Maximum speed a plane can reach on the ground

Del2005 · 28-01-2019 10:47AM #1

Was on a plane last night and was thinking that if you had a long enough appropriate surface how fast could a plane get on the ground? I'm not asking about take off speed but going full throttle till it can't accelerate any more. If a 737 can do 900km/h at cruise altitude would it get anywhere near this on the ground?

Simon Gruber Says · 28-01-2019 10:58AM

There is a maximum ground speed limit, as aircraft tyres have a maximum speed they're rated for. Exceeding this could cause the tyres to fail.

This can become a limiting factor at a hot temperature, high altitude airport. You can have all the runway in the world but the low air density means that you'll exceed the tyre limit before you can get airborne.

agentblue · 28-01-2019 11:08AM

The SR-71 had problems with tyre integrity at speed. They lost a number of aircraft because of this.

Rows Grower · 28-01-2019 11:20AM

I'm gonna guess that it wouldn't get anywhere near 900km/h.

Maybe around 160-200 km/h?

Often wondered the same thing myself and then as usual forgot about it completely once we'd taken off.

mick121 · 28-01-2019 11:29AM

I could be wrong here but would the aerodynamics of the plane naturally make it airborne once you went beyond a certain speed?

robbie1876 · 28-01-2019 11:44AM

I believe that all 737 tyres including on the Max 8 are limited to 225mph along the ground.

Avatar MIA · 28-01-2019 11:47AM

mick121 wrote: »

I could be wrong here but would the aerodynamics of the plane naturally make it airborne once you went beyond a certain speed?

Yes, even some cars are in danger of lifting (if not actually flying) at certain speed and can have large spoilers to keep them grounded.

I imagine if an aeroplane had it's ailerons and flaps down it would keep it grounded for longer, but those big wing shaped... er… wings are going to make it lift eventually. So, nowhere near 900km.

faoiarvok · 28-01-2019 12:43PM

Del2005 wrote: »

Was on a plane last night and was thinking that if you had a long enough appropriate surface how fast could a plane get on the ground? I'm not asking about take off speed but going full throttle till it can't accelerate any more. If a 737 can do 900km/h at cruise altitude would it get anywhere near this on the ground?

Assuming your spoiling the lift to stay grounded, and ignoring the tyre limits as above, the aerodynamic forces on the plane would be the limiting factor I think. Using flaps and the like would lower the airspeed required to damage the aircraft. Of course you could add a massive tailwind in your hypothetical scenario to have an airspeed close to zero with a huge ground speed.

plodder · 28-01-2019 02:01PM

Concorde's take-off speed was around 400km/h. To be efficient at high speed meant the wings didn't produce very much lift at low speed.

Stovepipe · 28-01-2019 02:35PM

Older fighter aircraft like the Lightning had such a high landing speed that it was common to have to change tyres after each flight. The tyres were very narrow, high pressure tyres. A fighter like a MiG 21 would land at 250 kph and need a minimum of 5000 feet of runway available. An A330 would land at about 140 kts / 163 mph / 260 kph, despite being many times heavier than a Mig-21. An A330 tyre would easily last for several hundred take offs and landings.

duskyjoe · 28-01-2019 02:53PM

Stovepipe wrote: »

An A330 would land at about 140 kts / 163 mph / 260 kph, despite being many times heavier than a Mig-21. An A330 tyre would easily last for several hundred take offs and landings.

131kts average Vapp. Several hundred take offs and landings on a 330 tyre? I know your an engineer with respect but that’s hogwash...I’d like to see a tire after 50 rotations.

28-01-2019 02:59PM

Without upgraded suspension I imagine a plane would bounce about quite erratically at higher then takeoff speeds ??

Stovepipe · 28-01-2019 07:07PM

duskyjoe wrote: »

131kts average Vapp. Several hundred take offs and landings on a 330 tyre? I know your an engineer with respect but that’s hogwash...I’d like to see a tire after 50 rotations.

Anytime you like. The average 330 in our fleet would do 2 take offs and two landings in any 24 hour period, so 50 rotations would give you 12 days, give or take. We are definitely getting more than 12 days out of a tyre. We changed from a certain French brand to Bridgestone and our average number of landings per tyre went up dramatically. Like any tyre, it all depends; you could fit a tyre on a Monday and it could get a cut that will have it changed the next day, or you will get a tyre that wears away quietly and gets several hundred rotations before it gets changed.No two share the same fate.

Irish Steve · 28-01-2019 07:50PM

plodder wrote: »

Concorde's take-off speed was around 400km/h. To be efficient at high speed meant the wings didn't produce very much lift at low speed.

Somewhat over stated.

Concorde had a take-off speed of 220 knots (250 mph) , and from memory, the tyres were limited to that speed as well, which was one of the issues that caused the problems that contributed to the eventual withdrawal from service. That speed is still considerably in excess of the range of take off speeds of other commercial types, and unlike other traditional aircraft that start to produce lift before rotation, the load on the tyres increased during rotation as there was no lift produced prior to rotation.

The landing speed was also considerably higher than the average speed for commercial aircraft, 217 Kts, and that (from a very memorable simulator session a long time ago) was an experience unlike any other commercial aircraft, for all sorts of reasons.

Rows Grower · 28-01-2019 07:55PM

Irish Steve wrote: »

Somewhat over stated.

Concorde had a take-off speed of 220 knots (250 mph) , and from memory, the tyres were limited to that speed as well, which was one of the issues that caused the problems that contributed to the eventual withdrawal from service. That speed is still considerably in excess of the range of take off speeds of other commercial types, and unlike other traditional aircraft that start to produce lift before rotation, the load on the tyres increased during rotation as there was no lift produced prior to rotation.

The landing speed was also considerably higher than the average speed for commercial aircraft, 217 Kts, and that (from a very memorable simulator session a long time ago) was an experience unlike any other commercial aircraft, for all sorts of reasons.

I like this version of facts the most because it makes my guess this morning seem more accurate.

Cheers Steve.

plodder · 28-01-2019 08:44PM

Irish Steve wrote: »

Somewhat over stated.

Concorde had a take-off speed of 220 knots (250 mph) ,

250 mph is approximately 400 km/h

Stovepipe · 29-01-2019 01:03AM

5 mph is equal to 8 kph; 6 knots is 7 mph. PPL groundschool. American aircraft with MPH, British aircraft with Knots, French aircraft with kph. Lots of fun....

Irish Steve · 29-01-2019 01:20AM

Stovepipe wrote: »

5 mph is equal to 8 kph; 6 knots is 7 mph. PPL groundschool. American aircraft with MPH, British aircraft with Knots, French aircraft with kph. Lots of fun....

And when American Gallons, Imperial Gallons, Litres and Kilograms get put into the mix for fuel quantities, that's a recipe for potentially lethal confusion ( Gimli Glider).

Momentary brain fade here earlier, Mph to Kph I can just about cope with, and with the way things changed here, I don't have a lot of choice, but I've not been using Kts for speed calculations now for the better part of 15 years, so I'm afraid there are times when I don't get it right,

Sorry Plodder, it was me that got it wrong

Brennus335 · 29-01-2019 05:54AM

Now what if it was on a conveyor belt.........

Fastest groundspeed I've seen at rotation was about 205kts. We were tyre speed limited for the takeoff according to the performance application.

Victor · 29-01-2019 08:04AM

Del2005 wrote: »

Was on a plane last night and was thinking that if you had a long enough appropriate surface how fast could a plane get on the ground? I'm not asking about take off speed but going full throttle till it can't accelerate any more. If a 737 can do 900km/h at cruise altitude would it get anywhere near this on the ground?

While tyres are mentioned above, you also need to consider brakes and length of runway. There is a point of no return on a runway where you either take off or you won't be able to stop before the end of the runway.

Carawaystick · 30-01-2019 12:04AM

Irish Steve wrote: »

And when American Gallons, Imperial Gallons, Litres and Kilograms get put into the mix for fuel quantities, that's a recipe for potentially lethal confusion ( Gimli Glider).

Momentary brain fade here earlier, Mph to Kph I can just about cope with, and with the way things changed here, I don't have a lot of choice, but I've not been using Kts for speed calculations now for the better part of 15 years, so I'm afraid there are times when I don't get it right,

Sorry Plodder, it was me that got it wrong

I presume theres a standard nautical mile used to give speed in knots? and it doesn't depend on the length of the nautical mile ( minute of degree of latitude) where the aircraft is?

Victor · 30-01-2019 12:15AM

Carawaystick wrote: »

I presume theres a standard nautical mile used to give speed in knots? and it doesn't depend on the length of the nautical mile ( minute of degree of latitude) where the aircraft is?

Nautical miles are always 6,000 feet or 2,000 yards. It is only equivalent to a minute of longitude at the Equator.

Irish Steve · 30-01-2019 12:52AM

Victor wrote: »

Nautical miles are always 6,000 feet or 2,000 yards. It is only equivalent to a minute of longitude at the Equator.

Arrrgggghhhh. Painful memories of trick questions in the old Nav Gen ATPL papers, flying supposedly around a square but not ending up back where you started. I don't miss that sort of stuff, but it had to be done at the time.

How many other people here can remember Dennis Slattery and Dlong Cos mean Lat???

Bussywussy · 30-01-2019 02:39PM

duskyjoe wrote: »

131kts average Vapp. Several hundred take offs and landings on a 330 tyre? I know your an engineer with respect but that’s hogwash...I’d like to see a tire after 50 rotations.

You'd be surprised how long they last.....I've seen them taken off after less than a day due to failure or damage...I'll try get an average when I'm back at work ..

SRFC90 · 30-01-2019 09:37PM

Irish Steve wrote: »

Arrrgggghhhh. Painful memories of trick questions in the old Nav Gen ATPL papers, flying supposedly around a square but not ending up back where you started. I don't miss that sort of stuff, but it had to be done at the time.

Going through all this stuff in GNAV at the minute! ATPL's are some craic...:eek:

Stovepipe · 30-01-2019 09:44PM

I recall so much of that stuff! Slattery had a way of nailing it into your skull. navigating around a square of the Atlantic, doing three-engine drift downs.....is he still alive?

Tenger · 31-01-2019 01:55AM

I did watch a video on YouTube a few weeks ago about a reason why the US never went metric was that the rep from the institute in France got hijacked by pirates while enroute with his Kilogram and Metre examples. He got there months later but it was too late by then.
Thus the US decided to just stay with the old British Imperial measurements.

Bussywussy · 31-01-2019 02:07AM

The wheels are lasting on about average 4 months....I've looked at high rotation aircraft...ie up and down to Malagas then across the pond....there's wheels lasting up to 6 and 7 months ..they're lasting well over 200 and 300 cycles...I've come across one on for 480 cycles....

smurfjed · 08-02-2019 09:39AM

is he still alive?

I believe that he has passed away.

From another of his extremely grateful students.

Stovepipe · 08-02-2019 11:32AM

His house was a treasure trove for navigation kit. Not a fan of pilots, except a rare few...:-)

Maximum speed a plane can reach on the ground

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