This thread set me thinking as I seem to detect a worrying and subtly casual attitude to flying out of sight of the surface in some responses. If I have mis-interpreted, then in PPRnNe tradition I am sure someone will admonish me.

1. If you get a vacuum or electrical failure in IMC and you do not have a backup source of either then, IMHO, that is an emergency. You need to tell someone fast and land as soon as possible, with all the monitoring and assistance you can muster. To do otherwise is certainly dicing with possible disaster.

2. Similarly, if you plan to fly or reasonably expect to fly in IMC (or at night) do not accept an aircraft with either power source in unserviceable condition. This is what pre-flight checks are for.

A few years back there was fatal accident where the pilot took off in a C15X with a known unserviceable turn coordinator and ended up (unintentionally) in IMC at night and then lost his only vacuum pump ...

3. There is nothing particularly difficult with flying in IMC if you have the appropriate training and experience, but you do have radar coverage don't you ? I understand there has never been a midair collision in IMC in UK airspace. We need to keep it that way.

Hi alpha,

I know where you are coming from by using the GPS to keep the wings level, and if you are lucky/practiced I guess it could work, but I still think you are more likely to end up in a spiral dive. Then you are SOL.

I have tried keeping straight and level under the hood with only a GPS and I eventually lost it. As you say, it might come in useful one day, so I shall go back and practice harder :)

There is a school of thought that suggests you fly partial panel as your primary scan.

Check out : http://www.avweb.com/articles/cp_ifr/index.html

There's sense in it.

I'm not, honest..... I didn't know anyone made a backup AI type of thing. It is something I was thinking about after reading this post and updating my pocketPC moving map GPS database.

(looking at the prices though, maybe I should start knocking these gadgets out :D )

Cheers
EA;)

In case, drauk, you are still interested in collecting opinions I also fly very regularly in IMC in a four-seater single, on my IMC rating with around 300 hours. Although it would be nice to have a co-pilot for extra safety, none of the people I fly with are pilots so that’s not possible but it doesn’t bother me too much. With our great British weather I find I am often in IMC for two hours at a time or more and am now virtually indifferent to conditions. You also get an RAS from many units which do not normally participate in LARS. However I do have gyro-failure paranoia and would certainly not consider myself the world’s greatest instrument pilot, so:-

1. I really do practice partial panel.

2. I have a fairly serious bit of GPS kit which would, I think, make a partial-panel recovery to VMC more manageable. It’s IFR-certified in the US and constantly monitors the integrity of the GPS signal. As a bonus it has thousands of published instrument approaches in the database which can be used supplementally to monitor (but not to fly!) the approaches for extra redundancy.

3. I always fly between VORs and NDBs so I never lose situational awareness if the GPS signal goes (which has happened more than once).

4. I watch the AI, TC and track (heading) indicator on the GPS like a hawk making sure that all three are consistent.

5. I let the AP do a lot of the work – it can be slaved to either the VOR- or GPS-receivers.

6. I have taken considerable trouble to read the AP handbook several times. Understanding how it works and how it would respond to AI and/or DI failure is absolutely essential.

7. If I lost the AI I would not fly on partial panel for a second longer than necessary but declare an emergency and fly to wherever I thought was the nearest VMC, no matter in which direction, including up into class A (with a clearance) if necessary.

Everyone should have a look at GPS, even if you only take a handheld up with you for situational awareness. I have taken Navbox Pro up with me and hooked the GPS upto my laptop and is absolutely brilliant!

Fly the VOR and see where you are when in the cloud, my view is you should use everything availiable to you to reduce your pilot workload and let you fly the plane. I have seen more than one post on here from guys saying they prefer to navigate by 'dead reckoning' by why???? Yeah learn it and be able to do it but why pick the hardest form of nav when you have so many more and much easier open to you? GPS is an excellent one and if you have a panel mounted IFR certified GPS then all the better, I have flown a few approaches using them, give em a go!

yawningdog

The article you quote encourages quite the opposite -- in a nutshell, if you have an AI, why not use it to fly better?

The problem is that instrument flying on a docile trainer without an AI (whether it failed or you just ignore it) is relatively easy. The faster and more slippery the aircraft, the more difficult it becomes.

I think for me the answer to the original question depends on circumstances. Two hours of bumpy IMC without an AP is certainly possible, but the concentration it requires and the toll it takes in fatigue gives you less mental capacity for the big picture, and thus increases the overall risk of the flight. It may remain within acceptable limits, or it may not. I can see circumstances in which I might well decline.