LH A320 rejected landing in Hamburg
#32
This has kind of been discussed ad nauseum already:
http://www.airlinepilotforums.com/sh...ad.php?t=17449
http://www.airlinepilotforums.com/sh...ad.php?t=17449
#33
If you read my post I specifically mention the 767. I have never flown the 737 or the A320 so I am no were near qualified enough to speak on behalf of these airframes. Some people have stated that landing BIG jets in a crosswind is different. I am simply gave them an example of one that is not. I mentioned the other aircraft simply to show, the kid who was asking about landing big ones in crosswinds, that it can be airplane specific.
#34
On the 767 I have never seen anyone not use a normal crosswind technique. (Wing low with rudder) The only exception to this is crosswinds over 22 knots. At 22 knots crosswind it is recommended that you still use wing low with rudder but keep the nose off parallel to the centerline by a few degrees and then at touchdown bring it all the way to parallel. This should prevent a pod strike but also prevent structural damage caused by landing with a side load.
In the aircraft I fly I have been instructed to land it normal in crosswind until the crosswind component reaches 22 knots. At that point the amount of aileron required to stay on the centerline track could cause the bank angle to come close to a strike. As a result you use enough rudder to bring the nose within a couple of degrees of being parallel to centerline thus the aileron required to track the centerline will not be great enough to strike something on the ground and the amount of side load on the aircraft at touchdown will not be great enough to cause any damage to the aircraft. I'm pretty sure this is directly from the Boeing 767 manual.
Three methods of performing crosswind landings are presented. They are the touchdown in a crab, the de-crab technique (with removal of crab in flare), and the sideslip technique.
(757/767 Flight Crew Training Manual p. 4.133)
(757/767 Flight Crew Training Manual p. 4.133)
In all the Boeings I've flown, the main mounts are engineered to land in a crab up to the maximum crosswind component for landing. I'm sure this does increase tire wear, however, and doesn't make much sense under normal circumstances on a non-contaminated runway. However, the de-crab in the flare maneuver aligns the aircraft with the runway centerline just prior to touchdown and does not place side-loads on the gear and/or tires. The hard part is judging the timing, but it's not like if you land in a slight crab the main mounts are going to snap off or the tires are going to blow. (Just like you don't actually have to flare, you don't really have to de-crab either, but everyone tends to like it better when you do both, conditions permitting!)
In the E-6 (707), which is quaileman's military background as well as mine, only the first two were permitted, due to very small clearances between the inboard nacelles and the ground.
In the 747, I continued to prefer the de-crab technique, because it was what I'm used to, although cross-control landings were permitted. Same in the 767. (I do put a tiny amount of upwind aileron accompanied by downwind rudder, which is a trick an E-6 IP taught me a long time ago that works surprisingly well to dampen oscillations due to gusts and smooths out the de-crab maneuver during the flare.) However, according to the charts in the FCTM, it's impossible to strike a pod at a positive pitch angle in a Pratt- or GE-powered 767, so this is pure personal preference. Depending on the pitch angle, you could drag a tip beginning at about 12 degrees of bank. Short of that, the tailskid hits first.
This video shows Boeing's test pilots using de-crab and touchdown in crab techniques during validation testing of the 777.
So it definitely varies from aircraft to aircraft and even pilot to pilot in some cases. I'm am surprised at how many people here are so quick to decree that another pilot's crosswind technique is dead wrong when they've never actually flown the aircraft in question, and have maybe only flown one large or heavy aircraft, or even none at all!
Last edited by StripAlert; 03-03-2008 at 06:30 AM.
#35
Actually, Delta's manuals allow all three techniques for the 767.
Landing in a crab is basically discouraged on dry runways, but is always permissible up to the landing crosswind guideline of 40 kts wet or dry. "On very slippery runways, landing the airplane using crab only reduces drift toward the downwind side at touchdown, permits rapid operation of spoilers and autobrakes because all main gears touchdown simultaneously, and may reduce pilot workload since the aircraft does not have to be de-crabbed before touchdown." Sideslip only (cross-control) landings are not recommended above 28 (757) or 26 kts (767) crosswind component due to nacelle clearance.
In the E-6 (707), which is quaileman's military background as well as mine, only the first two were permitted, due to very small clearances between the inboard nacelles and the ground.
In the 747, I continued to prefer the de-crab technique, because it was what I'm used to, although cross-control landings were permitted. Same in the 767. (I do put a tiny amount of upwind aileron accompanied by downwind rudder, which is a trick an E-6 IP taught me a long time ago that works surprisingly well to dampen oscillations due to gusts and smooths out the de-crab maneuver during the flare.) However, according to the charts in the FCTM, it's impossible to strike a pod at a positive pitch angle in the 767, so this is pure personal preference. Depending on the pitch angle, you could drag a tip beginning at about 12 degrees of bank. Short of that, the tailskid hits first.
In all three aircraft, the main mounts are engineered to land in a crab up to the maximum crosswind component for landing. I'm sure this does increase tire wear, however, and doesn't make much sense under normal circumstances on a non-contaminated runway. However, the de-crab in the flare maneuver aligns the aircraft with the runway centerline just prior to touchdown and does not place side-loads on the gear and/or tires. The hard part is judging the timing, but it's not like if you land in a slight crab the main mounts are going to snap off or the tires are going to blow. (Just like you don't actually have to flare, you don't really have to de-crab either, but everyone tends to like it better when you do both, conditions permitting!)
This video shows Boeing's test pilots using de-crab and touchdown in crab techniques during validation testing of the 777.
So it definitely varies from aircraft to aircraft and even pilot to pilot in some cases. I'm am surprised at how many people here are so quick to decree that another pilot's crosswind technique is dead wrong when they've never actually flown the aircraft in question, and have maybe only flown one large or heavy aircraft, or even none at all!
Landing in a crab is basically discouraged on dry runways, but is always permissible up to the landing crosswind guideline of 40 kts wet or dry. "On very slippery runways, landing the airplane using crab only reduces drift toward the downwind side at touchdown, permits rapid operation of spoilers and autobrakes because all main gears touchdown simultaneously, and may reduce pilot workload since the aircraft does not have to be de-crabbed before touchdown." Sideslip only (cross-control) landings are not recommended above 28 (757) or 26 kts (767) crosswind component due to nacelle clearance.
In the E-6 (707), which is quaileman's military background as well as mine, only the first two were permitted, due to very small clearances between the inboard nacelles and the ground.
In the 747, I continued to prefer the de-crab technique, because it was what I'm used to, although cross-control landings were permitted. Same in the 767. (I do put a tiny amount of upwind aileron accompanied by downwind rudder, which is a trick an E-6 IP taught me a long time ago that works surprisingly well to dampen oscillations due to gusts and smooths out the de-crab maneuver during the flare.) However, according to the charts in the FCTM, it's impossible to strike a pod at a positive pitch angle in the 767, so this is pure personal preference. Depending on the pitch angle, you could drag a tip beginning at about 12 degrees of bank. Short of that, the tailskid hits first.
In all three aircraft, the main mounts are engineered to land in a crab up to the maximum crosswind component for landing. I'm sure this does increase tire wear, however, and doesn't make much sense under normal circumstances on a non-contaminated runway. However, the de-crab in the flare maneuver aligns the aircraft with the runway centerline just prior to touchdown and does not place side-loads on the gear and/or tires. The hard part is judging the timing, but it's not like if you land in a slight crab the main mounts are going to snap off or the tires are going to blow. (Just like you don't actually have to flare, you don't really have to de-crab either, but everyone tends to like it better when you do both, conditions permitting!)
This video shows Boeing's test pilots using de-crab and touchdown in crab techniques during validation testing of the 777.
So it definitely varies from aircraft to aircraft and even pilot to pilot in some cases. I'm am surprised at how many people here are so quick to decree that another pilot's crosswind technique is dead wrong when they've never actually flown the aircraft in question, and have maybe only flown one large or heavy aircraft, or even none at all!
I'm farely sure your last paragraph was not aimed at me since I never decreed another pilots post nor did I ever suggest that crosswind landings were the same for all planes. With that being said I'm pretty sure any good crosswind technique would require the pilots to be in control of their aircraft. It is hard to tell from this video if the pilots were just along for the ride or if they actually had control.
Anyway no need to split R.C.H.s here. That was one hell of a video.
#36
As for the de-crab technique not producing sideloads, I disagree. If you de-crab and only hold the wings level the aircraft will drift from upwind to downwind thus causing sideloading. Obviously if you are a hotshot and can time it perfectly every time you may not even feel the sideload when you land. [...] With all of that said, these planes are obviously designed to withstand massive amounts of side force and the crab and de-crab techniques have other advantages like you mentioned before ie.. spoilers, less workload, etc...
You pretty much covered it with the last sentence. Any remaining drift from mis-timing the de-crab is tiny in comparison to what the aircraft was designed to withstand and probably more comfortable for the passengers than spending the last minute or two of the flight wondering why they are being dumped out of their seats with the slip.
I'm farely sure your last paragraph was not aimed at me since I never decreed another pilots post nor did I ever suggest that crosswind landings were the same for all planes.
#37
If you read my post I specifically mention the 767. I have never flown the 737 or the A320 so I am no were near qualified enough to speak on behalf of these airframes. Some people have stated that landing BIG jets in a crosswind is different. I am simply gave them an example of one that is not. I mentioned the other aircraft simply to show, the kid who was asking about landing big ones in crosswinds, that it can be airplane specific.
I guess I was going a roundabout way at asking the question of whether or not having castoring main gear would have made a difference in the LH A320 landing or not.
#39
Ahhhhhh Correct technique? What part was correct? maybe the ZERO rudder use? Or perhaps the dragging of the wingtip? Maybe the go around procedure
after grinding the wing tip off?
Geez pal, You won't be "demonstrating" that technique in my cockpit.
Thanks Siskel, for your blow-by-blow of the film
Lets make sure we don't ever have to share the cockpit together
after grinding the wing tip off?
Geez pal, You won't be "demonstrating" that technique in my cockpit.
Thanks Siskel, for your blow-by-blow of the film
Lets make sure we don't ever have to share the cockpit together
#40
Read the NTSB report, winds were from the left, and shortly before TD, the stick actuator neutralized the xw controls and didn't flare....so the acft was drifing right as the left main impacted first with a significant sideways acceleration, resulting in a hard rock onto the right main, which collapsed.....not just landing in a crab.
The left main impact was just beyond the limit of 12 fps @ 12.5, the right hit @ 14.5 fps
http://www.ntsb.gov/publictn/2005/AAR0501.pdf
The left main impact was just beyond the limit of 12 fps @ 12.5, the right hit @ 14.5 fps
http://www.ntsb.gov/publictn/2005/AAR0501.pdf
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