Limited Panel Flying

[KCDW]

Currently prepping for my IMC course next month, armed with Thom number 5 and my trusty Microsoft Flight Simulator!!

Now I understand that the course includes limited panel flying for both Gyroscopic failure and Static Vent Blockage. However, Thom totally concentrates on the former, with absolutely no guidance on flying with the latter.

This is curious, as frankly I can't figure out how anyone can stay alive with the VSI, ASI and altimeter failed while in IMC.

Thom's only guidance is to switch to the alternate static source, or break the glass on the VSI.

So the question is, do you only get trained on flying with the HI and AI down (gyroscopic failure), or is there a method which Thom doesn't go into?

Hope you can help

Thanks

[Final 3 Greens]

KCDW

I'm by no means 'king of IFR' and you'll get better responses than this, but for starters you can use the tacho and AI for approx airspeed, likewise for climb/descent control.

As I recall, both are taught one is called partial panel and the other limited panel - but I can't remember which is which!

[rustle]

KCDW,

I don't remember ever flying simulated static-out. (Bit tricky to simulate anyway.)

I do remember learning what to do if the statics freeze-over.

Are you sure you have to fly statics-out?

PS - did you decide whether you are doing your IMC as a step towards FAA/IR or JAA/IR?(remember that thread a while ago :D)

[bluskis]

Thom makes it clear that a blocked static should be resolved by using alt static or breaking glass, therefore there should be no need to fly without those instruments which would be affected. However it is necessary to be able to recognise a blocked static exists in order to decide to use the alternative static sources.

Flying without an operational or accurate ASI may still be called for and Thom and 3 greens has the answer for that.

In the modern world a GPS will give you altitude but so should alt static.

[KCDW]

Hi rustle,

I remember you and the thread. You're the guy who pointed in the direction of PPRuNe from the Flyer Forum!!

After a fair bit of soul searching, I decided that I could never justify and maintain an IR just for the occasional jaunt to the Med. Planning in a few extra days holiday to cover for weather, and flying VFR makes more sense.

However I, as well as most of us I reckon, have been in a few uncomfortable situations with marginal weather. So the IMC is primarily an insurance policy, as well as an opportunity to improve my flying skills.

I haven't spoken to my instructor about the detail of the course (I'm in the States at the mo), but looking at the CAA website:

http://www.caa.co.uk/docs/175/Lasors_Section_E.pdf

Section 2.3 strongly implies there is training involved for static pressure loss.

3 Greens

as you can see Partial Panel is Static loss, and Limited Panel is gyroscopic loss - you learn something every day eh
:)

[bookworm]

Since you can stay the right way up with just an AI and the AI and static systems are unlikely to fail together, partial panel (in UK-speak, with failed pressure instruments) is not as immediately serious a situation as limited panel (failed gyros).

That said, it's interesting to think through how you'd get down from fairly low IMC after a static failure. My favourite would be an ILS approach with a very long final to find the glideslope.

It's not something I've practised, and I think you've persuaded me that I should.

[flickoff]

Of course, if IFR a/c were fitted with a GPS with a quasi panel like the Garmin 196, it would be less of an issue, but I guess we cannot expect that sort of technology to be recoginsed until ooh, 2060:=

Bit of topic, but is it now possible to do a PPL IR again; has the lack of ground school been resolved?

[rustle]

Of course, if IFR a/c were fitted with a GPS with a quasi panel like the Garmin 196, it would be less of an issue, but I guess we cannot expect that sort of technology to be recoginsed until ooh, 2060

Rest assured the limitations of these sorts of devices have been recognised as early as 2003 :p

...but is it now possible to do a PPL IR again

Always has been, if you want to be pedantic, because you could have done the ATPL theory exams whilst there were no PPL ones.

But yes, there are now schools offering the JAA-PPL/IR theory courses.

[Doghouse]

Both limited panel and partial panel are part of the IMC course. Of course, in 15 hours it's difficult to do more than a demo, but your instructor should cover the ASI, Alt and VSI for both IMC flight and a VMC recovery. I certainly make students do at least one landing with those three failed in VMC during the course.

Remember that the AI, slip ball and RPM gauge are your control instruments, so flying shoudn't be an issue. It's not somewhere I'd like to be though and making a cloud-break would be a major bum twitcher. I think if it happened to me I'd try to get VMC on top and ask for a formation escort to a PAR or ILS glideslope. Failing that I guess it's out over the sea and start descending to cloud break.

Just to add my two-penneth, I've had a vacuum failure in IMC and I have a big beef with the IR that we aren't trained to fly a limited panel let down. For the IR we do a lot of limited panel timed turns, in real life I did none (the controller gave me start/stop turn commands). For the IR we do no limited panel let downs, so the first time I ever had to try one was for real. I can tell you that a PAR to 400ft with no AI made for a very strong tea when I got down. Am I being a bit 'train me for the 1 in 1 million possibility' or does anyone else have this gripe?

[Tinstaafl]

I was given partial & limited panel approaches in my IR training. Subsequently I included them when I taught IR.

Not easy & not fun. Like others, I'd also plump for an ILS if available. Getting on the correct G/Slope would still be do-able. Altitude info - of sorts - is available through ATC & the a/c transponder.

[PhilD]

I don't think the transponder altitude readout is much use without the static......

[rustle]

Doghouse

"...I have a big beef with the IR that we aren't trained to fly a limited panel let down. For the IR we do a lot of limited panel timed turns, in real life I did none (the controller gave me start/stop turn commands). For the IR we do no limited panel let downs, so the first time I ever had to try one was for real. I can tell you that a PAR to 400ft with no AI made for a very strong tea when I got down. Am I being a bit 'train me for the 1 in 1 million possibility' or does anyone else have this gripe?"

Exactly - hence my surprise that it's required for an IMC rating (is this a new thing? I didn't do it for my IMC either)

I was also surprised we didn't do engine-out and partial panel together - just to test the nerves :eek:

Guess what I'm going to do just before my next IR renewal - some static-out gubbins. (Presume a "post-it" stuck over both Alt's, the VSI and the AIS will have to do?? Tinstaafl what do you use when training?)

[FlyingForFun]

I'm starting an IMC rating next weekend, so this is a well-timed thread! But, with no practical experience, here's a couple of snippets of theory for you:

First of all, as PhilD said, Mode C will not work if your static source fails. In fact, I'd have thought ATC will probably ask you to squawk Mode A only to avoid incorrect readouts.

Also, using a GPS for altitude sounds like a nice get-out-of-jail option. But remember that the altitude indicated on your altimeter won't be the same as the altitude your GPS shows you. It certainly won't be the same if you're flying flight levels, but even with QNH set, the GPS will show the actual altitude, whereas the altimeter will have errors due to temperature variations from ISA, regional pressure variations and so on. If everyone else is flying around on their altimeter altitudes, and you're using a GPS altitude, guess who's going to be at a different altitude to everyone else?

So, I think if this happened to me, my first priority would be to ensure that I was high enough not to fly into anything - set an attitude for a climb, and hold it for long enough to gain a couple of thousand feet. My second priority would be to tell ATC - they would hopefully get everyone else out of my way, including anyone on the airways above me if necessary. Even if I have a GPS, I'd still make sure that ATC know I'm not able to fly altitudes accurately.

What do the experts think about this? Does it sound reasonable?

FFF
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[Stan Evil]

Rustle. There are no requirements for limited panel or 'no static' approaches on either the initial or revalidation of a UK or JAA IR. The only limited panel (no gyro compass and no AI) requirements on the initial IR are straight and level, straight climbs and descents, level rate 1 turns and unusual attitude recoveries. On the IR revalidation/renewal only the turns and UA recoveries are required.

Be careful of defining 'partial panel' as loss of static instruments. In the RAF and other organisations it means loss of the main AI but availability of the standby AI.

As far as the IMC rating is concerned, Para 4 of Appendix B to Section E of LASORS lists the test requirements (see KCDW's link). The only limited panel work is exactly the same as the initial IR. There is no 'no static' work on the test.

Whilst it is important to realise that attitude plus power equals performance and so the aircraft can be flown without the ASI and altimeter in order to climb out of cloud or descend (if cloud base allows) - it's not something to get really excited about. BTW don't believe all the stuff in the books about the ASI freezing on the speed when the pitot gets blocked - when it's happened to me it just slowly drops to zero because of the leaks in the system.

[bluskis]

FFF.

If you've got GPS use the altitude it shows.
If you have really lost static and alt and breaking glass have failed, you are in difficulty anyway and a few hundred feet error, if that, is a lot better than knowing nothing at all.

Assuming the static pressure failure compounded by engine out is not also accompanied by radio failure, your GPS altitude should be sufficient for ATC in the circumstances to vector you onto an ILS.

[Tinstaafl]

Rustle,

I've used a variety of things. Synthetic trainers (FNPT2 devices in JAR-speak) such as ATC-710 & -810s, another by Hawker Pacific, Frasca types including one on hydraulic rams and lastly a Link trainer on gymbals.

These all let you fail just about any combination of instruments. Some better than others. Some allowed you to either program a type of failure or manually change instrument displays.

In the air I used suction cup covers. Available from various pilot shops for not very much (Not very much for aviation, that is. A lot considering what they are! :* )

I'd cover up various combinations to simulate single failures up to a system failure.

It's not really possible to simulate the subtlety of instrument failures in the aircraft (apart from electric gyros: pull the circuit breaker when the student isn't aware) - unless you have a real failure.

Don't laugh too hard. I had one unlucky student get avac. pump failure at night in a C172 then a week or so later get an AH failure while I was doing his Night VFR test. :eek: He handled it well enough to pass comfortably, BTW. It was fortunate that all the mandatory test items were completed.


System/instrument failures are one of the truly great advantages of good synthetic trainers.


FFF has suggested what my initial actions would be: Ensure terrain clearance by climbing. Then scream like *@****** to ATC!

[rustle]

Stan Evil

Thanks - I didn't think I'd forgotten anything ;)

Tinstaafl

Thought about the suction cup idea too!

But a static ice-up or leak would be much more insidious than that - do your sims allow you to do realistic failures, or are they "on-or-off"?? Same problem with the (simulated) gyro failures - it's bloody obvious when there's a suction cup in place, but not so when AI/HSI spins-down because of a genuine failure...

[BEagle]

Interesting comment about how few people have any training in limited panel let-downs. When I was a RAF UAS QFI, many of my instructor colleagues weren't keen on aerobatics or formation tail-chasing above 8/8 cloud in case the AH toppled and wouldn't re-erect, meaning that the poor dears might have to fly without an AH in cloud...... Bunch of wimps - the IR tested the ability to recover to DH on limited panel with no AH or DI. You took off, did a full panel self-positioned VOR/DME to ILS then climbed up for full panel 45 deg AoB turns, full panel UPs and then limited panel UPs. Recoveries from very extreme attitudes were commonplace; after that you fixed your position by VOR/DME, then homed to the aerodrome overhead using timed turns at Rate 1, followed by a limited panel PAR or SRA to land.

The value of this IF cannot be over emphasised; when I do IMC Rating tests, I'm far more interested in good core IF skills than radio navigation. Sadly, I've found that too many FIs waste students' time pratting about with NDB holds than making them fly accurate IF!

[Tinstaafl]

Rustle,

Some had a system failure mode eg static leak, blocked pitot, gyro failure or whatever. Others had individual verniers for each instrument so you could gradually wind in the changes.

Some were just on or off but even that beat the a/c because the student didn't get the visual warning from my hand applying the cover-ups.


At BAe in Oz we also used to do full & partial panel climbing/descending/turning exercises with the a/c on the back of the power curve. Quite good for developing scan & coordination. The tolerances were (I think) +/- 100', 100'/min, 5kts, 5 deg hdg for a minimum pass. A better pass if you halved those.

[englishal]

I'm not sure what the IMC course contains with regards to PP [failed gyros] flight but the FAA IR the course had a very strong emphasis on PP including unusual attitudes and stall recover PP under the hood. I wouldn't say I'd be happy suffering a gyro failure in IMC, but I wouldn't be unduly worried about it either. In my opinion whenever practicing instrument flight / approaches in VMC then you should always do them PP, and not shy away from PP training, no matter how much you don't enjoy it. In my limited experience I've seen a suction pump failure on a Seneca, which although has two pumps, failed the gyro system, and a PA28 with a decidedly dodgy AI that started to roll for no reason, even though the suction was fine. The hard part is not the PP flying but deciding that an instrument has failed and to ignore it. Its a good idea to carry one of those suction type soap holders in your flight bag, so if an instrument fails, you cover it up to stop yourself reacting to it. [cheaper than anything 'aviation' :D]

Cheers
EA:D

[FlyingForFun]

When I was a very new PPL student, I was chatting to my instructor one day, and he mentioned that he'd had a very embarassing IMC lesson earlier that day. It was his first IMC student for some time, and he was doing partial panel - but discovered he only had one suction cup. It was fine for covering a single instrument, but when he wanted to fail more instruments, he had to resort to using post-its.

I suggested that maybe he should have used post-its for all the instruments, then his student may not have even known of the existance of suction cups, let alone known the the instructor had lost most of his! Instructor thanked me, and used post-it notes from then on!

FFF
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[andrewc]

After my IMC course I went and bought some suction cups
just in case I ever need to take dodgy instruments out
of my scan...

-- Andrew

[Tinstaafl]

It's surprising just how intrusive a non functioning - or worse, gyrating - AH is. :}

I always keep one or two of the suction cup instrument coverups in my headset or nav. bag.