Sun May 13, 2018 11:03 am
#1611493
Anyone with knowledge and experience to comment on the below please? (WigglyAmp springs to mind).
Our group aeroplane has some oddities with its GTN650.
First thing is to replace the internal battery. The manual requires this to be done by a dealer (we use the aeroplane for IFR so need to maintain it to the book).
Assuming that does not fix the problems, detailed below, it needs some investigation. Our usual maintainer has done the basic checks of wiring so I think it is probably not something obvious.
Details of the problem:
After power-on of the aeroplane, the GTN takes about fifteen minutes to come to life. Once on, it acquires a position only occasionally and for short periods. The radio and VOR functions of the GTN are fine. The aeroplane did spend six months last year and three months this year not flying for mechanical work to be done. Mechanically it is now fully serviceable and back in use. Having myself flown the aeroplane several times recently, including for some two hour flights, I can almost convince myself that the more it is used the less the GTN650 misbehaves (i.e. does not take so long to start then acquires a position fix more often and for longer) almost as though not being used in some way confused it. All this seems completely irrational! I did also notice that when I landed for a quick fuel stop and the power was off for only about half an hour that the GTN came to life almost immediately on restart.
The database is currently out of date. Normally we update it monthly but I am not doing that while it is of such doubtful serviceability. I believe that this has no bearing on whether the unit works, just whether t is legal for IFR.
Our group aeroplane has some oddities with its GTN650.
First thing is to replace the internal battery. The manual requires this to be done by a dealer (we use the aeroplane for IFR so need to maintain it to the book).
Assuming that does not fix the problems, detailed below, it needs some investigation. Our usual maintainer has done the basic checks of wiring so I think it is probably not something obvious.
Details of the problem:
After power-on of the aeroplane, the GTN takes about fifteen minutes to come to life. Once on, it acquires a position only occasionally and for short periods. The radio and VOR functions of the GTN are fine. The aeroplane did spend six months last year and three months this year not flying for mechanical work to be done. Mechanically it is now fully serviceable and back in use. Having myself flown the aeroplane several times recently, including for some two hour flights, I can almost convince myself that the more it is used the less the GTN650 misbehaves (i.e. does not take so long to start then acquires a position fix more often and for longer) almost as though not being used in some way confused it. All this seems completely irrational! I did also notice that when I landed for a quick fuel stop and the power was off for only about half an hour that the GTN came to life almost immediately on restart.
The database is currently out of date. Normally we update it monthly but I am not doing that while it is of such doubtful serviceability. I believe that this has no bearing on whether the unit works, just whether t is legal for IFR.