|Cambridge Flight Recorders|
Cambridge GPS Error & Repair
The Cambridge line of flight recorders by Cambridge Aero Instruments have reported a rash of Cambridge Model 10/20/25 and 302/302A faults in which the units lose track of the date and do not record a flight log, or record a flight log with an incorrect date. The problem is related to the internal Garmin GPS engine’s UTC date. This is a new issue, but there have already been many reported instances – especially from areas in which there are soaring flights this time of year. It is very likely that many 302 and GPS-NAV owners that have their gliders put away for the winter will, unfortunately, have the same issue during their first flight in the spring.
Below is some reference information which may be useful to users of these flight recorders.
Note - The Cambridge 302A is very similar in features and functions to the 302 without the LCD display or the audio vario. It is an approved flight recorder and it will supply power/data to/from many PDAs or PNAs.
Cambridge 302 Tones Explained & Decoded
When I purchased the Cambridge 302 I was somewhat bewildered by the various tones that the 302 can make during flight.
You can easily "keep your head out of the cockpit" by being able to listen for lift, sink, speed to fly (speed up or slow down), gear/airbrake warnings, slow speed alarm and even SUA alarms (initiated externally e.g. from PDA software). After flying with the 302 for a while the various tones start to make some more sense.
Unfortunately, the 302's manual is not very good (IMHO) at describing these tones and their meaning and usage. The manual has the information scattered in several sections and with less than clear explanations (again, IMHO). To help make this information clearer and simpler, I wrote a short one-page synopsis of the various 302 tones.
To download my 302 tone synopsis, please click here.
Please let me know if I messed up or forgot something. Thanks.
Manuals and Software
Paul Remde's Cumulus-Soaring store's web site has some very good information on the Cambridge line of equipment. See this web site.
Paul has also produced a very nice training video on the Cambridge 300 series equipment. See this web site.
Simulators and Cambridge software is available here.
Cambridge 302 Logging Errors
There is a fairly well known "bug" with a few Cambridge 302 flight computers (and the 302A I assume) in which one of a number of issues can arise;
Conjecture: Later when you go to download your "split" log file, the two log file pieces may not be correctly joined back together into a single file and the above issues can surface. Maybe. Who really knows? However, these issues have been reported often enough that this issue has been given wide credence. I believe that Cambridge has commented that this may have been caused by a batch of sub-standard components.
The commonly held solution to this problem is to clear the 302's memory. Unfortunately, doing so will erase all your log files in the 302 including the one you desperately want! Before resorting to this quite drastic cure, you should make every attempt to download log files several times, and in as many different ways as you know how (via Cambridge software, SeeYou (desktop), Naviter ConnectMe, GlideNav, etc), talk to friends, find a contest score, etc.
If you are really desperate, you could ask Paul Remde of Cumulus-Soaring if he could work with you to retrieve your log files. I'd suggest sending him the unit for recertification which should be done every 5 years in any case (changed from every 2 years in 2013). Ask Paul to help on the log file retrieve and/or clearing the memory.
Here are some instructions;
Cambrige 302 "Fake" Issues
There are a couple of things that can happen to a Cambridge 302 that seem like the unit has failed but isn't really a major problem. I call these "fake" issues.