The limited panel sign off is carried out in an aircraft or simulator of the relevant class with the six pack layout and the HSI/AI blanked. In effect a different type if your training was in a glass cockpit aircraft.
In a Super Cub, unblessed by any gyro instrument, the traditional emergency let down is carb heat on, 1500 RPM, full rear trim, 55 mph IAS and using the whisky compass on a Southerly heading where the compass is over sensitive, in the direction of the turn – keeping the compass heading with rudder input. So arguably with an ASÍ and a wet compass there is a technique available.
NIL: This pas week, I just had my first couple of IR training sessions in the simulator. Yesterday I was about an hour into flying procedure turns when the AI keeled over. I managed to transition to the TC quickly enough and didn’t loose to much altitude or crash, but I was pissed off ’cause I thought the simulator was “broken” ! The CFII had a good laugh over that and I felt pretty stupid when I realized he had “switched on” an AI failure .
At least I survived my very first gyro failure and I WILL be prepared for the next ! 
If you lose all your gyro instruments, you have to fly ASI, VS and compass. GPS track is useful but you can’t use it as primary due to the lag so you should adjust heading once established but steer off the compass.
With glass, the key failure modes are either a display, AHRS or ADC. How you handle it must depend on whether you have backups and reversionary modes. I personally don’t think there is much point practicing complete black cockpit as you are unlikely to have any way to navigate or commnicate.
If you lose all your gyro instruments, you have to fly ASI, VS and compass
That will work in smooth air and if you start with wings nicely level, only. I have tried it many times, and I have a vertical card compass which makes it easier.
as you are unlikely to have any way to navigate or commnicate.
Most private pilots (IFR) will be carrying a GPS and a handheld radio (or should be). And then you just need a working AI and an altimeter.
However I have never heard of any checkride testing any of the above.
Peter wrote:
Most private pilots (IFR) will be carrying a GPS and a handheld radio (or should be). And then you just need a working AI and an altimeter.
I would question anyone’s ability (including mine) to fly an approach in actual IMC with an AI, iPad, compass and handheld radio. I am not talking a let down to 1000ft.
Sure, but there are radios with an ILS, so you need to be able to fly a heading and hold a VS figure. Should work down to 200ft
mh wrote:
And with the ball centered, the plane just turns when the wing drops……then the spiral dive begins and all is lost.
Peter wrote:
Sure, but there are radios with an ILS, so you need to be able to fly a heading and hold a VS figure. Should work down to 200ft
And not lose control while retrieving, turning on and tuning the radio.
Yes; I think in any real scenario you need some luck on your side too.
But most IFR flight time is in VMC so the chances are that the failure(s) will happen then. Also it’s a bit like this … you have to hope that the really bad scenarios won’t happen at the worst possible moment.
In most traditional SEPs you have the vacuum AI and with that you can keep the plane safe until you sort out a nav backup. It’s a totally independent system.
then the spiral dive begins and all is lost.
The pendulum will enable you to prevent this.
