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Flaperon777
2nd Dec 2008, 09:45
I don't know if this has been discussed earlier or not.But this is a unique issue which has been bothering me for quite a few weeks now.
I have just moved onto the B777 from a slightly smaller jet.Whilst I have had no problem in adjusting to the slightly higher main gear flare height(that is to say that the mains touch down just fine and smooth),I am consistently having trouble getting the nose wheel down smoothly...!!
Either it's held up too long or too little.Both ways it keeps coming down with an embarrassing thud.
Is this just a design feature or is there a particular nose wheel landing technique.If so,please help here.Cause this one's bloody embarrasing.......to say the least.
The worst are the x-wind landings.Where the mains come down real smooth,but even if the nose is'nt held up too long,it STILL comes down with a disheartening grind.To say the least...! Of course this could also be due to the airplane body angle (yaw) with respect to the runway,which is typical of a x-wind approach anyways.But why the same on a calm day......??!

Old Smokey
2nd Dec 2008, 10:10
I had the same problem for the first couple of thousand B777 hours, and then a smart F/O told me (F/Os usually have all the answers):ok:

I was applying steady back pressure on the wheel after a "good" main gear touch down, in an endeavour to reduce the rate of descent of the nose-wheel to the runway..............WRONG!:=

Instead he suggested applying a small forward force to fly ther nose-wheel onto the runway, with a very small back pressure at the last moment to arrest the nose-wheel rate of descent.:uhoh:

It works a treat!!!!!!!!:ok::ok::ok::ok::ok::ok:

Regards, and happy (smooth) landings,

Old Smokey

Flaperon777
2nd Dec 2008, 11:41
Hey OS,
Thanks firstly for ur quick response.I'm gonna try this on my very next landing on this baby.And believe me,if this works,I'll owe you a lifetime supply of six packs!
Essentially what you're saying is that after the mains come down,one should ease off on the back pressure on the column.Because once the autobrakes kick in,i'm quite sure they would accelerate the rate of de-rotation.Therefore instead of adding a little forward pressure,I understand one could essentially just ease off the back pressure.And then,when the nosegear is closer to the ground,one should reduce the rate of de-rotation.Right.
Once I get this right bro,I owe u!
Glad to know there are others with an identical problem......
Smoothies for all.

haughtney1
2nd Dec 2008, 11:55
flaperon777, what were you flying previously? because the method Old Smokey described works well for most other larger Boeings i.e. 747/757/767 etc

Flaperon777
2nd Dec 2008, 12:40
Spamcan,
For which company did u do the sim ride on the 777's if I might ask?
Thanks.
And yes,thats another touchy point.Reversers to idle latest by 80kts.Or look out for a boom boom on those 115k big ones....
The 757/67 dont have the same problem.At least i never had it on the 767's.The reason I was told was that the sheer length of the fueselage on the 777's makes for a higher main gear strut and therefore a higher than normal(or what we're used to)nosegear height to ground on touchdown.
Was never so pronounced or ever a problem on the earlier boeing versions.Therefore this "second landing" of the nosewheel......

mach 84
2nd Dec 2008, 13:05
after landing the maingear you have to land the nosegear as old smokey has written, about the reverse thrust, you usually let the autobrake decellerate the aircraft, you use just idle reverse unless the runway is wet. it is then up to the pilot how much the reverse thrust is used, ofcorse it will be best at high speeds, once you are below 80kts the reverse thrust becomes quite ineffective.;)

zlin77
2nd Dec 2008, 13:54
I think the flight crew training manual has words similar to : once the mainwheels have ground contact, "fly" the nosewheel smoothly onto the runway, no attempt should be made to hold it off......

Pugilistic Animus
2nd Dec 2008, 15:13
Old Smokey --that technique works well on the Archer too :}

PA:)

Old Smokey
3rd Dec 2008, 17:37
It seems to be universal Pugilistic Animus, I wish I'd learned it 44 tears ago, it might have meant 44 years of good landings instead of the occasional fluke.:ugh:

Odometer just passing 60, 2 years to refine the technique, never too late to learn:ok:

Look out for an E-mail PA, been a bit slack in the communications department, the powers of darkness (otherwise known as crew scheduling) seem to be keeping me away from your part of the world of late:bored:

Regards,

Old Smokey

Selfloading
4th Dec 2008, 16:04
I don't know about anyone else, but I can't wait to find out how Flaperon777 got on :)

eckhard
4th Dec 2008, 16:22
Take care not to overdo the 'derotation'. An Air Europe 757 was damaged at Funchal in the late 80s and there have been several other examples of structural damage caused by excessive derotation rate and/or vertical speed of nosewheel touchdown.

Some examples:

http://www.smartcockpit.com/data/pdfs/flightops/flyingtechnique/Preventing_Hard_Nosegear_Touchdowns.pdf

http://www.aaib.gov.uk/cms_resources/dft_avsafety_pdf_507740.pdf

http://www.ntsb.gov/recs/letters/1994/A94_118_121.pdf

http://www.ntsb.gov/recs/letters/2000/A00_92_103.pdf

As with a lot of things, moderation and an appreciation of the risks involved seem to be in order!

Take care and fly safe.
:ok:

TO MEMO
4th Dec 2008, 23:04
Old Smokey,

The technique also used to work pretty well on 737 and A300. And it still does for the A320... though on this one the best one I believe is to use neutral stick after landing and the nose touches down smoodly

That 757 incident in Funchal... does anyone know the wareabouts of the report?:suspect:

cheers

Flaperon777
5th Dec 2008, 06:11
Hey OS,
Just tried your tech on a 20 kt X-wind landing.And it worked like an egyptian charm!! Was the smoothest "nosewheel" landing I ever did(in my defense may i add the rwy surface was damp too....hehe...:p ).
Also tried the same a day earlier on a calm day.Same results! The trick,as u rightly pointed out,is to let the autobrakes kick in and then reduce the derotation JUST before u expect the nosegear to touch.Effectively flying the nosewheel onto the rwy surface,whilst it is still aerodynamically flyable.
TO MEMO-The 737 OR the 320 would'nt even draw comparison with the 777 in this regard.Its a different ball game altogether! I did'nt ever face this problem on my few thousand hours on the 767 either.It's kind of a 'one of' issue.Done some time on the 744 too.No issues there either.Its a 777 "thing" which OS seems to have successfully resolved for me.
So much for the mysteries of flight...
Now about those beers......

sleeper
5th Dec 2008, 08:07
Quote "And yes,thats another touchy point.Reversers to idle latest by 80kts." unquote

I hope that's for RR engines. On our GE's the boeing manual dictates:

"By 60 knots, start movement of the
reverse thrust levers reach the reverse
idle detent before taxi speed."

Big difference!

I have been doing this for 2 years now and never had a "bang".

Flaperon777
5th Dec 2008, 08:15
Yes sleeper its for RR's. GE's say 60 kts(the 115K big ones would'nt bang even at lower).And SOP's differ......need I say that.

sleeper
5th Dec 2008, 08:43
No need obviously.
I just didn't know there would be so much difference in limitations between engine models. Never flew a RR.
Any more significant differences between the two? Also makes me think of the BA 777 that crashlanded.

forget
5th Dec 2008, 09:02
This is a fascinating thread, from a non-pilots viewpoint. Flaperon777’s been around the block a few times, takes pride in doing things right, but he’s discovered he’s got a ‘simple’ flying problem. He’s also got the nous to ask others.

Along comes guru Old Smokey with ‘Yeah, it’s a quirk of the aircraft. What you need to do is this ………’

Full marks to Flaperon for asking. :ok:

PS, Flaps, you didn’t by chance land your 777 in Dubai early last week - before you perfected the knack. ;)

Flaperon777
5th Dec 2008, 09:41
Forget.....
Am glad to see that a "non-pilot",appreciates these very 'simple' flying problems,that we as pilots face constantly and everyday.So well....
Please take particular note of the aporstorfies(" " ).
Sometimes it takes great humility to achieve greatness.And as we all know theres no greatness ever achieved in flying and in aviation is there.
So all thats left is great humility......:)
PS-Did u get the reset button fixed on ur wrist timepiece....??
Cheers all....:ok:

Spooky 2
6th Dec 2008, 12:43
I don't believe Boeing differentiates between the RR/PW/GE's in the the most recent B777 FCTM dated 10/13/2008. Could be wrong as I don't have a copy with me but have instructed in the aircraft for the last year and do not recall any mention other than 60 Kts.

Flaperon777
6th Dec 2008, 13:21
Spooky,
You're right.Its 60 kts for all versions.Dunno where I got the 80 kts from.Probably a hangover from another ppruner who earlier said 80 kts and the engines went 'bang'( in a sim ie )!
However,that was'nt the question at hand......
Thx anyways.....:).

Pugilistic Animus
10th Dec 2008, 17:33
Old Smokey,

Look out for an E-mail PA
m Yass:}

I did receive your prior emails I still appreciate those humorous little messages they keep me balanced -- I also have been a little lax in communications trying to organize my plans---I've written some new poetry I'll send you those I hope you like them ---I do miss your emails, but I understand---still playing with the Tiger Moth? if I'm ever in your part of town I hope you'll give me some aerobatics lessons on it

and how's the behemoth getting along--ever took a joyride?

anyways I hope all is well---also I'm on Pprune more than my email so drop me a PM next time you are on line

and hotels do carry the best tasting mouth wash;)

Happy Greasing,
Pugilistic Animus