On Nov 2, 4:09*am, Chris Nicholas wrote:
*All this seems to be a very demanding requirement for official
observers.

Chris N

Yes this does increase the work for OO and contest CD in principle.
There are demanding requirements for the OO now depending on the
individual flight recorder approval--like possibly sealing the
recorder to the aircraft in some circumstances. How often do you think
OOs are 1. aware of these requirements for a particular flight
recorder approval and 2. follow them?

The trade-off is do you want to provide pilots with the option or an
IGC flight recorder pressure altitude that is sourced from the static
line (and therefore should line up after QNH calibration better with
their altimeter) or is the extra choice(=possible confusion)/
complexity/hassle not with it?

I'm not aware of any other vendor offeing this - does anybody know of
any. The LX 8000/9000 do not and the C302 does not - they all record
ambient pressure altitude. I just did a quick check and it looks like
the ability to use static line pressure altitude was introduced in the
GNSS Flight Recorder Technical Specifications AL4 ~2001 (not sure of
the exact adoption date - but it was *not* recent).

Darryl