Peter wrote:
Does that include ice protected AOA products?
(An important requirement is that the AOA system must be completely independent of other aircraft systems. It can’t use the regular pitot-static system and it can’t feed any ADC or such.)
It can’t be completely independent if it is ice protected, because it needs to be powered from the aircraft and there is some wiring and a circuit breaker to be installed. So there is an extra load, which at 8A is not insignificant – see here and subsequent posts.
Also, does CS-STAN support mounting away from an existing inspection cover, using a doubler-plate?
Peter wrote:
It can’t be completely independent if it is ice protected, because it needs to be powered from the aircraft and there is some wiring and a circuit breaker to be installed. So there is an extra load, which at 8A is not insignificant – see here and subsequent posts.
I was summarising what CS-STAN said. Here is the whole of it:
3. Acceptable methods, techniques, and practices
The following standards contain acceptable data: — FAA Memo AIR100-14-110-PM01
Note: as an alternative to the FAA approval letter referred to in the FAA Memo, Part-66 approved certifying staff may accept also a declaration of compliance with the ASTM F3011-13 standard issued by the manufacturer of the AoA to be installed.
Additionally, the following applies:
— the installation of the system neither requires an interface with the pitot-static system nor relies on direct pressure input from the pitot-static system;
— the probe is located in such a way that it interferes neither with the functioning of the flight controls nor with the pitot-static system or aircraft stall warning system;
— accuracy of stall indication coincides with existing stall warning;
— the installed AoA indicator system shall not interfere negatively with previously installed stall warning or AoA systems;
— the installation of the probe is in a non-pressurised area, preferably on an inspection panel;
— the system is not used as an input source to any other system, such as an AFCS, stick pusher, envelope protection system or comparable function, unless certified separately;
— the installation and electrical wiring is installed in accordance with acceptable practices such as the aircraft maintenance manual or FAA Advisory Circulars AC 43.13-1B and AC 43.13-2B;
— the system is suitable for the environmental conditions to be expected during normal operation; and
— instructions and tests defined by the system manufacturer have to be followed.
My AOA is heated.
I fly base leg at 90 kt then convert to the AOA on final. When the doughnut goes green I’m on-speed and I aim to achieve that at about 100 ft.
It’s most useful for warning about low speed before you want to be at low speed i.e. on base or early final. The audio and amber chevrons are impossible to ignore.
In the context of your proposed mountain rating and steep sloping runways, I don’t think an AoA gizmo is going to be useful (perhaps that’s why I’ve yet to install mine) because:
(a) we need a reserve of kinetic energy to flare through more than twice the usual angle, and to cater for unforseen wind gusts and down-drafts;
(b) after the flare we often add power to climb the slope;
(c) most of our aeroplanes are more limited by take-off than landing performance (absent a steam catapult);
(d) if there’s enough doubt about the take-off and climb to warrant an AoA indicator, perhaps best not to land;
(e) alpine runways rarely have obstacles on short final.
Unless the teaching in Austria is radically different from France, your mountain FI will expect you to nail airspeed to 1.3 Vso (or 1.2 in special circumstances) and to fix a splatted bug on your windscreen to your chosen “aiming point”, usually about 50 yards short of your chosen touch-down point. An AoA indicator won’t help with that.
I don’t know anyone brave enough to use the flatlander’s “stall-down” or chopper pilot’s “constant apparent fast walk” approach methods for steep mountain runways.
It’s a different story approaching short flat-ish surfaces over obstacles. For that, both of the above techniques are useful and would surely benefit from an AoA indicator.
P.S. Welcome to mountain flying – it’s what aeroplanes are for. 
Thanks, Airborne_Again. That sounds pretty good. No mandatory installation on inspection covers. Funny how they reference FAA documents
@Chrisparker, have you tried yours at/near the operating ceiling? Whether it works up there was one of the questions I never got an answer to from one of the makers.
Use of Angle of Attack indicator
The few SR22s I fly have an AoA indicator. However, I haven’t found any reference in the POH about “flying the AoA”, and all the instructors I’ve asked about it also don’t use it (they focus on the book speeds).
Does anyone here know good resources about flying the AoA on the Cirrus?
Is it a green doughnut on the speed tape? Or an indexer in the glareshield?
Green gauge near the speed tape
OK, I found a better picture.
That is a normalised angle of attack indicator.
1 is a fully stalled condition. .6 is Vref (ideal short final speed at 1.3 x stall speed in landing config)
Normally best rate of climb is 0.35 and long range cruise 0.3
