Flying skills on limited panel in IMC
 

The June 2016 issue of Business & Commercial Aviation published an accident report to a PA44 Piper Seminole. It departed with an MEL on one of the two engine driven vacuum pumps which was inoperative.

During cruise in IMC the second vacuum pump failed. With the loss of the artificial horizon and HSI, the pilot lost control and the aircraft broke up. The aircraft was equipped with an electrically powered Turn coordinator as a back up source of attitude.

In October 1997, a Moonee M20 VH-KUE was lost in similar circumstances 113 kms NE of Balranald NSW. During dark night cruise flight the pilot reported vacuum pump failure but that he had back-up electrics. Shortly after the pilot's last radio transmission he lost control and crashed. The ATSB report stated:
“An examination of the wreckage indicated the aircraft had impacted the ground at high speed, in a steep nose-down attitude, consistent with loss of control. With the exception of the vacuum system, the aircraft was considered to have been capable of normal operation prior to impact.” See ATSB link: https://www.atsb.gov.au/publications...aair199703221/

For some general aviation aircraft, flying on limited panel instruments such as a typical Turn Coordinator or Turn and Balance indicator with no AH or HSI/DI, requires not only considerable instrument flying skill but also to be current on limited panel flying. Few pilots have both. Today’s synthetic trainers used by most flying schools are ideal for keeping current on limited panel with minimum cost. It is good life insurance.

It is all too easy to become complacent on the aircraft you currently fly. For example:

A private pilot owner was practicing full panel instrument flying in a flying school synthetic trainer in preparation for his command instrument rating. All his practice was on full panel. His instructor suggested he needed practice at limited panel as well. The student disagreed saying his own aircraft had a glass cockpit with reversion modes and limited panel would never happen.

During the conduct of a holding pattern prior to an ILS, the instructor failed the artificial horizon without first warning the student. In less than 45 seconds after the AH failure the student went into an ever steepening spiral dive and lost control. Worse still, the student accused the instructor of deliberately setting out to cause him to crash. The student had the wrong attitude in more ways than one.

It is easy to practice things you are good at. It takes dedication and a good attitude to practice something you are not good at. Today’s synthetic trainers are excellent for instrument flying practice. You can’t cheat by looking outside. Practicing limited panel flying on the standby flight instruments is best done in a synthetic trainer until you are truly competent. Then keep in regular currency

I preface this by saying I have not been in a ga aeroplane for over 20 years, but from what I hear not much has changed :)

My question is...these new electronic panels with everything on them, attitude indicator, compass rose, terrain display etc, are they outrageously expensive and difficult to fit? I am guessing there is an ongoing cost associated with keeping the machine in the IFR category (again I am clueless - yes yes on more than just this!) but even if not maintained in the IFR category could they be used in a pinch - I assume that they don't use a vacuum source but a cheap AHRS type setup.

Are these type devices better insurance than trying to keep current on limited panel and trying to fly on a turn coordinator (which again is something I have long forgotten).

Honest question and no criticism, suggestion or anything else implied

How good are the synthetic trainers?
 

Doing limited panel training is certainly a must, but I'm not sure how good it is in your typical synth trainer for the sole reason of realism. Now, if the trainer can simulate some form of turbulence (jiggling the gauges, little swings of the compass etc) then great but all the ones I've used are nice and smooth. Get up in the air with an instructor on a nice bumpy day, slap a cover over the instruments you want and do some practice (and some recovery from unusual attitude while you are there!).
The other important tool you should always carry (if you are on stream gauges) is to carry the stick on instrument covers because if the AH does fail it is all too easy in times of stress to look at it and try to fly accordingly.

Funny you should mention the use of the autopilot. Forgive yet another "war story or Warry" but in another era I was flying an old RAAF Lincoln bomber from Townsville to Darwin with an ETA an hour before dawn.
I vaguely recall we were around 8000 ft in cloud half way to Darwin at 160 TAS meaning about three hours to go. Without warning the one and only artificial horizon failed spectacularly leaving us with just the basic turn and bank indicator similar to that in a Tiger Moth.

Fortunately the autopilot was engaged at the time. I had done plenty of practice limited panel flying during our training on Wirraways but this was the first time for real. It was not a pleasant feeling to be in cloud for the next three hours on (very) limited panel. We arrived over Darwin an hour before dawn and still in cloud. ATC said there were lower patches but an instrument approach was available. That military instrument approach was called Lucero which was something like a bastardised DME arrival.

I wasn't game to try and hand fly that on limited panel or autopilot since the autopilot was a steam driven affair so that was out. So we simply twiddled the autopilot to fly in circles while still IMC until dawn came up and we could see holes in the clouds. We weaved our way through them and eventually saw the airport. It was that experience that made me feel grateful for the accent on limited panel flying during our pilots course on Wirraways.

Re limited panel practice in synthetic trainers. Although the sensation of turbulence cannot be adequately replicated in fixed base synthetic trainers, nevertheless there is inestimable value in practicing of instrument scanning techniques without an AH or gyro compass, since the scan pattern and scan rate can be quite different. Of course if the standby flight instrument is another AH and not a turn coordinator, then it becomes almost a non-event.

Folks,
Aaaahhh, for the good old Link Mk.4.
Tootle pip!!

I would suggest so did the Instructor. Rather than trying to convince the student that he needed partial panel on a traditional 6-pack, I suggest they should have worked with the student to identify possible failure modes for his EFIS and practiced them if possible. My own RV is similarly equipped to the student's, though I haven't installed a backup EFIS yet. Partial panel in something like that is like flying partial panel in an A320 with the electronic ISIS. Possible, but effectively pointless.
Dual ADAHRS, Dual screen, independent backup batteries and a G5 as a 3rd ADAHRS reference and display, how realistic is partial panel in something like that?

Dirt cheap, for the small ones, and absolutely brilliant as a backup - to the point where I would suggest anyone flying single-pilot IFR that doesn't have one is a fool.

Dynon's D10A is now STC'd for a bunch of different aircraft, Garmin has their new G5 in the same size that looks very nice (And you don't even need to interface this one with the Pitot/Static system if all you want is Attitude, turn rate and heading), and Aspen Avionics has a TSO'd EFIS that can replace the whole 6 pack while not taking up more room than an AH & TC!

The Dynon and Garmin G5 can be had for less than $1,500 AUD, plus installation costs, which shouldn't be that much...

ISTR CAsA published a notice a while back that said you could have a full Dynon/Garmin experimental EFIS in your certified aircraft, so long as it didn't replace any equipment required by CAO20.18.

I have the Dynon Skyview system in my RV and even though I only have 15 hours behind it so far, would have no hesitation in flying IMC with it, provided I had a G5 or dissimilar EFIS as a backup should the screen go dark.

Be very careful with the ASPEN Pro 1000 EFIS systems, they can and do fail completely without warning in flight; it happened to mine but I had prudently left most of the analogue instruments in the panel as a back up.

Probably not certified by any NAA, but in a pinch...

https://www.ixellence.com/index.php/en/products/ixgyro

So the pilot in the synthetic trainer did not have the basic instrument flying skill to use a turn coordinator and crashed when his AH failed. The OP described two crashes that killed all aboard because they too lacked the skill to fly on turn coordinators. Isn't there a message there somewhere? And you blame the instructor for failing the AH rather than blame the pilot in the synthetic for not practicing his limited panel flying.

I do indeed.

Knowing the student did not have an aircraft with a traditional 6-pack, he decided to proceed with what was essentially a box-ticking exercise, rather than impart any meaningful education to the student. And in doing so, decided to prove a point to the detriment of the student. Yes, I have an issue with that.

Here is a panel that is virtually identical to mine, albeit with a D-10 instead of a Garmin G5 as the standby. How do you do meaningful partial panel practice in an aircraft so equipped?

Modern aircraft require modern approaches to training, something that seems to be difficult to comprehend for some instructors.

According to Centaurus the pilot was practicing prior to taking his CIR. Since this would allow him to fly IMC in any aircraft of the class it does not matter that his own aircraft was not fitted with 'traditional' instruments. It might be okay for airliner flying, where the IR is type specific but the same cannot be said for the CIR and GA aircraft. The pilot should have been able to fly on limited panel, on steam gauges in order to pass the CIR (and for very much more practical reasons). Anything else is a bit like teaching someone to pass their driving test rather than how to actually drive their car properly.

His instructor suggested he needed practice at limited panel as well.

My initial GA issue was 40-odd years ago so I might be a bit out of touch .. don't folk still have to demonstrate competence on limited panel for the test ? In my case it was a limited panel takeoff, circuit and landing .. with the takeoff and landing pattered just sufficiently to avoid frightening the examiner excessively. While I hadn't done any practice in that sort of thing during my training, I had done 20 hours or so of such good fun at the conclusion of my PPL training 10 years or so earlier.

The student disagreed saying his own aircraft had a glass cockpit with reversion modes and limited panel would never happen.

An interesting philosophical approach .. a bit like presuming the idiot in the car on the left really won't go through the intersection wiping you out in the process ?

I have no familiarity with the present crop of GA glass toys so I don't know what can and can't be failed in flight .. but the dinosaur bit of paper/cardboard can cover up a lot of useful stuff on the training/test day.

During the conduct of a holding pattern prior to an ILS, the instructor failed the artificial horizon without first warning the student.

Many years ago, the first batch of AN DC9 pilot endorsements were in the US, as I recall. One of the folk involved related a tale that the instructor pulled an engine on the very first aircraft training sortie takeoff .. the reason given post flight was along the lines that "well, son, we don't know just when a failure might occur .. "

I recall, as a newly minted F27 FO departing out of DPO on a nil pax positioning flight .. my go and the (quite experienced line) captain pulled an engine during the rotation .. OK, I handled it appropriately .. but the surprise factor makes it (and any other significant failure) a whole lot different to the training environment where one is full of enthusiastic anticipation.

More realistically (and without any knowledge of this particular student's training and progress), some students are sufficiently thick skinned that progress stumbles due to pig headedness and they need a short sharp wake up call .. perhaps this was one of those occasions ?

In less than 45 seconds after the AH failure the student went into an ever steepening spiral dive and lost control.

Methinks that suggests something about the student's attitudes and competence at that stage of his training ?

Worse still, the student accused the instructor of deliberately setting out to cause him to crash.

Quite apart from attitude, such a sequence is suggestive of a poor approach to the learning process.

he decided to proceed with what was essentially a box-ticking exercise

I suggest that the more reasonable conclusion is that the instructor's intent was diametrically opposite ?

Modern aircraft require modern approaches to training, something that seems to be difficult to comprehend for some instructors.

I guess that's why mishaps such as the Air France stall and subsequent hull loss lead to paradigm changes in training evolution ?

What happens when the individual feed to an 'instrument' fails or becomes unreliable?

That is the key point. It is not a question of how good the panel happens to be on your personal puddlejumper. It is a question of still being able to do what your license requires you be able to do.

Isn't that the truth when discussing the original and subsequent posts?

A better analogy would be Budget and Thrifty that allow you to hire a truck on a car licence. Even an automatic - notwithstanding you've never before driven anything bigger than a Suzuki Swift. But that too, is completely legal..
Depending on the individual EFIS, in Dynon's case, you get an "ADAHRS CROSS CHECK ERROR" (It even speaks into your headset so if you are eyes-out you still get notified), and it will display the two ADAHRS outputs on a single screen, with flags listing the discrepancy. You can then choose to take the offending ADAHRS offline, and it will continue to provide a full dual-screen capability, albeit driven by a single ADAHRS and annunciated as such. In my case, with the Garmin there as well for dissimilar redundancy, I still have two independent EFIS'.

I would ask you read Volume 2 of the Part 61 MOS, specifically the requirement to perform limited panel flight based upon the failure of the primary AH, DG or ASI.

Nothing in there any more about having to fly without using a full set of standby instruments, either traditional or EFIS. The regulations have (sensibly) changed, but this discussion shows people aren't up to speed with them.

Now, having said that, I fully agree that doing your test on an EFIS-equipped aircraft, and then attempting to fly your typically-equipped 182 in IMC is not smart, and will more than likely end in tears if you do have a vacuum failure. I am not arguing that point at all. But that possibility is legal now, and whether it is liked or not doesn't change that. And that is why I believe the instructor in Centaurus' example was remiss in not trying to work with the student to provide appropriate training, rather than "what we've always done".

Not always Raptor. Sometimes the Autopilot sensors are fitted to the AH. If the AH fails so does the autopilot. Many years ago I worked in an instrument repair shop for Rex Aviation at Bankstown. The boss was a little hurried in in refitting an AH to a Cessna and reassembled the AH case with the Autopilot pickups out of alignment. On the test flight the aircraft keeled over when the autopilot was engaged. (in clear blue sky.) Similarly if the AH topples the aircraft will topple with it.
Greedy

Just a comment here from my own experience.
I have never experienced a gyro failure for real but have experienced it multiple times in the sim. The first time I did what the first post indicated in those accident reports - ended up in a steep descending turn that would probably would have ended badly if for real

So WHY - WHAT happened

A couple of things - gyros can spin down slowly causing erratic, unpredictable or even insidious behaviour that in my case indicated a very slow increasing turn to the left which i blindly followed maybe over several minutes as it slowly spun down - by the time I realised I had almost lost control

And by the way I had already practiced and was reasonably competent at flying on partial panel with the instrument covers on in the aircraft

So what did I learn
(1) importance of a comprehensive scan - they only way to detect a failure is to use supporting instruments to detect and verify a failure
(2) the AH is evil when it dies - it can be initially undetectable - be wary !!
(3) while it is good to practice partial panel in the aircraft - its actually not to difficult when the instructor has just told you the instrument has failed and covered it up - you know whats happening and adjust your scan - much, much more difficult and realistic in the sim with a "real" simulated failure
(4) last point - always carry a few instrument covers or post notes that can be used to cover up failed instruments as it can be distracting - in my case I had a TC fail in IMC - not a problem but distracting

As I get ready to do an IPC in a few weeks having not flown for 18 months I wonder how my scan would go on limited panel after reading this post.
Failed the AI in a sim and yep I stared at the AI while the the turn co ordinator showed a steepening bank and the VSI wound down extremely fast. Took a while before getting it to a wings level and finally maintaining attitude. Lost about 2000ft in a short amount of time. Could only imagine what it would be like in cloud and hearing the rushing of the wind.
What I use for backup on an iPhone is to run Xavion the makers of Xplane. It provides an AHRS and will even glide you down to an airport in case of an engine failure. Great for a last line of defence.

Garmin produced this nifty guide for Examiners and Instructors on what are the possible failure mechanisms, how to simulate them and how the student should respond for their G1000.

https://www.faa.gov/training_testing...edia/G1000.pdf