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View Full Version : KE 773 landing incident at NRT


akerosid
13th Jul 2009, 17:34
Incident: Korean B773 at Tokyo on Jul 13th 2009, tail strikes on landing (http://avherald.com/h?article=41c9d338&opt=257)

BBC NEWS | Special Reports | Korea plane lands on its tail (http://news.bbc.co.uk/1/hi/8148527.stm?ls)

Aircraft was HL 7532.

rwy_hdg
13th Jul 2009, 17:48
Crikey! Is it just me or does this remind anyone else of Fedex? The video doesn't show it, but it would be interesting to see whether the nose-gear bounced after a first hit on the ground....

akerosid
13th Jul 2009, 18:26
From what I can see of the footage on the BBC report, the nosegear doesn't get involved at all until the rollout and there doesn't seem to be any evidence of a bounce.

PAXboy
13th Jul 2009, 18:44
It does look as if the nose gear did not touch down before an unfortunate combination of wind and events lifted the nose very high. The BBC web page informs us: A plane carrying 380 passengers had a bumpy landing in Japan. Unless I have misunderstood the config of a 773, I suspect that the arrival of an a/c called the '380' has got in to the BBC's auto-story generator software ...

CptRegionalJet
13th Jul 2009, 18:48
Mhh,
the video looks more like a V-MU test than a landing to me:confused:...

BusyB
13th Jul 2009, 19:23
CX has 380 pax on its 773 with no F/C:ok:

Rainboe
13th Jul 2009, 19:38
Did I miss something? It was simply a tailscrape, people, with no evidence of anything untoward to the nosegear! Because it was:
on landing
at Narita,
does it mean everyone should draw parallels with the Fedex? Simply a tailscrape on landing. I have seen one close up, and startling though it is to witness close by, it is essentially a non-event, and is not likely to lead to hard nosegear touchdown before, or after, the scrape. Some of the remarks seem naive and are better directed to that place where the hysterical aviation kids hang out, not a professionals forum.

fc101
13th Jul 2009, 20:30
Rainboe.. Did I miss something? It was simply a tailscrape You must be new around here ;-) Good job this wasn't an Airbus or they'd all be screaming about how dangerous FBW is and drawing tenuous conclusions from Hamburg and Air France and....not to mention Korean pilots, CRM...and how they could all do better in MSFS

fc101 *

yes there is some deep irony in there too....

einhverfr
13th Jul 2009, 20:57
You must be new around here ;-) Good job this wasn't an Airbus or they'd all be screaming about how dangerous FBW is and drawing tenuous conclusions from Hamburg and Air France and....not to mention Korean pilots, CRM...and how they could all do better in MSFS
Now that you mention FBW, it is worth noting that the 777, like the A330, is FBW. I wonder if there is a link to AF447....

[/sarcasm]
Mods:
Feel free to delete this post. However, sometimes humor is needed....

md80fanatic
13th Jul 2009, 21:35
The poor angle of the poor quality video looks almost as if tail contact was right of the pavement. There's quite a bit of dust being kicked up.

EDIT: the above is an observation, not speculation.

Rainboe
13th Jul 2009, 22:24
Unless you know where the camera was located and know the airport, I don't think you can make any comments about where the scrape occured. Are you seriously suggesting a crew missed the runway? Rather than a sensible discussion taking place on reasons for pitch-up after touchdown causing a scrape, we are getting daft 'shoot from the hip' speculation. If the quantity of smoke leads you to think that they 'landed in the dirt' then you should know a scrape produces prodigious smoke and sparking for a short duration.

Let's keep comment sensible! No simmer theories please! Was it an overzealous attempt to smooth touchdown leading to a strike? Pitch up due to reverse thrust? Poor handling habits? I think only a 777 pilot should speculate likely causes, but 'off the pavement'? Really!

SMOC
14th Jul 2009, 05:13
A center hydraulic system failure would cause a pitch up with spoiler extension or lack thereof.

llondel
14th Jul 2009, 06:30
Was there much of a crosswind? I know the headlines mentioned 60kt winds, if there was a reasonable crosswind component in that then it could have blown the dust cloud to one side, giving the appearance of it being off the runway from the cctv camera.

gengis
14th Jul 2009, 07:37
Was there much of a crosswind? I know the headlines mentioned 60kt winds

I won't get into speculating about anything, except to point out that 60 km/hr is not the same as 60 kt!

glad rag
14th Jul 2009, 09:37
It would be very interesting and informative if we were to find out the cause of that dramatic and sudden pitch up...but I doubt that we ever will.

joojoo
14th Jul 2009, 09:58
@glad rag
It would be very interesting and informative if we were to find out the cause of that dramatic and sudden pitch up...but I doubt that we ever will.

Yes, my heart goes out to all those on board and their families. I doubt if they will ever find the FDR. Another non-tragic incident for which we will never really have an answer. Speculation is pointless, we must await the outcome of a full investigation.

Farrell
14th Jul 2009, 10:20
"It would be very interesting and informative if we were to find out the cause of that dramatic and sudden pitch up"

Why?

CDRW
14th Jul 2009, 12:15
Because, dear Farrell, some of us out there, do 12 to 15 landings a month in this type. This tail scrape, after what looks like a normal touch down ( and I emphasize "what looks like") can shorten ones career dramatically!! This is not a normal thing to happen and would think this may constitute an accident report!!

YWG-JFK
14th Jul 2009, 12:33
I was at Narita last week. Very gusty crosswind on landing and takeoff a couple of days later!
Anyone know if they EVER plan on making taxiway C into a runway as I believe was the origional plan? It would come in handy at various times of the year!

Crazyworld
14th Jul 2009, 13:13
pilot saved the plane or the plane saved the pilot?

badgerh
14th Jul 2009, 14:36
Do commercial aircraft really land in 60kt crosswinds - that is very close to hurricane force (average 64 kts)? I would be happy not to be SLF in such a situation.

Baldur
14th Jul 2009, 15:09
Where does the 60KTS come from?

BBC story clearly states 60 kmph

Metars:

RJAA 130400Z 22019KT 9999 FEW030 BKN/// 32/21 Q1006 WS R16L BECMG 22020G32KT RMK 1CU030 A2971
RJAA 130330Z 22017G32KT 180V250 9999 FEW030 BKN/// 32/22 Q1006 WS R16R WS R16L NOSIG RMK 1CU030 A2973

Dairyground
14th Jul 2009, 15:41
Is Rainboe sllipping?

Let's keep comment sensible! No simmer theories please! Was it an overzealous attempt to smooth touchdown leading to a strike? Pitch up due to reverse thrust? Poor handling habits? I think only a 777 pilot should speculate likely causes, but 'off the pavement'? Really!

From the Turkish 737 thread, I thought that I had learned that increasing forward thrust from low-slung engines could produce a strong nose-up couple. Surely reverse thrust should tend to pull the nose down, and so the tail up.

Will Fraser
14th Jul 2009, 15:46
Then there's the off chance that was full reverse thrust without first selecting reverse thrust.

Chuck Canuck
15th Jul 2009, 06:53
Heard this from a former colleague....line check flight of training dept honcho by a check airman who was also under audit by a foreign auditor. So checkee was pretty nervous in gusty X-winds, landed with a little skip, selected reverse and neutralise controls...aircraft did a little skip and checkee decided to go around.....attempted to rotate but could not engage TOGA as reversers unlocked; so tail strike!!! All told, bad training by Alteon gets bad results!!

Noddys car
15th Jul 2009, 10:15
http://img193.imageshack.us/img193/7917/img00031veh.jpg

54fighting
15th Jul 2009, 11:44
Foreign Auditor probably will catch the blame for creating a bad "aura".
Pretty impressive show by a "training dept. honcho," pull reverse then go-around attempt. Any clown with a korean air farce connection can get that training department gig.
Go around attempt after pulling reverse also happened not to long ago on a KAL A300 at Gimpo Airport, with a predictable tail strike....but that one got airborne again. That particular flight was a case study in ground school. Guess someone was sleepy at his groundschool, but then again a trainer probably should've known that call, a long time ago.......When will these guys ever learn ???

BRE
15th Jul 2009, 12:54
Interestingly, neither this one nor the Airbus tailstrike have made it into ASN database. Got a link on the Airbus?

jimjim1
15th Jul 2009, 14:10
Seems to me that journalists producing material for UK audiences now seem to use kilometers an hour in many cases. I presume the idea is to confuse people into thinking that the event was more dramatic than it in fact was.

Some success in this case anyway. Got the 15% nautical bonus too.

What does the panel think is the next "more dramatic unit of speed" that our friends will come up with?

lomapaseo
15th Jul 2009, 14:20
What does the panel think is the next "more dramatic unit of speed" that our friends will come up with?

furlongs per fortnight?

Molokai
27th Jul 2009, 23:52
Chuck CanuckHeard this from a former colleague....line check flight of training dept honcho by a check airman who was also under audit by a foreign auditor. So checkee was pretty nervous in gusty X-winds, landed with a little skip, selected reverse and neutralise controls...aircraft did a little skip and checkee decided to go around.....attempted to rotate but could not engage TOGA as reversers unlocked; so tail strike!!! All told, bad training by Alteon gets bad results!!

Got comfirmation that it was a botched attempt at aborting the landing; apparently the 2 jump seat occupants who were checking the PF screammed to him to " abort " the abort landing attempt as the thrust reversers were already deployed......unfortunately, he had already started the pitch up maneuver, leading to tailstrike. A bad day.......

HeadingSouth
28th Jul 2009, 09:06
so assuming the TOGA story hits:

- They were on approach in gusty crosswinds
- landed accordingly (plane needs wheels firmly on ground to deploy thurst reversers) within the touchdown zone (?)
- thrust reversers out
- folks screaming "go around" after (what I presume is) a "smooth" landing
- PF hits TOGA (for whatever reason apart from jumpseat screaming ?)
- Tailstrike occurred ?

Re-read the occurrences mentioned by the two previous posters and now I can follow :-)

extreme P
7th Aug 2009, 19:03
11 knots crosswind is what created this drama. Choose your carrier carefully.

Paradise Lost
7th Aug 2009, 21:45
Yes, they couldn't possibly be doing anything as simple as converting to metric (the standard units in UK education for decades) or giving people a unit more familiar than knots, could they?
Yep, they could have converted it into m/sec too, but despite rumours to the contrary, there are still a vast proportion of the population who understand imperial measurements, and prefer their use when appropriate....as in aviation or shipping!

411A
8th Aug 2009, 02:10
Surely reverse thrust should tend to pull the nose down, and so the tail up.

LOL....you might think so, however on some types , selecting agressive reverse definitely does result in a nose-up moment....easily corrected by straightarming the column.

totempole
9th Aug 2009, 11:10
According to a friend who had been in KAL, Alteon instructors had been training KAL B773 pilots with flawed cross wind landing techniques! They only emphasised the decrabbing method at flare or about 100' AGL...this is not an exact science especially in strong gusty and variable crosswinds. The decrabbing causes significant high descent rate coupled with automatic retardation of the thrust levers by the autothrottle invariably results in heavy landing strut compression which can be misinterpreted as a bounce, hence the botched attempt to reject the landing. Most of the older Alteon instrucors/checkers have never physically flown a B777 and think that the simulator ( which has plenty of nonsensical bugs anyway ) has the perfect fidelity to behave exactly as the real aircraft.

CDRW
9th Aug 2009, 14:10
Totempole - are you saying that the Alteon instructors should have been teaching that awful crosswind method known as wing down?? Been on the 767 for 10 years, the 777 for nigh on 8 and have only ever used the decrab method, and have never had what you described. This method is FAR better than the wing down crosscontrolled method.

cactusbusdrvr
11th Aug 2009, 05:07
Yeah, I have never heard of using a cross controlled X-wind technique in a large transport catagory jet. You will certainly come close to scraping a wingtip or an engine pod on a 4 engine jet. I had a F/O pull one on me a while ago and it was not only uncomfortable , he still landed with the nose canted off the centerline before he derotated the nose. His abrupt rudder movement to straighten the nose just added to the lack of control he showed.
Use rudder to decrab and lower the upwind wing a little to touchdown on the upwind main, then fly the other side and then the nose down. It does not have to be dramatic.

canadair
11th Aug 2009, 05:52
well, then again, qouted in MPS, Kts, KPH, FPM, or the beaufort scale, wind is wind, and its effect is only truly understood when you look at the runway out the window, whichever window you need to look out to see it, (LH side, fronts, RH side)
Before that, you saw what correction you needed to hold the loc, but thats heading.
Visual is when you know the wind, by effect, and what you previously heard it in is now insignificant,

adjust accordingly.
Thats why they give us a really big rudder or two, and ailerons.

I am constantly amused when I go to certain UK airports, and on a gusty day the controller insists on giving us a running commentary of spot winds, what do they think we do with this updating info?
(no offense to controllers, I know you are only trying to help)

aguadalte
11th Aug 2009, 11:55
Use rudder to decrab and lower the upwind wing a little to touchdown on the upwind main, then fly the other side and then the nose down. It does not have to be dramatic.Agree...
Here's an example:
http://thumb18.webshots.net/t/55/555/8/84/56/2804884560105458118pRfSmQ_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/74/174/4/92/66/2102492660105458118crWTQs_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/74/174/5/35/28/2902535280105458118MPOihf_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/96/96/6/79/48/2233679480105458118ALvuCl_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/55/555/3/30/35/2168330350105458118FxPCEf_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/96/96/0/79/38/2593079380105458118IyTqZs_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/74/174/7/29/68/2059729680105458118RVWxFX_th.jpg (http://www.pprune.org/%3Ca%20href=)
http://thumb18.webshots.net/t/75/175/8/83/82/2203883820105458118VvsZwZ_th.jpg (http://www.pprune.org/%3Ca%20href=)
Photos by J. Sequeira (Azores)

filejw
11th Aug 2009, 14:15
And if you are on the money you don't have to fly the other wing down..LOL.... this is really the best way to land a large jet.

Tote ..You may get better results by turning off the A/T in gusty xross wind.

A-V-8R
11th Aug 2009, 15:01
So right you are, Filew....

Can't count the number of times I've climbed the stairs at the Narita View with a bottle of Jack Daniels to watch people try to land in the fall and spring winds....

Autothrottles really hinder in gusty conditions. Speed goes low, Autothrottles spool up and nose pitches up, speed goes low, nose pitches down.

Better to turn them off and maintain one throttle setting that works, let the gusts average out.

PJ2
11th Aug 2009, 16:22
411a;

Quote:
Surely reverse thrust should tend to pull the nose down, and so the tail up.
LOL....you might think so, however on some types , selecting agressive reverse definitely does result in a nose-up moment....easily corrected by straightarming the column.
The L1011-500 was particularly susceptible to this if you grabbed a mit-full of reverse, especially as the speed and stabilizer effectiveness reduced. The solution was of course, as you say, obviously done with care. The FCOMs had very clear cautions on reverse thrust selection as well as the effect of spoiler deployment but seasoned crews understood the dynamics.

One had/has to be careful with the B767-300 to ensure the nosewheel didn't slam down in an over-aggressive response to spoiler deployment followed by a handful of reverse, however. The phenomena is known and has damaged more than one airplane.

There's nothing sweeter in flying than a well-executed, pretty crosswind landing.

aquadalte, great photos.

JammedStab
12th Aug 2009, 00:04
Totempole - are you saying that the Alteon instructors should have been teaching that awful crosswind method known as wing down?? Been on the 767 for 10 years, the 777 for nigh on 8 and have only ever used the decrab method, and have never had what you described. This method is FAR better than the wing down crosscontrolled method.

Was trained on the 727-200 to use the wing down method. Works fine much of the time. The book says to lower the wing into the wind at 300 feet. I add some power at the same time as you will lose some speed.

Our ops manual for the aircraft has a table which I assume comes from Boeing that lists Max crosswind for no crab. It is 24 knots at max landing weight of 164,000lbs. 20 knots at 120,000 lbs.

fdr
12th Aug 2009, 01:11
As always there are various methods to skin a cat. While wing down/cross controlled works fine in a Cessna/Piper or similar, and various straight winged large planes, it has issues when applied to a swept wing aircraft.

Wing down can be flown by a competent pilot on most aircraft. On the A320/330/340 etc it is not the recommended method due to the interaction of the roll control laws. (AI test pilot comment on matter: "Why would you want to do that?" (in French accent).

The application of cross control on the swept wing jet, based on flight data, shows positive correlation with Euler angle instability in roll/pitch/yaw, randomised rudder inputs resulting in roll deviations, and variations in total drag, causing airspeed variation, requiring compensation in thrust, causing changing thrust/pitch couples and flight path instability from the trim change and speed stability for the off speed conditions. The most significant factor isolated in analysis if stability on approach was the activity of the rudder; the tracking task requires changes in the rudder angle, which results in a lag before roll occurs (which is a variable lag dependent on aoa amongst other issues). In almost 50% of the cases examined where cross control was applied, the aircraft resulted in a forward slip that was pilot induced due to excessive rudder application, and resulted in high lateral loads on the gear axles.

In comparison, an approach flown does into the flare in crab has effectively no crosswind issue to deal with until the decrab is initiated, which can be after the flare has been initiated and developed. The tracking task is simplified to roll control only to adjust the track to maintain the centreline, which is an everyday tracking task. Once in the flare, the nose can be accurately yawed to align to the centreline or runway QDM visually, using very large visual cues. The associated roll lags slightly and is offset by aileron as required.

2 cases may occur to confound the above; floating or wind change around the flare changing drift. In both cases the aircraft can either be landed with drift on, (all planes can do that) if required to maintain the lateral landing zone of the runway, or can have slight into wind roll applied to minimise downwind drift.

Horses for courses; every pilot I know is the worlds best, (with every fighter pilot being the best of the best of the best) so this doesn't apply to anyone other than.... me, naturally. Unfortunately, from a systems reliability view, we work with the lowest competency that is acceptable to the system on the worst day, which is obviously no one who is reading this post.

As far as this threads topic of tail skid adjustment is concerned, as has been mentioned previously the crosswind was hardly a big deal, so any issues that are apparent have little to do with crosswind. With respect, this is not the first tail strike of a geometry limited design; I have personally watched 4 in the last 30 years (none were Asian carriers) while waiting at the holding point. The neatest was a US carrier B757-200 where the APU touched down before the main gear on a calm day.

The majority of pod scrapes, and high lateral g landings I have had to look at in the past have been related to poorly conducted cross control approaches. This doesn't mean you cannot do it, it just intimates that occasionally it is not done very well.

As far as landing on a single wheel, while the CS25 requires a single wheel touchdown load analysis to be conducted by the manufacturer, 14 CFR Part 25 does not. Boeing however does assess the structural load as such. ( At least one other manufacturer didn't...)

Alteon (Boeing) generally teaches what the customer has requested, if it is within the discretionary bounds of operational technique.

Final thought: if you really wish to persist with crossing controls on a swept wing jet, for those who have spoilers incorporated for supplementary or primary roll control, have you thought of what your stall speed becomes when you are in unbalanced flight, with spoilers up on a single wing? I lost a friend in such a case, along with the whole crew when they unfortunately found the answer at 5000' agl.

Warm Springs, GA

totempole
12th Aug 2009, 02:04
Typical quick draw Mcgraws........I have not advocated cross controls all the way to touchdowns! By all means crab all the way ( that's what I do ) to about 100 feet, then ease on the downwind rudder to decrab but ease the upwind down. In very strong gusty/variable crosswinds, it would be prudent to keep some crab and straighten on the runway....you will get some uncomfortable " twisting sensation " but no harm. You have to understand the B777 have a long wheel truck but aft steerable wheels ( which touches downfirst ), so this " twisting sensation " is just the mechanics of the aircraft forward inertia/momentum at work. Non B777 qualified instructors misinterpret this as hard landing with residual drift. The autopilot touches down in crosswinds in this fashion.

I have seen people decrabbing fully on flare only to overcontrol with upwind wings lifted up or have the aircraft with one wheel truck bearing the full weight for extended periods due to too much into wind control inputs due to abrupt last minute decrab at flare.

fdr
12th Aug 2009, 05:18
the B777 has a couple of very minor unusual crosswind characteristics:

Both 200 & 300 in a strong crosswind will (without rudder input) will initially diverge track towards the downwind side... up to approximately 60kts, thereafter the aircraft will start to diverge track towards the windward side of the runway. The B747/744/757/767, MD11, A300, A320, A330 and A340 don't do this... The -200 simulator does replicate this characteristic.

The B777-300 in a strong crosswind, above 35kts component, when doing a decrab, the cockpit (pilot eye) lateral position relative to the runway does not move downwind, the gear position shifts upwind. A B747/744 or B767 does the opposite, as do long body Airbus', the pilot eye position moves downwind, and the gear position remains fairly constant in relationship to the runway centerline. -200 simulator doesn't do this, nor does the plane, -300 simulator unknown.

In respect to the lateral forces on touchdown, the aircraft acts as a normal plane with the cg forward of the gear, and will align fairly tidily with the aircraft track as a natural dynamic. The lateral load at touchdown is quite high in such a case, landing with full decrab, but if the pilot has applied a yaw input prior to the touch, it makes a significant reduction to the peak lateral g recorded and felt in the aircraft. As long as the yaw rate has been initiated, there is a lessening of the peak acceleration going from no yaw* to the inertially developed rate.

A similar issue occurs in the measurement of landing g, if the data analysis is merely based on peak recorded values; the accelerometer is not at the cg, or at the centroid of all forces, and records both vertical acceleration against the fixed body axis, and also the rotation of the body. So a late flare will result in additive accelerations being measured, that of the pitch rate and the gear rebound. (simplistically). The -300 accelerometer is... almost exactly the fuselage plug size forward of the -200's (surprising as the location is determined normally by analysis of the natural fuselage harmonic node locations, and is located at or near a node...) and the screening value for hard landings where applied is about 0.2g higher as a result to give rational data. Same issue apples for the lateral g sensing.

In relation to the simulator fidelity in general, the landing phase is not a bad representation at all, and is required by existing MOS to be valid. The values of almost all parameters of static and dynamics is in the the region of no more than 10% (very simplistically) from flight data, and the time transport delays are pretty small. The simulator problems of fidelity should (if the sim is being maintained with any semblance of quality assurance) only be significant outside of the normal operational envelope. Within the envelope the data has to have been either recorded or modeled for validation. The biggest problem is wherever the operation encounters non linear effects such as cross coupling in a stall condition.

Fidelity issues of note were a 3 holer (XXL size) fully stalled at 630,000 climbing at 6000 FPM, with 186,000 lbs of thrust installed, small twin jet stalled with full rudder applied, and ailerons controlling the roll comfortably (accident data shows same aircraft condition cross coupling with a roll rate in excess of 180 degrees a second). Latter case dynamics are now updated, finally, and may be more representative of reality, an off center axis entry into the microburst model will result in departure if the plane is stalled while at a high yaw rate due to the microburst. (now crew occasionally complain about the "unreasonable" handling of the simulator in this situation). A related issue that was noted on a series of sims evaluated a few years ago was that out of wind aileron did non give any roll effect in crosswinds up to 50kts, until the nose wheel was lifted off the ground, then it made quite a difference. In this case there are aerodynamic and geometry issues that effect the roll authority at low angels of attack, but there was no discernible effect identified by the meta centric height at any of the gear. Flight data showed that real planes do notice aileron input and crosswind effects, particularly swept wing aircraft.

The NRT thread says more about things unrelated to crosswinds, and if recent mutterings from Randy Babbitt are valid, are not isolated geograpically, but are an indication of global systemic malaise.

Warm Springs, GA

BeechNut
12th Aug 2009, 14:44
As always there are various methods to skin a cat. While wing down/cross controlled works fine in a Cessna/Piper or similar, and various straight winged large planes, it has issues when applied to a swept wing aircraft.

Spam can driver here... interestingly even in the spam can crowd there are differences. I have flown and owned Cessnas, Pipers and Beechcfrafts.

I currently own an (aerobatic) Beech Sundowner 180. The Cessna (a 150) worked just fine with the wing-low method. My Cherokee managed it OK as well. But my current Beech doesn't do so well with that method. The cross-control creates a lot of drag, and in gusty conditions juggling the power, amount of rudder, and aileron makes for an unstabilized approach. Like you big boys, this is a plane that does best with a stabilized approach with speed nailed right on 80 knots (flapless or 1 notch), 75 knots (2nd notch of flaps) or 70 knots (full flaps). It's a plane that has a "reputation" of biting on landing with porpoising, and tight speed control is the antidote to this. The one-wing-low method makes this very difficult to achieve and results in very sloppy x-wind landings.

So my x-wind method is to crab it down all the way into the flare and then straighten with rudder, adding a touch of in-wind aileron and downwind rudder to land on the upwind main first.

It gives a very nice chirp-chirp-chirp every time, very elegant and using this method it is very easy to control even at the max demonstrated 17 kt crosswind limit (and beyond if you get it right). I've impressed many a flying buddy with this method, but the reality is that the very responsive roll rate of the Sundowner deserves most of the credit! Working in this manner, I have never been "bitten" by a impending series of pilot-induced oscillations.

Beech

gleneagles
12th Aug 2009, 22:30
Wow, fdr....impressive but my gyros toppled in the midst of reading it. What totempole had described, I have seen it happened. Me thinks the easiest approach would be to do like what the autopilot do in a crosswind approach and landing to touchdown.

The KAL B773 NRT incident was exacerbated by the airline's recent emphasis on " reactive " simulator training requiring bounced landing recovery. Just because other fleets ( A330, B737, B744 and A300-600 ) had many incidences of botched bounced landings, the smart asses made it compulsory for all fleets to practise bounced landing recovery......sometimes with the unfortunate overemphasis. As far as I have experienced on the B777 for the last decade, it is extremely hard to bounce. The recent sim training must have contributed to the PF's misdiagnosing gear strut compression as a bounce.

JammedStab
12th Aug 2009, 23:32
Final thought: if you really wish to persist with crossing controls on a swept wing jet, for those who have spoilers incorporated for supplementary or primary roll control, have you thought of what your stall speed becomes when you are in unbalanced flight, with spoilers up on a single wing? I lost a friend in such a case, along with the whole crew when they unfortunately found the answer at 5000' agl.



Can't say that I have thought about it. But it seems to work, so I guess Boeing did think about it.

What happened to the crew at 5,000 feet?

fdr
13th Aug 2009, 02:28
the aircraft stalled approximately 50kts above Vs1.0g speed. The resulting rotation rate was sufficient to throw an outboard engine off the pylon.
Splash,
grief,
flowers,
eulogies etc.

This was an extreme case, as it occurred in a VMCA demonstration with rudder boost off, but the physics remains, high beta angles, and spoiler rise results in an elevated stall speedparticularly on a swept wing. If trying to maintain a total lift evel such as in level flight, or a constant flight path, then the aoa is increased. Recently listened to a qualified & experienced group of crew discussing the IAS bands on a B744 with speedbrake raised, comment was that the increased indication is "just a glitch in the display...". Really?

Being out of balance wil increase the stall speed where spoilers are used for roll control. Using speedbrake will for a 1.0g condition increase stall speed. The amounts are dependent on the aircraft design.

Willoz269
13th Aug 2009, 03:01
A few examples of Croswind landings at NRT...all footage taken on the SAME DAY allowing for comparison of technique and aircraft performance...

An ANA 777

YouTube - Crosswind Landing - by All Nippon Airways (ANA) Boeing 777-200ER ?JA717A? (http://www.youtube.com/watch?v=sJko7mAedBU)

An MAS 777

YouTube - Crosswind Landing - by Malaysia Airlines Boeing 777-200ER ?9M-MRJ? (http://www.youtube.com/watch?v=lhnrjDiNNVU)

A QF A330

YouTube - Crosswind Landing - by Qantas Airbus A330-300 ?VH-QPG? (http://www.youtube.com/watch?v=PatP3YEVj1Y)

A FEDEX MD11

YouTube - Crosswind Landing - by FedEx Express McDonnell Douglas MD-11(F) ?N587FE? (http://www.youtube.com/watch?v=gWZzxqQMoro)

An SIA A380

YouTube - [720p] Crosswind Landing - by Singapore Airlines Airbus A380-800 ?9V-SKD? (http://www.youtube.com/watch?v=lcHmgHFZFNw)

An AF 747

YouTube - [720p] Hard Landing!! @ Narita - by Air France Cargo Boeing 747-400ERF ?F-GIUC? (http://www.youtube.com/watch?v=VXUs-712PF0)

FullWings
13th Aug 2009, 06:22
fdr
The B777-300 in a strong crosswind, above 35kts component, when doing a decrab, the cockpit (pilot eye) lateral position relative to the runway does not move downwind, the gear position shifts upwind.
Having only flown the -200, I'll take your word for it but I'm interested in the physics of it... From the description, it sounds like the CG rotates around the nose of the 'plane rather than the other way round as per normal aircraft. Are Boeing using some sort of exotic matter to build the -300? ;)

I'm approaching 5 digits of flying time on the 777 and, like gleneagles, would say that aping what the autopilot does is not a bad place to start. I've witnessed many different approaches to the problem, some of which resulted in valid solutions!

As an aside, the proponents of decrab vs. wing down usually demonstrate what I call the "very late wing down" technique...

HarryMann
13th Aug 2009, 14:17
From the description, it sounds like the CG rotates around the nose of the 'plane rather than the other way round as per normal aircraft. Are Boeing using some sort of exotic matter to build the -300? :):):)

I imagine it's a case of inertial Vs aero forces dominating the movement... if the resistive forces to slow(er) movements are dominated by aero forces the overall aero centres move the effective 'hinge' - in this case the fuselage yaw centre, fwd of the c.g.
If only a nosewheel is on the ground then it's not hard to picture this as the pont where rotation might be centred due to it's lateral friction, regardless of the c.g.

411A
13th Aug 2009, 14:30
This was an extreme case, as it occurred in a VMCA demonstration with rudder boost off, but the physics remains, high beta angles, and spoiler rise results in an elevated stall speedparticularly on a swept wing.

Hmmm, sounds like the RAAF 707...bad news (as they found out) if tried.

PJ2
13th Aug 2009, 16:54
HarryMann;
If only a nosewheel is on the ground then it's not hard to picture this as the pont where rotation might be centred due to it's lateral friction, regardless of the c.g.
Regarding "inertial" vs "aero" forces, were you thinking solely of the above case, "only a nosewheel on the ground"? While I'm trying to picture the dynamics you describe for an aircraft in the air, I can't imagine where any transport would be only on the nosewheel, "about which the airplane would pivot", so I'm sure I'm misunderstanding what you mean.

fdr;
This may be "off-thread" but the thread has wandered anyway so I will risk it in favour of understanding.

While your comments were a good read, I'm still puzzling over the dynamics that you describe thus:

The B777-300 in a strong crosswind, above 35kts component, when doing a decrab, the cockpit (pilot eye) lateral position relative to the runway does not move downwind, the gear position shifts upwind. A B747/744 or B767 does the opposite, as do long body Airbus', the pilot eye position moves downwind, and the gear position remains fairly constant in relationship to the runway centerline. -200 simulator doesn't do this, nor does the plane, -300 simulator unknown.

Landing the DC8-61 and 63 series aircraft on US runways (150' wide, Canada's and the ones used in Europe were 200' wide), in a heavy crosswind meant that one placed the cockpit slightly on the upwind side of the centerline so that the gear was on the centerline at touchdown.

A de-crabbing of a long fuselage meant either the cockpit was on centerline and the gear was off the centerline on the downwind side, or the cockpit was flown slightly upwind of the extended centerline to place the gear on the centerline. I would have thought this was well understood on even longer aircraft such as the B777-300 and A340-600 but you say these two aircraft, for example, behave exactly opposite to one another in very high crosswinds. One decrabs "at the cockpit" and the other "at the center of gravity", roughly. I'm trying to understand how.

I can see, given the mass involved, that the pivot may shift slightly due to the effects of the crosswind upon the fuselage's length but it seems that this would apply uniformly over all types.

I'm also still trying to understand the following comment from fdr and hope perhaps a more detailed explanation might be offered. Not doubting, yet, but trying to imagine the dynamics and "why?" For me, it makes no sense at all but I'm suspending judgement in favour of curiosity:
Both 200 & 300 in a strong crosswind will (without rudder input) will initially diverge track towards the downwind side... up to approximately 60kts, thereafter the aircraft will start to diverge track towards the windward side of the runway. The B747/744/757/767, MD11, A300, A320, A330 and A340 don't do this... The -200 simulator does replicate this characteristic.

Regarding the vertical 'g' parameter for the B777 and your comment:
A similar issue occurs in the measurement of landing g, if the data analysis is merely based on peak recorded values; the accelerometer is not at the cg, or at the centroid of all forces, and records both vertical acceleration against the fixed body axis, and also the rotation of the body. So a late flare will result in additive accelerations being measured, that of the pitch rate and the gear rebound. (simplistically). The -300 accelerometer is... almost exactly the fuselage plug size forward of the -200's (surprising as the location is determined normally by analysis of the natural fuselage harmonic node locations, and is located at or near a node...) and the screening value for hard landings where applied is about 0.2g higher as a result to give rational data. Same issue apples for the lateral g sensing.
A UDRI, (University of Dayton Research Institute) paper for the FAA entitled, Statistical Loads Data for the Boeing 777-200ER Aircraft in Commercial Operations (http://www.tc.faa.gov/its/worldpac/techrpt/ar06-11.pdf), discusses these factors at length. The paper also discusses, as do your comments, the variability of the vertical loads accelerometer. In fact we noticed early on that the B777-300 and -200 series vertical acceleration parameter was unreliable, tending to be "spikey", triggering many false "hard landing" events. Here are the comments from the FAA document.

The installation of acceleration sensors in the cockpit rather than near the center of gravity is a deviation, albeit approved by the appropriate airworthiness authorities, from the Federal Aviation Regulation specifications. The transfer functions and filtering techniques used in the transfer of the sensed accelerations at the cockpit to those expected at the center of gravity are oriented towards flight conditions. As a result, the aircraft dynamics experienced during landing conditions are not properly accounted for and the recorded accelerations for these conditions will include unknown errors. These errors were clearly manifested in the vertical and lateral load factors recorded for the touchdown condition when comparing the B-777-200ER load factors with those of other aircraft. This is of particular concern if vertical load factors recorded during touchdown were to be used by the airlines for routine hard landings identification or by the National Transportation Safety Board in landing accident investigations. In such cases, the use of the recorded values would be very questionable. It is recommended that a task be considered that will install a center of gravity accelerometer in one airplane and record both the converted and direct measured accelerations to determine the extent of the differences that may exist. Perhaps some airline might be willing to consider such a task on one airplane for a few hundred hours to at the very least resolve any hard landing concerns.

The B777 AMM states quite clearly at the beginning of the hard landing check, that unless the pilot reports the landing as hard, it didn't happen and no maintenance inspection will take place. The inspection procedure then goes on to outline the 'g' limits requiring different inspection levels. The 'g' limits change according to roll angle and samples per second, (8x or 16x - ours were 10x).

My main question is about the de-crabbing phenomenon you describe and how it happens. Thanks fdr.

punkalouver
14th Aug 2009, 14:16
An AF 747

YouTube - [720p] Hard Landing!! @ Narita - by Air France Cargo Boeing 747-400ERF ?F-GIUC? (http://www.youtube.com/watch?v=VXUs-712PF0)

Looks to me like most of the spoilers on the left wing didn't deploy after touchdown(anyone know why) and he might have come close to scraping an engine pod.

aguadalte
14th Aug 2009, 15:07
Looks to me like most of the spoilers on the left wing didn't deploy after touchdown(anyone know why) and he might have come close to scraping an engine pod.

(Not a 74 driver) I've noticed that too, punkalouver. Could it be because the pilot applied full right yoke? (during the roll out, after touch down.)

PJ2
14th Aug 2009, 18:16
aquadalte;
Could it be because the pilot applied full right yoke? (during the roll out, after touch down.)
That is precisely why all the spoilers except for the one ground spoiler on the left wing are down; they are responding as ordered, with right full control wheel. Notice how deeply the right wing dips at touchdown as the right wing spoilers come up - the left wing is still flying - exactly the opposite outcome intended by the use of full-right control wheel, (which is, "keep the upwind wing from rising"). The engine comes very close to the runway. The left spoilers slowly come up near the end of the landing roll as the wheel is neutralized.

A-V-8R
14th Aug 2009, 20:08
Can't speak for other airlines, but my flight manual (B-777) says to to forward slip up to 31 knots crosswind component, and use a combination of crab/slip up to 45 knots crosswind componet, lining up on the upwind runway edge lights.

Always fun to watch the First Officers face.

When you kick out of the crab/slip, the airplane lands on the centerline.

Be that as it may, I have been flying in and out of Narita since 1988. Narita can have the worse oreographic turbulence landing on 16 that I have ever encountered.

Usually approaches to NRT are smooth (laminar air) until the last 300 feet if there is a strong crosswind. Then all hell breaks loose.

Never did like golf or golf courses, even though I live on one. For those of you that don't know, there is an undulating golf course right next to the NRT airport. Source of oreographic turbulence.

Uncle Fred
14th Aug 2009, 21:36
Is it not "orographic" turblulence that you meant instead of "oreographic?"

I thought that the latter came in both a regular and a double stuff variety and were best ingested when in need of a serious amount of sugar.

JMHO but the last thing I would be looking at when solving the drift/crab/slip equation during a 40K landing in the flare would be the other pilot's face!http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/eek.gif

A-V-8R
15th Aug 2009, 02:08
"JMHO but the last thing I would be looking at when solving the drift/crab/slip equation during a 40K landing in the flare would be the other pilot's face! "

It's an art form, not a science.

I've been flying for the airlines since 1972.

You'd be surprised at what First Officers have taught this Captain.

Never a day goes by when I don't learn something. I turn 60 this year, and it will be my final day of flying.

After 2 August 2010, look for me in Nha Trang, Vietnam. If I'm not in my Condo on the beach, look for me at the Microbrewery south of town.

It will be easy to pick me out. Unlike the Russians, I don't smell bad nor do I smoke. And the woman with me will not have a mustache.

fullforward
15th Aug 2009, 18:17
Hey AV8!

Well put, you're a hell of guy.
It would be great to share a beer with you, learning from your histories and vast knowledge.
Nice to know your preserve your humbleness.

Kudos, buddy!:ok:

Amstrong
15th Aug 2009, 22:42
Can someone pls comment and/or explain why there is only the right wing spoilers that kicks in at touchdown of the Air-France B74F in NRT from the link posted by Willoz ? Strangly the left wing spoilers seems to extend fully only way down the runway (1'38'')

Link again : http://http://www.youtube.com/watch?v=VXUs-712PF0

411A
16th Aug 2009, 18:17
Be that as it may, I have been flying in and out of Narita since 1988. Narita can have the worse oreographic turbulence landing on 16 that I have ever encountered.


Yup, true enough...and I flew out of Narita since the days it opened, long ago.

Just a thought to those who suggest copying what the Autoland crosswind technique is, on my types the Autoland crosswind limit is about half of that for a manual landing suggesting that maybe the Autoland technique may not be appropriate at the higher crosswind components.

Not on the L1011 it isn't...a superior design, straight from the factory.:ok:
Think otherwise?
Just ask the folks that fly this truly remarkable airplane....still.:)
My present First Officer has flown both the L10 and the A320 extensively...he knows the difference...and according to him, the L1011 is far superior in both automatic and manual crosswind adaptability.

And, why not...it's a Lockheed design.:)

With the L1011, four spoiler panels on each wing extend fully when landing, panels 5&6 are used for roll control, throughout the landing maneuver.
A well thought out arrangement.:ok:

Scratch Pad
16th Aug 2009, 18:25
Yeah, yeah, yeah, we know. If you don't tell us in every post how good you are it's the L1011. It's like listening to a stuck record :rolleyes:

411A
16th Aug 2009, 18:32
Yeah, yeah, yeah, we know. If you don't tell us in every post how good you are it's the L1011. It's like listening to a stuck record

Tain't just me, Scratch Pad, average pilots have the same result.
A superb design that makes average pilots perform like an ace...everytime.
Yes, the design is really old, but superb nevertheless.

Scratch Pad
16th Aug 2009, 19:12
Tain't just me, Scratch Pad, average pilots have the same result.

Now there's a telling statement :rolleyes:

PJ2
16th Aug 2009, 19:29
Scratchpad;

It may sound like a broken record and 411a may not have to deal with the industry on the same basis as most of us do where we have permitted the Lorenzo's, Icahn's and Crandall's and their collective use of de-regulation to destroy this profession. We may not see what we want to see from 411a in CRM-ish responses or the silly abiding respect for bluster and blather we often see elsewhere, but 411a speaks the truth about the airplane and about the requirement for original high level of skill, experience and dedication to high standards and a constant learning of one's craft regardless of source or if one is paid-to-learn.

I suspect the piss-off is, all seasoned veterans already know all this intuitively and properly hate to be mothered or "told"; we also know that bragging in aviation is a dangerous thing an react poorly to it and so we should. Once in a while we hear CEOs stupid enough to brag to the world that their airline is the "safest in the world" - it broadcasts a huge ignorance about the business.

I've got lots of time in Lockeed, Airbus, Boeing and Douglas equipment and hands-down the L1011-500 is the finest airliner ever built. Doesn't mean the rest don't do the job really well but the airplane is a pilots' airplane. Expensive to maintain, with higher burns than the 330/340 it wasn't the success it ought to have been especially against the MD Death Star but that's politics, economics and a bit of ethics, not design.

Flintstone
16th Aug 2009, 19:39
Think you might be missing Scratchpad's point here PJ2 and if we're talking CRM then 411's statement distancing himself from "average" pilots rings alarm bells. I'm sure I'm about to be told how wrong I am though :hmm:

PJ2
17th Aug 2009, 00:13
Oh I get the point. There's just no percentage in arguing it. Arrogance is as arrogance does. But the Lockheed is one beautiful aircraft...right from the factory.

411A
17th Aug 2009, 00:45
...rings alarm bells.

Can't imagine why.
I personally have a slight advantage, as I was originally trained onto 4-engine heavy jets by....PanAmerican.
Finest training I have personally ever received, bar none.

Also, there was none of this 'CRM' nonsense back then.
We had something far better, it was called crew co-ordination'.

Worked far better than the psycho-babble baloney we hear nowadays.:}

pilotbear
19th Aug 2009, 09:36
'Crew co-ordination'
now reasoning for your anti-CRM is starting to make some sense. The Captain is still in charge as the responsibility is his/hers. How can a 'junior' develop the respect, aspirations and desire to absorb and learn from the 'Senior' when all you gain in the modern CRM world once in the left seat is the blame when it goes wrong.
There has to be a leader, democracy does not work:E