I was wondering if it would be possible to simulate the autobrakes system and the way it works as on a real NG.In MSFS it's quite weird that the Autobrake starts braking the airplane when the main gear hits the ground and the nose wheel is still in the air. If the Autobrake brakes the airplane while still in nose up attitude the nose would downfall and crash into the runway.Maybe you guys could make the autobrake system activate only when aircraft is on the ground AND pitch is less than 1 degree nose up. This could be achieved by making a new gauge which brakes the AC when FSUIPC variables tell that the aircraft is on ground and pitch is less than 1

"In MSFS it's quite weird that the Autobrake starts braking the airplane when the main gear hits the ground and the nose wheel is still in the air."Are you sure you haven't misunderstood something you've read, Bruno? I thought it would have been dangerous to have had an autobrake system which didn't brake at all until the nose wheel touched down. I'm not familiar with NG braking systems, but some 767's have a braking system where full brakes are not applied until the aircraft attitude goes below 1 degree. There is no mention of an attitude input in our NG maintenance manual... nor any mention of pressure "ramping" (which I thought to be quite odd).Can you quote the relevant manual?Thanks.Cheers.Ian.

Hi Ian!Let me talk to a real captain how flies the NG, I'll have an answer for you by Friday. :-zhelp I can't quote any manual since I didn't find any information on them. However, I do think the autobrake system does not brake the airplane while the nose is still in the air because the only thing it would do is drop the nose considerably. I may be wrong tho :-shy As an example: On a bike; If you are doing willies and you hit the brakes, what happens? The gear that is located forward drops. I believe the same theory can be applied. Bruno Francescoli.

"However, I do think the autobrake system does not brake the airplane while the nose is still in the air because the only thing it would do is drop the nose considerably."Thanks for looking into that, Bruno :-)The brakes are applied with nose off the ground on the 737NG's bigger cousins (aunts, uncles, etc) for sure, but in most cases, the pressure is ramped (increased over a certain time period... albeit not very long). This should help with the fast nose dropping problem. There will also be some sort of pitching up, I'd say, from spoiler activation which would offset the nose-down tendency from the brakes. I'm sure you've seen some 747's with their nose hanging in the air for a long period of time during rollout. The pilots think they are using the underside of the wing to create drag, but it has been found that the brakes and spoilers are more effective with a nose down attitude (If the brakes on these aircraft didn't work at all until the nose dropped, the "nose up technique" pilots would never stop their 747's :-)).Cheers.Ian.P.S. The Autobrake system is influenced by an Air/Ground system. This looks at which wheels are on the ground/off the ground. The Boeing 737NG Wiring Schematics show that there are a few types of Air/Ground computers. The "-4" doesn't appear to look at the nose gear at all for Autobrakes. The -2 and -3 can use the nose gear, but only if the signals are not present from the main gear... or if the airplane lands on the nose gear first! (ouch!).

From what I understand about the AIrbus from an A320 captain, the wheel brakes are not at their peak effectiveness until between 60-80 knots, and reverse thrust is effective from taht range on. thats part of the reason why you come into idle by 60 (and then also to account for FOD) but on the airbus 320/319, from what I have heard, the wheel brakes don't really take full effect until the speed has significantly dropped because they arent too effecient and just wear tires and increase brake heat? can anyone confirm this?

Hi Jamie,I think what the Captain was trying to explain is a fairly standard procedure for landing a large transport category Aircraft. I know the company I work for prefers not to use brakes on all a/c until below 80 knots, if conditions allow, to minimize brake wear and heat build up. But believe me, if you set for Max Autobrakes, when the main wheels touch down, you will get an immediate deceration that is very noticeable. The Autobrake system, as Ian has described several times before, uses a set metered pressure depending on the selected setting. For example, low may be 1800 PSI to the brakes, Med 2400 psi and High full 3000 psi. You would normally only use the High setting if Landing in actual Cat III conditions or with a Very short runway. Most of our pilots set up the A/C with a minimal amount of auto brake (ie:1 or 2 on a boeing, Low to Med on and Airbus) and use Reverse Thrust as soon as the a/c touches down to decelerate more quickly to 80 knots where they stow the reversers to avoid FOD ingestion. This also saves brake wear and major heat buildup. Hope this helpsRegards Paul Gollnick :-coolTechnical Operations/Customer Operational SupportPrecision Manuals Development Groupwww.precisionmanuals.com

Yep lol i guessed MAX auto would disregard this--thanks a ton for the PSIs really helps a ton! Are you able to tell me what airline you work for--you referred to "most of OUR pilots set up the A/c with minimal amt. of auto brake...." be really interesting to find out whatthanks a ton!

The autobrake system applies pressure (up to 2,000-psi) to the brakes based on the selected setting (1-3, MAX), deceleration rate based on feet/second and will never give

Great info... Thanks, Sean.Cheers.Ian."In an effort to reduce brake wear, some operators suggest using only reverse thrust to 80 kias and then applying the brakes."So it's not that they aren't effective at higher speeds? (It's that they are too effective... at self destructing :-)).

Great Info Sean,I can vouch for that RTO scenario. Rode along on a Boeing Delivery flight and we accomplished an RTO from over 80 knots. Lots of bad noises coming from that airplane as it Ground to a stop :-)RegardsPaul Gollnick :-coolTechnical Operations/Customer Operational SupportPrecision Manuals Development Groupwww.precisionmanuals.com

ok wow an RTO sounds exciting--I dont wanna say fun, but it does seem exciting--does anyone here with jet ratings know if you are required to perform them in the plane. I was a passenger on the RTO but it wasnt super violent I think we might have been going only about 80ish knots, and it was on a long runway at KORD in a 737-500 so he didnt have to brake harsh. Ive doen a couple of go-arounds wher I was pilot in a Cessna but never in a jet (not wishing too either--they are probably safe but i like to land)Thanks for all of the info!

Hi Jamie,Most training is done in a simulator, so the first opportunity a line pilot has to experience a rejected takeoff is for real. As Paul mentions, it is typical on delivery flights, usually on a new

>Great Info Sean,>I can vouch for that RTO scenario. Rode along on a Boeing>Delivery flight and we accomplished an RTO from over 80 knots.> Lots of bad noises coming from that airplane as it Ground to>a stop :-)>Regards>Paul Gollnick :-cool>Technical Operations/Customer Operational Support>Precision Manuals Development Group>www.precisionmanuals.comHere's a question... in the PMDG sim, on takeoff, with TOGA active, I believe that if I want to activate the RTO mode (assuming I've got the autobrake set for RTO), I have to deactivate the autothrottle and then yank the throttle back.Is that correct, and will the autobrake fire? I'm writing this on the way to work and can't check it myself.If it works, I'm really looking forward to SU2, mapping the autothrottle disconnect function to a button and being able to yank back the throttle. Bring on the high-speed aborts!

RE: RTO'sAn RTO as required for aircraft certification is done at max T/O gross weight and just prior to V1. No thrust reverse is allowed. This is a pretty exciting test and must show that the aircraft can stop on the runway length it is designed for. It has been a long time since I was involved in these tests, early 737 and 747, but as I remember the airplane also has to be able to taxi off the runway before stopping.A max effort RTO generates so much heat that the brakes become red hot. This heat then conducts to the wheels which get so hot the fuse plugs melt and the tires go flat. This is to prevent the pressure in the tire from getting so great that they would explode and blow all sorts of parts around with devasting force. The tires will quite often become so hot that they will catch fire. It also has to be demonstrated that any fires will not become to severe for a period of time that would allow fire equipment to arrive.I have been onboard through quite a few of these tests and can assure you they are exciting.When you are involved with the tests a new aircraft is put through, you realize just how well built and safe they are.TomTom

i bet it is--thanks a ton for sharing the experience--really appreciate it!!!