I too had my first experience in IMC yesterday. I got my ticket last
summer too and have kept current but haven't had a chance to go solo. I
was going to go from Indianapolis Executive (TYQ) to Capitol City in
Lansing Michigan (LAN). The weather was 1000 OVR until 50 miles north of
TYQ and then it was clear all the way to LAN. THis was going to be a
quick trip because the weather in Indiana was forecast to get worse as
the day wore on.

I was a little bit apprehensive because I have a respect to IMC but I
thought it would be good practice too. I got set up, picked up my
clearance and was off. Just as forecast I entered the clag at 1000 feet.
Right away I spotted something wrong with the attitude indicator. It was
looking like I was in a steep climbing turn. Oh **** I thought great
time for the AI to go out. I had a weird feeling of ending up as an
Aftermath column. I must say that I was pretty scared but strange
enough not panicked. I reduced power, used the Turn Coordinator to level
the wings, used the Airspeed Indicator to level off altitude. I called
ATC and told them that I was having a problem with the AI and needed
their assistance. They asked if I wanted vectors back to TQY to shoot
the ILS 36 there. I said yes. I started back to the field and the AI
started to act like I expected it should. After a few minutes I was
still in the clag but all instruments were working correctly. I thought
about just continuing on back to Lansing but I quickly talked myself out
of it.

Really after I "calmed" down and the AI started acting correctly I
didn't have any problems navigating in the clouds. I shot the ILS 36 and
broke out 1000 feet above the runway, canceled my IFR flight plan and
made an uneventful landing. ATC wanted to know if I wanted to refill my
flight plan and I said no thanks. I was glad to be on the ground. I was
thinking about what just transpired and decided to talk it over with my
CFI.

We determined that what probably happened was that the extended period
of idling on the ground caused the AI gyro to spool down some. It took
several minutes at cruise power for it to come back up to speed and
after that it indicated correctly.

Here is what I'll do different next time:

1. Make sure that I have had the vacuum indicator "in the green" for
several minutes before departing to ensure that the gyros are spooled up.

2. Have the approach for returning to the airport loaded or in standby
just in case you need to return quickly. I did not do this and it added
needless stress loading everything.

It is true what they say:
"It is better to be on the ground wishing you were in the air, then
being in the air wishing you were on the ground"

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

In a previous article, Jon Kraus > said:
>1. Make sure that I have had the vacuum indicator "in the green" for
>several minutes before departing to ensure that the gyros are spooled up.
>
>2. Have the approach for returning to the airport loaded or in standby
>just in case you need to return quickly. I did not do this and it added
>needless stress loading everything.

It couldn't hurt to have a mechanic look at your vacuum system.


--
Paul Tomblin > http://xcski.com/blogs/pt/
"The means of defense against foreign danger historically have become the
instruments of tyranny at home." - James Madison

I didn't mention that in my post but first thing tomorrow I am calling
the shop and have them check everything out. Thanks!!

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Paul Tomblin wrote:
> In a previous article, Jon Kraus > said:
>
>>1. Make sure that I have had the vacuum indicator "in the green" for
>>several minutes before departing to ensure that the gyros are spooled up.
>>
>>2. Have the approach for returning to the airport loaded or in standby
>>just in case you need to return quickly. I did not do this and it added
>>needless stress loading everything.
>
>
> It couldn't hurt to have a mechanic look at your vacuum system.
>
>

Jon Kraus > wrote:
> We determined that what probably happened was that the extended period
> of idling on the ground caused the AI gyro to spool down some. It took
> several minutes at cruise power for it to come back up to speed and
> after that it indicated correctly.

You should be getting full vacuum at normal ground idle speeds (1000 RPM
or so). If your gyros are not spinning up in the time it takes you to
taxi to the runway and do a normal runnup, something is wrong with the
vacuum system or the gyros.

In any case, congrats on a job well done.

"Jon Kraus" wrote:
> Right away I spotted something wrong with the attitude indicator. It
was
> looking like I was in a steep climbing turn. Oh **** I thought great
> time for the AI to go out. I had a weird feeling of ending up as an
> Aftermath column.

Holy sh**!

[snip good job of getting back on the ground]

> Here is what I'll do different next time:
>
> 1. Make sure that I have had the vacuum indicator "in the green" for
> several minutes before departing to ensure that the gyros are spooled
> up.
>
> 2. Have the approach for returning to the airport loaded or in
> standby just in case you need to return quickly. I did not do this and
> it added needless stress loading everything.

My first thought if I have trouble in IMC is to get to VMC if I can do
it quickly. Did you have any idea of where the tops were? If you could
have made a short, straight ahead climb above the clouds, your
destination was in the clear; you could have avoided a bunch of IMC
maneuvering with a flaky AI.
--
Dan
C172RG at BFM

On Sun, 02 Jan 2005 13:46:31 GMT, Jon Kraus wrote:

Good job Jon! I ran into a similar situation with my VFR ticket and Vacuum
pump failure. It was a night flight. See
http://groups-beta.google.com/group/rec.aviation.student/browse_frm/thread/d4d6b0bf244a3765/87ff0985c67799e8?q=vacuum+pump+lieberma&_done=%2Fgroups%3Fq%3Dvacuum+pump+lieberma%26&_doneTitle=Back+to+Search&&d#87ff0985c67799e8
for my experiences. (learning systems on the fly)

> Here is what I'll do different next time:
>
> 1. Make sure that I have had the vacuum indicator "in the green" for
> several minutes before departing to ensure that the gyros are spooled up.

I am surprised that your preflight procedures after engine start up doesn't
check for vacuum. Mine has it twice. Once after engine start, and then
once again after runup.

> 2. Have the approach for returning to the airport loaded or in standby
> just in case you need to return quickly. I did not do this and it added
> needless stress loading everything.

VERY GOOD TIP! I have generally had my arrival airport and alternate
airport approaches readily available on my kneeboard, but I will add my own
departure airport for future flights.

I don't have an IFR GPS, but couldn't you have hit the NRST button to
quickly get your airport information loaded???

Allen

"Jon Kraus" > wrote in message
...

Glad it worked out. It would be useful to file an ASRS report of the event.

> Really after I "calmed" down and the AI started acting correctly I didn't
> have any problems navigating in the clouds. I shot the ILS 36 and broke
> out 1000 feet above the runway, canceled my IFR flight plan and made an
> uneventful landing.

I hope you waited until you were below 700' AGL before canceling IFR. (If
not, that's another good reason for the ASRS report.)

--Gary

You are correct... The tops were just at 4000 but I wanted to get down
so I could clean out my pants!! :-)

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Dan Luke wrote:

> "Jon Kraus" wrote:
> > Right away I spotted something wrong with the attitude indicator. It
> was
>
>>looking like I was in a steep climbing turn. Oh **** I thought great
>>time for the AI to go out. I had a weird feeling of ending up as an
>>Aftermath column.
>
>
> Holy sh**!
>
> [snip good job of getting back on the ground]
>
>
>>Here is what I'll do different next time:
>>
>>1. Make sure that I have had the vacuum indicator "in the green" for
>>several minutes before departing to ensure that the gyros are spooled
>>up.
>>
>>2. Have the approach for returning to the airport loaded or in
>>standby just in case you need to return quickly. I did not do this and
>>it added needless stress loading everything.
>
>
> My first thought if I have trouble in IMC is to get to VMC if I can do
> it quickly. Did you have any idea of where the tops were? If you could
> have made a short, straight ahead climb above the clouds, your
> destination was in the clear; you could have avoided a bunch of IMC
> maneuvering with a flaky AI.

Thanks for the advice Gary. I am familiar with what a ASRS report is but
was wondering how to file one and why one is needed?

Yes I was below 700 feet when I cancelled my IFR plan. Thanks again!!

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Gary Drescher wrote:

> "Jon Kraus" > wrote in message
> ...
>
> Glad it worked out. It would be useful to file an ASRS report of the event.
>
>
>>Really after I "calmed" down and the AI started acting correctly I didn't
>>have any problems navigating in the clouds. I shot the ILS 36 and broke
>>out 1000 feet above the runway, canceled my IFR flight plan and made an
>>uneventful landing.
>
>
> I hope you waited until you were below 700' AGL before canceling IFR. (If
> not, that's another good reason for the ASRS report.)
>
> --Gary
>
>

"Jon Kraus" > wrote in message
...

Well you sure got a lot more practice than you were planning on. After that,
your next flight should seem like a walk in the park.

> 2. Have the approach for returning to the airport loaded or in standby
> just in case you need to return quickly. I did not do this and it added
> needless stress loading everything.

This was one of a handful of things my CFII really hammered on about.
Anytime you departed in IMC, the rule was to have the plate for the approach
in use up on the yoke, with one box tuned to the approach in use, and one
box tuned to get you to the first fix in your clearance.

Still, it's good to get tested under pressure and pass. You can't be
prepared for every event. I got my IR back in September and haven't done
solo IMC yet, but I do hope my first experience will be a bit smoother than
yours!

-cwk.

On 1/2/05 8:46 AM, in article , "Jon
Kraus" > wrote:

>
> Here is what I'll do different next time:
>
> 1. Make sure that I have had the vacuum indicator "in the green" for
> several minutes before departing to ensure that the gyros are spooled up.
>
> 2. Have the approach for returning to the airport loaded or in standby
> just in case you need to return quickly. I did not do this and it added
> needless stress loading everything.
>
> It is true what they say:
> "It is better to be on the ground wishing you were in the air, then
> being in the air wishing you were on the ground"
>
> Jon Kraus
> PP-ASEL-IA
> Student Mooney Owner
>

Congratulations Jon! Sounds like a "fun" flight.
We should all remember that aviation quotes are first written in blood and
tears.

It seems you're like me, you learn a few good items to add to that checklist
every time you fly. Happy new year and fly safe.
--
Jeff 'The Wizard of Draws' Bucchino

Cartoons with a Touch of Magic�
http://www.wizardofdraws.com

More Cartoons with a Touch of Magic�
http://www.cartoonclipart.com

"Jon Kraus" > wrote in message
...
> Thanks for the advice Gary. I am familiar with what a ASRS report is but
> was wondering how to file one and why one is needed?

You can get the form and instructions at
http://asrs.arc.nasa.gov/main_nf.htm. The ASRS program analyzes reports of
hazardous situations in order to figure out how to improve aviation safety.
(Their limited-immunity policy is an extra incentive to file reports when
pilots inadvertantly violate the FARs, but that aspect isn't pertinent in
this case.)

> Yes I was below 700 feet when I cancelled my IFR plan. Thanks again!!

Cool. Pilots often get that wrong, canceling before they have the required
VFR cloud clearance in controlled airspace, and sometimes get busted for it.

--Gary

> Jon Kraus
> PP-ASEL-IA
> Student Mooney Owner
>
> Gary Drescher wrote:
>
>> "Jon Kraus" > wrote in message
>> ...
>>
>> Glad it worked out. It would be useful to file an ASRS report of the
>> event.
>>
>>
>>>Really after I "calmed" down and the AI started acting correctly I didn't
>>>have any problems navigating in the clouds. I shot the ILS 36 and broke
>>>out 1000 feet above the runway, canceled my IFR flight plan and made an
>>>uneventful landing.
>>
>>
>> I hope you waited until you were below 700' AGL before canceling IFR. (If
>> not, that's another good reason for the ASRS report.)
>>
>> --Gary
>>
>>
>

Once I calmed myself down it was "kinda" fun. I would have preferred to
have this happen after many flights in IMC though..

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Wizard of Draws wrote:

> On 1/2/05 8:46 AM, in article , "Jon
> Kraus" > wrote:
>
>
>>Here is what I'll do different next time:
>>
>>1. Make sure that I have had the vacuum indicator "in the green" for
>>several minutes before departing to ensure that the gyros are spooled up.
>>
>>2. Have the approach for returning to the airport loaded or in standby
>>just in case you need to return quickly. I did not do this and it added
>>needless stress loading everything.
>>
>>It is true what they say:
>>"It is better to be on the ground wishing you were in the air, then
>>being in the air wishing you were on the ground"
>>
>>Jon Kraus
>>PP-ASEL-IA
>>Student Mooney Owner
>>
>
>
> Congratulations Jon! Sounds like a "fun" flight.
> We should all remember that aviation quotes are first written in blood and
> tears.
>
> It seems you're like me, you learn a few good items to add to that checklist
> every time you fly. Happy new year and fly safe.

On Sun, 02 Jan 2005 15:35:59 GMT, Jon Kraus wrote:

> Thanks for the advice Gary. I am familiar with what a ASRS report is but
> was wondering how to file one and why one is needed?

Hey Jon,

Go to http://asrs.arc.nasa.gov/forms.htm for the form and instructions on
how to file one.

Allen

Gary Drescher wrote:
> Cool. Pilots often get that wrong, canceling before they have the required
> VFR cloud clearance in controlled airspace, and sometimes get busted for
it.

I hear it here (SJC) at bunch. GA plane gets a IFR to VFR on top, and
reports: "OK, we just broke out, tops 2400, cancel IFR" - something like
that. When I get that clearance, I feel bad spending more than a minute in
perfect visibility while the 'big iron' sits on the ground at SJC, but it's
the rules and it does prevent one of those 'big-irons' climbing into me (or
at least helps prevents it).

Hilton

My guess is you have a failing vacuum pump. It might have been acting up
then corrected itself during flight once you had full RPM. Even if the
vacuum is below green during idle, it should not take more than a few
seconds to bring the gryos to full speed at takeoff power. I would
definitely have the vacuum system checked out.





(Paul Tomblin) wrote in news:cr8uan$4n2$1
@allhats.xcski.com:

> In a previous article, Jon Kraus > said:
>>1. Make sure that I have had the vacuum indicator "in the green" for
>>several minutes before departing to ensure that the gyros are spooled up.
>>
>>2. Have the approach for returning to the airport loaded or in standby
>>just in case you need to return quickly. I did not do this and it added
>>needless stress loading everything.
>
> It couldn't hurt to have a mechanic look at your vacuum system.
>
>

"Gary Drescher" > wrote in message =
...
> "Jon Kraus" > wrote in message=20
>=20
>> Yes I was below 700 feet when I cancelled my IFR plan. Thanks again!!
>=20
> Cool. Pilots often get that wrong, canceling before they have the =
required=20
> VFR cloud clearance in controlled airspace, and sometimes get busted =
for it.
>=20
> --Gary
>

You might be referencing that odious piece of fiction from (I think) =
IFR.
Someone (I forget who) fabricated such a circumstance and wrote a
magazine article about it as though it really happened a couple years =
ago.
I think that was unforgivably dishonest journalism.
It's OK to write about observing rules concerning IFR cancellations,
but I object to sensationalizing *fictitious* enforcement actions.

Dry vacuum pumps normally fail catastrophically by shattering their
graphite vanes. Personally, I've never detected warning signs other =
than
gradually accumulating carbon dust around the pump outlets.
When I see that, I schedule pump replacement without waiting for =
failure.

Jon's doing right by getting the whole vacuum system checked.
He could have a clogged filter, a small leak, or even a bad gyro =
bearing.

"Andrew Sarangan" > wrote in message =
1...
>=20
> My guess is you have a failing vacuum pump. It might have been acting =
up=20
> then corrected itself during flight once you had full RPM. Even if =
the=20
> vacuum is below green during idle, it should not take more than a few=20
> seconds to bring the gryos to full speed at takeoff power. I would=20
> definitely have the vacuum system checked out.
>
> (Paul Tomblin) wrote in news:cr8uan$4n2$1
> @allhats.xcski.com:
>=20
>> In a previous article, Jon Kraus > said:
>>>1. Make sure that I have had the vacuum indicator "in the green" for =

>>>several minutes before departing to ensure that the gyros are spooled =
up.
>>>
>>>2. Have the approach for returning to the airport loaded or in =
standby=20
>>>just in case you need to return quickly. I did not do this and it =
added=20
>>>needless stress loading everything.
>>=20
>> It couldn't hurt to have a mechanic look at your vacuum system.
>>=20
>

I think I'll get this IFR thing more practice first. This incident
helped cement the fact that I don't know diddly about IFR flight. But
for the grace of God that I got down safely. Have you been solo IMC yet.
It is quite a rush (even without the instrument issue)

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Cecil Chapman wrote:
> GREAT JOB!!! Sounds like you did just fine despite having 'this is NOT a
> simulation' flashing in your brain <GRIN>
>
> So, when are you going to get your CFII... sounds like your instructor did
> you right! :0)
>

I think I'll get this IFR thing more practice first. This incident
helped cement the fact that I don't know diddly about IFR flight. But
for the grace of God that I got down safely. Have you been solo IMC yet?
It is quite a rush (even without the instrument issue)

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Cecil Chapman wrote:
> GREAT JOB!!! Sounds like you did just fine despite having 'this is NOT a
> simulation' flashing in your brain <GRIN>
>
> So, when are you going to get your CFII... sounds like your instructor did
> you right! :0)
>

GREAT JOB!!! Sounds like you did just fine despite having 'this is NOT a
simulation' flashing in your brain <GRIN>

So, when are you going to get your CFII... sounds like your instructor did
you right! :0)

--
--
=-----
Good Flights!

Cecil
PP-ASEL-IA
Student - CP-ASEL

Check out my personal flying adventures from my first flight to the
checkride AND the continuing adventures beyond!
Complete with pictures and text at: www.bayareapilot.com

"I fly because it releases my mind from the tyranny of petty things."
- Antoine de Saint-Exupery -

"We who fly, do so for the love of flying. We are alive in the air with
this miracle that lies in our hands and beneath our feet"
- Cecil Day Lewis -

I think I'll get this IFR thing more practice first. This incident
helped cement the fact that I don't know diddly about IFR flight. But
for the grace of God that I got down safely. Have you been solo IMC yet.
It is quite a rush (even without the instrument issue)

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Cecil Chapman wrote:

> GREAT JOB!!! Sounds like you did just fine despite having 'this is NOT a
> simulation' flashing in your brain <GRIN>
>
> So, when are you going to get your CFII... sounds like your instructor did
> you right! :0)
>

I think I'll get this IFR thing more practice first. This incident
helped cement the fact that I don't know diddly about IFR flight. But
for the grace of God that I got down safely. Have you been solo IMC yet?
It is quite a rush (even without the instrument issue)..

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Cecil Chapman wrote:

> GREAT JOB!!! Sounds like you did just fine despite having 'this is NOT a
> simulation' flashing in your brain <GRIN>
>
> So, when are you going to get your CFII... sounds like your instructor did
> you right! :0)
>

In article >,
"Hilton" > wrote:

> Gary Drescher wrote:
> > Cool. Pilots often get that wrong, canceling before they have the required
> > VFR cloud clearance in controlled airspace, and sometimes get busted for
> it.
>
> I hear it here (SJC) at bunch. GA plane gets a IFR to VFR on top, and
> reports: "OK, we just broke out, tops 2400, cancel IFR" - something like
> that. When I get that clearance, I feel bad spending more than a minute in
> perfect visibility while the 'big iron' sits on the ground at SJC, but it's
> the rules and it does prevent one of those 'big-irons' climbing into me (or
> at least helps prevents it).
>
> Hilton

Yes, you're right that it's illegal, but it sounds like a victimless
crime. Let's say you're climbing at 500 fpm. By the time the
controller acknowledges your call, you're already a few hundred feet
above the tops. By the time he releases the next guy, you're 500 feet.
Even if he climbs at 2500 fpm, by the time he hits the tops, you're 1000
feet above.

On the other hand, if your plan is to cancel when you break out at 2400
and cruise at 2500, I'd be a little more concerned.

In a previous article, "John R. Copeland" > said:
>Dry vacuum pumps normally fail catastrophically by shattering their
>graphite vanes. Personally, I've never detected warning signs other than
>gradually accumulating carbon dust around the pump outlets.
>When I see that, I schedule pump replacement without waiting for failure.
>
>Jon's doing right by getting the whole vacuum system checked.
>He could have a clogged filter, a small leak, or even a bad gyro bearing.

We had an AI once that was very slow to erect. First the mechanic
increased the suction to try and spin the gyros faster, but when that
didn't help we ended up replacing the AI.


--
Paul Tomblin > http://xcski.com/blogs/pt/
I treat shops as military objectives to be penetrated and stripped of needed
resources in as little time as possible. She has adventures in them.
-- Joe Thompson

Well, I have seen signs of dry pumps show signs of failure. True, the
ultimate failure is catastrophic, but every time I found a low vacuum
reading they found some problem with the pump. After replacement, the
vacuum was back up to where it should be.



"John R. Copeland" > wrote in
:

> Dry vacuum pumps normally fail catastrophically by shattering their
> graphite vanes. Personally, I've never detected warning signs other
> than gradually accumulating carbon dust around the pump outlets.
> When I see that, I schedule pump replacement without waiting for
> failure.
>
> Jon's doing right by getting the whole vacuum system checked.
> He could have a clogged filter, a small leak, or even a bad gyro
> bearing.
>
> "Andrew Sarangan" > wrote in message
> 1...
>>
>> My guess is you have a failing vacuum pump. It might have been acting
> up
>> then corrected itself during flight once you had full RPM. Even if
> the
>> vacuum is below green during idle, it should not take more than a few
>> seconds to bring the gryos to full speed at takeoff power. I would
>> definitely have the vacuum system checked out.
>>
>> (Paul Tomblin) wrote in news:cr8uan$4n2$1
>> @allhats.xcski.com:
>>
>>> In a previous article, Jon Kraus > said:
>>>>1. Make sure that I have had the vacuum indicator "in the green"
>>>>for
>
>>>>several minutes before departing to ensure that the gyros are
>>>>spooled
> up.
>>>>
>>>>2. Have the approach for returning to the airport loaded or in
> standby
>>>>just in case you need to return quickly. I did not do this and it
> added
>>>>needless stress loading everything.
>>>
>>> It couldn't hurt to have a mechanic look at your vacuum system.
>>>
>>
>

I've had both my attitude indicator go out (itself) and the vac pump go
out in my Mooney. The attitude indicator failure was MUCH more
upsetting. A vac failure takes awhile to effect instruments and usually
gives a good warning on a Mooney(red light, voice annunicator, etc).
The attitude indicator failure was worse. It appeared to work, but just
slowly started indicating a turn to the right. However, it responded in
pitch and roll just fine, giving the impression it was good. The
failure was in IMC. I decided then to try for a backup electric unit. I
see almost zero value in the backup vac systems, they don't do anything
for the more upsetting attitude indicator failure.

Mine did that before it failed.

I totally agree and they are on my taxi checklist.

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Gary Drescher wrote:

> "Jon Kraus" > wrote in message
> ...
>
>>Allen,
>>
>>Yes my preflight procedures do have a "check vacuum in the green". I might
>>have a vacuum pump that is worn and in need of replacement.
>
>
> Another important item is to monitor the vacuum instruments, the turn
> coordinator, and the compass while taxiing, especially during turns.
>
> --Gary
>
>

> It is true what they say:
> "It is better to be on the ground wishing you were in the air, then
> being in the air wishing you were on the ground"


Ahh that take all the fun away from flying.








































































gotcha

>Have you been solo IMC yet.
> It is quite a rush (even without the instrument issue)

Nope, still a solo IMC 'virgin'..... The commercial flight training is
eating up my flying hours, as is. A couple of times this month I want to
squeeze in some hard IFR with a CFII there (still only have a couple of
hours of 'actual' and that was just in coastal fog layer, for the most
part).

--
--
=-----
Good Flights!

Cecil
PP-ASEL-IA
Student - CP-ASEL

Check out my personal flying adventures from my first flight to the
checkride AND the continuing adventures beyond!
Complete with pictures and text at: www.bayareapilot.com

"I fly because it releases my mind from the tyranny of petty things."
- Antoine de Saint-Exupery -

"We who fly, do so for the love of flying. We are alive in the air with
this miracle that lies in our hands and beneath our feet"
- Cecil Day Lewis -

Glad to hear that you kept your cool and everything worked out ok Jon.
Sounds like you made the right decisions in the process.

Not the first time I've heard your #2 suggestion of having the approach
from where you just took off ready to go should you need it. Mental
note to self: Add this to my IFR checklist items.

I had an AI act strange on me one VFR night. On the ground and during
runup, everything was fine. Took off for a few trips around the patch
and it started doing a happy dance, wandering all around the place. At
times, it would freeze in place, other times, it just wandered around.

--
Jack Allison
PP-ASEL, IA Student, airplane partnership student

"When once you have tasted flight, you will forever walk the Earth
with your eyes turned skyward, for there you have been, and there
you will always long to return"
- Leonardo Da Vinci

(Remove the obvious from address to reply via e-mail)

>
> Not the first time I've heard your #2 suggestion of having the
> approach from where you just took off ready to go should you
> need it. Mental note to self: Add this to my IFR checklist items.

Sometimes the best emergency approach is to a neighboring airport
whose FAF is ahead of you on takeoff. That would be the one to have
ready.

r.a. student trimmed
Jose
--
Freedom. It seemed like a good idea at the time.
for Email, make the obvious change in the address.

Jon,

Here are some tips that you might consider adding to your IFR
pre-flight checks.

1. After start note the time; and prior to taxi, note the minimum rpm
it takes to get the vacuum gauge to read in the green. If your vacuum
system is in good shape, it will be in the 800 to 1200 rpm range. Much
more than that and it is a symptom of something wrong. Also watch over
time (months) for a change in this number. If it is increasing,
something is wrong, and that is usually a precursor to pump failure.
The aircraft manufacturers do not typically spec that the vac should be
in the green at any rpm below 1700 (see your runup checklist), but if I
have to go above about 1300 rpm to get 4.8 inches vacuum then I begin
to consider that this is not an IFR-capable airplane, especially if
there is no backup system.

2. In the taxi, do not go below the minimum rpm required to maintain
4.8" vacuum. If this means riding the brakes, ride the brakes.

3. During the taxi, do a gyro check; make three shallow taxi s-turns,
one for each of the gryos, and call out loud to your self the results
of each check. My mantra runs like this: "Attitude indicator less than
one degree, left and right; heading indicator correct direction of
turn, left and right; turn coordinator correct direction of turn, left
and right; ball free in the race." I know the FAA says the AI can be
up to 5 degrees off in bank and be legal, but I have found that
anything over 1 degree error in the AI is a symptom of either not
enough time since spin-up, or the thing is on its way out. I wont go
in the clouds with an AI that is telling me that it is on its way out,
even if the feds say its 'within service limits.'

4. After the standard three-s-turn gyro check, do a check for proper
damping of the turn coordinator. Make just enough of a taxi turn to
get a standard rate indication on the TC (its not much of a turn); and
then suddenly straighten out visually. The TC indication should come
back towars zero rate of turn, but only slowly. It should reach a
half-standard rate of turn in 2 to 4 seconds. Faster than that and it
is underdamped, slower than that is an indication that the gryo is
spinning too slow. Either condition warrants cancellation of the
departure, and restriction of the aircraft to VFR onlyl until
corrected. (If you think IFR is a thrill, wait until you try it
partial panel with an underdamped TC.)

5. At the runup area, make sure you never idle below the rpm number
you found in the post start area; i.e. keep the vacuum at least at the
bottom of the green.

6. During the pre-takeoff check, there typically is an item called
"Flight Instruments CHECK" At this point, look for the AI to be
indicating zero bank, and adjust it for zero pitch; set the heading
indicator to agree with the mag compass; and check that the TC shows
zero rate of turn. If the TC is off zero more than about a half a
wingtip, taxi back and get it overhauled.

7. Note the time. If the gyros have had any less than five minutes of
uninterrupted vacuum in the green, don't call ready for release until
they do.

8. When ready for takeoff, note the three gyro indications again. If
the AI has changed noticably in pitch or bank, cancel. If the heading
indicator has drifted more than a degree or so, cancel. Any noticable
precession in this short a time, assuming they have the full five
minutes of vacuum, is an indication of problems; either they are not
spinning at full speed, or they are failing or both.
Glad you lived to tell the tale.

Regards,

Gene
CFII, ASC

> wrote in message
oups.com...
> (If you think IFR is a thrill, wait until you try it
> partial panel with an underdamped TC.)
>

That's how I took my instrument checkride!

"Robert M. Gary" > wrote in message
ups.com...
>
> failure was in IMC. I decided then to try for a backup electric unit. I
> see almost zero value in the backup vac systems, they don't do anything
> for the more upsetting attitude indicator failure.
>

As I understand it the odds of a vacuum failure are a lot higher than the
odds of an AI failure. Either kind of backup is a darn sight better than no
backup.

-cwk.

Colin,

That's true--but nobody seems to have any hard data on the MTBF of a
vacuum pump. I've seen some run 2000 hrs plus, and others quit at 200
(factory new.)

Airborne publishes a 'TBO' for their pumps that ranges from 400 to 1000
hrs, depending on the model. That should say something...

Hey, here's a (non)trivia question for you guys...

What is the (technical, operating) differnce between the old
turn-and-bank and the newer turn coordinator?

Gene

> What is the (technical, operating) differnce between the old
> turn-and-bank and the newer turn coordinator?

I'm not sure what you mean by "technical, operating" difference, but
to me "turn and bank" and "turn coordinator" are the same. There is a
difference between the "turn indicator" (the needle of the needle and
ball) inasmuch as the needle just indicates rate of turn and has no
bank information, while a "turn coordinator" aka "turn and bank"
indicator has a bank accelerator sensor. As bank is increasing, the
instrument indicates a turn in the direction of the bank, but as the
bank steadies out, the input to the sensor from that part of the
instrument dies out. By then the aircraft is (presumably) turning,
and the instrument indicates only the rate of turn, rather than a
combination of rate of turn and rate of bank increase.

The indicator ("little airplane") looks like it's banking to indicate
some combination of increasing bank and changing heading (turn).

I don't know the details of its construction or the formula for the
combination of indication that results.

If there is a =newer= turn coordinator I'm not aware of it, and I'm
listening.

r.a.student trimmed, as I don't follow that group.

Jose
--
Freedom. It seemed like a good idea at the time.
for Email, make the obvious change in the address.

> Sometimes the best emergency approach is to a neighboring airport whose
> FAF is ahead of you on takeoff. That would be the one to have ready.

hehehehe. Runway 28L or 28R at SFO for me :) coming out of SQL
Rwy30. The landing fee will be more than than having a new vacuum pump
installed.

Gerald

If I remember correctly (always doubtful), the gyro is canted upwards in the
new "turn-and-bank" instruments, so that changes in roll and changes in yaw
both show the same indication, whereas in the older "needle" gauges, the
gyro was straight ahead, thus only exerting force when a change was made
about the yaw axis.

It's a lot easier to explain with pictures and models. :-)

-Rob

"Jose" > wrote in message
...
>> What is the (technical, operating) differnce between the old
>> turn-and-bank and the newer turn coordinator?
>
> I'm not sure what you mean by "technical, operating" difference, but to me
> "turn and bank" and "turn coordinator" are the same. There is a
> difference between the "turn indicator" (the needle of the needle and
> ball) inasmuch as the needle just indicates rate of turn and has no bank
> information, while a "turn coordinator" aka "turn and bank" indicator has
> a bank accelerator sensor. As bank is increasing, the instrument
> indicates a turn in the direction of the bank, but as the bank steadies
> out, the input to the sensor from that part of the instrument dies out.
> By then the aircraft is (presumably) turning, and the instrument indicates
> only the rate of turn, rather than a combination of rate of turn and rate
> of bank increase.
>
> The indicator ("little airplane") looks like it's banking to indicate some
> combination of increasing bank and changing heading (turn).
>
> I don't know the details of its construction or the formula for the
> combination of indication that results.
>
> If there is a =newer= turn coordinator I'm not aware of it, and I'm
> listening.
>
> r.a.student trimmed, as I don't follow that group.
>
> Jose
> --
> Freedom. It seemed like a good idea at the time.
> for Email, make the obvious change in the address.

To have an AI "spool down" when the engine is running is totally
unacceptable. The gyro should spool up in seconds not minutes. You have
either a vacuum problem or the AI needs to be overhauled. It is probably the
AI as I assume that your vacuum guage reads OK since you didn't mention it.
Take this seriously! A failing AI is not something to take lightly.

Mike
MU-2

"Jon Kraus" > wrote in message
...
>I too had my first experience in IMC yesterday. I got my ticket last summer
>too and have kept current but haven't had a chance to go solo. I was going
>to go from Indianapolis Executive (TYQ) to Capitol City in Lansing Michigan
>(LAN). The weather was 1000 OVR until 50 miles north of TYQ and then it was
>clear all the way to LAN. THis was going to be a quick trip because the
>weather in Indiana was forecast to get worse as the day wore on.
>
> I was a little bit apprehensive because I have a respect to IMC but I
> thought it would be good practice too. I got set up, picked up my
> clearance and was off. Just as forecast I entered the clag at 1000 feet.
> Right away I spotted something wrong with the attitude indicator. It was
> looking like I was in a steep climbing turn. Oh **** I thought great time
> for the AI to go out. I had a weird feeling of ending up as an Aftermath
> column. I must say that I was pretty scared but strange enough not
> panicked. I reduced power, used the Turn Coordinator to level the wings,
> used the Airspeed Indicator to level off altitude. I called ATC and told
> them that I was having a problem with the AI and needed their assistance.
> They asked if I wanted vectors back to TQY to shoot the ILS 36 there. I
> said yes. I started back to the field and the AI started to act like I
> expected it should. After a few minutes I was still in the clag but all
> instruments were working correctly. I thought about just continuing on
> back to Lansing but I quickly talked myself out of it.
>
> Really after I "calmed" down and the AI started acting correctly I didn't
> have any problems navigating in the clouds. I shot the ILS 36 and broke
> out 1000 feet above the runway, canceled my IFR flight plan and made an
> uneventful landing. ATC wanted to know if I wanted to refill my flight
> plan and I said no thanks. I was glad to be on the ground. I was thinking
> about what just transpired and decided to talk it over with my CFI.
>
> We determined that what probably happened was that the extended period of
> idling on the ground caused the AI gyro to spool down some. It took
> several minutes at cruise power for it to come back up to speed and after
> that it indicated correctly.
>
> Here is what I'll do different next time:
>
> 1. Make sure that I have had the vacuum indicator "in the green" for
> several minutes before departing to ensure that the gyros are spooled up.
>
> 2. Have the approach for returning to the airport loaded or in standby
> just in case you need to return quickly. I did not do this and it added
> needless stress loading everything.
>
> It is true what they say:
> "It is better to be on the ground wishing you were in the air, then being
> in the air wishing you were on the ground"
>
> Jon Kraus
> PP-ASEL-IA
> Student Mooney Owner
>

The consensus that I've heard is that dry pumps should be replaced every 500
hours. I have to say that the more I learn about dry vs. wet pumps, the less
I understand how the latter came to be replaced by the former.

-cwk.

> wrote in message
oups.com...
> Colin,
>
> That's true--but nobody seems to have any hard data on the MTBF of a
> vacuum pump. I've seen some run 2000 hrs plus, and others quit at 200
> (factory new.)
>
> Airborne publishes a 'TBO' for their pumps that ranges from 400 to 1000
> hrs, depending on the model. That should say something...
>
> Hey, here's a (non)trivia question for you guys...
>
> What is the (technical, operating) differnce between the old
> turn-and-bank and the newer turn coordinator?
>
> Gene
>

I do take it very seriously... I contacted the shop this morning and the
plane goes in tomorrow.. No IFR until it is determined what is broken...
Thanks for your comments..

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

Mike Rapoport wrote:
> To have an AI "spool down" when the engine is running is totally
> unacceptable. The gyro should spool up in seconds not minutes. You have
> either a vacuum problem or the AI needs to be overhauled. It is probably the
> AI as I assume that your vacuum guage reads OK since you didn't mention it.
> Take this seriously! A failing AI is not something to take lightly.
>
> Mike
> MU-2
>
> "Jon Kraus" > wrote in message
> ...
>
>>I too had my first experience in IMC yesterday. I got my ticket last summer
>>too and have kept current but haven't had a chance to go solo. I was going
>>to go from Indianapolis Executive (TYQ) to Capitol City in Lansing Michigan
>>(LAN). The weather was 1000 OVR until 50 miles north of TYQ and then it was
>>clear all the way to LAN. THis was going to be a quick trip because the
>>weather in Indiana was forecast to get worse as the day wore on.
>>
>>I was a little bit apprehensive because I have a respect to IMC but I
>>thought it would be good practice too. I got set up, picked up my
>>clearance and was off. Just as forecast I entered the clag at 1000 feet.
>>Right away I spotted something wrong with the attitude indicator. It was
>>looking like I was in a steep climbing turn. Oh **** I thought great time
>>for the AI to go out. I had a weird feeling of ending up as an Aftermath
>>column. I must say that I was pretty scared but strange enough not
>>panicked. I reduced power, used the Turn Coordinator to level the wings,
>>used the Airspeed Indicator to level off altitude. I called ATC and told
>>them that I was having a problem with the AI and needed their assistance.
>>They asked if I wanted vectors back to TQY to shoot the ILS 36 there. I
>>said yes. I started back to the field and the AI started to act like I
>>expected it should. After a few minutes I was still in the clag but all
>>instruments were working correctly. I thought about just continuing on
>>back to Lansing but I quickly talked myself out of it.
>>
>>Really after I "calmed" down and the AI started acting correctly I didn't
>>have any problems navigating in the clouds. I shot the ILS 36 and broke
>>out 1000 feet above the runway, canceled my IFR flight plan and made an
>>uneventful landing. ATC wanted to know if I wanted to refill my flight
>>plan and I said no thanks. I was glad to be on the ground. I was thinking
>>about what just transpired and decided to talk it over with my CFI.
>>
>>We determined that what probably happened was that the extended period of
>>idling on the ground caused the AI gyro to spool down some. It took
>>several minutes at cruise power for it to come back up to speed and after
>>that it indicated correctly.
>>
>>Here is what I'll do different next time:
>>
>>1. Make sure that I have had the vacuum indicator "in the green" for
>>several minutes before departing to ensure that the gyros are spooled up.
>>
>>2. Have the approach for returning to the airport loaded or in standby
>>just in case you need to return quickly. I did not do this and it added
>>needless stress loading everything.
>>
>>It is true what they say:
>>"It is better to be on the ground wishing you were in the air, then being
>>in the air wishing you were on the ground"
>>
>>Jon Kraus
>>PP-ASEL-IA
>>Student Mooney Owner
>>
>
>
>

Mike Rapoport wrote:
> To have an AI "spool down" when the engine is running is totally
> unacceptable. The gyro should spool up in seconds not minutes. You
have
> either a vacuum problem or the AI needs to be overhauled. It is
probably the
> AI as I assume that your vacuum guage reads OK since you didn't
mention it.
> Take this seriously! A failing AI is not something to take lightly.
>

I have to go with Mike here. An AI that malfunctions for a little
while, then goes back to normal, is the classic symptom of an AI that
is losing its bearings (no pun intended). Every AI that I've had to
overhaul exhibited this kind of behavior for months prior to its
complete failure (I fly VFR). I would suspect the AI particularly if
you noticed no deviation on the DG and the vacuum pressure was reading
normally.

The main problem with troubleshooting is that it won't do it on every
flight until the bearings get much worse.
John Galban=====>N4BQ (PA28-180)

G. Sylvester wrote:

> hehehehe. Runway 28L or 28R at SFO for me :) coming out of SQL
> Rwy30. The landing fee will be more than than having a new vacuum pump
> installed.

Hmmmm, would they wave the landing fee if you declared an emergency? :-)


--
Jack Allison
PP-ASEL, IA Student, airplane partnership student

"When once you have tasted flight, you will forever walk the Earth
with your eyes turned skyward, for there you have been, and there
you will always long to return"
- Leonardo Da Vinci

(Remove the obvious from address to reply via e-mail)

Colin W Kingsbury wrote:

> The consensus that I've heard is that dry pumps should be replaced every 500
> hours. I have to say that the more I learn about dry vs. wet pumps, the less
> I understand how the latter came to be replaced by the former.

Same here. Maybe they are cheaper to make, but I can't for the life of
me understand why an airplane designer would use a dry pump on purpose.


Matt

The DG had precessed about 30 degrees in 5 to 10 minutes so I am
wondering if it isn't a vacuum problem. Reguardless it is in the shop
tomorrow for a through going thru. I just hope that this doesn't scare
me out of instrument flight... Time will tell.. Thanks!!

Jon Kraus
PP-ASEL-IA
Student Mooney Owner

wrote:
> Mike Rapoport wrote:
>
>>To have an AI "spool down" when the engine is running is totally
>>unacceptable. The gyro should spool up in seconds not minutes. You
>
> have
>
>>either a vacuum problem or the AI needs to be overhauled. It is
>
> probably the
>
>>AI as I assume that your vacuum guage reads OK since you didn't
>
> mention it.
>
>>Take this seriously! A failing AI is not something to take lightly.
>>
>
>
> I have to go with Mike here. An AI that malfunctions for a little
> while, then goes back to normal, is the classic symptom of an AI that
> is losing its bearings (no pun intended). Every AI that I've had to
> overhaul exhibited this kind of behavior for months prior to its
> complete failure (I fly VFR). I would suspect the AI particularly if
> you noticed no deviation on the DG and the vacuum pressure was reading
> normally.
>
> The main problem with troubleshooting is that it won't do it on every
> flight until the bearings get much worse.
> John Galban=====>N4BQ (PA28-180)
>

On Tue, 04 Jan 2005 01:15:15 GMT, Jon Kraus wrote:

> The DG had precessed about 30 degrees in 5 to 10 minutes so I am
> wondering if it isn't a vacuum problem. Reguardless it is in the shop
> tomorrow for a through going thru. I just hope that this doesn't scare
> me out of instrument flight... Time will tell.. Thanks!!

Jon,

Don't let it scare you. This incident will only make you a better pilot.

What you experience was the real deal, and while no simulated practice will
duplicate the adrenalin rush you got, the nice thiing was that the
simulated practice had you well prepared for this incident.

The plane doesn't care if it's IMC or severe clear.

The beauty of ownership is that YOU KNOW what's in the plane, and the care
taken to maintain the mechanical proficiency.

I will be interested to see if indeed it was the AI or vacuum pump.

Allen

Jose,

You are halfway there.

There is a small, but very important difference between the (older)
turn-and-bank instrument (vertical needle, plus ball), and the newer
turn coordinator (symbolic airplane seen from behind, plus ball.)

The vertical needle on the turn and bank deflects in an amount
proportional to the rate of turn. Only the rate of turn.

When autopilots became more common, the designers needed rate of roll
information to feed the autopilot. So, they canted the gyro axis
(typically 30 deg), such that the front end of the gyro is lower than
the back end. In this manner the gyro will respond to both rate of
roll and rate of turn. This makes life easier for the autopilot
designer, but potentially much more complicated for us pilots.

The problem with the turn coordinator is that its deflection is
proportional to our rate of roll if we are rolling, and then to the
rate of turn after we stop rolling. Unfortunately, there is nothing on
the instrument to indicate when it is showing roll rate and when it is
responding to turn rate.

If the instrument were undamped (no internal 'shock absorber'), in
turbulence it would bounce back and forth from full left to full right
indications as the aircraft takes roll hits left and right, and you
would never get to see the rate of turn. That is in fact what it does
if the dashpot wears out, as is true in many a light aircraft,
especially a lot of rentals.

This can be *very* disconcerting if you are, say, in a right turn, but
at the moment you scan to compare the bank on the AI with the turn
rate, the aircraft has just taken a left roll 'hit;' the AI will show
the valid right bank angle, and theTC will show a full left deflection
(which is really a response to roll rate, but again it doesnt tell us
that). It sure looks like a gyro failure. Having been there done
that, I can tell you it ratchets up the pucker factor quite a bit,
especially night IMC.

This effect is largely eliminated by the dashpot (minerature shock
absorber) inside the TC.

It isn't that expensive to OH a TC, and if you ever get caught in IMC
with turbulence (almost all IMC includes turbulence) with a dead AI or
a vacuum failure, you would at that point pay many tens of thousands of
dollars for a newly-overhauled TC.

In fact, the liklihood of making it back to the airport and down an
approach in IMC with an underdamped TC is right up there with the
proverbial 'ice cube's chance in hell.'

My point is, 1) understand what the TC is saying, and 2) check it for
proper damping, and 3) if it fails #2, stay out of the clouds until you
get it overhauled.

Gene

> [big snip]
Thanks for the full explanation. I had forgotten how the instrument
was engineered (the 30 degree cant) and don't think I ever realized
how important the damping was. How do you propose to check it on
preflight (and to what tolerance?) I make gentle turns during taxi to
see how it responds, but I obviously can't give it a roll hit very easily.

Jose
--
Money: What you need when you run out of brains.
For Email, make the obvious change in the address.

Jose > wrote:
> > [big snip]
>Thanks for the full explanation. I had forgotten how the instrument
>was engineered (the 30 degree cant) and don't think I ever realized
>how important the damping was. How do you propose to check it on
>preflight (and to what tolerance?) I make gentle turns during taxi to
>see how it responds, but I obviously can't give it a roll hit very easily.

Watching the TC as you make taxi turns is a pretty good preflight
check. It confirms that the gyro has power, is spinning, bearings
haven't siezed, etc. It's hard to imagine any failure which would
cause it to react properly to yaw inputs (i.e. taxi turns) but not to
roll.

Jose and Roy,

The problem with a TC that is getting a little worn is not that it does
not respond to roll, but that it responds too much to roll. The
internal dashpot is supposed to damp out its response to small,
instantaneous roll hits, so all we see on the needle is either turn, or
a continuous roll. But if the dashpot is worn (the seal wears out and
the fluid leaks out just like the McPherson struts on your car), the
needle goes 'nuts' on every little roll bump, and pegs the needle to
whichever side the roll was towards, regardless of your direction of
turn. The result is that in turbulence all you see is a series of
full-scale left and right deflections, none of which represent your
rate of turn. It's pretty much impossible to control the aircraft
partial panel this way, and if you try you are very likely to get into
an extreme unusual attitude.

The test: during taxi, put the aircraft in a taxi turn at standard rate
on the TC. Suddenly straighten the turn out; the needle should take
2-4 seconds to get back to 1/2 standard rate of turn. If it comes back
faster than that, it is underdamped. If slower than that, the gyro is
probably not turning at full speed, usually due to the bearings wearing
out (tho this is usually hailed by an annoying whine when you first
apply electrical power, something like a Boeing jet starting up...)
Gene