# Tag Info

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 ...

53

Just for a bit of flavour, I recall an article from Air Progress from the late 70s about Darryl Greenamyer setting the low altitude absolute speed record, in his "homebuilt" F-104, of Mach 1.3 (mentioned in this article) in 1977. For the run he had to cross very low over timing trigger devices at the start and end of the speed course at the dry lake bed ...

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 ...

41

In a lot of areas, sonic booms are illegal over land or near residential areas. Yes it's loud, yes it's potentially damaging, especially at low altitudes. I've been to a lot of airshows, I've never seen a supersonic demo.

36

Note that 747's and other jumbo jets operating out of Bradley could not have produced sonic booms because they do not fly above the speed of sound (they only do 500 to 550 MPH at high altitude cruise) and, in any case, far slower than that (~250 MPH) when near the ground as for landing and takeoff. Therefore, whatever it was you heard, it was assuredly not a ...

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, ...

24

Sonic booms have a lot of, lot of, lot of throw. There would be no way to confine a sonic boom to just the airfield. People two towns over would have have car alarms set off and houses shaken. It would upset animals, it would upset people! It would trigger PTSD for some and panics for others. It would generate hundreds of phone calls to 911. Keep in ...

19

The Concorde didn’t “refuse” to go supersonic over land; it was legally prohibited from doing so by every country it flew to/over. The Tu-144 produced the same sonic boom, but aside from a few exhibitions, it flew only to/over countries that had no such law.

14

It was either not a sonic boom, or it was not a commercial jet. As Niels has pointed out, civilian aircraft are prohibited from operating faster than 250 knots Indicated Airspeed below 10,000 feet MSL in most cases. You would have to get special permission from FAA leadership (not ATC controllers) to otherwise perform such a stunt. §91.117 Aircraft speed. (...

12

If you lived near an international airport with commercial traffic, then it couldn't possibly have been sonic booms, as others have noted. What you likely have heard is jet noise. Jet noise has been known to be notoriously bad. If you google sound scale, jet noise is pretty much always near the top. That's one of the primary reasons why city airports haven't ...

9

No. Sonic booms are caused by shockwaves which form on the aircraft structure as it moves through the air, not by the engines. Completely unpowered craft can create sonic booms, for instance the Space Shuttle and other spacecraft on re-entry. Even if you accelerate the air along the airframe you aren't going to be able to stop the boom, because it's not ...

7

The short answer is a bad PR fallout following the Oklahoma City sonic boom tests, even though the tests were generally positive. [The National Opinion Research Center] reported that 73% of subjects in the study said that they could live indefinitely with eight sonic booms per day. (...) The FAA's poor handling of claims and its payout of only \$123,000 led ...

6

Another reason is that much of the flight was over the huge land mass of Kazakhstan with very low population density. So few people live in the steppes there that Roscosmos lets the first stage of rockets taking off of Baikonur simply fall to the ground. You wouldn't want to do that over France or England.1 Population density is higher in Russia close to ...

6

John K has already provided an example of what a sonic boom feels like from very close, and Harper - Reinstate Monica describes it in general terms. Let me give you a practical example of what a sonic boom did in a radius of 100 km. On 22 March 2018, Air France flight AF671A from Réunion to Paris Orly was flying over northern Italy when it lost radio ...

5

The sound barrier is a function of airspeed and air density. If you have a strong enough tailwind, your ground speed would be above what most lay people would consider the speed of sound without breaking the actual sound barrier. Aircraft (or any object moving through the air alone) are governed by airspeed. Ground speed is only relevant when traveling on ...

5

I did some reading and this is what I could find out so far: https://www.nasa.gov/aero/nasa-prepares-to-go-public-with-quiet-supersonic-tech This article is similar to the Engagdet one but goes into slightly more detail(though not enough for a proper explanation) about the dive maneuver. However, Lockheed Martin is in the process of designing and building a ...

5

When you want to know why the FAA or any other US government agency created a rule, the answer will be found in the Notice of Proposed Rule Making (NPRM) that is required to published prior to implementation of a new rule (with limited exceptions for emergency rules). All NPRM are published in the Federal Register, after which there is a period for public ...

5

What would real sonic booms have been like? The other answers do a good job of explaining how commercial airliners have gotten quieter over the years and how you were probably hearing jet noise, not sonic booms. But how do you know it wasn't a sonic boom? What would it have been like to live under regular sonic booms? Well the only way to know that for sure ...

5

You may have been hearing the Concorde reaching supersonic speed after its takeoff from the JFK and Dulles airports. I heard them frequently while on Cape Cod during the summer months. Interesting studies were done about this phenomenon and its effect on the population.

4

In addition it's also worth noting that the TU-144 only made 102 commercial flights. It wouldn't really have got to the point where anyone would complain.

4

I was doing some research when I came across this question and thought that maybe someone still cares about an answer. In fact both answers given so far are almost right but lack some background. To elicit low sonic booms, commonly also described as sonic thumps, the F-18 first ascents to a height of a couple of thousand feet (40-50k). Once the height is ...

1

The speed of sound is measured in relation to the medium an object (or sounds waves) are moving. The actual speed is dependant on the tempreture and some other factors of the medium. Let's take for example the the information here : From the EngineeringToolbox We can see that in dry air, 20 celsius, the speed of sound is about 340 m/s. In adtition, if we ...

1

Direct answer – Some weather patterns can cause some booms to be heard tens of miles away and urban and suburban growth was quickly extending into formerly rural areas, so the theoretical corridors weren't going to be practical. Background – I lived in both rural and urban areas during the years while supersonic flight was allowed. While the noise did not ...

1

By flying straight up before exceeding Mach 1, to spread the boom more widely. The commentary says: at 2:10, "pull up" and the smoke trail suddenly points upwards; "[2:16] subsonic below thirty thousand feet," "point zero nine Mach [for?]ty thousand [feet?], thump, copy one point zero nine Mach, more thumps, [2:39] one point zero eight Mach." In the dive ...

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