Brake pressure

[MadKreator]

Just curious why the brakes in the f-16 are so bad? In comparison with other jest like the a-10 or harrier ? Landing in the f-16 and jamming full brakes takes forever to slow down.  I know that is not the correct way to land, nor do I land any aircraft that way, strictly curious. With the exception of a short runway emergency landing.  Is that how the real jet is, possibly due to the narrow gear/ instability? 

[darkman222]

I guess its because of the philosophy how western cold war fighter jets are designed. Compared to russian Migs that can take off basically from a grass field, western air force jets rely on a well maintained runway. That way they can save weight on reinforcement structures of the wheels and put it into something else. Payload for example. Weaker gear and weaker brakes can be constructed very leightweight.

Navy jets that are slammed onto a carrier deck and ground attack aircraft like the A10 are of course again designed differently.

Other airforce jets gear like the F15s does not look very strong to me either.

Edited November 18, 2022 by darkman222

[Deano87]

40 minutes ago, =617= Evil said:

The brakes on the Viper have always been weak when compared to other jets. This is primarily, from my understanding, just an organic by-product of having a very small front landing gear that can only accommodate small brakes. 

 

The front gear has no brakes. It’s only on the main wheels.

But to answer the OP, the brakes on the viper are as big as they need to be… that is to say fine when then aircraft is flown properly. Aerobraking is a huge part of slowing the F-16 down efficiently. Remember that kinetic energy goes up by 4x with every doubling of speed. So jumping on the brakes at 180 knots is asking them to deal with 4x more energy to stop the aircraft than at 90 knots, and the F-16 brakes are not really designed to cope with that… at least more than once.  
 

Adding brakes to the aircraft that can cope with regular use from higher speeds requires much heavier brakes and wheels, which in turn reduces your useful load etc etc. As with everything with aircraft it’s all a trade off. 

Also the short field landing procedure (minimum landing distance) still calls for aerobraking at 13AoA, so getting the nose down and getting on the brakes as soon as possible is not the fastest way to stop an F-16 in any situation, and you’re likely to have no brakes left at all by the end of the runway, and burst fuse disks in the wheels shortly there after.

There is a reason why the drag chute is a popular addition to the F-16 for a lot of its customer nations who operate from shorter runways.

Edited November 18, 2022 by Deano87

[MadKreator]

26 minutes ago, Deano87 said:

The front gear has no brakes. It’s only on the main wheels.

But to answer the OP, the brakes on the viper are as big as they need to be… that is to say fine when then aircraft is flown properly. Aerobraking is a huge part of slowing the F-16 down efficiently. Remember that kinetic energy goes up by 4x with every doubling of speed. So jumping on the brakes at 180 knots is asking them to deal with 4x more energy to stop the aircraft than at 90 knots, and the F-16 brakes are not really designed to cope with that… at least more than once.  
 

Adding brakes to the aircraft that can cope with regular use from higher speeds requires much heavier brakes and wheels, which in turn reduces your useful load etc etc. As with everything with aircraft it’s all a trade off. 

Also the short field landing procedure (minimum landing distance) still calls for aerobraking at 13AoA, so getting the nose down and getting on the brakes as soon as possible is not the fastest way to stop an F-16 in any situation, and you’re likely to have no brakes left at all by the end of the runway, and burst fuse disks in the wheels shortly there after.

There is a reason why the drag chute is a popular addition to the F-16 for a lot of its customer nations who operate from shorter runways.

 

Perfect answer! 

[alexscott292]

The joke in the 1960s was that if the USAF built a runway so long it went all the way around the world, Northrop would make a plane that needed it.

Central design philosopy, which comes from the situation.  Huge open spaces in the US, no history of territorial threat - huge runways, weak brakes.

Back when the UK had an independent aircraft industry - the Harrier.  A tiny, crammed island with a history of devastating air raids begets a dispersible aircraft system that can operate from a farmer's field.  Sweden - the Gripen, and its dispersible operations, simple maintenance, reinforced roads for takeoff and landing.

The US Marines requirements intersect with the more European restrictions and threats - so they got the Harrier and now the F-35B.

[Deano87]

If you really want to stop fast you can do fun stuff like this...

[Sarge55]

Lol’d… great photo. 
Would have thought drag chutes would require WOW’s to deploy. At least on the mains, anyway. 

[Deano87]

16 hours ago, Sarge55 said:

Lol’d… great photo. 
Would have thought drag chutes would require WOW’s to deploy. At least on the mains, anyway. 

Nope! It would be unfortunate to go off the end of the runway because of a faulty WoW switch. So they trust their pilots to be "sensible" with it.

[Sarge55]

Looks like that trust was misplaced on at least one occasion, eh.

[Bob1943]

Can we be sure that image has not been Photoshopped?  The reason I ask is that there is a lot of exhaust heat blur that is really distorting the lower part of the background tree foilage.  Yet the lower part of the drag chute, that is in that same heat blur area, does not appear to exhibit any heat blur distortion.

[QuiGon]

On 11/19/2022 at 1:56 AM, Deano87 said:

If you really want to stop fast you can do fun stuff like this...

Well not with USAF Vipers and thus not in DCS.

[Dragon1-1]

10 hours ago, Bob1943 said:

Can we be sure that image has not been Photoshopped?  The reason I ask is that there is a lot of exhaust heat blur that is really distorting the lower part of the background tree foilage.  Yet the lower part of the drag chute, that is in that same heat blur area, does not appear to exhibit any heat blur distortion.

It is because the exhaust is flowing below the chute and spreading out behind it. You can see the blur behind the jet is a cone, the chute is close to the aircraft and pointed into the airflow, while the engine is pointed quite a bit down. At least, that's what I think it is.

Deploying the chute before touchdown can be done if really fast deceleration is required. Obviously, this commits you to the landing.

[Deano87]

12 hours ago, Bob1943 said:

Can we be sure that image has not been Photoshopped?  The reason I ask is that there is a lot of exhaust heat blur that is really distorting the lower part of the background tree foilage.  Yet the lower part of the drag chute, that is in that same heat blur area, does not appear to exhibit any heat blur distortion.

That image isn’t photoshopped.

5 hours ago, QuiGon said:

Well not with USAF Vipers and thus not in DCS.

Well obviously. It was a discussion about IRL and not the sim.