Honeywell KFC225 autopilot roll servo failure

In sci.electronics.design Peter wrote:
I've just had my 6th failure of the roll servo, since 2002.

"Doctor, it hurts when I do this."
"Then don't do that."

Can anyone offer me any info

Try
http://www.rockwellcollins.com/produ...ols/index.html
maybe?

Matt Roberds

Peter wrote:
I've just had my 6th failure of the roll servo, since 2002. This time
I got a video of it, showing that the power-up tests pass even with a
dead roll servo:

http://www.zen74158.zen.co.uk/misc-f...ure-2005-1.mpg

Evidently Honeywell have not fixed this - even though the KFC225 has
failed on every aircraft whose owner I have managed to contact over
the last few years.

Can anyone offer me any info on this servo, e.g. schematics? I already
have the KFC225 main unit schematics so I have the interface (which is
very simple).


Peter.
--

Did you contact Honeywell in Phoenix Arizona?

Mark

On Sat, 24 Sep 2005 01:37:37 GMT, wrote:

In sci.electronics.design Peter wrote:
I've just had my 6th failure of the roll servo, since 2002.

"Doctor, it hurts when I do this."
"Then don't do that."

Can anyone offer me any info

Try
http://www.rockwellcollins.com/produ...ols/index.html
maybe?

Matt Roberds


Hmmm...RC try to be customer-responsive these days, but I CAN remember
when they upgraded the FMS 800 and the roll command (used to steer to
the desired track), was reversed from its previous polarity - made for
interesting waypoint/turn capturing!

Brian W.

In sci.electronics.design Brian Whatcott wrote:
On Sat, 24 Sep 2005 01:37:37 GMT, wrote:
http://www.rockwellcollins.com/produ...ols/index.html

Hmmm...RC try to be customer-responsive these days, but I CAN remember
when they upgraded the FMS 800 and the roll command (used to steer to
the desired track), was reversed from its previous polarity - made for
interesting waypoint/turn capturing!

I based my suggestion on a few different observations. I used to work
at a flight simulator company and it was a lot easier to make the
Collins radios work right than the King ones. At that job, and since
then, I have also noticed that the "cheap" avionics package often
involves King radios, while the "upgrade" packages involve Collins
radios. Finally, I went on a job interview with Collins in 1996 and was
totally impressed by the amount of shiny! stuff at the plant in Cedar
Rapids. (Got an offer, too, but chose another offer in Dallas over
Cedar Rapids. Probably should have picked Cedar Rapids.)

Matt Roberds

On Mon, 26 Sep 2005 07:13:17 GMT, wrote:

///. I used to work
at a flight simulator company and it was a lot easier to make the
Collins radios work right than the King ones.
///
Matt Roberds


Hmmm.... radios are one of the items where simulators invariably use a
front panel mock-up with switches and pots signaling the host.
They are not designed or provided by the avionics makers.
Making a mock-up work doesn't have much relation to the
avionics OEM, seems to me??

Brian W

In sci.electronics.design Brian Whatcott wrote:
On Mon, 26 Sep 2005 07:13:17 GMT, wrote:
I used to work at a flight simulator company and it was a lot easier
to make the Collins radios work right than the King ones.

Hmmm.... radios are one of the items where simulators invariably use a
front panel mock-up with switches and pots signaling the host.

Not always. Many of the radios I worked with (business jet and up) were
the kind where there was just a control head in the panel and the actual
guts (tuner, etc) were someplace else. We used the real control heads
and just dispensed with the remote guts. For the Collins radios, you
could read the spec, set up the control and data lines to the control
head, and get it right fairly quickly. For the King radios, reading the
spec was only the first step of a long journey into undocumented
goofiness. This pattern repeated itself with other hardware where we
used the actual aircraft item complete, such as a FMS.

Matt Roberds