backup for vacuum pump/attitude indicator failure

"Kelly" writes:

I would be interested in getting opinions about backup systems for a
vacuum pump failure and/or AI failure. I have a 172P [...]

Considering the nature of the 172, you likely don't engage in too much
heavy duty IMC, so backup equipment could be of the "help me land now"
kind rather than "help me fly for a few hours more" kind.

[...] While I haven't seen the panel page/"6-pack" page on the 396
or 496, I have read (in Aviation Consumer) that it's good enough to
keep control of the airplane in an emergency situation. [...]

You should also consider the iQue3600a, which has essentially the same
aviation features as the 396, at half the price, and with ground-side
utility as PDA and car GPS. (The other backup technologies you
mentioned have no separate ground utility.)

In any case, you should test it out. Borrow someone's
296/396/496/iQue or other portable aviation GPS, set it up in your
cockpit, go under the hood and do some partial-panel with a mostly
covered-up instrument panel. An hour or two might suffice.


- FChE

(Frank Ch. Eigler) wrote in
:

Considering the nature of the 172, you likely don't engage in too much
heavy duty IMC, so backup equipment could be of the "help me land now"
kind rather than "help me fly for a few hours more" kind.

Why would you say this based on a model of a plane?

Original poster sounded like an owner, not a renter looking to upgrade /
install backup redundancy.

I own a Sundowner (might as well say a 172 equivelant) and do hard IMC as
much as I can so I have been following this thread rather closely myself.

Just because it's a C172 doesn't mean the plane won't be flown in hard IFR
on a frequent basis unless of course it's not an IFR certified bird in
which that kinda plane shouldn't be anywhere near a cloud anyway.

Allen

A Lieberma writes:

(Hm, I am talking to myself. :-)

Considering the nature of the 172, you likely don't engage in too much
heavy duty IMC, so backup equipment could be of the "help me land now"
kind rather than "help me fly for a few hours more" kind.

Why would you say this based on a model of a plane? [...] Just
because it's a C172 doesn't mean the plane won't be flown in hard
IFR on a frequent basis [...]

The inherent limitations of range and speed complicate bad weather
diversion planning, power limits altitude reach and icing risk
exposure, small amount of redundancy turns malfunctions into
emergencies. So sure, it can be flown in hard IFR on a frequent
basis, but such greater risks have to be accepted.

- FChE

Why not install a 4 inch Venturi on the side or the belly of the
aircraft ( 50 bucks aircraft spruce) then route to a selector valve
then you could switch between engine pump or venturi. This will drive
BOTH AI and the DG.

Or you could install the venturi to drive a back up CHEAP ( older type;
black face) Gyro Horiz. I am sure an instrument shop will sell you one
at a good price as every one wants a color faced type.

Now what about BACK UP electrical power thats CHEAP and portable!


I use one in my Airplane it provides 5 hours of FULL Avionics power !
It cost LESS than 30 bucks to make and all parts are from WAL - MART!


Hint: GARDEN TRACTOR

Hint, unless a homebuilt, all parts must be approved parts.


My vote for safety and redundancy would be for the Sporty's
AI [not as a replacement for T&B] and the 496 GPS. The 496
is aviation, marine and highway, it is your XM radio too.

Unlike the emergency attitude indicators used in jets, the
Sporty's AI does not have a separate battery for power.
You can have your shop create a redundant power source with
a small battery that will be charged from the bus, but
isolated if the alternator fails.



"wise purchaser" wrote in message
ps.com...
|
|
| Why not install a 4 inch Venturi on the side or the belly
of the
| aircraft ( 50 bucks aircraft spruce) then route to a
selector valve
| then you could switch between engine pump or venturi.
This will drive
| BOTH AI and the DG.
|
| Or you could install the venturi to drive a back up CHEAP
( older type;
| black face) Gyro Horiz. I am sure an instrument shop will
sell you one
| at a good price as every one wants a color faced type.
|
| Now what about BACK UP electrical power thats CHEAP and
portable!
|
|
| I use one in my Airplane it provides 5 hours of FULL
Avionics power !
| It cost LESS than 30 bucks to make and all parts are from
WAL - MART!
|
|
| Hint: GARDEN TRACTOR
|

Hint, unless a homebuilt, all parts must be approved parts.

Is this really true? I cannot mount an unapproved CD player someplace
so that it won't flop around in flight?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

yes


"Jose" wrote in message
m...
| Hint, unless a homebuilt, all parts must be approved
parts.
|
| Is this really true? I cannot mount an unapproved CD
player someplace
| so that it won't flop around in flight?
|
| Jose
| --
| "Never trust anything that can think for itself, if you
can't see where
| it keeps its brain." (chapter 10 of book 3 - Harry
Potter).
| for Email, make the obvious change in the address.

Thanks for all the helpful comments so far. In thinking about what you
all have said, with my current setup (and yes I am an owner), I would
realistically have a DG with either a vacuum pump failure or AI
failure. In the case of a vacuum pump failure, I could still get
current ground track from the 430. And, obviously with the AI failure
alone, I would still have the DG.

While I don't do a lot of flying in actual IMC, I do enough that I'm
willling to spend some extra money to hopefully prevent a major problem
in the event of vacuum pump failure. I don't know about the rest of
you, but if I encounter a situation where I end up flying partial
panel, I plan to get in VMC ASAP, or if I can't do that, land.

I haven't yet flown with any of the Garmin handhelds, but my guess (and
I could certainly be off on this) is that would be harder to use the
panel page on the handheld as a backup versus having a backup electric
AI and thus the traditional instrument panel gauges and layout that I
trained on. The electric AI from Sporty's also has the ball
inclinometer built into it and can replace the turn coordinator.

So, if anyone else wants to weigh in on best bang for the buck backup,
here again are the options in contention:

1. Engine driven backup vacuum (such as Precise Flight)
2. Electric AI
3. Garmin 396/496
4. $2 failed-instrument covers (I need these anyway, but I had to
throw this in as an option).

Thanks again.

Kelly

The 396/496 gives you XM-WX capability, which you can also add to your '430.
If you already have the weather capability in your '430, I'd opt for a
lower cost Garmin, like a 196, to provide backup GPS and, most critically, a
backup for the DG (by placing the 196 in the HSI mode). Either way, I'd
also add an electric backup AI

-Elliott Drucker

4. $2 failed-instrument covers (I need these anyway, but I had to
throw this in as an option).

5: MSFS and practice.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.