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Installing an Auxiliary vacuum pump - Turbo Arrow

Is it possible for my maintenance organisation to install a back-up vacuum pump on my PA-28RT-201T with Continental TSIO360-FB engine? Or would it be more cost effective to install a back-up electric Attitude Indicator instead?

Either will be very expensive, many thousands. It depends upon how the accessory drive pads are arranged on the engine. If there is an unused pad, there may be an opportunity, however, if that pad is a second one on the starter adapter, I would suggest that you not use it. Some starter adapters are not as robust as one might hope.

Have a look at this:

We installed one on a friend's 182RG. Though it had an operating range with limitations, but it did what it said on the box, and would get you home safely. Simple and inexpensive....

Home runway, in central Ontario, Canada

One option is an electric vac pump such as one of these

I have flown a number of planes which had that.

It's quite heavy, because the motor required to drive a vac pump needs to be suprisingly powerful - as I found out when building this

so the autopilot (which needs the KI256 vac AI) could be set up on the ground, in the hangar. The motor will draw a lot of current.

A backup electric AI is easy but only if there is a second alternator - either like in e.g. a Cirrus, or a little one dedicated to the AI. Otherwise, you would be looking at one of the very pricey self contained units like this one

That one is an "EFIS" product (horizon plus the two tapes for speed and altitude) which under FAA regs cannot be installed without an STC...

There are a number of products like that e.g. this which uses a remotely mounted battery

Yesterday I sat in a Citation 525 (was due to fly to Iceland RHS but it was cancelled) and that had something that looked exactly like that, with its own power source.

Administrator
Shoreham EGKA, United Kingdom

I have one like the second in Peter's post. Manual switch on and separate battery.

EGTK Oxford

.....and I assume that it's own internal battery is constantly recharged from the aircraft's charging system is that correct? Seems like the sensible option.

You can also look at installing the one that connects to the Cyl. inlet pipe, I had this arrangment and it was good. The only thing that I am not sure if this will work with a turbo'ed engine.

If your aircraft is an EASA aircraft and you install the electric stand by after so many years you MUST send it for an overhall, even if you did not use. A friend had to remove his and send it away, it had 45min. total time on it, all checks before take off.

Ben

If your aircraft is an EASA aircraft and you install the electric stand by after so many years you MUST send it for an overhall, even if you did not use. A friend had to remove his and send it away, it had 45min. total time on it, all checks before take off.

Presumably the manufacturer of that item has lifed it at 10 years, not realising that outside the USA this is likely to be taken literally.

This kind of total stupidity, not based on any engineering principle, is why I am staying N-reg even though it costs me

  • a BFR every 2 years
  • the FAA trust fee
  • an FAA medical
  • the N-reg altimeter/transponder test every 2 years

The wider problem we have is that the generation of new EASA approvals (STCs usually) is monopolised by EASA Part 21 companies, who are usually avionics installers, and they

  • want to sell you the latest €xxxxx collection of eye candy
  • the latest €xxxxx eye candy is all made by Garmin and comes with EASA AML STCs so there is no need for approvals

So nobody bothers with pushing through EASA STCs (or FAA STCs for that matter) for "useful" stuff like an electric AI powered by a little alternator mounted on a vac pump drive location. If you are installing a G500, you throw in the cheapest nastiest vac AI as "the backup" and the job is done.

Administrator
Shoreham EGKA, United Kingdom

Either will be very expensive, many thousands. It depends upon how the accessory drive pads are arranged on the engine. If there is an unused pad, there may be an opportunity, however, if that pad is a second one on the starter adapter, I would suggest that you not use it. Some starter adapters are not as robust as one might hope.

Have a look at this:

Presumably only good for normally aspirated engines?

EGPD / OMDW / YPJT, United Kingdom

On a quick look, that arrangement looks like it will suck fragments of the disintegrated carbon vac pump vanes into the inlet manifold...

There must be a filter which they are not showing.

Administrator
Shoreham EGKA, United Kingdom
9 Posts
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