Angle of Attack

[Dave Krall CFII SEL SES]

Yeah right, then I could wonder if the efing AoA indicator was working and reporting properly instead.

I've actually had an audio/visual one installed in the FC from the beginning, just never use it and can't imagine relying on it for stalls or landings, but some of the other things, maybe....

...because the airspeed indicator is infallible? at all weights? in all configurations?

The certified aircraft with stall warning indicators are essentially AOA sensors on the leading edge. That little tab that moves is just calibrated to move at a given AOA, which happens to be at a given airspeed in a given configuration/weight. Same with the Cessna "sucker" horns. People have been relying on those for decades. The new AOA systems work exactly the same way, they just present the information in different ways.

Nope, of course not, the AI is just another unreliable instrument like all the others.

Yep, people have been relying on them for decades, and that unfounded reliance continues to be a substantial factor in a good chunk of accidents. Instruments should just be a cautionary reinforcement and backup to the main "instrument" operating the aircraft.

[danerazz]

I get what you are saying, but that doesn't work in all circumstances. When you are "on the edge" of the envelope, seat of the pants doesn't cut it any more. Experience is extremely important, but if you are really pushing things you end up either leaving a larger than necessary margin for error or things will catch up to you. For 99% of the flying that 99% of the Highlander builders do, leave the margin in and go to it. But for that other 1% I don't think you can properly use it without some form of instrumentation. I used to fly a champ with an airspeed indicator that worked about 50% of the time, and never worried about it. But I probably could have cut my speed on final by 25% if I had reliable instruments or ANYTHING to give me an indication of the stall margin other than a stick that was completely ineffective when you were close. I didn't need to worry because I wasn't trying to land on a minimum length runway.

Also, the instruments give us confidence to learn what the right seat of the pants sensations are. So it can work both ways.

[Dave Krall CFII SEL SES]

I get what you are saying, but that doesn't work in all circumstances. When you are "on the edge" of the envelope, seat of the pants doesn't cut it any more. Experience is extremely important, but if you are really pushing things you end up either leaving a larger than necessary margin for error or things will catch up to you. For 99% of the flying that 99% of the Highlander builders do, leave the margin in and go to it. But for that other 1% I don't think you can properly use it without some form of instrumentation. I used to fly a champ with an airspeed indicator that worked about 50% of the time, and never worried about it. But I probably could have cut my speed on final by 25% if I had reliable instruments or ANYTHING to give me an indication of the stall margin other than a stick that was completely ineffective when you were close. I didn't need to worry because I wasn't trying to land on a minimum length runway.

Also, the instruments give us confidence to learn what the right seat of the pants sensations are. So it can work both ways.

True, to a large extent.

The most valuable thing a pilot can have is lots of practice at a safe altitude stalling out and quickly recovering throughout the entire range of GrWt/CG/DA for that aircraft -all done primarily without instruments of any kind but, with a quick glance at them for reference ( or cockpit videos viewed later). That will help show them more definatively any error margins in each instrument.

Can you amplify on your Champs AI being accurate 50% of the time?

[danerazz]

I didn't say it wasn't accurate, I said it didn't work. It was a "communal" champ that was available to a few of us who flew at a freight company (DC-3s and BE-18s) which isn't in business any more. It was in good condition, just not perfect. Flew great, made me appreciate champs better than cubs (HERESY!). Once in a while you would look at the ASI after takeoff and it would read "0" or something well below anything possible, and would stay there throughout the flight. Didn't really bother me, but again, wasn't really pushing the envelope.