Taxiing big planes

Tommay85

Tommay85

Well-Known Member
This is a question for anyone who flies anything excessively long.

Is it hard taxing those planes. I know the 747 is probly hard due to being 30 or 40 feet in the air. But its wheel base is only 84 feet compared to the airbus A340's 107 or the boeing 777's 102 feet. I would thing that would be worse than trying to drive a big rig in down town chicago. I know taxiways are accomadating to there turning radius but I've see many pics of those two planes turning to sharp and running off the taxiway.

Tom
 
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This is a question for anyone who flies anything excessively long.

Is it hard taxing those planes. I know the 747 is probly hard due to being 30 or 40 feet in the air. But its wheel base is only 84 feet compared to the airbus A340's 107 or the boeing 777's 102 feet. I would thing that would be worse than trying to drive a big rig in down town chicago. I know taxiways are accomadating to there turning radius but I've see many pics of those two planes turning to sharp and running off the taxiway.

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The biggest widebodies are really pushing some of the taxi way layouts. I was in SEA yesterday and had to hold while an EVA air 747-400 exited the runway on the reverse highspeed. He was really taking his time, it looked like it was a little challenging.

Whereas I can zip aorund in a 737 about anywhere it looks like, by observation, the jumbos have to take it slow and make sure to overshoot the turns by quite a bit. I believe the 777 and others may have some gear cameras. And of course the new 380 can't use most of the airports and certainly most of the taxiways in the world until they are modified.

Dave
 
Actually the A380 is only 99 feet long on the wheelbase.

Even with the cameras I think taxiing the 777 would be hard as hell.

I think I read somewhere that on the smaller airport runways, when they turn to line up on the centerline they pull straight out from the taxiway and when their seat is over the grass they push the tiller all the way to the right (or left) and they end up right on the center line.

Tom
 
Just have to be careful and think about each turn before you are committed to it. Taxi speed is a big consideration for the larger widebodies also, with sidewall and landing gear stress and heat buildup issues during taxi.
 
Boeing brought a 777 to Salina last fall to test tailwind approaches and landings. I saw them land on the runway ( at the time it was 13337 x 200). They sat there for awhile and then did a 180 on the runway and took off in the other direction. It was awesome.
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Hey Guys....I have taxied both the 767-300 and the DC-8-73...The DC-8 being uniqe as to having a "circular" steering wheel on your left and the 767 having a "Tiller".....As an Instructor on both airplanes and having taught many Captains, the guys pick it up fairly quickly!!! But as stated in your question, there can be many variables!!! The distance the nose gear is behind the crew, main gear distance, width, and of course turning radius.....When taxing a "wide body" or something as long as a DC-8 you must always think "where are my main gear tracking" and adjust your "turn point" and "turn rate" as to keep the mains tracking on the centerline...On many of your 10-9 (airport diagrams) there are notes that say"judgemental oversteering required"....There are also many notes restricting a/c due to both weight restrictions as well as wingspan rest...I hope this answers some of your questions, If you have any more just let me know............
 
haha, makes me laugh. The RJ is the biggest thing I've ever taxied. I try sometimes to do the "wide body" lineup on the end of the runway. I wait until the centerline is lined up with my shoulder and crank the tiller full to line up. I get it right about half the time- the other times I just tell my FO I'm "centerline impaired!"
 
Actually, the toughest thing to learn to do (and teach a new capt student) is getting a good alignment into the gate when the taxi distance after lineup can be just half the aircraft length or a bit less (sure LOOKS less!). Bit of an art to it, and on the MD-11 or MD-10-30 with the center gear, it's easy to see how well you did. If either tire is touching the centerline I view that as I screwed it up, personally, but takes practice and a lot of currency to get that thing perfectly centered.
 
The other problem area is speed control. I've seen a few new Capt's trying to turn off the runway after landing while still at an excessive speed. I've had the "pleasure" of sitting through more than a couple "smoking" nose gear tires as we've exited too fast. A300 is bad about that. The tower gets excited and that gets me excited!
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Sitting up high gives the illusion of taxiing at a slower speed. As visibility lowers, the illusion becomes more pronounced. The trick is to keep an eye on the IRS/GPS GS readout until getting a feel for it. Folks tend to catch on pretty fast though with few problems. Most have taxied large aircraft in a previous life and it's like riding a bike.

I agree that lining up with the gate can be one of the more challenging things to do. Got to remember you have a lot of metal following you from behind.
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You guys do have the advantage of being higher up, so you can actually see which direction the taxiway goes - we just see a plethora of asphault.

My mate always said that finding the airport 1000s of miles away was easy compared to finding the gate.
 
Well how does a "tiller" work exactly?

Is it easier to manuver an airliner around on the ground with either the tiller or rudders?

Is it common practice to taxi an airline on to the active runway when ready for takeoff with the tiller vs. the rudders.

Do you think that might lead to the pilot flying maybe forgetting to unlock the rudder on takeoff or in the air and maybe cause an accident.


Matthew
 
This is all really interesting. Thanks for the posts guys.

Do you guys have to do differential braking for really tight corners. I wouldn't think it would roll very well by its self if the nose wheel were turned all the way.

Tom
 
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Do you think that might lead to the pilot flying maybe forgetting to unlock the rudder on takeoff or in the air and maybe cause an accident.


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Checklists, but if they do 'forget' to run through the checklists it could be a potential problem.
 
There's nothing like that. You can use the tiller and the rudder at any speed, but it wouldn't be pretty if using the tiller at high speed.
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Do you think that might lead to the pilot flying maybe forgetting to unlock the rudder on takeoff or in the air and maybe cause an accident.


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Checklists, but if they do 'forget' to run through the checklists it could be a potential problem.

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Yea I thought bout checklist as well...but when i was flying outa TUS class C.

ATC in the late afternoon say bout 3pm would often give the airliners. What I refer to as a "rolling start".

By that I mean there at the end of the taxiway and turn on to the runway without stopping, power up and takeoff.

All about that fast too so it might be easy to forget to take the tiller off.

When this occurs I mostly noticed the rudder turning as the airliner entered the active .

Which just made sense prior to reading this thread and hearing that sometimes the tiller is still in use when the plane is entering the active runway and lining up with the centerline.


Matthew
 
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Well how does a "tiller" work exactly?

Is it easier to manuver an airliner around on the ground with either the tiller or rudders.

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Tiller is like the steering wheel of a car. They come in different shapes but have the same basic function. The system uses hydraulic pressure to turn the nose gear upwards of 65 degrees either side of center.

The rudder pedals also move the nose gear through hydraulic pressure but the steering authority and sensitivity is not as great with the rudders as with the tiller. The tiller also overrides any inputs by the the rudder pedals.

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Is it common practice to taxi an airline on to the active runway when ready for takeoff with the tiller vs. the rudders.

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You'll use the tiller to steer onto the runway and line up with the centerline. Once you start your takeoff roll you steer with the rudder pedals.

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Do you think that might lead to the pilot flying maybe forgetting to unlock the rudder on takeoff or in the air and maybe cause an accident.

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We can't lock the rudder. If there's hydraulic pressure the rudder moves. You're probably thinking about tailwheel airplanes like a DC3.
 
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Do you guys have to do differential braking for really tight corners. I wouldn't think it would roll very well by its self if the nose wheel were turned all the way.


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Mostly a little differential thrust on the outside engine works great for tight turns.
 
So is there a lock for the tiller. Is there a certain weight or size of airplane where they start using tillers. I was in a falcon once and I dont believe it had a tiller.

Tom
 
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So is there a lock for the tiller.

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No locks on the tiller. There is a bypass pin located on the nose gear strut that a mechanic uses to disable the nose gear steering when pushing the aircraft back with a tug.
 
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