Supersonic?

Question

Am I right that a Spitfire broke the sound barrier whilst in a dive,recollect reading it somewhere.

Answer 1

Wow I don't know if you guys are breaking the sound barrier or breaking wind..
No the spitfire didn't break the sound barier even in a dive. The first plane to do it in a dive was the xp-86s. The timing is debateable but I think 50+ years later if Welch would have gotten there first it would be public record by now. I think he got going fast in a dive but because no Pitot tube could read the speed at that time it is pretty much irrelavant. The X-1 also broke this in straight/level flight and was actually testing to see what happened to control surfaces at those speeds.. not trying to set a record.

But further proof the Spitfire couldn't have broken the sound barrier is that is that the A-2d skyshark can't even in a dive with over 5000 horsepower and a counter rotating prop compared to the lowely Spitrire with 1100 horsepower and a single prop.

The XF-88B is the only propeller equiped airplane to ever break the sound barrier. This was done with Allison XT38 (3000 HP) and 2 3000 LBS Westinghouse XJ34-WE-13 turbo jets in the back.

calnickel: Who ever said the XF-88 had emergency landings? Not me. But don't get your models confused there is obviously a huge difference between the XF-88A and the XF-88B. The B model had a propeller-

The XF-84 had all kind-of problems and only flew twice as I recall.

Answer 2

A Spitfire or any presupersonic aircraft can't break the sound barrier and survive because of the following reasons:

At transonic velocities, the center or lift on the wing moves rearward, causing the aircraft to dive (Mach Tuck).

When this happens the speed increases and shock waves form in front of the flight controls (particularily the elevators) rendering them useless.

Transonic and supersonic aircraft use all-moving stabilizers and vortex generators to keep flight controls effective at high speed.

Thus the aircraft is unable to pull out of the fatal dive.

Control reversal was another nasty that I believe was discovered on a diving Spitfire. A high speed the ailerons produce too much force and twist the wing the opposite direction, reversing the roll (and causing structural damage I assume). Newer fighters like the Mustang had thicker laminar-flow airfoils that didn't twist as much.

BTW, the XF-88 only had two flights that didn't end in emergency landings.

Answer 3

I just cut and pasted the following info in.

Hans Guido Mutke claimed to have broken the sound barrier on April 9 1945 in a Messerschmitt Me 262. However, this claim is disputed by most experts as the Me262's stucture could not support high transonic, let alone supersonic, flight and lacks a scientific foundation.

George Welch apparently broke the sound barrier on October 1 1947 while diving the subsonic XP-86 Sabre. 13 days later and 30 minutes before Yeager's historic flight, Welch apparently repeated his supersonic flight. Although evidence from witnesses and instruments strongly imply that Welch achieved supersonic speed, the flights were not properly monitored and cannot be officially recognized. (The XP-86 officially achieved supersonic speed on April 26, 1948.)

Chuck Yeager (then a Captain in the US Air Force) is the first person accepted and documented to have broken the sound barrier in level flight on October 14 1947, flying the experimental Bell X-1 rocket plane to Mach 1 at an altitude of 45,000 feet. Yeager's flight was part of a test program with the goal of achieving supersonic flight so proper monitoring was in place for the flight.

Chuck Yeager is officially credited with being the first person to break the sound barrier "in level flight" (see the video below). This leaves the door open for claims of previous supersonic flights made while diving.

The sound barrier was first broken on land in 1948 by a rocket-powered test vehicle at Muroc Air Force Base (now Edwards AFB) in California. It was powered by 50,000 pounds of thrust, reaching 1,019 mph [1].

Jackie Cochran was the first woman to break the sound barrier on May 18, 1953 in a Canadair F-86 Sabre.

Despite all these breakages, the bullwhip or stockwhip was the first man-made object to move faster than the speed of sound. The tip of the whip changes direction faster than the speed of sound, thus breaking the barrier.


History of breaking the sound barrier
During the Second World War, it was rumoured that several fighter aircraft, in particular the Supermarine Spitfire, exceeded the sound barrier in a dive. However, since (it is thought) that getting close to this speed in these aircraft caused the aircraft to become uncontrollable and crash, none of the pilots of these flights survived to tell the tale, so these rumours cannot be confirmed.

Why the loss of control? The increased speed caused a shockwave to form on the wing and tail, and as the speed increases this shock wave moves back along the wing and tail. This changes the presssure distribution on the aerodynamic surfaces, which reverses the effect of the the ailerons and elevators. It was this effect that is thought to have caused the crash which killed Geoffrey de Havilland, in the middle of flight testing the dh108, de Havilland Swallow. The flights were close to or possibly achieved the speed of sound, but since they ended in tragedy, it cannot be claimed that they ever broke the sound barrier.

Answer 4

I think this is a myth brought about by a British 1950,s film called "The sound barrier" where a fighter pilot experienced extreme buffetting in a steep dive,lost control and regained control by pushing his stick forward instead of back to pull out.I don't think a spitfire would achieve any thing approaching supersonic speed without disasterous consequences.

Answer 5

The Spitfire was built of aluminium not plywood. It was the hurricane that was made of wood and canvas.

The following link has some information although it doesn't confirm or deny whether a spitfire broke the sound barrier since in doing so it would have crashed kiling the pilot.

Answer 6

The propeller is is like an air brake as the aircraft approaches the speed of sound. This alone will prevent any prop driven aircraft from breaking the sound barrier. This is also part of the reason why supersonic aircraft have various devices to slow down air feeding the jet engine. The engine will not work if fed by supersonic air.

Answer 7

A couple of things: the Spitfire is an aluminuim monocoque aircraft.In its later versions such as the MK25 ,when it was engined with a Rolls Royce Griffon power unit,it developed over 2000bhp.More than double what the MK1 Merlin engined ones did..Its last operational use was in 1952.Pretty good going for an aircraft first designed in the late 1930`s..And in my opinion it is the prettiest of aircraft.
The Hurricane was a semi monocoque. Its ancestry is clearly visible in such biplanes as the Hawker Hind.It was a tough and stable gun platform much loved by its pilots.It was built of stell tube and from the airscrew to the rear of the pilots cabin was aluminium covered.The rear of the aircraft was fabric covered.The wings were all metal.
The deHavilland Mosquito was an all wooden monocoque comprised of 2 layers of birch plywood sandwiching a layer of balsa.It was powered by a pair of Rolls Royce Merlin engines and was a versatile little bird.Bomber,fighter,reconnaisance,weather recon.Hell they even mounted a bloody great cannon in her for use against shipping.Not bad for a aircraft that was nearly cancelled at birth.Google Freemans Folly for more info.

Answer 8

I doubt that a Spitfire could break the sound barrier
because this excellent aircraft was built from plywood.
At the speed of sound the wind pressure on the wings
would tear them off.

Answer 9

reached the sound barrier is one thing, breaking it is a whole different story. Many planes during WW II reached the sound barrier, but those that kept on going ended up falling appart. The Bell X-1 was the first to actually 'break' the sound barrier.

Answer 10

you are probably talking of what happened on feb.1952 when the flight lieutenant Ted Powles hit the altitude record of 51,550 feet and then dived.Evaluation of the recorded flight data suggested that, in the dive, he achieved a speed of 690 mph (1110 km/h) or Mach 0.94, which would have been the highest speed ever reached by a propeller-driven aircraft. Today, it is generally believed that this speed figure is the result of inherent instrument errors and has to be considered unrealistic.