747 Taxi Speeds

[Dangly Bits]

I was watching a 747-400 taxi to the runway this week and wondered what speed they taxi at. Given their size, it is hard to estimate. Anyone out there able to tell me what speed they travel? In a straight line, turning, turning in the wet etc?

Much appreciated.

DB

[Pontius]

Straight line (assuming it's all clear, with nobody coming out of ramp areas etc): 20-25kts ish. I've taxyed faster when it's a long, straight taxyway and, obviously, slower when there's stuff around to hit/hit you.

Cornering (dry): assuming it's not some horrendous 120 degree turn, with a narrow bit of unlit tarmac, 10-maybe 15kts.

Cornering (wet): less than 10kts. There's very little weight on the nosewheel (compared to the arse end) so you can turn the tiller and this will turn the nosewheel but bugger-all happens 'cos the tyres just skid sideways across the wet tarmac and the Jumbo keeps going in a straight line :)

Sitting up so high, you get a false illusion of taxy speed. You think you're going reasonably slowly until your mate points out that the Formula One has finished......and we won. So, your eyes wander to the groundspeed readout a fair bit to keep the numbers under control.

How many posts do you think it will take before someone jumps on the indignation bus and lectures me on how I shouldn't taxy faster than I can walk etc etc etc :hmm:

[18-Wheeler]

As mentioned just above, though the company I used to work for had a 30kt limit on straight taxiways. Some other airlines also impose a 20kt limit when the big plane is over 320 tonnes.
To keep the speed down after landing I'd often wait three minutes and shut-down #3 engine.
And yes you have to use the groundspeed readout (after landing use the lowest of the two or three as they all drift a little after a long flight) as it's difficult to judge your speed at times.

[Yeti Breath]

Same as above for me too.

Straight line 30kts max usually around 20-25kts, near anything that can hit me or I can hit 10kts or so, turning dry 10kts if it's wet and I'm heavy 7 or 8kts.

I find the speed I use in a turns depends a lot on how sharp and how long its going to be and whats around me, don't want to get so slow I need a stack of power to keep moving when there is a light twin behind me.

[Checkboard]

How many posts do you think it will take before someone jumps on the indignation bus and lectures me on how I shouldn't taxy faster than I can walk etc etc etc:hmm:
Actually, I was going to accuse you of being a bit soft! I do those speeds on snow! ;)

[By George]

Not above 5kts in a turn on snow/contaminated for us and not above 10kts in a normal turn. I think the 'snitch box' dobs on 14 and above in any turn. Straight line agree with everyone else.

[Atlas Shrugged]

How many posts do you think it will take before someone jumps on the indignation bus and lectures me on how I shouldn't taxy faster than I can walk etc etc

I shouldn't think anyone would!

Try taxiing a 747 from Qantas International Gate to 34R (assuming of course, that you can use it for takeoff) at SSY at walking pace and see how efficient that is. ;)

[Starts with P]

Technically it can (under contingency arrangements)

[Old Fella]

It used to depend on whether or not the Captain was into Extra Flying Pay. If he was, not above 5 Kts and always use the runway, if available, which gave the longest taxy.

[SNS3Guppy]

Our policy is 20 knots straight, and max 10 knots in a turn