Use of wheel brakes after touchdown

[Cali]

You would be surprised how much the brakes heat up just in normal braking. One of the first items we have to check when recovering a jet is for hot brakes.

 

ACFT tires are made so the should (key word being should) deflate themselves if they overheat but that doesn't always happen. If an A-10 main or nose tire blows and your not directly in front or rear of the tire there is a good chance you won't be alive after.

 

Same with F-16's, during H-70 responses that was the first thing the first person went in and checked. We always went in from behind to check them, I never felt any hot brakes and I'm glad.

[LcSummers]

Very interesting thread.

 

For me i d like to have some of these great informatins like Eddie wrote:

 

Quote" Additionally as has been said before, when you are in an armed aircraft, exiting at anywhere other than the designated taxiway (generally at end of runway) will cause problems as there will be no arming crew there to put the safety pins back in to any remaining weapons, guns and flare dispensers. And without pins you're not going ANYWHERE near the ramp."

 

I was and never had the chance to see military aircraft in action. For a civilan i think its very hard to get close to them.

So i am pleased if someone explains me, how, why etc pilots acting this way.:pilotfly:

 

Great.:thumbup:

 

Cheers

 

LC

[Snoopy]

Same with F-16's, during H-70 responses that was the first thing the first person went in and checked. We always went in from behind to check them, I never felt any hot brakes and I'm glad.

 

When I was in High School living in England (father stationed at RAF Mildenhall) I was in JROTC and each year we got an incentive ride on a KC-135. Not real exciting but fun when you're flying out over the Atlantic to meet a flight of F-15s :D. The 3rd flight I got to go on we landed with suspected hot brakes, nothing like being on a 135 still over half full with JP8 with suspected hot brakes. I don't think i EVER ran so fast in my life.

Very interesting thread.

 

For me i d like to have some of these great informatins like Eddie wrote:

 

Quote" Additionally as has been said before, when you are in an armed aircraft, exiting at anywhere other than the designated taxiway (generally at end of runway) will cause problems as there will be no arming crew there to put the safety pins back in to any remaining weapons, guns and flare dispensers. And without pins you're not going ANYWHERE near the ramp."

 

I was and never had the chance to see military aircraft in action. For a civilan i think its very hard to get close to them.

So i am pleased if someone explains me, how, why etc pilots acting this way.

 

Great.

 

Cheers

 

LC

 

To piggy back off of what Eddie said. Every sortie we fly at Moody (and deployed but locations vary) EOR or End of Runway is required. At Moody (see picture below) we have two locations EOR is conducted, depending on the active it switches but one end is the Arm the other Dearm.

 

At the arm end the jet taxies from the parking spot (Shark or Claw ramp, where I work in the Reserves) to EOR. There are two crew chiefs and a weapons crew (made up of three individuals). One crew chief (the lead) marshals the jet to park, the other chocks the nose tire, we inspect the tires, do a roll over (remove chocks and the jet moves forward slightly so we can inspect the hidden part of the tires). After the roll over the lead crew chief hooks up his or her comm. cord, the other crew chief does a final walk around/visual inspection. They are looking for any leaks (fuel, oil, hydraulic fluid), any damage that may have occurred during taxi, and that the three landing gear and slat safety pins were removed. The weapons crew at the same time is removing any weapons safety pins (gun, chaff/flare pins, pylon safety pins, AIM-9 DRA pins) and conducting any checks/tests on the weapons prior to flight. Once that is done the lead crew chief disconnects their comm. cord, the other pulls chocks and we move to the next jet. The jets then taxi to the active runway and takeoff for their respective sortie. At different locations we conduct EOR at the parking spot, for example when I was stationed at Osan AB during exercises we would conduct the entire launch and EOR while the A-10 was still in the HAS.

 

At the dearm end the jets land from their sortie and taxi to EOR. There is one crew chief and a weapons crew (again three individuals). One crew chief (the lead) marshals the jet to park, one weapons crew member chocks the nose, a roll over is accomplished, and then nose chocked again. The lead crew chief hooks up their comm. cord and installs all three gear pins and the slat safety pin (this varies by base, some have the crew chief recovering the jet pin the gear/slat). The weapons crew at the same time will “roll back” the gun if fired (this is basically repositioning GAU-8 rounds for safety purposes), installed the gun safety pin and all other weapons/pylon safety pins. Once all pins are installed the chocks are pulled and the jet taxi’s back to its parking spot for recovery.

[Cali]

Lol, I could image that! So you got to see them refuel? It's funny how easy they make it seem, at least thats how they made it seem everytime I have seen an a2a refuel.

 

I bet you guys had a fun time with that jet that crashed huh?

[Snoopy]

Lol, I could image that! So you got to see them refuel? It's funny how easy they make it seem, at least thats how they made it seem everytime I have seen an a2a refuel.

 

I bet you guys had a fun time with that jet that crashed huh?

 

Luckily I wasn't down there when that happened. The official investigation report was just published, duel engine failure during FCF...bla bla bla. As is normally the case the "rumor" on what actually happened is way different that the official report.

[Cali]

I bet, it's a little scary when they come in and pull all the maintenance records and wondering who worked on the jet last.

[Speed]

:lol:

 

Also, challenge accepted. Split-S into landing:

 

~200% max gross weight "landing" after edit of mission file (96 Mk-82s aboard). Not pretty, but I lived :D

 

Probably shouldn't have come in so hot... but also, it is important to touch the wheels first to pavement, not tail.

 

Deliberately slid out at the end of the runway to avoid going nose-first into grass... better to go sideways or tail first, I think. Tried to use nose wheel steering, but I think it died as soon as the nose wheel slammed down.:smilewink:

 

Anyway, what a stupid waste of my time, lol.

superheavylanding.trk

[Wichid]

Interesting! I've always landed and used the wheel brakes to stop as quick as I can. I'll adjust my flying!

 

On a slightly related topic - where do you touchdown exactly? as you go down the glide slope and then flare planes generally touch down later than they could. Do real pilots ever dip slightly under the glide slope so that the flare puts them down bang on?

[effte]

In big planes, no, you go for the aim point and then you flare - the landing will be somewhat beyond and that's expected/taken into account. The performance calcs are built on an on-glide threshold crossing height. Just dont hold out for a greaser - arrest the sink rate and plant it. In small aircraft VFR into short fields, you can be more creative, but you will want to consider the terrain before the threshold before going down a route putting you there if the aircraft spontaneously converts to Real Flying (i e gliding).

Edited January 20, 2012 by effte

[Chops]

In a jet typically, you want the aircraft to be at 50 feet crossing the runway threshold, while bringing the throttle levers smoothly back to idle power, and touching down approximately on the big white blocks (aim points) 1000 feet down the runway from the threshold. You definitely want to land within the first third of the runway.

[bluepilot76]

In a jet typically, you want the aircraft to be at 50 feet crossing the runway threshold

 

This is true for civilian operations where the calculations are based around 50 feet over the threshold as already described; nice safety margin to avoid undershoots.

 

But I think I will be right in saying that military pilots are aiming a lot closer to the start of the runway than that, ie "on the numbers" I have watched them at my local military base and they are only a few feet up as they cross the threshold. (RAF Tornados)

[OutOnTheOP]

I noticed that while aero braking was mentioned a couple times in this post, no one seems to have explicitly explained what it is.

 

I may be wrong in my assumption, but I assume what you're referring to is holding a nose-high attitude with the nosewheel off the ground after touchdown for as long as possible; it turns the entire wing and stabilizer surface into a giant airbrake.

[superfluid]

I noticed that while aero braking was mentioned a couple times in this post, no one seems to have explicitly explained what it is.

 

I may be wrong in my assumption, but I assume what you're referring to is holding a nose-high attitude with the nosewheel off the ground after touchdown for as long as possible; it turns the entire wing and stabilizer surface into a giant airbrake.

 

In addition to the aerodynamic advantages, it looks like you've popped a totally bad-ass wheelie while landing. :D

[GGTharos]

Yes, for a bunch of fighters that is what it is.

 

For the A-10 though, it's your airbrakes. No need to keep the nose up - those barn doors will do the job for you.

 

For a MiG-29 or a Su-27, you have the parachute, so again you don't need to hold the nose up.

 

For an F-15, F-16, F-22 and probably F-35A, you'll hold the nose up to perform aerobraking.

 

I noticed that while aero braking was mentioned a couple times in this post, no one seems to have explicitly explained what it is.

 

I may be wrong in my assumption, but I assume what you're referring to is holding a nose-high attitude with the nosewheel off the ground after touchdown for as long as possible; it turns the entire wing and stabilizer surface into a giant airbrake.

[OutOnTheOP]

airbrakes + nose-high attitude !> airbrakes ?

 

it's not like the F-15 has no ginormous airbrake....

[GGTharos]

I don't know the exact details, but keep this in mind: With a nose-high attitude, you may be masking part of the airbrakes (specifically the top part).

 

Whether this is inferior or superior to 'just airbrakes', I don't know. Maybe it's just the same, and it is preferable to be able to see the runway well instead.

[OutOnTheOP]

Good point on runway visibility.

 

As to masking the airbrakes, I dunno... if you're masking the airflow to the upper half of the airbrakes, you're doing so by masking it with... an even larger aerodynamic surface. And presenting a larger surface area/ flatter angle to the flap surfaces.

 

I'm not sure I've noticed much difference in deceleration in DCS between airbrakes versus airbrakes+nose-high.

 

I know in Falcon 4, nose high beats airbrakes every day. Can't speak for the real aircraft one way or another.

[GGTharos]

The F-16 has puny little airbrakes. Just saying. :)

[Snoopy]

A-10s, real world don't aero brake...I've watched my jet land more times than I can count and the only time you see a pilot try it is when they've transitioned to an A-10 from 15s or 16s....just not needed....

[RobbySpike]

 

These look pretty much how I usually do it in DCS. Unfortunately you cant see em rolling out in the vids

[effte]

Regarding AD braking, I'm going to spoil all the fun had through speculation and quote chapter and verse.

 

If available runway does not require maximum braking, speed can be reduced by aerodynamic braking or by extending speed brakes. Following aerodynamic braking, smoothly lower the nose to the runway prior to loss of elevator effectiveness.

 

As you can see, our resident Op guy is correct in his assumption.

[ralfidude]

I like to do aerodynamic breaking. It's fun. Can keep that nose up still at 90 knots.

[effte]

Ah, good to know it's indeed possible to keep it up all the way to 90!

[LcSummers]

So i have to make my landings like you wrote paulrkiii.

 

Thanks for so much information. If this is a real sim, i want to act the way, how real pilots are doing.

 

Next time when landing, i will try not to use wheelbrakes and txi to the end of the runway.

 

Thanks

 

LC

 

PS: if i understood it Airbrakes fully open only after touchdown, no wheelbrakes, no NWS until i arrived at the end of runway.

Edited January 22, 2012 by LcSummers

[JCook]

I've got the Saitek Combat pedals and can't seem to brake at all. As far as I can tell the left and right brakes are assigned properly in the Axis controls. I don't recall running any Saitek config software for the pedals other than the drivers installing. Maybe I need to edit the brake axis settings for deadzone, X saturation, Y saturation and curvature? Can anyone who is sucessfully braking with these pedals offer some help?

 

Thanks