# Tag Info

90

I don't think this had anything to do with military jets breaking the sound barrier nearby; it does sound more like strips of metal recovered from chaff dispensers on the jets; countermeasures systems which eject hundreds of strips or threads made of metal foil used to thwart enemy radars. Most likely the aircraft discharged their chaff dispensers during ...

59

In an aircraft designed to go supersonic, it's an absolute non-event, and one is only aware of it by observing the instruments, and noting diminished control authority-- slower roll rate, etc. At least, that was my experience in the T-38, and according to every account I've read. If the aircraft is NOT designed to go supersonic, then the experience can be ...

59

The actual 'legal' reasons have already been mentioned. However, there was a bit more to it. Tu-144 was meant to fly over land from the beginning; there was no way around it, unlike Concorde. So it was designed to fly higher. In particular, Tu-144 had about 20% lower wing loading and 20% higher thrust-to-weight ratio (at MTOW) than Concorde. (The reality ...

49

The Tu-144 uses much smaller wheels than comparably-sized subsonic aircraft. This makes it possible to rotate the gear bogie sideways towards the middle of the aircraft, so it can be stowed vertically inside the wheel well. Your picture already hints at that: Note that the gear strut is offset inside the wheel well, so it would leave more space on one side ...

47

The Tu-144 landing gear rotates 90 degrees when retracted up between the engines. Source: Tu-144 Landing Gear Retraction Source: Tu-144 Landing Gear Retraction

43

Yes, actually you can only hear a supersonic aircraft after it has passed over you and is now flying away from you since it is moving faster than the sound moving towards you. The sound waves will still propagate in all directions and will eventually reach you: The frequency will be shifted according to the Doppler formula:  f = \frac{c \pm v_r}{c \pm ...

38

That's definitely not true, metal shredding off an airplane is the sign of a structural failure, and is a serious problem. It certainly doesn't happen often. It's unlikely that they would be going supersonic over land, you'd know it if they did as it creates a very loud bang. As for what that metal was I couldn't tell you, perhaps they came from the ...

38

No. The Boeing 747 was not designed for supersonic flight, though during testing, it was pushed quite close to the sonic speed: Tom Cole, a spokesman at Boeing Commercial Airplane Co., said original flight tests of 747s conducted in 1969 and 1970 took 747-100 models to speeds of Mach 0.99. However, the aircraft is not built for sustained supersonic speeds: ...

37

Yes, the ground speed of a subsonic aircraft could be larger than the speed of sound. As an example, during the record time for a subsonic Atlantic crossing a Boeing 747 reached speeds of up to 1327 km/h: Experts are hailing a British Airways flight as the fastest subsonic New York to London journey. The Boeing 747-436 reached speeds of 825 mph (1,327 km/h) ...

36

Currently there is no rotary wing craft capable of supersonic flight. Combined with the forward motion through the air, the rotating blades attack the air on one side and retreat backwards on the other. As the aircraft moves faster this poses 2 problems: The retreating blade has a point of zero air speed, starting from the axis at hover and moving to the ...

34

The Tupolev Tu-144 was just as loud as the Concorde. As it was already pointed out, the Concorde was legally prevented from going supersonic over land by the US, UK, but it was more than capable of going supersonic over land. There were no similar restrictions over the Soviet Union for the Tu-144. Both planes had a sonic boom. The plane's chief designer, ...

32

Sonic booms aren't created by the aircraft's engine noise. They're created by the aircraft moving through the air. The aircraft has a non-zero volume (an aircraft with zero volume is like the emperor's new clothes; you can argue all you want how much design and engineering work it took but all anyone will see is an empty spot on the flight line), meaning it ...

31

While tungsten does have a high melting point (I'm not sure what's the relevance of boiling point here), it has little else to offer for aircraft construction. The main issue of course is weight. One of the main goals of aircraft design is to reduce weight while achieving all the required performance parameters and tungsten is among the heaviest elements ...

30

A number of things happen when you rotate the canards by 90°, and in no way I see how these could be addressed by not too many modifications 1. Transient Once you land, you need a certain amount of time to rotate the canards. During this time the canards will not produce a perfectly horizontal force, but it will have also a vertical component. Whether ...

29

This PDF indicates an increase by ~10 dB for an F-8K in afterburner versus the same aircraft in 100% dry thrust. This PDF indicates smaller increases: +5 dB for an F-15 +4 dB for F-22 and F-35

28

There a several reasons for the demise of commercial supersonic aircraft. And there is a strong possibility we may be able to take a ride on a supersonic aircraft by 2021. Supersonic commercial aircraft have a lot of constraints on them which are not present on subsonic commercial aircraft and which military aircraft are not subject to. Prohibitive ...

26

Both are ways to create compression shocks in order to compress and decelerate supersonic air. Spike intakes The central spike is characterized by: undisturbed flow, light weight and compactness, and easy adjustability to speed and mass flow at high flight speeds by translating the spike. Its disadvantages are: large loss of efficiency with angle of ...

25

Actually, the Boeing design for the SST (Super Sonic Transport), the Boeing 2707 had a swing wing (swing wing was the hot thing during that time). It is instructive to look at what happened to that design. Image from up-ship.com The 2707 concept was a larger aircraft, with a 174' wingspan for TO/landing and low speed regime (In comparison, Concorde had a ...

25

Yes, In the U.S.A there are many privately owned ex-military jet fighters that are capable of exceeding Mach 1. It is quite conceivable that a privately owned fighter jet has exceeded Mach 1 but not reported it or been caught by the authorities. You can search the FAA civil registry by type: FAA REGISTRY Make / Model Inquiry Here is just a partial list of ...

24

You can watch for yourself 4 minutes in on this video. Can't tell at all, so much so that they have to let people know with a big sign. Once the issues of buffeting during the transition were fixed in the design of supersonic aircraft, pretty anticlimactic.

24

The three competing supersonic designs are discussed in this video – The Forgotten American Concordes. Two competing designs from the USA were proposed to the US government, which was going to fund 75% of the development cost: one from Lockheed, and the B2707 from Boeing which was the winning design. The B2707 was meant to be bigger and faster than Concorde,...

24

It has been around 20 years since I've been on a carrier deck, but I recall that it wasn't as dramatic of an increase as you might think. It may have gotten a little bit louder, but what I remember more is that the tone changed. The sound was more "full" when the afterburner was engaged. I realize this is a rather subjective answer.

23

To answer the question: Yes, and even more, both would be able to notice the sonic boom of the other aircraft. Why To understand why, you have to understand how sonic booms are created. Sound is nothing more than waves of different air pressure travelling through the air. Once released by an aircraft or other object, they start to propagate in all ...

23

Yes, a sonic boom produced at 60,000' can be heard on the ground. First of all, a sonic boom consist in a steep increase of air pressure, followed by a slow, linear decrease below the nominal ambient pressure, and again a steep increase back to the nominal pressure. It is therefore called N-shaped wave or just N-wave. Here is a graph with several sonic ...

23

Shock wave is a physical phenomenon and as such is unavoidable. The best we can do is to reduce their intensity and reduce their effects on ground. A method to eliminate the shock wave (theoretically) was proposed by Adolf Busemann. His airframe, called the Busemann's Biplane which consists of two triangular cross-section plates a certain distance apart (so ...

23

Here is a video that shows several aircraft breaking the speed of sound, including several still images of it. You'll notice that none of the images show the skin of the aircraft being affected. Supersonic Flight and Sonic Booms There are a lot of misunderstandings regarding breaking the sound barrier, including several theories, that still linger from ...

22

I think it is a matter of where you stand (literally). From the front or the rear the shock waves from the propeller tips would hit your ears continuously, and the result would be constant noise. When standing laterally, the propeller tips would move towards and away from you and produce a variation of noise intensity of the frequency produced by the ...

22

There are numerous reasons. They are not all economic ones by the way, even if most of them are. First, you must build your supersonic airliner Neither of the two supersonic airliners that once flew fly anymore, and none of the aircraft that still exist are likely to made airworthy ever again. Someone's going to have to design and build a new one. ...

20

The control problems are caused by a shift of the aerodynamic forces. In subsonic flight, they are mostly created in the forward part of the wing (the lift increase with angle of attack works at the quarter chord point of a wing, regardless of sweep), while in supersonic flow they work equally over the full chord. The center of lift in pure supersonic flow ...

19

Supersonic level flight? No. The fastest propeller-driven aircraft is either the turboprop-powered TU-114 with a measured top speed of Mach 0.73 or the turboprop-powered XF-84H "Thunderscreech" with a design top speed of Mach 0.9 and an actual top speed of either Mach 0.83 or Mach 0.7 (sources disagree). The latter is an indication of why supersonic ...

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