Proline 21 RT Frequency lost or missing
 

Hi All

My company has had some issues lately with our Proline 21 equipped Kingair. I was wondering if anyone else had experienced anything similar.

On more than one occasion crew have found themselves on the wrong frequency or on a dead frequency, with the assigned frequency nowhere to be found (i.e. not in standby). This is after having checked in on the correct frequency.

As I understand it the RTU is the primary tuning unit although I know some crew prefer to use the CDU and there are gotchas with that. So although, "finger trouble" would seem like an obvious place to look, has anyone experienced any technical bugs in the system that could cause this?

Cheers

lost freqs
 

Yep had that when the proline 21 airplanes were new in the company in 2004/5.
The company upgraded/adjusted the software and the problem was solved.
Also a problem we had in the beginning was that if we punched the e.g. PERF button on the FMS twice too quickly, the whole FMS went offline.

Also solved after a software update.

Good luck.
N. :ok:

Challenger 300's and 605 also with Pro-Line 21 suffer similar, caused by a bad SRAM chip somewhere in the bowels of the system locking up the system.

Rockwell-Collins should be your next port of call; there are a few vendor
service bulletins addressing the cause.

ttfn

Thanks guys, very helpful.