNS 80 flashing on and off; and clear of clouds decided landing best option. Winds unfavorable for RW36 and aircraft on ground waiting for RW18; sidestepped to left pattern for RW 18 and looked for light signals from tower. None seen; so overflew RW 18 and rocked wings. At that time flying pilot remembered that he had a hand held radio in bag so I took over flying while he got the handheld and reached the tower. Handheld was difficult to use but we were cleared to land after another aircraft in pattern. Could not get visual of that aircraft so extended left downwind until cleared to land by tower. Landed without problems and taxied to ramp. Primary pilot called tower after landing and thanked them. Presumed failure was partial alternator or unusual electrical short.
Two PA28 pilots experience a partial electrical failure during an ILS approach in IMC causing partial instrument failure; transponder and comm failure. The approach is continued to VMC then the VFR pattern is entered but no light signals are received. Eventually a hand held VHF is used to receive landing clearance.