Cambridge Flight Recorders



	Cambridge Flight Recorders

	Background
		The Cambridge flight recorders by Cambridge Aero Instruments are very popular with soaring pilots, especially the model 302 which combines GPS, an approved flight recorder, audio vario, a flight computer (speed to fly, etc), supply power/info to/from PDA's, G-meter, temperature (internal/external), myriad of informational tones, an airbrake warning system, etc, etc. Below is some reference information which may be useful to users of these flight recorders. Cambridge 300 series user manuals can be found here. Cambridge 302 dataport reference manual can be found here. 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
	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 (other than lift/sink tones that is!). After flying with the 302 for a while the various tones started to make some sense. You can "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). However, the 302's manual is not very good (IMHO) at describing these tones and their usage. The manual has this 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.
	Cambrige 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; Will not record flights Cannot download log files "Could not get FAT" error message when downloading log files Flight log review, or scoring, reports a security error These issues seem to be caused by the 302's memory becoming "full" at which point it will not store any additional log files. Per Cambridge, the 302 should continue to store your flight's log entries even when reaching the end of memory by automatically "wrapping around" the end of memory and overwritting the oldest log file. However, the issues mentioned above have been reported often enough that this problem has been given wide credence. I believe that Cambridge has commented that this may be caused by a batch of sub-standard components. The commonly held solution is to erase the 302's memory. Unfortunately, doing so will erase all log files in the 302! Before resorting to this drastic cure, you should make every attempt to download log files several times, and in several different ways. If you are desperate, you may want to send the recorder into Cambridge as they may be able to retrieve your log files. At the very least they will clear the memory for you and, optionally, recertify the recorder (which should be done every 2 years in any case). Please see this document for more details from various authors and sources (thanks!) on the procedure to clear the 302's memory. Paul Remde also has a good explanation of this issue and a fix in his November 2007 Newsletter. Good luck!