AOA-indicator useful ?

[Volume]

Just seen on this (http://images.airliners.net/open.file?id=857101&size=L&width=1024&height=695&sok=JURER%20%20%28cynpr%20%3D%20%27Cnevf%20-%20Yr%20Obhetrg%20%28YOT%20%2F%20YSCO%29%27%29%20%20beqre%20 ol%20cubgb_vq%20QRFP&photo_nr=97&prev_id=857194&next_id=857100) picture, that the DC-10-10 is equipped with an AOA-indicator. I´ve seen it on a L1011-500 also, but on a lot of other large transport like all Boeing or Airbus, I´ve never seen one.

I heart from a friend of mine who is flying fighters, that they control the approach mainly by the AOA and don´t care for airspeed indication.

Does an AOA-indicator come useful when landing a large transport, or is it just another indicator that makes the panel look more professional ;)
Do you miss it, when changing from an aircraft with AOA-indicator to an aircraft without ?

[SE210]

Hi Volume

Some years ago I was flying the older Dash-8s , which had a slow/fast indicator on the left side of the ADI.

This in fact was a kind of an angle of attack indicator, and you could use it using it during the approach.

The "on-speed" indication was a 1.3 of the VS (stall speed at a given configuration).

Since the calculated Vref is based on the stall speed in landing configuration, the AOA indication is usefull.

I believe many fighter pilots entirely rely on AOA (not speed) during approach and landing.

Brgds

SE210

[Piltdown Man]

An AoA vanes are fitted to lots of (most?) Public Transport aircraft. Their output is used for things like stall warning, windsheer prediction/protection, V2 calculation and other such stuff. It's greatest use would be AoA presentation for landing. This would allow approaches at any weight and configuration without having to do stupid sums to calcuate values to generate speeds which the AoA indicator would generate, without error, instantanously! However...

[wiggy]

Um
seem to recall 19.2 units was a good last ditch.........................

Anyhow I seem to remember AOA not such a good idea on the big jets 'cos C of G moves a lot vs a fighter....suggest wait till John F or similar provides chapter and verse

[Cornish Jack]

Interestingly, the point was made years ago by the presenter of the AA unusual attitude recovery video, that AoA is available as an input to the FDR but not to the pilot's instrumentation!! Nice to know that the ubiquitous "they" can tell you, AFTER the event, what you should have done but can't be bothered to invest in the instrumentation to allow you to avoid the incident!! Plus ca change :mad:

[chuks]

The Dornier 328's ASI has a red band that represents the stall speed. If you watch it as you are flying at a relatively low, steady speed in turbulence, on approach say, you will see that it is continuously moving, representing the critical AOA as a speed value as the AOA itself shifts slightly due to gusts and slight changes of pitch.

I seem to remember that same 'slow- on speed- fast' AOA indicator on the glareshield of the Cessna Citation that is probably also used on the Dash 8. No one ever said why, but I was told by the instructors at FlightSafety that the FAA didn't like the idea of us civilian types having a direct indication of AOA that we should use. Perhaps it was the KISS principle at work?

[Engineer]

AN124 as an AOA meter. On board computer determines the required angle which is presented on an indicator and the pilot simply adjust aircraft attitude to match.

[Clarence Oveur]

Air France had them on their A300's. Don't know if they still have on the newer stuff.

Very handy gizmo for such things as unreliable airspeed indication, or to check how reliable the handling agent were.

[Intruder]

There is an interesting presentation on AoA use on the bluecoat forum for those who are members. If you're not a member, and fly or are interested in "glass" cockpits, go to www.bluecoat.org (http://www.bluecoat.org)

The short summary is that it may be useful in some circumstances for some airplanes, but it's not as easy as "the fighter guys do it, so we should, too."

[AirRabbit]

Hey folks:

Going back more than a couple of years, in early 1969 through late 1970, when the KC-135A models were first transitioned to a “new” pilot instrument display arrangement, using, among other “new” instruments, the Collins FD-109 flight director system – we found, much to our surprise, and later avid enthusiasm, a direct reading AOA instrument. It was relatively small (inch and a half, two inches?) located just above the left seat altimeter. We used it a lot for some of the missions in SEA – for performance and/or fuel conservation. We also made good use of the information for instructive purposes during traffic pattern practice. I found myself cross checking that instrument as much as any in the cockpit. Now, with the new engines and new skins and new cockpit update, the AOA is still there, same place, above left seat altimeter; but now the same gauge is located above the right seat airspeed indicator (about time to let the other pilot in on the good stuff!) -- graduations are from zero (0.0) to one (1.0) -- and I would have bet money (and lost) that they would have upgraded that darn counter-drum airspeed indicator by this time!

http://www.airliners.net/open.file/110380/L/

____________
AirRabbit

[NigelOnDraft]

In a similar fashion, A32x, A330/340 etc. have AoA indications...

Just watch the Alpha max indicator move as you turn / retract flaps etc.

Anybody who watches the attitude on Final Approach, or in the hold, and adjust speeds as a consequence i.e. concluding the weight on which Vapp/ref is based on is in error, is also effectively using AoA