Jumbos windy approach

[pandus13]

I drive under one of the main route/landing at ORD, and with lateral winds is a nice eye candy wonder seeing the big planes approaching the course kind of lateral (11:55 clock position) while "dancing" in the wind to keep control of the plane in the winds...

also counted 4 planes in just 5 minutes....


all the best to the unnamed pilots/flyers....

 

[The motor guy]

You have to do the same thing with boats on a crosswind

 

[IndyIan]

We sometimes stop by Pearson in Toronto and watch the planes land. Most of them now have some sort of auto steer on the back wheels so they point down the runway while the plane yaws all over the place. Often you can hear the wheels and control surfaces moving too.


I think some try to land as close to the end of the runway as is reasonable so they can turn off sooner and get to their gates?

 

[Virtus_Probi]

After my father's stroke, he was in hospital doing rehab for a few weeks before being transferred to a nursing home with rehab.
I was visiting him in the hospital one day and asked him if he got bored sitting in his bed between rehab sessions, and he told me that he kept occupied watching the traffic. I told him that the traffic on Dempster St didn't look too interesting to me (locals can probably figure out the hospital in question now), but he pointed to the sky outside his window and said, "THAT traffic!"
There was a line of planes stretching out to the limits of my vision in queue to land at ORD. It WAS pretty interesting to watch!
Unfortunately, the only rehab that ended up doing any good was for his swallowing. His right side remained mostly paralyzed and he was in a wheelchair for the rest of his life.

 

[757guy]

Originally Posted By: IndyIan
We sometimes stop by Pearson in Toronto and watch the planes land. Most of them now have some sort of auto steer on the back wheels so they point down the runway while the plane yaws all over the place. Often you can hear the wheels and control surfaces moving too.


I think some try to land as close to the end of the runway as is reasonable so they can turn off sooner and get to their gates?


No such thing as auto-steer for landing gear on commercial aircraft during landing. Your photo of the Air Canada 777 shows the main landing gear in tilted position which is done through hydraulic system pressure. A 757 will have the landing gear trucks tilted towards the rear (like the photo above) while a 767 will have the landing gear tilted forward. Why? It has to do with how the landing gear is designed to fit in the gear well after retraction. During landing in a crosswind, a pilot will remove the crab angle in the flare to align the aircraft down the runway while simultaneously dropping the upwind wing to prevent lateral drift. It is a matter of timing to coordinate the technique properly. The same thing happens during takeoff in a crosswind.

You comment about landing as close to the end of the runway is inaccurate. There are markings on the runway and we generally try to land at 1000'-1500' from the threshold. When I'm landing, I don't care about turning off early - I just want to make it a safe landing. Once cleared to land, I own the runway until I can turn off at a safe and reasonable taxi speed. The noise you hear after landing is coming from the grooved surfaces of the runway which helps drain water on wet runways allowing better stopping performance during wet weather.

Hope the information helps,

757Guy

 

[IndyIan]

I guess my eyes and memory have failed me? I'm sure though that a few of the larger aircraft were angling their main gear with the crosswind... Must've been an optical illusion but were were standing pretty much under the flight path with a strong gusty crosswind, and they were on and off the power at times. Maybe 10 deg yaw on average? It was impressive to watch from right under them anyways and you hoped they got it right! If I recall I think they were big Emirates planes and maybe some big cargo ones doing the rear gear steer, but your saying it was the up angle on a 3 long set of rear gear making it look that way?

 

[757guy]

Indylan,

There are no commercial aircraft that angle their main gear to the crosswind. None. Landing gear on all aircraft are on a fixed position aligned with the centerline of the aircraft.

A crosswind happens for 98% of every landing: The crab angle will vary with the velocity of crosswind component of the wind. The wind varies a great deal on the approach - I've seen the wind go from 55 knots at 500' to 8 knots at ground level- while changing direction. The crosswind component is really never an issue (unless it exceeds the aircraft limitation). Remember that we fly a ground track to the runway meaning we fly whatever angle it takes to fly along the extended centerline of the runway. As we begin the flare, we will use the rudder and ailerons to align the centerline of the aircraft with the centerline of the runway and lower the upwind wing to remove any lateral drift caused by the crosswind component. We then land on solid - fix position - wheels. We fly the aircraft all the way to the ground. No different than a boat crossing a fast moving river - you would have to angle the boat into the current to get to a point directly across from you on the other side. If you didn't, you would end up still pointing straight ahead - just further downstream and away from intended point across the river.

Hope that explains it better,

757Guy

 

[Danno]

Originally Posted By: 757guy
Indylan,

There are no commercial aircraft that angle their main gear to the crosswind. None. Landing gear on all aircraft are on a fixed position aligned with the centerline of the aircraft.

757Guy


At the 30second mark, this 777 pilot explains how the landing gear trucks do move left and right.

And are used during taxi.

https://www.youtube.com/watch?v=oQGzAspDR-s

 

[kschachn]

Right, just during taxi. They are locked during take-off and landing and will result in an annunciation warning if they are not.

 

[Astro14]

757 guy explained it well. The wide-bodies, the 777 and 747-400 for example, have steerable main gear to reduce tire scrubbing during ground operations. Not all of the main gear caster (for example, on the 747, only the body gear steer, the wing gear are fixed, and on the 777, just the rear truck, of the three trucks, steer.

The only airplane of which I'm aware that casters the wheels in flight is the B-52. There may be others, but it's certainly not common.

As far as arrivals, well, 757guy got it again: we are looking for a safe touchdown. Period.

The runway exit plan, which includes braking action and landing distance analysis (that I now perform on EVERY landing, more on that another time) is briefed, but we don't ever land shorter than normal because, frankly, it reduces the safety margin by putting the gear, and other parts of the airplane, unreasonably close to objects on the ground. Go low on the path, land short, in San Diego, for example, and you're going to hit a building with your gear...or worse...not good...

But we are spaced closely on arrival and ATC counts on us making a reasonably quick exit from the runway to accommodate the airplane behind us. If I need the runway, I'll use it without concern about ATC's priorities, but we do try to be good users of the airport.

For example, in Dublin last weekend, I landed a 767-300 about 06:30 AM local time. "High-tempo operations in effect. All aircraft plan to exit on taxiway B6" said part of the ATIS...well, B6 is only about 6,000 feet down the roughly 8,500' runway, with a normal touchdown, that left me less than 4,000 feet to stop a 270,000 lb airplane with over 200 people on it. I did stop it (Autobrakes 4, for you 757guy...they worked great...) but my concern was a safe landing, and taking the airplane off the runway at an unsafe speed wasn't part of my plan.

We planned to accommodate ATC, and we do our best, but we will never compromise the safety of the operation to do so...

 

[757guy]

Astro14,

Flew a ferry flight MSPDTW many years ago and wanted to try Autobrakes MAX. All I can say is WOW! (We were obviously very light, but we were slowed to 80 knots before I could get my hand up to the reversers.) Brakes applied firmly and very smooth. Landed on 21R in DTW and made the 4th turnoff. Impressive indeed. It's nice to know what it will do if you ever need it!

757Guy

 

[757guy]

Danno, You are correct. Just during ground operations.

Kschachn said: "Right, just during taxi. They are locked during take-off and landing and will result in an annunciation warning if they are not."

I am very familiar with moveable gear from my 747 days. There is an annunciator that says "Gear Not Centered" while taxiing and using large tiller inputs. The 747's have pivoting center main gear to assist with cornering on tight turns during ground ops but I left it out of the conversation because I thought it might confuse the issue. Pivoting main gear are not used during landing. Pivoting gear will only unlock during large nose wheel steering tiller inputs while taxiing.

Thanks!

757Guy

 

[IndyIan]

I did some googling as well, and I guess I was just seeing things.

At certain points in this video it looks to me like the main gear wheels have turned inline with the run way, but at others it doesn't and especially when it lands its clear the wheels didn't compensate for yaw.
The odd time I will see things in reverse perspective for a while(like the land and sea sections of a tire tread reversed, which freaked me out a bit as I knew that can't be right), so maybe that's what was going on.

 

[PimTac]

Many years ago I came as a passenger on a 747 into SFO and we did the sideways thing landing on the North-South runways. Flew in and out of there many times. From the A consourse one can watch the takeoffs and landings on all 4 runways. (2x2 intersecting). The timing of ATC is something to watch.

 

[EdwardC]

Originally Posted By: Virtus_Probi
After my father's stroke, he was in hospital doing rehab for a few weeks before being transferred to a nursing home with rehab.
I was visiting him in the hospital one day and asked him if he got bored sitting in his bed between rehab sessions, and he told me that he kept occupied watching the traffic. I told him that the traffic on Dempster St didn't look too interesting to me (locals can probably figure out the hospital in question now), but he pointed to the sky outside his window and said, "THAT traffic!"
There was a line of planes stretching out to the limits of my vision in queue to land at ORD. It WAS pretty interesting to watch!
Unfortunately, the only rehab that ended up doing any good was for his swallowing. His right side remained mostly paralyzed and he was in a wheelchair for the rest of his life.


Usually stuck in traffic on 90 or 90/94, I love seeing the planes lined up for miles on a nice clear night.

For the pilots, I'm curious, I've watched youtube videos of landings in strong cross winds and as I think 757guy was describing below, right before touching the ground, the aircraft is rotated to be aligned with the runway. Is that all manually done by the pilot? Or is the computer capable of making those adjustments to the control surfaces at exactly the right time?

Another question, I apologize for the likely improper terminology, would it be possible to trim the controls (control surfaces and individual engine thrust) in a way that the aircraft fuselage stays parallel to the runway during the landing? Maybe it's a matter of how much crosswind there is? I haven't thought it through all the way, but maybe it is impossible to do all three: keep the aircraft flying parallel to the runway, keep it centered in the middle of the runway, and keep the fuselage parallel.

Originally Posted By: 757guy


As we begin the flare, we will use the rudder and ailerons to align the centerline of the aircraft with the centerline of the runway and lower the upwind wing to remove any lateral drift caused by the crosswind component. We then land on solid - fix position - wheels.

757Guy


Thanks for sharing!!

 

[757guy]

Originally Posted By: EdwardC
Originally Posted By: Virtus_Probi
After my father's stroke, he was in hospital doing rehab for a few weeks before being transferred to a nursing home with rehab.
I was visiting him in the hospital one day and asked him if he got bored sitting in his bed between rehab sessions, and he told me that he kept occupied watching the traffic. I told him that the traffic on Dempster St didn't look too interesting to me (locals can probably figure out the hospital in question now), but he pointed to the sky outside his window and said, "THAT traffic!"
There was a line of planes stretching out to the limits of my vision in queue to land at ORD. It WAS pretty interesting to watch!
Unfortunately, the only rehab that ended up doing any good was for his swallowing. His right side remained mostly paralyzed and he was in a wheelchair for the rest of his life.


Usually stuck in traffic on 90 or 90/94, I love seeing the planes lined up for miles on a nice clear night.

For the pilots, I'm curious, I've watched youtube videos of landings in strong cross winds and as I think 757guy was describing below, right before touching the ground, the aircraft is rotated to be aligned with the runway. Is that all manually done by the pilot? Or is the computer capable of making those adjustments to the control surfaces at exactly the right time?

Another question, I apologize for the likely improper terminology, would it be possible to trim the controls (control surfaces and individual engine thrust) in a way that the aircraft fuselage stays parallel to the runway during the landing? Maybe it's a matter of how much crosswind there is? I haven't thought it through all the way, but maybe it is impossible to do all three: keep the aircraft flying parallel to the runway, keep it centered in the middle of the runway, and keep the fuselage parallel.

Originally Posted By: 757guy


As we begin the flare, we will use the rudder and ailerons to align the centerline of the aircraft with the centerline of the runway and lower the upwind wing to remove any lateral drift caused by the crosswind component. We then land on solid - fix position - wheels.

757Guy


Thanks for sharing!!


EdwardC,

Crosswind landings are routine and are done without too much thought - we are manually flying and making the necessary control inputs. It's relative easy and very safe. It's possible that you could line up with the extended centerline from a considerable distance from the runway, but you would have to counteract the drift with bank angle into the wind and cross controlling the turning tendency with opposite rudder input. That maneuver is called a slip, and slips are not allowed on transport category aircraft due to various reasons like controllability, uncomfortable pitch and roll angles, and stresses on the rudder and control surfaces. There is no reason to do that when a normal crosswind landing technique works so well. It's also no exaggeration to say that I fly that airplane all the way to the gate.

Airplanes have the ability to autoland (without any manual control input on either the yoke or throttles) and will brake automatically to a full stop. An autoland with a crosswind has limitations, however the airplane will align to the runway at around 50' above touchdown, lower the upwind wing (just as it is done manually), flare, reduce power to idle, and stay on centerline until a complete stop. Works like a charm and I have done it several times during periods of extremely low visibility (300-600' forward visibility) in Seattle and Los Angeles.

Your questions concerning trim and engine adjustments to keep it aligned is not realistic. We fly a track - meaning a ground track to our intended waypoint or fix. We do that at every phase of flight including cruise, where you can have a 150 kt. left crosswind at 35,000', and the airplane will fly 5 degrees to the left to counteract the left to right crosswind. Again, think of crossing a rapid river; pointing your boat directly at a location straight across means you will drift downstream and reach a point away from your intended location. To counteract that drift, you need to adjust the angle to that you reach the proper point. It's the very same concept in airplanes.

Hope the information helps,

757Guy

 

[EdwardC]

757Guy,

Thank you for the response! Very informative and interesting, thanks for taking the time to write that up. Aviation is such a fascinating topic for me, I love all the posts from you and Astro14.

Is it the choice of the pilot to use the autoland vs. landing manually, at least, lets say, in average/good weather conditions?

Ed

 

[757guy]

Originally Posted By: EdwardC
757Guy,

Thank you for the response! Very informative and interesting, thanks for taking the time to write that up. Aviation is such a fascinating topic for me, I love all the posts from you and Astro14.

Is it the choice of the pilot to use the autoland vs. landing manually, at least, lets say, in average/good weather conditions?

Ed


EdwardC,

It is a choice, and I prefer to fly the aircraft. Nobody likes to give up a landing to the autopilot. We are occasionally asked by maintenance to perform an autoland to verify the certification of the system, but that is quite rare. We constantly train for autolandings in the simulator, so there really is no advantage do doing them while out flying the line. Sometimes when the visibility is very, very low, (zero ceiling, 300 RVR-downrange visibility) a CAT III auto land is the only option left for completing the approach. Autolandings require that the airplane, airport, and aircrew all be certified to conduct that type of approach during CAT III operations.

757Guy

 

[pandus13]

Originally Posted By: 757guy
Crosswind landings are routine and are done without too much thought - we are manually flying and making the necessary control inputs. It's relative easy and very safe.

757Guy, semi_287 and Astro14,
I know for you it is second nature
but for us 4 wheelers, the "dance of the big birds", still kind of amazing and fascinating.

LOL mention: Astro's mention in the other thread about "quite sporty"... of course with some many rocket engines under your bottom...

Thank you gentlemens for a glance in the air world...