It actually happened today!! Vacuum failure in IMC.

What was the reason for the 7700? Were you in controlled airspace?
Didn't ATC already have a positive ID on you before you changed the
transponder code?

-Robert, CFI

It is my understanding that 7700 is what we are supposed to dial into
the xpdr when we declare an emergency. I was in controlled airspace.
Does that make a difference?

On 10/7/2005 6:02 PM, skym wrote:

It is my understanding that 7700 is what we are supposed to dial into
the xpdr when we declare an emergency. I was in controlled airspace.
Does that make a difference?


You only need to do that if you need to get someone's attention.
If you're in radio communications already, all you need to do is
declare it. There is no *requirement* to change your xponder code.


--
Mark Hansen, PP-ASEL, Instrument Airplane
Sacramento, CA

If you're already talking to ATC just tell the controllr what the
problem is, no need to change the transponder. Doesn't matter what
airspace you are in.



skym wrote:
It is my understanding that 7700 is what we are supposed to dial into
the xpdr when we declare an emergency. I was in controlled airspace.
Does that make a difference?

Thanks to both. Didn't know that. Hope I don't ever need it again!!

skym wrote:

Thanks to both. Didn't know that. Hope I don't ever need it again!!

You did nothing wrong by squawking 7700. Better to error on the
conservative side, and that is what you did.

Also, the 7700 squawk really wakes up the system to work in your behalf.
;-)

On Sun, 09 Oct 2005 18:12:28 -0700, wrote:

Also, the 7700 squawk really wakes up the system to work in your behalf.
;-)

This is an understatement. 7700 will light up ATC systems.

The one time I squawked 7700 on an in-flight cylinder failure to L31
(Covington-St Tamminy LA), I contacted 121.5 and squawked 7700.

Once I got transferred to New Orleans apporach, they couldn't give me a
standard squawk code to change to fast enough.

As others said, no fuss no muss afterwards. All New Orleans approach asked
for of me was to contact FSS to advise I was safe on the ground. Never
heard a thing afterwards.

I shared my experiences with rec.aviation.student. Original post can be
found at
http://groups.google.com/group/rec.a...c3724728?tvc=1

Allen

"skym" wrote in message
ups.com...
It is my understanding that 7700 is what we are supposed to dial into
the xpdr when we declare an emergency. I was in controlled airspace.
Does that make a difference?

Yes - it lights you up distinctly (a different colour, I believe) on the
radar screen. So although the controller would see you no matter what code
you were transmitting, if you switch to an emergency code (7700, 7600, 7500,
etc) the equipment makes you more prominent and so lightens his workload a
little.

D.

David Cartwright wrote:
"skym" wrote in message
ups.com...

It is my understanding that 7700 is what we are supposed to dial into
the xpdr when we declare an emergency. I was in controlled airspace.
Does that make a difference?


Yes - it lights you up distinctly (a different colour, I believe) on the
radar screen. So although the controller would see you no matter what code
you were transmitting, if you switch to an emergency code (7700, 7600, 7500,
etc) the equipment makes you more prominent and so lightens his workload a
little.

That's funny. Completely wrong, but funny.

skym wrote On 10/06/05 17:26,:

3. An STEC A/P which runs on the TC, rather than the vacuum
instruments, is the way to go.

I agree, the STEC even has a separate altimeter (actually a
differential pressure transducer) with its on dual air inlet
placed midsection.

One question: was the A/P engaged during the AI fail ? Do you
think that would have made a big difference in keeping the
aircraft under control ?

If it wasn't engaged, did you engage it immediately ? Did you
wait to get the aircraft under control with the T&B before
engaging it ?

Thank you, and congatulations on your sucessful handling of
the situation.