Taxi speeds - how fast is too fast

[j-line]

Should there be a aircraft limitation to taxi speeds. At some airlines, SWA for example, taxi speeds are at times approaching V1. Could their operating attitude of max speed been a contibuting factor in their accident at Midway? We have inflight limiting speeds due to aircraft structure and operational safty but none for ground opeations - why?

[Dream Land]

Have they had any taxi incidents?

[alf5071h]

Dream Land The safety judgment is not if they have had any accidents, it is whether they could have an accident.

If the Avro RJ auto-spoilers come out, then you are taxing too fast, and every one can see it (approx 33kts GS).

[ratarsedagain]

At some airlines, SWA for example, taxi speeds are at times approaching V1.

Now that I'd (not?) like to see!

Come on, I know some people taxi too fast, but V1!!!!!! Methinks a tadge of poetic licence there!

Our FM states a max taxi speed of 30kts straight line (conditions permitting), and 10kts round corners.

I'm also guessing that ATC would say something if you were tearing round somewhere like LHR at 120kts!!!!!!!!!!

Rgds.

[rigpiggy]

you might also hit my pet peeve of the 4kt taxi for 2.5 miles ie 15,000ft or one side of the a/p to another. our company doesn't pay O/T until 100 hrs/month. I endeavour to get my day done asap. so hurry the hell up!

[Captain Stable]

There is a certain LoCo operator who were clocked by radar gun at a certain Essex airport doing 80 mph on the taxyway. :uhoh: :rolleyes:

[tiggerific_69]

i dont think the captains realise just how fast they are taxying sometimes,it doesnt matter to them how fast they are going because they are sitting down,however they dont realise that often the cabin crew will be doing the safety demonstration and securing the cabin in preparation for take off.
there are a few select captains where i work who repeatedly offend and despite being told about it,they still dont change their ways,and i often come home,my legs covered in bruises.
Taxi safe,and think of all the crew onboard and people around you :ok:

[catchup]

3o kts straight, 15 knots for corners in my company.

regards

[Carmoisine]

Captain Stable, I heard it was more like 60 Knots if we are talking about the same company?

[Bealzebub]

How fast is too fast ?

The simple answer is statute and judgement . The company should normally state a maximum taxying speed for the aircraft type within its operations manual. That will normally stipulate a reduced taxying speed when conditions dictate. It might allow a higher speed in the event of an "emergency". Being late isn't an emergency ! The Captain should then apply and both Pilots should ensure that the actual speed applied is commensurate with the actual conditions experienced and within the written limits.

The comment about taxying speeds "approaching V1" may well be a little tongue in cheek, but since V1 is actually an accelerate stop distance speed, the analogy isn't too far from the truth.

From a safety standpoint the brakes will have absorbed a lot of energy after a landing and taxying fast means those brakes having to absorb a lot more energy in a short time period which might be very unwise. Similarly prior to departure, loading the brakes will make them much more vulnerable to overheating in the event of a subsequent reject.

Fortunetaly the standards of good airmanship displayed by so many pilots means that the mavericks and companies that employ them stand out like a sore thumb.

[Willit Run]

I fly classic 747 freighters, we are paid from the time the plane moves, so taxi speed relates to strict dollars for us. However, our ops manuel limits us to 20 knots straight and level, and 10 knots in turns. I can remember many times exceeding 20 knots and watching 737's fly by us like we were standing still, thinking, holy cow dude, don't pull back!!!

Merry Christmas!

[Trentino]

Having flown on SW many a time and having shared a taxiway with an SW 737 I must admit they are extremely aggressive.
Paxing on the 737 down in Florida I was convinced that in the dogleg turn of the taxiway that we approached at 35kts, I thought the plane would lift one of the mains and do a wheely.
At many airports that Southwest operate to I am almost certain they 'grease palms' Because when they are on approach or taxying around they have precedence, atc looks the other way while another 121 carrier will not get the same treatment from ATC

But then again what do I know

[TR4A]

Having flown on SW many a time and having shared a taxiway with an SW 737 I must admit they are extremely aggressive.
Paxing on the 737 down in Florida I was convinced that in the dogleg turn of the taxiway that we approached at 35kts, I thought the plane would lift one of the mains and do a wheely.
At many airports that Southwest operate to I am almost certain they 'grease palms' Because when they are on approach or taxying around they have precedence, atc looks the other way while another 121 carrier will not get the same treatment from ATC

But then again what do I know

SWA max taxi speed is 30 knots. It may seem like we have "precedence" but we do not "grease palms". Try to not bitch too much and maybe you will get better treatment from ATC.

[GlueBall]

What about when you're having to backtrack on a runway...? Tell us that you'll never exceed 20kts and not ever expedite because your SOP says that 20kts is max, eh? :rolleyes:

[Faire d'income]

What about when you're having to backtrack on a runway...? Tell us that you'll never exceed 20kts and not ever expedite because your SOP says that 20kts is max, eh?
Taxi speeds refer to taxiways. Thankfully on runways we are certified for higher speeds or else it would mean very big wings.

For those of you who like to make up the 20 seconds or so by taxiing fast remember your ops monitoring is watching you. If the CCM above that claims she got bruises were to take a case ( and a bruise ) which matched a taxi speed exceedance of yours it would mean you paying the legal bills. Even if someone else takes a wrong turn or ATC change your clearance late it would be still your fault.

[Mr Moustache]

I always thought 25 kts was ok and 30 kts max, but since they built those new runways at Barcelona and Amsterdam, I do feel I need to reconsider!;)

[Dozza2k]

I've heard rumours of CC being able to sue Captains (not the airlines) if they fall over whilst turning or braking harshly. Any truth to this? Personally, in most cases I think its a load of cobblers
d2k

[Perro Rojo]

Whatever keeps the tyres on the rims on the corners.

[Ignition Override]

When your tires slide due to reverted rubber steam and you slide off of the end of the taxiway, or a slower speed seems to concern the other pilot.

This happened years ago to an AirCal B-737 at Las Vegas. :ugh: It is a long taxiway to runway 25L, and the slope is not noticeable, from what I remember years ago.

[Snape]

You're taxiing too fast when you can't bank steep enough to make the turn from alpha to bravo.

[ettamakwetta]

Hi Guys
This is actually quite a complicated problem. I am currently finishing off some analysis regarding safe operating speeds, and have been curios to know what the highest speeds are that anybody might have seen. The problem with calculating these types of stability margins is the fact that you have so many non-linearities, especially from the tyres and the oleos. This means that you can get crazy situations that you could have two wildly different behaviours, even though you have the same thrust and steering angle settings.
Regards
Etta

[Boeing Freighter]

Hi ,

I have no figures to give unfortunately but some airports have taxiways that are certified ( or something ) for controllers to give pilots " high-speed taxi " clearence.

Frankfurt-Mail is one such airport , but i am unsure of the requirements to have a high-speed taxiway , or just how fast you can go.

[kenparry]

There is no simple answer. One of the critical things on long taxi distances is tyre heating. About 10 years ago Boeing brought out a training package about the topic; one bit I remember is that if you taxi at MTOW (MTOM if you are using JAR) for 10 km at 60kt you will heat up new tyres to the temperature at which the safety plugs will blow. OK, I don't know an airport where you would taxi for 10km, but if you taxi that fast for say 6km (which is possible at a few places) and then start the take-off with no delay, are the tyres going to survive? If you reject the T/O, it's going to be worse. Boeing advice was, if I recall correctly, don't use sustained speeds above 20kt. But, as someone already said, it should be in the ops manual - and if so, that's what to do.

[Bungfai]

Depending on taxiway surface condition and most of the time thinking of passengers comfort, 30 kt and max 15 round the corner. Anyway if faster than 80kt, auto brake will activate!

[777fly]

I remember the Boeing training document, about taxi speeds and tyre heating, mentioned by Kenparry. It contained a graph which illustrated the amount of heat that was going into the tyres Vs taxi speed, due to tyre hysteresis. I was fairly linear up to about 20kts, then went semi-exponential through the 25-30kts range and upwards. The message, as I remember it, was that a MTOW 'heavy' which was taxiied at 25kts for 5Km in 25-30 degrees ( very possible at a number of Middle East airfields) was going to be near tyre fuse-plug failure nearing the end of 2Km+ takeoff run. The main issue was tyre carcase heating. 20kts, briefly 25kts was recommended for taxy. If tyres are designed to handle speeds of around 150kts and heavy braking on runways and 40kts on high speed turn-offs, taxiing at ANY speed, short of getting airborne, is possible for short periods. Safety and common sense dictate otherwise and most company flight manuals give recommended taxi speeds in the 20-25kt range ( maximum figures, good conditions, etc)