The other day I see reference to St Kitts. I didn't know where this was, so I google it up and see it's another one of those Caribbean Islands. Oh, that's pretty and scroll through the images.

I happen across this one, can't help but notice something missing. With the angle of attack and flaps, he's on final approach. Wouldn't you think by the time you've reached street light altitude you'd have your gear down? What am I missing?

From that angle it appears that the plane is sitting on the end of the runway waiting to takeoff.

Yeah, looks like it's setting on an elevated ridge, and we can't see the gear because of the hill. . .

How can you possibly tell angle of attack without cockpit instrumentation?

What's the airspeed of that aircraft?

Looks to me like it's sitting at the runway threshold of Runway 25, preparing for takeoff.

Ah, ok, I see that now. I wasn't looking at it from that perspective.

Guppy, I was judging angle of attack relative to street lights.

Nonetheless, it's an interesting photo. Thanks for the help noodling out what I was, or was not looking at.

Angle of attack is a measurement taken using vanes attached to the side of the fuselage; for a given pitch angle, (nose up, nose down), AoA can be any value; it varies with patch and piitch and airspeed; for a given pitch anlgle, as airspeed increases, AoA changes. One can't tell AoA without instrumentation, and the AoA value may not may not be cited in the cockpit.

Pitch angle on approach is sometimes thought of as being the same thing, but it's not, and the angle of attack varies with approach speed for a given configuration and pitch.

One way to think of it is if the aircraft had no forward speed, but were descending vertically with it's nose on the horizon; zero degrees pitch, but a 90 degree angle of attack. If the aircraft has no airspeed or airflow, it has no angle of attack. If the aircraft were to be raised vertically, like in an elevator, it would have a negative angle of attack.

An aircraft flying forward with an airspeed of 200 knots at a pitch angle of say, five degrees nose-up would have X angle of attack for a given configuration (gear and flaps/slats extended to a specific value). That same configuration at a slower speed would experience a higher angle of attack, at a given descent rate, etc. Airspeed is an important consideration, as it pitch angle...but neither tells you what the angle of attack is on their own, or without instrumentation to make that determination.

The picture is an illusion, because of it's vantage point at an elevation lower than the aircraft, as well as the grainy appearance and the dark shadows, and no reference as to the aircraft's motion or state.

You're right, however: if the aricraft were in flight at that point, the aircraft would likely be making a low pass, but gear not down would cause gear warnings in the cockpit if certain requirements were not met.

I had always heard that the angle of attack was inversely proportional to the mass of the ass. With some adjustment for the enthusiasm level displayed by the copilot.

On Mondays, yes.

Completely different, come Tuesday. Taking into account, of course, the itnerval beyond midnight, measured in minutes, and in most cases, shots.

quote:

Originally posted by Stlhead:
I had always heard that the angle of attack was inversely proportional to the mass of the ass.

And what about the angle of the dangle?

quote:

Originally posted by rburg:

And what about the angle of the dangle?

It’s inversely proportionate to the heat of the beat.