66

Make sure to read this answer to understand what is special about Mach 1. Pilots regularly report that, approaching Mach 1, the airplane is shaken by oscillating shocks (they don't use that term, though, they speak of buffeting) and once the Mach meter needle crosses the 1, the airplane becomes calm and flight smooth again. Since the flow speed around the ...


44

There is actually some data (albeit limited) on this scenario: On August 21st 1961 this test was performed in a DC-8. When this test was performed they were supersonic for about 16 seconds which took a lot of planning to pull off. You first need to climb higher than the plane typically does to have enough altitude to pull this off, then make sure you ...


22

Such design, with hyperbolic leading edges, has been invented by MBDA (Airbus branch for missile systems) represented by BAE Systems (defense contractor), and is described in the European patent 3 599 442 A1 filed on July 2018: The curve helps reducing drag, especially at supersonic velocities, an important factor for missiles and rockets, for which fuel is ...


16

The TWA Flight 841 accident in 1979 involving a Boeing 727 comes pretty close to your conditions. Not a zero-G dive but an unintended spiral dive starting at 39,000 feet, reaching mach 0.96 at 31,800 feet, becoming a 90 degree nose-down dive at 29,000 feet with total loss of control authority. With speed brakes ineffective, the pilot extended the landing ...


6

Drag forces grow quickly as you approach the speed of sound, and then fall off somewhat after you are above the speed of sound. This means flying near the speed of sound puts you in a high-drag regime, where you are putting work into the flow as shock waves are trying to establish themselves at various points on the airframe. Unless your airframe is ...


6

After you break the sound barrier, a shock wave will be generated in front of your main wings and tail wings. Though the design of wings on modern planes may hold that situation and can still generate some lift (which is impossible for traditional wings, leading to a fatal stall), the control surfaces on your main wings and tail wings will nearly lose their ...


5

The best you can do is to make the wing loading low. Wing aspect ratio helps, too, and if you look at existing designs, it will be similar to that of gliders and certainly higher than that of airliners or GA airplanes. This answer covers the characteristics which make a high altitude possible and, besides wing loading, mentions the factor $\text{Mach}^2 \...


4

Could an airliner exceed Mach 1 in a zero-G power dive and safely recover? There is only one answer here and that is NO, especially for the A320 in your example (there are other airliners better suited to tolerate higher transonic speeds). Yes, it's possible to recover from such a condition, but nothing about it would be safe. Recovering from this ...


4

Mach buffet precedes mach, and begins in the transonic range. The transonic range does not begin or end at 1.0 M1. It begins typically around .85 and may continue to 1.2 to 1.5. Buffeting may occur at any point within that range. Mach is not a point that is reached uniformly by the entire aircraft. This is to say, mach airflow will be reached at some ...


4

The rearward shifting center of pressure in the transonic regime is the culprit, which messes with the balance, though there seems to be workarounds: [...] the rearward shift in center of pressure at transonic speeds has made the problem of achieving balanced hinge moments throughout the speed range difficult. Such was the case for the horn-balanced, flap-...


3

Concorde afterburners were reducing overall fuel consumption. To understand why there is a special drag penalty around Mach 1, please read this answer. Now to your graphs in the question body. The first one with the steep drag peak at Mach 1 is for a straight wing which never was designed to fly trans- or supersonically. You do get such results, but only if ...


3

That is because as you approach the transonic regime, the drag on the airframe begins to rise and can reach up to ten times the subsonic drag. after you go supersonic, the drag falls down again- and this makes the transonic regime the worst place to operate a plane from a fuel burn standpoint. So you either stay subsonic, operating below the drag rise point, ...


2

It really depends on the aircraft. A DC-8 is known to have done this. (https://www.airspacemag.com/history-of-flight/i-was-there-when-the-dc-8-went-supersonic-27846699/) There are 2 sources of stress on the airframe in this situation- airliners aren't designed to fly past Mach 1 (except the Concorde and Tu-144...), so there's one issue. There's also the ...


1

Pretty much every early jet comes to mind. Think the Me262, the F-86, the Mig-17. All could go slightly supersonic in a dive without damage (if not kept up for long, obviously) but not in level flight. I've heard that some jetliners can go slightly supersonic in a dive without damage. Again, only if they pull out quickly and don't stay in the supersonic ...


1

Edges like these reduce drag. They originated on Falcon9, where they fold away on ascent and fold out on return. BUT, on Starship they don't fold away, saving the mass of the folding mechanism AND incurring the drag of flat edges on the way up. @ElonMusk. Rotating the pointy edges to face upwards during launch will likely save drag on the way up too. Then ...


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