History, Media Criticism, Popular Culture, Space, Technology and Society

Supersonic Flight

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Over @NRO, Josh Gelernter is far too credulous of Airbus’s announcement of a supersonic transport:

In April 1976, Congress banned supersonic passenger planes from landing in the United States. The ban was overturned by the courts in 1977, after it was pointed out that the Concorde — which flew at subsonic speeds around the airport — was in fact quieter than conventional jets. Never mind: Like irrational fears about nuclear power or GMOs or vaccines, sonic-boom panic sustained anti-Concorde campaigns, which successfully throttled its business. When the Concorde was announced, airlines around the world placed combined orders for more than a hundred planes. By the time it made its first flight, a quarter of the orders had been withdrawn. By the time the production line was up and running, three-quarters of the remaining orders had been canceled. Only 20 Concordes were actually built; all 20 were bought by the British and French governments, which had paid for the Concorde’s development. They were flown by BOAC and Air France.

When Pan Am launched the first transatlantic passenger flights in 1939, a round-trip ticket cost $675 — which is about $11,000 in today’s money. Clipper flights were even more exotic than Concorde flights; nonetheless, within a few decades, they had driven ocean liners out of business. Because so few Concordes made it into service, service prices never came down, part prices never came down, operation never became routine. In 2003, the Concorde died, and mankind did something it does rarely: It took a step backward.

Concorde’s problem was not laws against supersonic overland flight, but very high operating costs, and limited range, due to the excessive wave drag. The real market for supersonic flight is transpacific, but Concorde could barely make it across the Atlantic. The initial orders were probably based on overoptimistic estimates of costs, and once reality sunk in, the orders dried up.

And to equate a commercial aircraft with Apollo and our later abandonment of lunar capability is a category error, unless he meant that in both cases they were economically unsustainable, in which case, it was best to end them.

So thank God for Airbus. Finally we — as a species — are back on track. Actually, Airbus isn’t the first aerospace firm to talk about bringing back supersonic passenger flight — but it’s the biggest and the most credible. An Airbus neo-Concorde is downright plausible. The new Airbus design, we’re told, will be able to fly from London to New York in one hour — two and a half hours quicker than the Concorde. Its top speed will be 2,500 mph to Concorde’s 1,350. And, for the hippies, it will have boom-dampeners, so the noise won’t bother western Long Island, and so it will be able to fly overland. Of course, the one, big, nagging problem is that Airbus is an Anglo-French company. Are we going to take that? I’m sure Boeing and Lockheed and Grumman all have e-mail addresses.

Key words: “…we are told…”

A 2500 mph aircraft will need much more exotic materials than the Concorde did to handle the high skin temperature, and its fuel consumption will be horrific, again with limited range. Note that there’s no mention of transpacific, it’s again just a faster way to get from New York to Europe. Its market would be just as, if not more limited than Concorde. I think that this is marketing hype (like Boeing’s Sonic Cruiser a few years ago). And he doesn’t seem to be aware of changes in the industry. “Grumman” is now Northrop Grumman, and it’s a company that has zero legacy of building a commercial transport. “Lockheed” is Lockheed Martin, and it got out of the airliner business in the late seventies, after the commercial failure of the L-1011 Tri-Star. The notion that either of them are going to get in against Boeing with a supersonic transport is a flight of fancy. I am working on a concept that might make supersonic flight practical, but I see nothing about Son of Concorde that would do so.

40 thoughts on “Supersonic Flight”

  2. I have a question I was doodling on the other day that sort of relates to a four-engine supersonic aircraft like Concorde or the B-1. For high speed you want a very low bypass ratio, essentially a pure turbojet, but for takeoff, climb, descent and subsonic cruise you want a high bypass ratio turbofan. I was thinking more specifically about the long subsonic cruise, supersonic dash, followed by a long cruise home.

    Anyway, suppose you took something like an F-135 engine, which is already set up to sometimes drive a large lift fan, and instead used it as one of the aircraft’s four engines, but driving all four fans through a common perpendicular shaft arrangement? The other three engines are low bypass like the F404 or pure turbojets. So cruising on the one core gives you a 4:1 bypass ratio, while lighting up another engine drops it to 2:1, and running all four engines gives you a very low-bypass for supersonic cruise.

    I haven’t crunched any numbers on it, but it seemed like a cheesy easy way to do a variable bypass engine.

    1. My version of this is a variant on the new Pratt and Whitney PurePower engine family, where they are “betting the company” on a gear-driven fan at insane horsepowers.

      My extension of this is to introduce a fluid clutch and a gear shift like they used to have on Greyhound buses. To change from subsonic to super and hypersonic flight, the pilot will have to manhandle this stick-shift lever, which will result in scrunching noises throughout the passenger cabin . . .

    2. Driving a bunch of fans with a bunch of turbines is the design idea for electric aircraft. The driving technology for this is sufficiently low weight superconducting motors and generators.

      Low weight superconducting generators are also very attractive for large wind turbines, to minimize the mass in the nacelle.

  3. Are there destination pairs that can be served by ‘supersonic’ that wouldn’t be accessible to suborbital/ballistic?

    If not by SpaceX’s approach, one of the others?

    1. Single-hop suborbital has a distance limit beyond which reentry deceleration kills the crew and passengers. One would either have to do multiple hops (requiring high L/D hypersonics) or use a fractional orbital trajectory (go to LEO and decelerate/reenter before finishing a single orbit).

      1. In re long distance single hop suborbital, the references I recall cite exposure to radiation in the Van Allen belts with increased apogee as the issue. Maybe the entry deceleration is too, but I don’t remember that being mentioned.

        1. Come to think of it, Apollo surely came back from Luna with much higher energy than a suborbital hop of any distance. Now if one wanted to, I’m sure one could come in intentionally like a rock and get killed by the g loads (or incinerated), but surely a suborbital would have at least the L/D of an Apollo capsule.

          Aside from the radiation exposure issue, the problem on a single hop beyond a certain distance is that you actually require more energy than to get into a low orbit. But that’s not the same as a lunar return.

          1. Apollo came back at a shallow entry angle (I think 5 degrees). To do the same for suborbital over a long enough distance would mean an extremely elliptical orbit, with delta-V greater than just getting to LEO.

    1. Apparently the “real” X-15 pilots had a thing for Scott Crossfield who worked North American at considerably higher pay, and according to them, had an even higher opinion of himself.

      The story was that these guys had a plan to get Crossfield’s X-15 into orbit. Unlike the prior rocket planes carried in the belly of a B-29 or B-50, the X-15 was carried off-center beneath the wing of a B-52.

      The plan, it was said, was to perform the countdown “5 . . . 4. . . 3. . .2. . . 1. . . Drop!” only the B-52 crew would not “toggle off” the X-15 but leave it on the wing when Crossfield hit the rocket engine start switch.

      This maneuver would spin the B-52 mothership around like a helicopter, propelling it along with the X-15 into orbit, with Crossfield yelling the whole time over the radio, “Bonus! Bonus!”

  5. I flew on the Concorde once, from DFW to Dulles, on Braniff. They sublet planes that arrived in the afternoon at Dulles, put their own crew on it and flew to DFW. It would overnight there and then fly in the AM to Dulles. The one I flew on was a BA plane. The seats were 4 across, only slightly bigger than coach, with little overhead bin space and a cramped aisle. The food was good, the drinks were free and better than normal brands of booze and wine, and there were free papers – all 3 local DFW papers and the NYT. It was a Sunday, so no WSJ. I think there were 6 passengers onboard, and about that many flight attendants.

    Takeoff was very fast and noisy (afterburners were on according to my wife, who watched the departure), similar to a Learjet I had flown on a few years before. The plane had to fly a non-standard departure for noise minimization, We then flew up to above 40k feet and cruised to Dulles at Mach 0.99 according to the meter at the front of the plane. As we deplaned, I got a look in the cockpit, which was very cramped for the 2 crew, similar to a military plane.

    It cost First Class + 10% airfare, and this was pre-deregulation, so fares were high. A customer needed me at a site outside DC on Monday morning, and it was the only flight that wasn’t sold out, so they agreed to pay the airfare.

    In contrast, a few years later I flew in a DC-3 built during WW II to a scuba diving site in Honduras.

  6. As I understand it, Concorde was operationally profitable, but lost money when you took account of the development costs, which had to be spread across a tiny number of aircraft. Tickets were expensive, but weren’t that expensive, when compared to the alternatives; I remember in the 90s thinking of taking a trip to New York and back on Concorde, just for the heck of it, and it wasn’t something I’d do every weekend, but wasn’t extortionate, either.

    And the last transatlantic first-class slowcoach flight I took was in the region of $10,000 return. So that’s potentially a million dollars per round trip if a Concorde is full each way.

    What really killed Concorde was the decline in passengers post-9/11, and the need for major upgrades to keep them flying.

  7. The real market for supersonic flight is transpacific…

    A major problem with high speed transportation of any sort is geographical and medical. The bulk of humanity is distributed east and west in the northern hemisphere with a corresponding range of times of day. The problem of adapting to a different time zone on arrival (jet lag) becomes more and more acute as transit speed increases. This largely negates the advantage of the faster speed as the adaption period is correspondingly longer.

    This tends to drive the market for high speed flight to a spectrum of special cases (like organ transplant delivery). Unfortunately, those markets combined are too small to finance a project with very high up front costs.

    Terrestrial transportation speeds seem to have reached the point of diminishing returns with the sweet spot in the high subsonic range.

    1. Jim, I’m a bit doubtful on the jet lag issue.

      The one time I flew Concorde was from NY to London, normally an 8 hour flight, one I’ve been doing at least a couple of times a year all my life (first time was at age 6 months). I’m thus fairly familiar with the jetlag effects on me on that route, both eastbound and westbound. I’ve flown long haul (US to South America) many times too, and that doesn’t give me jetlag due to, I think, the lack of actual time change Short haul flights like LA to NY don’t bother me either.

      My point is that Concorde didn’t give me jetlag. Maybe it was the excitement (I was in college, an aviation buff, and had a window seat) or just the short duration, but I had no sense of jetlag, at all. I’ve only got this one anecdote to go on, but it makes me doubt the supersonic jetlag issue.

      I’d be delighted to try a hypersonic transpac flight. And, even if it did give me bad jetlag, jetlag is a nuisance, whereas 17 hours on a plane is utter hell (I’;ve done that several times, and hated it more each time).

      1. For a few years my wife and I flew at least once a year from Fairbanks to Chattanooga, a 12-hour trip due to layovers and plane changes as well as distance. It covered five time zones, to boot.

        If I had jet “lag” I never noticed. Usually what busted my ass was the unpleasant experience of airports, layovers, and hours at a time bottled up in a jet plane. It wasn’t “lag,” it was flat-out fatigue.

        Probably if I could somehow have made that trip at Concorde speeds I might have actually noticed “lag,” but the lack of jet fatigue would have made up for it.

        1. If I had jet “lag” I never noticed. Usually what busted my ass was the unpleasant experience of airports, layovers, and hours at a time bottled up in a jet plane. It wasn’t “lag,” it was flat-out fatigue.

          My wife and I have had similar experiences. It’s kind of funny how tiring airline travel is when you consider that about 95% of the time, you’re just sitting. It could be a combination of the noise, cabin pressure*, and low cabin humidity that add to the fatigue, along with being crammed in like cattle in a boxcar.

          *We lived in Colorado Springs (elevation > 6000 feet MSL) for 27 years, so low cabin pressure and humidity shouldn’t have bothered us. More likely it’s the cramped seats and noise that make airline flight so tiring. We just returned from a 2800 mile car trip and weren’t as tired as we get on some airline flights.

      2. Jim, I’m a bit doubtful on the jet lag issue.

        I know some guys who feel much the same about menstrual cramps. 🙂

        And seasickness. And allergies.

        About 25 years ago, when I was working for GE, NASA had a program called High Speed Civil Transport which I contributed to. One of the things that became very clear early on was the almost complete lack of enthusiasm that the airlines had for supersonic flight. One of the major issues they raised was jet lag, pointing out that a large number of businesses had strict rules about how long one of their reps had to be on the ground before he was permitted to conduct any business whatsoever. This period was typically in the range of 12 to 48 hours.

        The point is that while some people don’t suffer from jet lag (or seasickness, or allergies, or…), many do. And the effects tend to become more pronounced with age.

        One of the engineers working on the HSCT project was also very skeptical of jet lag. He came in one Monday complaining about how daylight savings time screwed up his whole day.

        …whereas 17 hours on a plane is utter hell…

        I’m going to guess you were flying coach. Why didn’t you upgrade to business or first class to avoid this hell? If cost was the issue why would an airline believe that you would pay much more to fly supersonic to avoid this hell?

        1. Even in first class, it’s a long time. The only really tolerable way for me would be full-bed (as some biz classes apparently offer). I simply cannot sleep sitting up. I did fourteen hours from TLV to Philly in January, it was miserable. But I don’t think it had anything to do with the environment, just a long time of being unable to sleep (when I boarded the plane at night after a full day).

          In retrospect, someone asked why I didn’t take some kind of sleep inducer. I guess it didn’t occur to me, because I’ve never done that in my life (other than alcohol).

          1. Even in first class, it’s a long time.

            You actually tried it in first class or are you just convinced that first class wouldn’t make a difference?

          3. I finally managed a configuration to sleep during a flight. Definitely needed the eye mask. I also would either wear ear plugs or earbud headphones depending on whether I needed some noise to relax me or not. On top of the plugs/buds, I would wear noise cancellation headphones. Only then could I get the wind noise to tolerable levels for sleep.

            This configuration worked well in first class where the FAs were likely to leave you alone. In coach, and on BA because of their nutty business class configuration, this system failed with the FAs constantly disturbing the rest. I grew up hearing that BA had great service, but my own personal experience is that BA FAs are demonic minions that believe if they must be up, so must you.

            Interesting comments from Jim Davis. I don’t get seasick, so I really enjoy vacations involving cruise ships rather than cramp airplanes.

          4. I sleep just fine sitting up. It just doesn’t seem really to help, except to make the mind-numbing tedium pass faster. I still feel like crap after landing.

            Probably because of the ozone problem Paul D mentions.

        2. Jim, I see your point. 🙂

          However, I very much do get jet lag (then and now) when I go on a conventional airliner on the same route I went Concorde, or of similar or greater length east or west. I also don’t get jetlag when I fly to South America (But I still feel like hell from the grueling journey)

          On the 17 hour Transpac being utter hell, I’ve done it in both first and cattle classes. Yes, coach (cattle class) is usually (but not always) worse. Both the best and worst transpac flights I’ve ever had were in coach (I’ll get to why later)

          First was still hell, just a higher level of hell. 🙂 At least with a recline-to-flat 1st class seat, I could fitfully sleep (I cannot sleep sitting up, but even in 1st when I did get to sleep, anyone walking by woke me up anyway). This was true even in the window seat.

          Cattle class was the lower bowls of hell, sometimes. Once, I went cattle class because I couldn’t get any other seat on the day I needed to fly, so I bit the bullet and went cattle class on a nearly sold-out plane. I knew it’d be hell, and it was.

          Other times, I went cattle class intentionally, because the plane was partially empty and it was late enough to have a good chance of staying that way. Why? Because when a plane is at least partially empty, there’s a mode of seating I prefer above all (first class included). The airlines tend to leave the middle aisles in the rear unfilled, so I get an assigned aisle seat in the rear. As the plane fills, I keep an eye out for the gold prize; an empty row. If I’m not sitting in it, I make a dash for it as soon as the plane pulls out from the gate. That empty row is the best seating ever; I pop up the armrests and make a bed out of it (using pillows, blankets, etc) and stretch out. It’s actually quieter and more peaceful than first, and I sleep far better. Plus, there’s the money; it gives me a better flight AND saves me thousands of dollars (I’m not wealthy) – a great mix. So, to me anyway, both the worst seating and the best is in coach, depending on whether or not I can snag a row.

          How much would I be willing to pay for hypersonic (say, LA to Sydney in under 3 hours) even if it made jetlag a bit worse? Depends on my financial state at the time, but definitely at least double a first class conventional fare. Same goes for Europe.

          And BTW, I did some googling, and to my surprise, I’m not the only one who found Concorde far less jet-laggy than a conventional plane. http://www.airliners.net/aviation-forums/general_aviation/read.main/2347574/

        3. One of the major issues they raised was jet lag, pointing out that a large number of businesses had strict rules about how long one of their reps had to be on the ground before he was permitted to conduct any business whatsoever. This period was typically in the range of 12 to 48 hours.

          This is interesting considering the fact that several companies are working on supersonic business jets. There’s a lot of interest in them. Admittedly, large business jets are far more comfortable than even first or business class on regular airliners but if companies have those 12-48 hour restrictions, why buy a supersonic business jet?

  8. On a very minor note, I’d disagree with Gelernter’s contention that Concorde was no noisier a than conventional jetliner. From the window seat of a 747 waiting to take off from Heathrow one night, I saw a Concorde take off. It was very noisy. And mighty impressive in all respects: with afterburners visibly acting, it took off like a rocket and quickly disappeared into the dusk.

    1. I used to live under one of Concorde’s flight paths from Heathrow. It would wake me up if I forgot to set my alarm clock.

      But who cares? It was Concorde. The neighbours had lived there for years, but they’d still go outside some days and watch it fly past.

  9. I remember standing in the garden of Perry’s house in Chelsea and watching Concorde on final. I do not remember it being particularly noisy. But oh, what a gorgeous beast when seen in its natural element!

    2. Few planes are noisy on final approach. It’s the takeoff noise of full power that matters. With its afterburners, the Concorde was likely as noisy as a B-1B bomber. I was only a hundred yards of so from the flight line at Oshkosh 96 when a B-1 took off. It was the noisiest thing I’ve ever experienced. One thing about a Concorde is that with all that power, it probably climbed out rather quickly.

  10. Well, I never “flew” on Concorde, but I did ride on serial 001 from the ramp to the hangar at Toulouse, back in ’73 or thereabouts.
    Very small inside (2+2, low overhead) but the plushest leather seats I’d ever seen.
    I was there visiting Gerard Defer, as part of a vacation with Gordon Corp’s family (they had a son my age). Gordon, Gerard, and my dad were the respective pilot reps for Concorde national certification for UK, France, and US. My dad, who flew almost everything ever built over his career, claimed that Concorde was his favorite.
    What a beautiful machine.

  11. At the same visit I saw the prototype A3xx land at Toulouse. After it taxi’d in, we noticed that the burst plugs on some of the left main tires had blown (from hard braking, I suppose). So…my first exposure to Airbus was a plane with a flat tire 😉

  12. FYI: There is a Concorde open for viewing at the Seattle Museum of Flight, as well as several other worthy aircraft and spacecraft.

  13. At what speed to supersonic engine-inlet “unstarts” become a problem?

    They were said to plague the SR-71 along with the XB-70 test aircraft for the Valkyrie bomber. The unstart has to do with the shock wave in the engine inlet supplying a good portion of the air compression supporting engine power and then that shock wave going unstable and losing that compression.

    When they gave up on the B-70 bomber and were using the XB-70 to get flight data for the SST program, some had commented that unstarts would make for fearful passengers the way they would get slammed around.

    Did the unstart have to do with a variable-geometry engine inlet and trying to get a fast enough servo to stabilize the shock wave? Did Concorde not suffer from unstarts owing to fixed inlets?

  14. Really, I think mach 2.0 is good enough. A Super Concorde with more passengers and trans-pacific range non stop (if possible) would seem to avoid the exotic structures and engines problems of mach 3 or higher.
    I’ve endured Sydney to LA and back a few times (15 hours or so non stop at M=0.8, if the CIA did that to people the human rights crowd would be up in arms) and cutting that down to 6 hours looks good to me.
    Early evening departure from Sydney gets you to LA, cleared through customs and immigration by around 9AM LA time.
    Afternoon departure (4PM) from LA gets you to Sydney by around 9AM Sydney time. Good for a business day each way.
    A couple of Temazapams after takeoff each way and you get 3 to 4 hours sleep on the way.
    Also works for Tokyo – LA and back. Over water both trips so no sonic boom issues.
    Extra speed over mach 2 in the air buys you less advantage when combined with check-in, customs and immigration.

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