I have a share in a G1000 Cessna 172. Recently the DME window on the MFD has begun to suddenly lose its distance information. For example it might be working perfectly showing say 8.4 DME and then suddenly start showing _ . _ One or two minutes later it can start working normally again. Distance from the airport does not seem to be a factor. Sometimes it can happen when say 20 miles away while at other times the problem can occur when say 5 or 6 miles away. Has anyone experienced anything similar? Could it be an antenna problem? Is it more likely to be a transmission problem or a reception problem?
Can you enable the DME on your audio panel? This should allow you to hear what's going on, whether the DME loses its lock-in or whether it's a G1000/DME connection problem.
If you know someone with an Aeroflex 8000, you can test it on the ground in various settings and further circle in on the source of the problem.
Achimha
Sometimes when I listen to the DME ident on the audio panel it sounds a bit garbled at first. It sounds like it is picking up something but you cannot clearly hear the morse. Eventually after a while some or all of the morse ident can be heard. The best way to describe it is that It sounds like something is interfering with the reception of the morse signal.
I just have had my DME serviced for the third time by yet another workshop on my 172S G1000.
It just stopped working, and then worked again.
The manager of the workshop told me that there was a dried up melting that he fixed. But once fixed, the DME would, after several hours, be less able to receive the signal and might stop working, depending on the distance and power of the DME beacon.
That’s what I understood anyway.
He advised me to pull the breaker on long flights and to push it back on arrival so that I have a fresh DME.
He advised me to pull the breaker on long flights and to push it back on arrival so that I have a fresh DME.
I think that is completely outrageous suggestion and you should look for a competent avionics repair shop.
I wonder what he means by “dried up melting”?
Unfortunately we have a difficult situation in Europe when it comes to avionics repairs, and very soon it’s going to become a worldwide problem, thanks to Honeywell’s money grabbing.
Once had similar problem, and in the end, it was linked to the DME antenna.
For some reason, the antenna was not solidly attached anymore to its base, and it resulted in instable reading.
Later, the antenna was “inserted” again, and operations resumed.
Maybe you can check this…
Peter, dried up melting is my translation of soudure sèche, he meant that he had to soldier again somme component.
Of course I did not pay the bill as the DME does not work at all now. The audio is almost dead, I only hear some unpleasant static
I’m still looking for a competent avionics repair shop around Paris because most ILS may not be flown without DME, and I don’t know to what extent GPS overlay is safe or not. I’m still not familiar with it, as I don’t fly IFR very often.
@Piotr_Szut, did you try Avionique Service at LFPT?
