Unusual Honeywell KLN94 aviation GPS failure - what could cause this?

http://www.peter2000.co.uk/aviation/kln94-failure/

This unit has been working perfectly for four years, and works fine
now.


Peter.
--
Return address is invalid to help stop junk mail.
E-mail replies to peter1124@peter2000XY.co.uk but remove the X and the Y.

I had something like this happen to me on my first flight with such a
unit (I've only used it a few times). It turned out to be that I had
not turned the GPS on properly (I don't remember what I did wrong) and
it was thus not feeding the display. After landing and reviewing, it
was a "duh!" but I couldn't troubleshoot in flight, and just went for
the backup instruments.

Jose
--
There are more ways to skin a cat than there are cats.
for Email, make the obvious change in the address.

Peter wrote:
You could have a loose Airinc buss wire causing intermittent errors.

Michelle P

I have seen that indication when the antenna did not have a clear view
of the sky.

The installed aircraft was an EADS/Socata TB-9 with gull wing doors.
Coming out of the pad, the pilot's door when up (as it was in the
summer) would obscure much of the sky and not allow the GPS to get a
position. Resolved by removing the blockage by repositioning the plane
or lowering the door. The antenna in this case was on the roof of the
cabin between the two gull-wing-doors.

Peter wrote:

Ooops. Only looked at pic number 1, not the ones showing the sat
reception. Only time I've had a slow position computation is when the
unit has been powered down for a LONG (weeks to months) time. Takes up
to 15 mins for it to "find itself" while remaining still.

An intermittent connection on the internal battery (there is a small
watch battery on the board inside - at least the KLN-89/B does) to keep
last known position and user waypoints stored. You didn't have any
error/hardware error messages on startup?

Dave

Dave S wrote: