Angle of Attack importance during and after landing.

[-NMS- Ikaros]

Hello guys.

 

I was listening to the fighter pilot podcast and they were talking about the Mirage. The french pilot mentioned that the aoa for landing should be 14 degrees and that 1.5 degrees more aoa during the flare and the engine nozzle would scratch the runway which is a very bad thing to happen.

 

Now in this machine the aoa is not shown in the hud while in landing visually. Only way to check is to turn sideways and check the instrument on the side which is very uncomfortable to do while landing.

 

Is there a way to have the aoa shown on the hud?

 

Also is there a way to show the nose point (gun cross) on the hud so to at least watch out for the flare and aerobraking angle not to exceed limits?

[MisterVince]

Is there a way to have the aoa shown on the hud?

 

You can tick a box in the "special" tab to have it on your hud. However, I reckon IRL this is only a feature of the Mirage2000-5.

[Thinder]

I was a bit surprised that you couldn't find any way to figure AoA from the HUD, I haven't started to play DCS but from other sims I believe that it is as the manual describes:

 

4. Flight Path Marker (FPM)

The Flight Path Marker also known as the Velocity Vector Indicator (VVI) is an

aircraft shaped symbols that shows in the HUD where the aircraft’s instantaneous

flight path with respect to the earth. The wings of the symbol always remain parallel

to the wings of the aircraft. The vertical relationship between the waterline and the

FPM indicates true AOA. The FPM displacement from the HUD centerline

indicates drift.

 

During landing, your FPM is what I believe is a "false" Velocity Vector, otherwise said, it shows where your aircraft is pointing, not where it is actually going, so in effect, it is your AoA indicator during landing, you should also check the APP mode chapter in the manual.

 

The instrument you mentioned otherwise is an analog repeater, it is not meant to be used in normal situations, more as a backup and it gives you the correct AoA parameter in green.

 

APP

It is a sub mode of NAV and is used during landings. In this mode the HUD display ILS

cues.

 

Before glideslope capture

1. Angle of Attack guide.

Indicates the optimum angle of attack for landing the aircraft. You must place both

the FPM and the AV chevrons within the brackets for a perfect landing.

The brackets represent an AOA value of 14º ± 0.5º

 

Note: The analog AOA indicator (refer to the flight instruments chapter) also has

the AOA for landing zone marked in green.

Note: In APP mode the BA, HS and IAS move from the top of the

combiner glass down to the center. In APP mode is necessary to

move the seat up in order to increase the field of view.

 

Something else, from what you said, I think the Mirage 2000 pilot was mentioning the Max AoA at landing, norm would be between 13 and 15* AoA.

 

file:///D:/DCS%20World/Doc/DCS%20M-2000C%20Flight%20Manual%20EN.pdf

Edited June 14, 2020 by Thinder

[-NMS- Ikaros]

Is the app mode available only for ILS approach only or can i use it in visual approach also? (without ils available airport)

 

How do i activate this mode?

 

I used to fly F-16 in the past and i just started training in the Mirage, looks a lot harder aircraft to manage.

Edited June 14, 2020 by Tlepolemos

[Steph21]

Is the app mode available only for ILS approach only or can i use it in visual approach also? (without ils available airport)

 

I used to fly F-16 in the past and i just started training in the Mirage, looks a lot harder aircraft to manage.

 

It's available and should be used for all approach. Mirage is way easier to manage than the F-16 imo.

Edited June 14, 2020 by Steph21

[-NMS- Ikaros]

Guys i just found the buttons for the HUD display modes on the left console and i will find my way through.

 

MisterVince, Thinder, Steph. Thank you for replying with your valuable info guys.

 

Happy flying. :)

[Steph21]

Only way to check is to turn sideways and check the instrument on the side which is very uncomfortable to do while landing.

 

Align the inverted T, displayed at the bottom of the hud with WoW, with the horizon bar. You'll then have the correct pitch for take off rotation and aerobraking when landing ;) it's designed for it.

[-NMS- Ikaros]

Align the inverted T, displayed at the bottom of the hud with WoW, with the horizon bar. You'll then have the correct pitch for take off rotation and aerobraking when landing ;) it's designed for it.

 

My friend thanks for this tip but i cannot find any inverted T displayed in the Hud, i don't know what wow is..

Please explain cause what you say looks promising. :)

[Steph21]

My friend thanks for this tip but i cannot find any inverted T displayed in the Hud, i don't know what wow is..

Please explain cause what you say looks promising. :)

 

See screenshot from the manual. It only appears with weight on wheels.

[-NMS- Ikaros]

Oh man i didn't notice that on the manual. Thanks!!!!!!

[S. Low]

See screenshot from the manual. It only appears with weight on wheels.

 

How can it be used for landing if it only appears with weight on wheels? It even says this on that page, page 95, "It also helps getting the best areobraking pitch when landing, while still avoiding tail strike."

 

I assume by "aerobraking" the devs mean AoA. So how can the inverted T be used for an AoA indicator during landing if it only activates with WoW? I'm so confused :book:

[Ramsay]

I assume by "aerobraking" the devs mean AoA.

Not in the sense you are thinking.

So how can the inverted T be used for an AoA indicator during landing if it only activates with WoW? I'm so confused :book:

On touchdown there is WoW of the main landing gear, the inverted T helps the pilot use "aerobraking" to decelerate down the runway before letting the nose drop.

[S. Low]

Not in the sense you are thinking.

 

On touchdown there is WoW of the main landing gear, the inverted T helps the pilot use "aerobraking" to decelerate down the runway before letting the nose drop.

 

Oh I see, makes more sense. So as far as monitoring AoA on approach, you either use the tape to the left of the hud controls or go into special options and add it to the hud?

[Ramsay]

So as far as monitoring AoA on approach, you either use the tape to the left of the hud controls or go into special options and add it to the hud?

 

I use approach mode and the HUD.

 

With the fpm in the square brackets

 

] -o- [

 

... you are on speed with an AoA of 14.0° +/- 0.5°

 

Obviously you should be stable durring the approach with the acc. chevrons also aligned with the fpm so the HUD looks like

 

>] -o- [<

 

Special options just adds the numerical read out of the AoA on the left side of the HUD which is only a feature of the D or -5 ?

Edited June 19, 2020 by Ramsay

[S. Low]

Yeah I align the FPM with glide slope brackets and acceleration chevrons as you've indicated there, but I wasn't sure if I should be double-checking my AoA tape or not, or if there was another AoA verification method.

[Ramsay]

Yeah I align the FPM with glide slope brackets ...

They are NOT glide slope brackets, they indicate AoA.

 

[S. Low]

Yeah, I had that wrong. Chuck's guide on page 76 labels those brackets as "Glide slope bracket." I just double checked Razbam's manual and you're right, they label those brackets as AoA guide. That clears it up for me, thanks!