Optimal AoA?

[Pocket Sized]

On every aircraft there is a specific AoA you want to fly for best turn performance. This is indicated by a "donut" in the F-4/14/16, changing beeps in the A-10C, or the yellow band on the Su-25's AoA indicator.

 

The F-15 doesn't appear to have any such indications, which I seriously doubt. I am fully aware of the HUD and gauge AoA indicators but they aren't very useful when you have to keep your eyes outside the cockpit.

Edited April 28, 2016 by Pocket Sized

[Sweep]

If you're fast/nose down enough, you have the double beeper (activates at ~7.7-7.8 g, IIRC) to judge stuff...Otherwise, keep your cross check going well - Except when in the first turn after the merge, usually you don't want to look down then...IDK, I always lose tally, lol. :doh:

 

To perhaps answer your question a bit better, I believe 22 AOA is usually the max for a rate fight...Anything over that and I *think* you're losing knots, usually...Depends on weight and stuff...

[mvsgas]

On every aircraft there is a specific AoA you want to fly for best turn performance. This is indicated by a "donut" in the F-4/14/16, changing beeps in the A-10C, or the yellow band on the Su-25's AoA indicator.

 

The F-15 doesn't appear to have any such indications, which I seriously doubt. I am fully aware of the HUD and gauge AoA indicators but they aren't very useful when you have to keep your eyes outside the cockpit.

 

Are you sure the AOA gauges indications are for turning AOA? For example, in the F-16, all AOA "gauges" markings are used for landing and aerobraking.

AOA Indicator

Refer to Figure 1-58. The AOA indicator, located on the

instrument panel, displays actual AOA in degrees. The indicator has a vertically moving tape display indicating an

operating range of -5 to approximately +32 degrees. The tape

is color coded from 9-17 degrees to coincide with the colorcoded symbols on the AOA indexer.

AOA Indexer

Refer to Figure 1-58. The AOA indexer, located on the top

left side of the glareshield, consists of three color-coded

symbols arranged vertically. The indexer provides a visual

head-up indication of aircraft AOA by illuminating the symbols individually or in combinations as shown. The indexer

lights display AOA correction (based on approximately 13

degrees AOA). This correction may be used during landing

approaches as visual direction toward optimum landing AOA.

The AOA indexer operates continuously with the LG handle

up or down.

A dimming lever, located on the left side of the indexer,

controls the intensity of the lighted symbols.

The indexer lights are tested by activation of the MAL & IND

LTS switch on the TEST switch panel. The test should be

performed with the dimming lever in the bright position.

HUD AOA Display

Refer to Figure 1-58. The HUD AOA bracket and flightpath

marker provide a visual head-up indication of aircraft AOA.

The flightpath marker aligned with the top of the bracket

indicates 11 degrees AOA. The flightpath marker centered on

the bracket indicates 13 degrees AOA. The flightpath marker

aligned with the bottom of bracket indicates 15 degrees AOA.

The HUD AOA display is only available with the NLG

lowered.

[mvsgas]

According to this PDF, page 88

http://www.avialogs.com/en/aircraft/usa/mcdonnelldouglas/f-15eagle/to-1f-15a-1-flight-manual-f-15a-b-c-d-aircraft-block-7-and-up.html#download

The F-15A AOA indicator is marked but for landing (20 to 22 units or angle)

[Pocket Sized]

For anyone who doesn't know what I'm talking about:

 

AFAIK being at the top of that curve is very important when your life depends on out-maneuvering your target.

 

E: So the only official reference to what I'm talking about is in Russian aircraft... I guess they have it figured out :huh:

(Not trying to start anything political)

Edited April 28, 2016 by Pocket Sized

[Bushmanni]

Your only concern regarding AoA in a turn fight is to not stall the aircraft (like the beeper in A-10). Other than that your actual AoA for turn is decided by other factors, mainly how much you want to bleed or gain speed. F-15, Su-27, F-18, etc. don't stall in the traditional sense but just turn tighter and bleed more speed so you can pull as much AoA as you see fit for the situation. A-10, P-51, etc. on the other hand need to be driven at the edge of the stall for tightest turn. F-16 is kind of special case as it can get into deep stall with too much AoA so the FBW limits AoA for the pilot.

[Pocket Sized]

Your only concern regarding AoA in a turn fight is to not stall the aircraft (like the beeper in A-10). [snip]

 

You... are probably right, thanks. I realize that the SU-25, A-10, Mig-21, etc. Are all completely different from modern fighters.

[Bushmanni]

One thing I forgot to mention is that in a plane like F-15 that stalls very gradually and only at very high AoA thrust will be a major factor turning the aircraft. Even if wings and body provide little lift at high AoA now thrust has a significant component pushing the aircraft into the turn. Also when you are low on fuel and have more thrust than weight, you can make the plane stand on its tail at very low speed and still have enough control to move the nose around to make a turn. Minimum speed at level flight is around 120kts for F-15 but in a climb you can go as low as 60kts and still be in controlled flight.