Typical take-off / landing figures

A

asl

Well-Known Member
As a Physics teacher
yeahthat.gif
I would like to set several questions for my advanced students on plane thrust and landing braking, but I need some typical figures for jets - I'm not too fussed which ones, but 747 would be nice.

Basically the figures I need are - aircraft mass, typical take-off mass of pax, freight, luggage, fuel; typical landing fuel mass, max forward thrust force available from engines (or that used in take-off configuration), max. braking / reverse thrust force available on landing. And also rotation speed for take- off and the specified landing speed for the aircraft, and also the speed reached at which the aircraft can safely vacate the runway. Typical roll-out length on landing and take-off. Oh- and some typical runway lengths. I know I'll have to convert the numbers into S.I. units (Newtons for force, kilograms for mass and so on) unless somone has them in that form already.

Those who studied Mechanics in physics will see there is a whole set of questions available from this data - using Force = mass x acceleration. Calculating resultant forces, kinetic energy on runway to Gravitational Energy in climb, and the runway length, versus acceleration using the constant acceleration equations of motion - also good for how longa runway does the plane need to stop - hehe!!

I'm thinking I might even throw in a min.spearation question on how far behind the next plane has to be to let the landing one get off the runway!

Probably all the typical stuff that you get the computers to do for you - but all good basic Phyisics - and with some in the class talking of wanting to become pilots I think it might help grab their attention.

Hopefully I'll set 'em some
banghead.gif
insane.gif


T-Y in advance.
rawk.gif
nana2.gif
 
I can pull up some pretty good numbers for an MD11 but won't be able to do it before Friday. Thrust is easy, but brake force is not something easy to come by. Most performance charts for most airlines just tell you what your max landing weight for that runway is -- not very helpful. Fortunately, mine doesn't do it that way, and I can give you a precise ground run stopping distance on a dry runway (or wet, if you want) based on max brake use (or min or med brakes if you want), without the use of reverse thrust, or with. You need to be more specific. Also, max landing flaps or min? What temp do you want to use, altimeter, winds, what airport? Lots of variables there. Assume you want ISA at a SL airport so no differential between TAS and CAS?
 
MD11
Max TOGW 630.5
BOW 252.3
MZFW 451.3
Max payload 199
MLGW 481.5
Max thrust 61.5/eng (3 GE engines, Pratts are 62k)
Max fuel 258.3 (note that max payload with full fuel not possible in this or any other transport).

I don't have reverse thrust numbers, but it isn't that much, relatively, but not insignificant either. The most we can go without is 1 and that does not change any of the below numbers.

I used LAX, 25R, 12091. I do not know the actual ground run,, but
Vr=176
V2=182 (it's going to unstick somewhere around 180, rough estimate, but don't have the numbers of that).
I used ISA, 126'MSL 15C 2992hg.

Min clean climb speed (what we use up to 10000') is 289kts indicated at that weight, and normal cruise climb is 355 kts indicated until cruise mach, normally about 0.835.

I do not have actual ground run, but you may be able to determine it from the above with a projected acceleration rate.

I do know that if you accelerate to V1 of 164kts and reject, that you will come to a stop with 1120' remaining, so that may tell you something. It may also confirm your numbers for brake force, which you'll have to reverse engineer.

I show the following for landing using flaps 35:
Vapp 166 kts
Vref 161 kts (stop distance based on Vref-4kts).

The following landing (ground roll) distances for LAX 25R:
w/reverse thrust
Brakes Min MED MAX
6230 5130 4280

I don't have any numbers for no reverse thrust, as the most that I can enter inop is 1 and that doesn't show a difference in the numbers I pulled up.

Hope this helps a bit.
 
Geez, I thought the heavy 'clean' speed on an MD-90 of 259 knots was bad!
smile.gif
 
Doug,
Being on 9 knots over 250 do you let ATC know that you will need a high speed climb? It's not over as much as 289 of course but still is above 250. Just wondered.
 
No requirement to advise them sans a restriction in your clearance or a published procedure. It is a courtesy call, which is useful if you think they're putting you behind slower traffic and ATC is not aware of the situation. I find that I give more of these types of calls for the approach environment, where they are putting me behind a 737 or A320 and my min approach speed for the conditions is more than 170 kts. ATC has thanked me for those calls more than once!
 
Nope, I don't tell them. It's an operational necessity. At some high density airports, they like you getting to 250 ASAP so they can launch another aircraft behind you.
 
You must log in or register to reply here.
Back
Top