Pod Scrape at LHR
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You're right, in normal circumstances it should have been 27R before 3pm, 27L after. However in strong SW winds it is known that turbulence is created by the hangers and so 27L is always used when the crosswind is above a certain limit.(I won't quote the figures in case I get them wrong!)
Yesterday morning because of the wind 27L was the nominated landing runway, I believe the aircraft in question landed on the departure runway in accordance with the TEAM procedures used to tactically enhance the landing rate.
The landing runway was not decided because of the pod scrape but because of the existing crosswinds.
Ps. hope it wasn't a case of sod's law for you when the very day you get 27L , you end up parking at Terminal 1 ?
Yesterday morning because of the wind 27L was the nominated landing runway, I believe the aircraft in question landed on the departure runway in accordance with the TEAM procedures used to tactically enhance the landing rate.
The landing runway was not decided because of the pod scrape but because of the existing crosswinds.
Ps. hope it wasn't a case of sod's law for you when the very day you get 27L , you end up parking at Terminal 1 ?
27L is not always used when there are strong south westerly winds. The runway used for landing will be in accordance with the weekly alternation plan. The ATIS will warn pilots of turbulence on short final during certian wind conditions.
Just to clear up the inaccuracies.
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Behind the second BMI 
I agree with you that on the day in question we did "de-alternate" due to the crosswind. However Del Prado does not seem to know what he is talking about I am afraid.
With regard to the last 200' wind, if you can when busy just give a call of "200ft wind 220/45" may be of help to the one following? However it is a very high workload situation I would expect so maybe not possible? Out of interest how helpful are our windchecks we give when you are in the final stages of approach after being given landing clearance.
I agree with you that on the day in question we did "de-alternate" due to the crosswind. However Del Prado does not seem to know what he is talking about I am afraid. With regard to the last 200' wind, if you can when busy just give a call of "200ft wind 220/45" may be of help to the one following? However it is a very high workload situation I would expect so maybe not possible? Out of interest how helpful are our windchecks we give when you are in the final stages of approach after being given landing clearance.
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Jon Lei,
As little as 5° to 6° angle of bank can result in a pod strike with the struts fully compressed.
JW411,
Not really true. I've yet to see any swept wing aircraft that will remain wings level if you 'KICK' off the drift. Gently 'PUSHING' off the drift while applying enough into wind aileron to maintain wings level is a different thing. Even having said that, have a look at a cross-wind autoland in the aircraft sometime.... It lands wing down every time. BOTH methods work, and from experience I can tell you that wing down generally results in a less 'agricultural' landing. A firm touchdown will only rapidly compress the oleo's reducing your pod/ ground clearance....Just my 2cents worth.
Just wondering... at a typical flare att, what is the AoB req for an outboard engine contact on the 744's.
JW411,
The 747 is a "kick-off drift" aeroplane (for very obvious reasons).
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>Out of interest how helpful are our windchecks we give when you are in the final stages of approach after being given landing clearance<
GT3 - Speaking for myself, if it's right on limits I'm working so damn hard the chance of me working out the sin/cos of the crosswind component is remote!
There's always the possibility of course that the wind you give me at 100' will be outside the limit, which raises the possibility of a G/A.
A change from 200/25 to 190/23 frankly isn't worth mentioning. But an instantaneous 180/50 would be worth a shout
However, I suspect it's one of those things 100 pilots would have 100 different views on.
GT3 - Speaking for myself, if it's right on limits I'm working so damn hard the chance of me working out the sin/cos of the crosswind component is remote!
There's always the possibility of course that the wind you give me at 100' will be outside the limit, which raises the possibility of a G/A.
A change from 200/25 to 190/23 frankly isn't worth mentioning. But an instantaneous 180/50 would be worth a shout
However, I suspect it's one of those things 100 pilots would have 100 different views on.
banana head:
I thank you for your explanation. Perhaps you missed the inverted commas around "kick-off drift"? It is, as you say, a combination of the two.
What I was trying to impart is that you simply cannot touch down in a 747 with 10° of wing down like you can happily do in a DC-10 which is a truly wing-down technique aeroplane.
You cannot scrape a pod in a DC-10 - you get the wingtip first!
I thank you for your explanation. Perhaps you missed the inverted commas around "kick-off drift"? It is, as you say, a combination of the two.
What I was trying to impart is that you simply cannot touch down in a 747 with 10° of wing down like you can happily do in a DC-10 which is a truly wing-down technique aeroplane.
You cannot scrape a pod in a DC-10 - you get the wingtip first!
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I expect to be shot down for this however -
I am a wing down for x-wind landing person. After 31 years from instructing on Piper Cubs, flying Twin Otters, Shorts 360 and Islander to over 12000 hours on Boeings B737, B747 and B777. Got into trouble a few times from trainers on the B737 and also intitially on the B747 Classic. Then came the B747-400 and hey it uses wing down in autoland. More so on the B777. So I have pretty much stuck to this and so far it has worked or I have I just been lucky?
I am a wing down for x-wind landing person. After 31 years from instructing on Piper Cubs, flying Twin Otters, Shorts 360 and Islander to over 12000 hours on Boeings B737, B747 and B777. Got into trouble a few times from trainers on the B737 and also intitially on the B747 Classic. Then came the B747-400 and hey it uses wing down in autoland. More so on the B777. So I have pretty much stuck to this and so far it has worked or I have I just been lucky?
JL, BH......
touchdown geometry for the B744 is shown in TBC's FCTM.
Unfortunately the values are based on rigid geometry for various cases of oleo extension/roll/pitch. Wing behavior and resultant engine pod relative movement is a result of dynamic interactions of oleo rebound, spoiler, aileron input and attitude, with both feedforward and feedback. I wrote an inhouse paper based on a (limited) FEA analysis of wing behavior and it indicated pod touch was possible outside of the margins provided by the manufacturer by up to roughly 1.5 degrees.
BTW, the certification criteria encompassed by CFR14 part 25.473 and methodologically expanded by the applicable AC's/TSO's & orders such as:
AC 25-7A Flight Test Guide for Certification of Transport Category
Airplanes
AC No. 25.723-1SHOCK ABSORPTION TESTS Date: 5/25/01
¡× 25.125 Landing
AC 25.735-1 4/10/02 2
¡× 25.301 Loads
¡× 25.303 Factor of safety
¡× 25.733 Tires
¡× 25.1501 General: Systems and equipment limitations (JAR25x1524)
¡× 21.101 Designation of applicable regulations
¡× 25.943 Negative acceleration (JAR 25x1315)
AC 25.1309-1A System Design and Analysis
TSO-C26c Aircraft Wheels and Wheel-Brake Assemblies with
Addendum I
TSO-C135 Transport Airplane Wheel and Wheel and Brake Assemblies
TSO-C62d Tires
Order 8110.4A Type Certification Process
Order 8110.8 Engineering Flight Test Guide For Transport Category Airplanes
don't account for isolated wheel loads. To consider the consequences of that look at the Mega Death 2 deal at HK-CLK (not just the deteriorating ROD[18-20FPS @ TD, enough to exceed limit and result in deformation] but the roll instability, resulting in RHW touch and catastrophic overload of the RH MLG aft bearing mount), and some sundry other deals (EWK MD11 report, P40...).
may be worthwhile being gentle with bank...or be as perfect as 411A.
did the VS guys do good? no one here is likely to know without the DFDR/QAR data, but they don't have to be incompetent to have a bad day, just like the rest of us. The eye witness report appears to be of a good operation, which is what the rest of the world generally expects, yet purveyors of the PPrune forum appear satisfied to besmirtch at the least opportunity.
cheers
touchdown geometry for the B744 is shown in TBC's FCTM.
Unfortunately the values are based on rigid geometry for various cases of oleo extension/roll/pitch. Wing behavior and resultant engine pod relative movement is a result of dynamic interactions of oleo rebound, spoiler, aileron input and attitude, with both feedforward and feedback. I wrote an inhouse paper based on a (limited) FEA analysis of wing behavior and it indicated pod touch was possible outside of the margins provided by the manufacturer by up to roughly 1.5 degrees.
BTW, the certification criteria encompassed by CFR14 part 25.473 and methodologically expanded by the applicable AC's/TSO's & orders such as:
AC 25-7A Flight Test Guide for Certification of Transport Category
Airplanes
AC No. 25.723-1SHOCK ABSORPTION TESTS Date: 5/25/01
¡× 25.125 Landing
AC 25.735-1 4/10/02 2
¡× 25.301 Loads
¡× 25.303 Factor of safety
¡× 25.733 Tires
¡× 25.1501 General: Systems and equipment limitations (JAR25x1524)
¡× 21.101 Designation of applicable regulations
¡× 25.943 Negative acceleration (JAR 25x1315)
AC 25.1309-1A System Design and Analysis
TSO-C26c Aircraft Wheels and Wheel-Brake Assemblies with
Addendum I
TSO-C135 Transport Airplane Wheel and Wheel and Brake Assemblies
TSO-C62d Tires
Order 8110.4A Type Certification Process
Order 8110.8 Engineering Flight Test Guide For Transport Category Airplanes
don't account for isolated wheel loads. To consider the consequences of that look at the Mega Death 2 deal at HK-CLK (not just the deteriorating ROD[18-20FPS @ TD, enough to exceed limit and result in deformation] but the roll instability, resulting in RHW touch and catastrophic overload of the RH MLG aft bearing mount), and some sundry other deals (EWK MD11 report, P40...).
may be worthwhile being gentle with bank...or be as perfect as 411A.
did the VS guys do good? no one here is likely to know without the DFDR/QAR data, but they don't have to be incompetent to have a bad day, just like the rest of us. The eye witness report appears to be of a good operation, which is what the rest of the world generally expects, yet purveyors of the PPrune forum appear satisfied to besmirtch at the least opportunity.
cheers
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…why do some pilots (I see it all the time in military pilots of non UK origin) transition way out to the wing down cross contol technique? Uncomfortable for SLF . So kick it off and plant it says I! It appears this is what they did and the gods where just not with them.
The last minute kick straight is basically turning a stable crabbed approach into a horribly unstable approach at the very worst moment – a nanosecond (or hopefully only a nanosecond) before touchdown. If you judge is absolutely right, you’re the ace of the base and the pax will think you’re wonderful.
However, the magic word is ‘if’…
If you misjudge it, particularly in a strong crosswind, you end up with, at best, a not very neat touchdown, and at worst, a potential disaster of crossed arms and legs and a very big aeroplane still airborne but with a lot of momentum heading off in God knows what direction – but usually towards the downwind side of the runway at an increasingly rapid rate because your last minute “kick it off and plant it says I!” has left the aircraft pointing downwind.
In an aeroplane as big as a 777 or an A340, you run out of runway width very, very quickly, (remembering that your seating position is a very long way away from your main gear, [on the 777, around 100 feet or 30 metres]). If things start gyrating, you might stil be not too far off the runway centreline. There's no guarantee your MLG is still on (or over) the runway.
I’m definitely in the same camp as Witraz on this point. Look at the way the 777 autopilot does it – exactly as flown it accuses ex-mil non RAF types (that’s me) of doing it.
The 777 manual says that technique shouldn’t be used in crosswinds exceeding 31 knots. Boeing recommends simply flying it on while still crabbed. The enormous momentum of the aircraft sorts it out quite nicely, although obviously most pilots help it along by instinctively kicking it straight after touchdown.
Don’t believe me? Take a look at these landings by Boeing test pilots. http://www.leathermans.net/content/view/25/39/
http://www.leathermans.net/gallery/m...09c4bf51024a51
Under 31 knots, the wing down, crossed control technique, (as the autopilot does), and aided by the track bar on the PFD, will almost always guarantee the aeroplane will roll on smoothly and stable – and that last word, in my opinion, is the most important one in the equation in big aeroplanes.
Last edited by Wiley; 6th Nov 2005 at 13:35.
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GT3
I did pass on the turb <200' after landing.
As for wind checks, fine up to about 200' then as long as the last one is in limits no more
Can't remember exactly but our wind read outs work until touchdown at least.
They are inhibited <80kts on take off.
On ths subject of x winds, I ahve always been a little confused.
Our Flying manual (757/767) states we can use either technique, or a combination of the two.
Now, don't all x-wind landings use a combination of the two in the end?
I crab in and then feed cross rudder and aileron in in the latter stages, but you will ALWAYS land cross controlled with aileron into wind, or the wing will rise even in a modest x-wind.
the difference really is at which point on the approach you cross the controls.
I did pass on the turb <200' after landing.
As for wind checks, fine up to about 200' then as long as the last one is in limits no more
Can't remember exactly but our wind read outs work until touchdown at least.
They are inhibited <80kts on take off.
On ths subject of x winds, I ahve always been a little confused.
Our Flying manual (757/767) states we can use either technique, or a combination of the two.
Now, don't all x-wind landings use a combination of the two in the end?
I crab in and then feed cross rudder and aileron in in the latter stages, but you will ALWAYS land cross controlled with aileron into wind, or the wing will rise even in a modest x-wind.
the difference really is at which point on the approach you cross the controls.
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After 10 years of operating the 747-400 I always found the tricky bit was after touchdown.
The upwind wing just wanted to keep flying and postive use of aileron, but carefully, was necessary .
I always used kick off drift and it worked for me.
The aircraft did use wingdown for autoland but its limit was only 15kts!
The upwind wing just wanted to keep flying and postive use of aileron, but carefully, was necessary .
I always used kick off drift and it worked for me.
The aircraft did use wingdown for autoland but its limit was only 15kts!
Are you seriously suggesting that on a day when the wings are clapping hands with windshear possible on finals and 35 knots across the runway that you would leave the automatics in to deal with it all on an autoland?
If so, then I am seriously glad that I am getting close to retiring!
If so, then I am seriously glad that I am getting close to retiring!
Just another number
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BusyB
The 747-400 that I fly has a crosswind limit of 25kts for an autoland. This is a limit on the autoland system, whether or not it is in low vis. I agree with JW411 in that I wouldn't dream of attempting an autoland with a 35kt crosswind.
Airclues
The 747-400 that I fly has a crosswind limit of 25kts for an autoland. This is a limit on the autoland system, whether or not it is in low vis. I agree with JW411 in that I wouldn't dream of attempting an autoland with a 35kt crosswind.
Airclues
Captain Airclues,
I can only assume that is an operators restriction. Both -400 and 777 in my company have an LWMO restriction (because of reduced visual ref) and the a/c restriction. Whether you use it or not is up to the individual. Having sampled it I am much happier with a 777 max x/w autoland than a -400 one although that was still satis.
I can only assume that is an operators restriction. Both -400 and 777 in my company have an LWMO restriction (because of reduced visual ref) and the a/c restriction. Whether you use it or not is up to the individual. Having sampled it I am much happier with a 777 max x/w autoland than a -400 one although that was still satis.