PA-46 Malibu/Malibu Mirage/Malibu Matrix
Flight Crew Commercial; Flight Crew Instrument
Flight Crew Last 90 Days 70; Flight Crew Total 5010; Flight Crew Type 131
Situational Awareness; Training / Qualification
Aircraft Equipment Problem Critical
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Human Factors; Aircraft
I was on vectors to final for the RNAV 15 approach into Sioux Falls when I had a total electrical failure after lowering the gear in IMC. I immediately informed ATC. The G500 and both my GPS and radios and all lights went out. I used my flashlight to see my backup attitude indicator; altimeter and airspeed. When I was stabilized I turned off my master switch and turned on my ground clearance delivery switch and was able to regain communication with ATC. I initially told ATC that I had a total electrical failure. They began giving me headings and I told them I needed direction of turn as I had no heading indicator. They provided this and cleared me for an ASR approach. After a few vectors I asked what heading I was flying and they provided that so I slaved the copilot DG and was able to follow headings. I then proceeded to trouble shoot and found that both of my generator breakers and my battery breaker had popped so I reset them and everything began to reboot. About that time I spotted Runway 21 and was cleared to land. I had lights but by the time the G500 rebooted I was already on the ground. Everything worked normally after resetting the breakers both that night and during my runup and flight the next day. I had the airplane checked out the next day and they found that one battery was weak. The main factor; however; was that there are a 60 amp and an 80 amp breaker on a 200 amp generator. I had three electric auxiliary heaters running; all of my deice equipment and windshield heat on. I was cognizant of the fact that I had a high electrical load and knew that I was using 148 amps before extending the gear. I thought that was well within the capacity of my aircraft. I have since learned that using all of my supplemental heat and all of my deice equipment for an extended period of time caused the breakers to eventually pop. This is according to the mechanics doing the trouble shooting. I did not know that I couldn't use all of my equipment. I did not read that in the POH nor was I informed of that during my initial training. I was trained that I cannot use over 70 amps on my backup alternator. I feel that I should have been taught to not use over 140 amps during normal operations. I am not aware of any deviation to FARs but hope that my experience will help other Jetprop pilots.
The reporter stated that the PA46 Jetprop is a conversion of the original PA46 with some changes to the electrical system. The original PA46 160 amp limit is apparently still in effect although not printed in the Jetprop POH. The confusion resulted due to the Jetprop's 200 amp generator. He believes this information should be disseminated to all Jetprop pilots.
PA46 Jetprop pilot learned the hard way that his 200 amp generator is limited by circuit breakers to 140 amps. During a night; IMC approach with three auxiliary failure occurs when the landing gear (50 amps) is extended. ATC provided assistance and a successful approach and landing ensues. The two main generator circuit breakers were found tripped and the electrical system functioned normally after being reset. The reporter indicates that he was never informed of the 140 amp limit in training nor is there a limitation in the POH.