An Aircrafts top speed...on land

[TurboMills]

Say you had a bit of room, like the Bonneville salt flats, and a passenger aircraft, a Boeing 737 for example, and you give it full tilt with the flaps up, what kind of speed would it reach if you could keep it in a straight line and on the ground?

In fact, which passenger aircraft would be fastest? Which component would self destruct first? Could it be done? Just a few questions i'd love to know the answer to.

Personally, I reckon Concorde would have won hands down, but I think the wheels may collapse before it got to 500mph, that, and it's no longer in use

Over to you...

[fathomfive]

Depends how fast you can make the conveyor belt go...

[AJI]

Well the Thrust SS2 world land speed record holder is in effect a plane without lifting wings.
Mach 1 is the speed to beat there.

A conventional plane that could get up to speed way past its take off velocity would surely destruct its landing gear before anything else.
The pilot would have to be giving it a pitch down motion on the controls in order to keep it from taking off.

[Racefan_uk]

AJI said:

Well the Thrust SS2 world land speed record holder is in effect a plane without lifting wings.
Mach 1 is the speed to beat there.

The fact that Thrust SSC had two jet engine bolted to it in no way makes it 'in effect a plane'! It was designed as a wheeled vehicle, albeit a fooking fast one.

I shouldn't think that any plane will get near a decent speed due to the landing/running gear being too fragile to stand anything much above usual take off speeds. Could be wrong though.

[Jem Thompson]

Racefan_uk said:

AJI said:

Well the Thrust SS2 world land speed record holder is in effect a plane without lifting wings.
Mach 1 is the speed to beat there.

The fact that Thrust SSC had two jet engine bolted to it in no way makes it 'in effect a plane'! It was designed as a wheeled vehicle, albeit a fooking fast one.

I shouldn't think that any plane will get near a decent speed due to the landing/running gear being too fragile to stand anything much above usual take off speeds. Could be wrong though.

Thanks for correcting that. It is beyond me as to why they would design something like a plane without to set a LAND speed record. Its objective is the exact opposite of a planes.

[IanMorewood]

According to something I read on the internet its possible to land a Tornado at 210 knots (wings fully swept (in case of actuator failure)) but you run a fairly high risk of a tyre burst, so without special tyres I would say 200 knots is about as fast as you would want to go on land.

Concorde’s take off speed is approximately 190mph by the way.

[dudleybloke]

the problem would be the tyres. they would struggle over 230mph. over a long run at lower speeds the problem would be build up of heat. aircraft tyres are normaly only at high speeds for short periods.

[Papoo]

You'll find that an aircrafts top speed on the ground (particularly air transport aircraft) wouldn't be that inspiring. Aside that the landing gear isn't capable of huge speeds; if it were modified for it, the sheer pressure of the wind (dynamic pressure) starts to tear the airframe apart at speeds far less than land speed record vehicles, little over 300mph in many cases. The reason they hit 500+mph in the air, is because the air is much thinner at 35,000 ft. They can withstand 300+mph of dynamic pressure, which in thin air, is faster motion than on the ground.

Shame really, as the jet engines themselves will produce astonishing amounts of thrust, it's the airframe which is the weak link, in that respect.

That said, I reckon a carrier equipped fighter (read: tough landing gear) like a Super Hornet could hit some big speeds and remain fairly unscathed..

[dudleybloke]

what about getting a concord engine pod and strapping 4 wheels to it! should be good for at least NSL!

[Papoo]

dudleybloke said:

what about getting a concord engine pod and strapping 4 wheels to it! should be good for at least NSL!

What about jacking all the trolleys from Tescos, removing their wheels, and bolting them on to Concord, all over the airframe. They're omnidirectional, and would keep the bird going if it flipped. I'll call Guinness.

Ps/ the trolley tires are good for 900mph. Never mind how I know this.

[CyprusCraig]

Regarding the landing gear. I would assume that the Safe working load is probably 25:1 like most other things when there's a risk of peoples lives. So i doubt that would be the first thing to break. Only an inference from other situations, possible and probably wrong tho.

[mattdaniels]

The tyres will burst or you'll be airborne long before any theoretical speed limit is reached.

[Jem Thompson]

Assume for a minute that the tyres can withstand any speed, and how fast do you think a 747 could go on land if its wings were attached up-side down?

[Talksteer]

Jem Thompson said:

Assume for a minute that the tyres can withstand any speed, and how fast do you think a 747 could go on land if its wings were attached up-side down?

Not particularly fast, the airframes rated indicated airspeed will be around the 300 kts mark. With the gear down and the vibration of running across the ground you would expect it to be heading for a structural failure before it starts challenging speed records.

The thrust lapse (the thrust drops off as you go faster) characteristics of high-bypass engines aren't to brilliant either. That is why fighter jets that go quick close to the ground have very different looking engines to airliners.

[squirrel2007]

I think the Thrust SSC (and other jet powered land speed record cars) have solid metal wheels to avoid the whole tyre blowing up problem!

[IforB]

Aircraft tyres have speed ratings in the same way that car tyres do. For example 737 tyres have a max rating of 195kts (225mph).

Landing gear also has a maximum extended speed, though on the 737 that is 320kts or .82M so I think you'll run into problems before that is reached!

The main problem with this hypothetical situation is that the aircraft will simply want to take off as the speed rises and you may not be able to hold it down.

[AJI]

Racefan_uk said:

AJI said:

Well the Thrust SS2 world land speed record holder is in effect a plane without lifting wings.
Mach 1 is the speed to beat there.

The fact that Thrust SSC had two jet engine bolted to it in no way makes it 'in effect a plane'! It was designed as a wheeled vehicle, albeit a fooking fast one.

The Thrust SS2 was in effect designed exactly like a plane.... they started off by looking at the Bell X-range of aircraft that initially broke the subsequent sound barriers. (Although they did have to start from the 'ground up').
Its fair to say that we both know its not supposed to fly, that wasn't my point. It was largely designed in a wind tunnel as are most planes, it was largely designed to cope with rear thrust from jet engines as with all jet planes, and it was designed to be stable going through the sound barrier as with many military jet planes.
They did have to engineer the thing to have negetive lift, so that the wheels always had enough pressure contact with the ground, oh and they used an ex-RAF pilot to drive it.

[fadeaway]

AJI said:

Racefan_uk said:

AJI said:

Well the Thrust SS2 world land speed record holder is in effect a plane without lifting wings.
Mach 1 is the speed to beat there.

The fact that Thrust SSC had two jet engine bolted to it in no way makes it 'in effect a plane'! It was designed as a wheeled vehicle, albeit a fooking fast one.

The Thrust SS2 was in effect designed exactly like a plane.... they started off by looking at the Bell X-range of aircraft that initially broke the subsequent sound barriers. (Although they did have to start from the 'ground up').
Its fair to say that we both know its not supposed to fly, that wasn't my point. It was largely designed in a wind tunnel as are most planes, it was largely designed to cope with rear thrust from jet engines as with all jet planes, and it was designed to be stable going through the sound barrier as with many military jet planes.
They did have to engineer the thing to have negetive lift, so that the wheels always had enough pressure contact with the ground, oh and they used an ex-RAF pilot to drive it.

That doesn't actually make it "like a plane" though. It just means that they faced some of the same challenges that plane designers do, and obviously referenced the lessons that have been learnt about going supersonic - which all happened to have been in the air.

[sneijder]

I work in an airport, and I was once wondering this waiting for a flight to do one from the gate. 737's gear looks far too feeble, 757's are far more likely to get a fair bit of pace going - big, chunky rear landing gear. Going up in size and an extra 2 engines, an A330 would get shifting given some room I reckon.

The winner I think would be JAL's 747-200's they are the last of the first Junbos still flying and about to be retired. They were designed for international flights, but were used for domestic trips. All the extra runway action meant they had the landing gear beefed up.

[IforB]

330's only have 2 engines.