How to Aerobrake?

[JazonXD]

Hi everyone, so I've been curious, how do you actually properly aerobrake and make it effective?

 

What I normally do is just bring nose up to around 15 degrees and hold it there with the airbrakes out and flaps out, but I find that if I dropped the nose and just slammed on the brakes, the plane stops much faster? Doesn't that defeat the purpose of aerobraking unless you lost your brakes or something (hydraulics failure, but since they screwed up the hydraulics modeling, that doesn't even happen anymore lol)

 

So I feel like I must be doing something wrong. Can anyone please enlighten me? Thanks.

[Sweep]

So the approach is 21 uAOA typically on a 2-3 degree glideslope, flare to 23 uAOA and hold til about 75-100 KCAS...You can either let the nose fall on its own or retard it (i.e. stick aft a bit) as necessary for whatever reasons. Heavy landings (basically above 36,000ish pounds) can be shallower as needed I think.

 

What you're describing is a short-field procedure which isn't exactly good for tires and/or brakes, AFAIK.

[MikeMikeJuliet]

The purpose of aerodynamic braking is to slow the aircraft down without the use of brakes, and only use brakes at lower speeds when the airflow is not enough to keep the nose up. This is done to conserve the brakes and avoid overheating them due to long application of brakes at higher speeds.

 

When it comes to wear and tear of the brakes... that has nothing to do with DCS since you always fly with a fresh aircraft.

 

If you really need to stip the plane quickly, reduce aircraft weight (by burning fuel and or jettisoning external loads) to achieve the lowest possible final approach speed, drop the nose right after touchdown and bake hard.

 

Regards,

MikeMikeJuliet

[DarkFire]

On the subject of aerobraking, is there a chart somewhere that shows expected landing run against aircraft weight? I couldn't find one here and the only -1 I could find was behind a (expensive) paywall.

[Dr.Goose]

On the subject of aerobraking, is there a chart somewhere that shows expected landing run against aircraft weight? I couldn't find one here and the only -1 I could find was behind a (expensive) paywall.

 

 

Here DarkFire http://www.avialogs.com/viewer/avialogs-documentviewer.php?id=3704 you can't download it, but you can read it.

 

Landing procedures are on page 126f.

[AnnaNass]

Hi everyone, so I've been curious, how do you actually properly aerobrake and make it effective?

 

What I normally do is just bring nose up to around 15 degrees and hold it there with the airbrakes out and flaps out, but I find that if I dropped the nose and just slammed on the brakes, the plane stops much faster? Doesn't that defeat the purpose of aerobraking unless you lost your brakes or something (hydraulics failure, but since they screwed up the hydraulics modeling, that doesn't even happen anymore lol)

 

So I feel like I must be doing something wrong. Can anyone please enlighten me? Thanks.

 

Aerobraking isn't more effective than mechanical braking but it's wear-free.

You don't need it for the arcade game planes. You need it for the realistic module but it's more common in real flying. As my old flight instructor said: "The plane needs no brakes! Pull the stick until you stopped!"

 

So you do it well! You create maximum drag and if your landing is good, you don't need wheelbrakes on the most runways. Otherwise you are too fast.

[DarkFire]

Here DarkFire http://www.avialogs.com/viewer/avialogs-documentviewer.php?id=3704 you can't download it, but you can read it.

 

Landing procedures are on page 126f.

 

Thanks, that clears things up :thumbup:

 

Aerobraking is a lot less effective than using wheel brakes and you have to be cautious that you don't delay putting the nose gear on the runway until elevator authority has decreased too much due to lack of speed.

In that case the nose gear will hit the runway really hard.

 

If I'm reading it correctly the -1 manual appears to suggest using aerobraking down to 90 Kts after which the nose should be lowered to avoid excessive nose wheel impact, and then wheel brakes should be used to further slow the plane.

[GGTharos]

The minimum ground run procedure says a lot more things.

 

The standard procedure is something most people know:

 

Approach at 21uAoA with 3 deg glideslope at ALL WEIGHTS, and then the moment of throttle reduction is weight dependent, post-flare.

 

For minimum ground run,

 

Approach at 23uAoA and a glideslope of 2 degrees at ALL WEIGHTS, throttle reduction as above but avoid floating (ie. don't pull VVI to horizon, but maybe half a degree down). Upon touch-down lower nose great and apply full brakes.

 

In-game you can always use full brakes since brake overheating and tyre damage is not simulated.

[DarkFire]

In-game you can always use full brakes since brake overheating and tyre damage is not simulated.

 

I'm surprised, does the DCS F-15 not model tire popping under heavy braking as some of the other FC3 aircraft do?

[GGTharos]

AFAIK it does not. You can smash the gear on landing, but the tyres won't pop.

 

AFAIK I'm not convinced they'd pop in RL either - rather, the brakes would overheat and cause the tyres to explode some time after landing (as long as 45 minutes, IIRC) potentially with deadly results for anyone standing at one or the other side of the tyres.

[DarkFire]

AFAIK it does not. You can smash the gear on landing, but the tyres won't pop.

 

AFAIK I'm not convinced they'd pop in RL either - rather, the brakes would overheat and cause the tyres to explode some time after landing (as long as 45 minutes, IIRC) potentially with deadly results for anyone standing at one or the other side of the tyres.

 

Bloody hell, that's like strapping a time bomb to your undercarriage!! I'm surprised there's no over temp indicator for the brakes or tires or both. If I were on ground crew I think I'd be a bit paranoid about that :unsure:

[GGTharos]

They are. There are charts in the -1 that show the amount of energy accumulated in the braking process. If the pilot applies brakes under 60kts, AFAIK probably not considered hot-brakes.

If he brakes above 60kts I believe they consider it hot-braked and it's parked somewhere far away from other jets and people and it's not flown for at least a couple of hours (heat dissipates even slower when the gear is tucked into the well, and it'll explode inside the the aircraft). I don't really know the exact process for this, hopefully someone more knowledgeable will chime in.

[FLANKERATOR]

Been a while since my last ride in a 25T but I do remember the nose tyre popping when braking vigorously, maybe not anymore?

[JazonXD]

Interesting, if you used the brakes above 60 knots and that means your aircraft has to be sanctioned and parked in another spot... that doesn't seem to make for very effect use of the airfield space huh? Safety first I guess.

[DarkFire]

Been a while since my last ride in a 25T but I do remember the nose tyre popping when braking vigorously, maybe not anymore?

 

If the Su-27 is anything to go by then the tires are tougher now than they were a couple of patches ago, though it's still possible to pop them if you land fast and simply hold down the brake key.

 

I suppose the obvious solution to hot brakes would be to pour a couple of buckets full of cold water over the disks & tires, but if they're that hot then maybe the disks would warp making them ineffective or even unusable.

[JINX_1391]

In-game you can always use full brakes since brake overheating and tyre damage is not simulated.

 

In game you don't even have to land...'Esc', pick a new slot

 

Much faster than landing procedure, landing, taxi, awaiting for the "Follow Me" truck, shut-down...I don't even think I've ever learned how to land :megalol: :smartass:

[GGTharos]

Where are the brake energy charts in the -1? 60kts seems to be very low. Especially considering the fact that you must not apply heavy braking below 30kts in the F-15.That means a useful range of just 30kts.

 

I'll find them ASAP. They're for continuous braking.

 

Furthermore a low weight the F-15 accelerates below 90kts so you have to start braking at least at 90kts.

 

I find that a little strange. There's no reason for the F-15 to accelerate with the throttle at idle.

[JazonXD]

Um, may be a really dumb question and irrelevant, but what are you guys referring to when you say "-1"? Thanks.

[GGTharos]

Pilot's manual. The USAF has a seriest of manuals, the -1's are the pilot's flight manuals, the -34's the non-nuclear weapons delivery manuals, there are classified series of manuals describing the weapons and RWRs and ECM/ECCM/radar modes in detail, maintenance manuals etc.

[pr1malr8ge]

-1 section2: Due to high idle thrust, the aircraft may not decelerate after the nose wheel is on the ground unless braking is used.

An F-15 IP told me that at low weight the F-15 even starts to slowly accelerate again.

 

I can confirm this as from my SME that once the f15 has broken from static/stationary that the engines produce enough thrust at idle to keep it moving and toe braking is needed to maintain taxi speed.

[Capn kamikaze]

Link that you can download from....

 

http://www.mstewart.net/subob/fighters/f15.pdf