Negative AoA while cruising

[average_pilot]

I've noticed that at medium speeds, like 400 knots, it flies level with negative AoA. Is that normal?

Thanks.

Edited May 24, 2024 by average_pilot

[Victory205]

Do you mean pitch attitude?
 

If so, you can adjust the attitude on the AJB-7 using the little knob on the lower right side of the instrument to your liking. It’s just a reference. 
 

The AOA indicator is absolute and can’t be changed. It probably shows that at 400KIAS that you are flying at a positive AOA. 

[Super Grover]

The angle of attack reported in the F2 view is for the reference fuselage line. The incidence angle for the F-4E wings is 1°, and the thrust line of the engines is rotated 5.25° exhaust-down. These facts and additional aerodynamic effects can lead to negative values of the angle of attack for the fuselage reference line when flying fast or applying high thrust.

[Raven (Elysian Angel)]

I'm pretty sure he means that if you switch to external view, the aircraft flies with a nose-down attitude even when flying perfectly level. I noticed that as well, and my guess is this is due to the -5 degree angle on the engine mounting?

At higher altitude and cruise speed, the aircraft is indeed perfectly level while other aircraft fly with a slight nose-up attitude indeed due to AoA.

I read somewhere this -5 degree angle is to make maintenance easier, but it might also be to make cruising at high altitude more efficient (aka with less drag)?


*edit* sniped by Grover

Edited May 24, 2024 by Raven (Elysian Angel)

[Victory205]

My recollection is the thrust line was chosen to offset the location of the engines which are below the cg. You see this as a pitch down moment when poetic increased. 
 

To be sure for the OP, the aircraft is flying at a positive aerodynamic alpha value. 

For more fun on angle of incidence and pitch references, see “B-52” 

[average_pilot]

47 minutes ago, Raven (Elysian Angel) said:

I'm pretty sure he means that if you switch to external view, the aircraft flies with a nose-down attitude even when flying perfectly level.

My bad. I forgot to mention I was referring to the AoA value shown at the info bar.

51 minutes ago, Super Grover said:

The angle of attack reported in the F2 view is for the reference fuselage line.

I had no idea. I always assumed naturally it was for the wings. Now it makes sense. Thanks for the explanation.

[Victory205]

Now that you know, isn’t it time to change your name to “above_average_pilot”?