Partial panel/loss of control in IMC

[Ibra]

2 hours ago, Vance Harral said:

You are talking about not losing gross control of the aircraft: getting upside down, ripping the wings off, etc.  I agree almost any "low end" backup attitude indicator is helpful in reducing that risk, including the imprecise AHRS in the GTX-345.  I also agree the risk of complete loss of control is reduced at slower speeds.

But I'm talking about executing an instrument approach to minimums, well enough not to get off course resulting in CFIT, even though the airplane is still flying at normal attitudes

Yes completely agree on that, an iPad backup is NOT useful for continue to destination land as planned with terrain & low IFR (plan A chances are close to zero)
I am talking about forget initial mission, fly to find VMC (or beach), land and fly again when the panel is fixed, an iPad backup does this plan B for me 
For LOC/CFIT in IMC, chances are nil if I fly 90kts, West at 6000ft (only need airspeed, wet compass and altimeter, UK MSA is an easy 6000ft)

My guess the quality of any backup is judged by plan B and what you really expect from it? and how much you are familiar with using it? 

I am sure those who wants to keep their mission 100% as planned, do seriously consider lot of redundancy (AIs, APs, alternators, GPSs, engines...) as well as keeping their pilot currency sharp for backup flying & partial panel & hand flying

Hoping I can get more out of my flying & backups when these GI275s & GFC500 come along 

Edited May 7, 2020 by Ibra

[bradp]

On 5/6/2020 at 1:43 AM, Eduleo said:

Like this?

My KG258 failed twice before I knew I had to replace it with an overhauled unit for around 3 AMUs. Once I got the unit from Mid-Atlantic it was a short install and autopilot calibration.

This video is from the second time it failed, and by then I had the FS210 AHRS on the iPad all of the time. Still annoying to not have the KAP150 autopilot but no problem keeping the shiny side up even at night. After this flight, even with the replaced unit, I always have the iPad on the FS210 and the iPhone with a Stratux velcroed to the glareshield any time I'm in IMC or at night. At least until I get the two GI275s in and lose the vacuum, standby vacuum, DG, and AI, hopefully by August. 

I have a video of ForeFlight getting incorrect data from a FS210 and making the synvis spin like a merry go round.  The portable electronics I do not trust in IMC. 

[BorealOne]

19 hours ago, Vance Harral said:

...

Having said all that, my original point stands: I've met pilots who changed their risk management profile based on having backup attitude information they have not actually practiced with.  That's a sketchy idea even with a high-end, certified attitude backup solution.  It's an even worse idea with a portable, uncertified solution.  Go practice with your backup, then adjust your risk management profile based on your experience.  Make the decision based on real flying, not armchair flying.

I couldn't agree more.

I've now had two vacuum failures in IMC in my flying career. In both cases, the KFC-150 AP followed the rolling KI256 AI into a bank as the gyro tumbled. The first time it happened, I was in a descent from 14k through cumulus, and in the clag and the turbulence, I didn't notice the bank until I was in a proper spiral dive. It got a little bit exciting as airspeed and VSI steam guages spun up and the altitude gauge spun down, but I was able to transition to hand flying on electric backup AI, and get straight and level in turbulent IMC before loss of control. Second time was more recently over the Rockies - climbing through icy stratus layers. Much less exciting, as I'd subsequently installed an Aspen and the uncommanded bank on the part of the AP was obvious in the scan on the PFD, and easily resolved by a simple transition to hand flying. It should always be that easy.

However, my own risk profile is conservative, and my SOP is simple - with only one functional AI, find a VFR alternate and land. But I do want to be aware of and proficient with all of my resources - so I'll be practicing partial panel with my iPad. Just in case.

[Eduleo]

4 hours ago, bradp said:

I have a video of ForeFlight getting incorrect data from a FS210 and making the synvis spin like a merry go round.  The portable electronics I do not trust in IMC. 

I had that happen to me too once, for a short moment. But all you need is a moment to find yourself upside down and out of control. I use 3 devices now, not ideal but at least the likelihood that two are going to fail at the same time is smaller, so I can find the non-agreeing device (the minority report) and reject its information. 

It still doesn't make me comfortable, so when I have the double GI275 setup finally installed this Summer I'll have 4 different AHRS in the plane, 3 of them panel mounted and a 4th firmly attached to the glareshield.

[bradp]

Same here.  I now have 3 certified AIs and a backup AHRS (GDL52R).  The likelihood of all failing simultaneously would probably be limited to a lightning strike or some other catastrophic electron failure.  

[midlifeflyer]

On 5/5/2020 at 5:01 PM, Vance Harral said:

Strongly suggest those of you relying on an iPad for emergency attitude information cover up your traditional instruments and actually spend some time flying with it during training.  I'm sure some of you have, but for those that haven't... when I gave it a shot, I found it surprisingly difficult. 

I discovered the opposite even before the iPad. Or panel GPS. Not that I would treat it as anything other than emergency, but I used to periodically fly partial panel with my ancient 396 handheld. 

I always felt that my basic aircraft control was decent but my issue was the reliability of my rollout in turns. Needing to calculate degrees to turn, then divide by 3 was an oversaturation  event. The  little HSI page on the 396 made a big difference. It was funny. The first time I did it, my friend with whom I had a standing date for currency flights, didn't realize what I was doing and couldn't figure out how a task which was difficult for me suddenly looked easy.

As an aside, I suspect the biggest problems with real partial panel come down to lack of recognition, inability to disregard the bad indications without a cover, and thinking it's OK.

My three takeaways.

1. Use the tools you have in an emergency.
2. Learn how to use those tools before the emergency.
3. Don't think you are so good (with or without those tools) that you don't treat it as an emergency.