So this guy on YouTube says that Boeing has an opportunity to “leapfrog” the competition, or the market, or a river in Hell perhaps, by pulling the “Future Small Aircraft” from the longer-term future to the shorter-term.
I say no way. Now maybe there’s a case, but so far I don’t see it. Here’s the video, and then I explain my thinking.... [Read More]
You’ve just taken off from an airport and bird strikes have disabled both engines on your airliner. Sounds like a recent movie based upon a masterful piece of airmanship and fortuitous circumstances ten years ago, doesn’t it? Here is a cockpit video of a flight crew handling a dual engine failure made in an EASA qualified Full Flight Simulator configured for a recent Boeing 737. The simulated bird strikes occur at an altitude higher than that of the U.S. Airways Flight 1549 incident, which permitted the crew in this case to return to the airport whence they took off, although bleeding off the excess energy was dicey.
Note that they landed faster than normally and with flaps not fully extended and hence had to use maximum braking which might have created a brake fire. The simulated fire trucks after wheels stop are particularly impressive.... [Read More]
As the jet age dawned for commercial air transport, the major U.S. aircraft manufacturers found themselves playing catch-up to the British, who had put the first pure jet airliner, the De Havilland Comet, into service in 1952, followed shortly thereafter by the turboprop Vickers Viscount in 1953. The Comet’s reputation was seriously damaged by a series of crashes caused by metal fatigue provoked by its pressurisation system, and while this was remedied in subsequent models, the opportunity to scoop the Americans and set the standard for passenger jet transportation was lost. The Viscount was very successful with a total of 445 built. In fact, demand so surpassed its manufacturer’s production rate that delivery time stretched out, causing airlines to seek alternatives.
All of this created a golden opportunity for the U.S. airframers. Boeing and Douglas opted for four engine turbojet designs, the Boeing 707 and Douglas DC-8, which were superficially similar, entering service in 1958 and 1959 respectively. Lockheed opted for a different approach. Based upon its earlier experience designing the C-130 Hercules military transport for the U.S. Air Force, Lockheed decided to build a turboprop airliner instead of a pure jet design like the 707 or DC-8. There were a number of reasons motivating this choice. First of all, Lockheed could use essentially the same engines in the airliner as in the C-130, eliminating the risks of mating a new engine to a new airframe which have caused major troubles throughout the history of aviation. Second, a turboprop, although not as fast as a pure jet, is still much faster than a piston engined plane and able to fly above most of the weather. Turboprops are far more fuel efficient than the turbojet engines used by Boeing and Douglas, and can operate from short runways and under high altitude and hot weather conditions which ground the pure jets. All of these properties made a turboprop airliner ideal for short- and medium-range operations where speed en route was less important than the ability to operate from smaller airports. (Indeed, more than half a century later, turboprops account for a substantial portion of the regional air transport market for precisely these reasons.)... [Read More]
I took an international flight today, and did something I’ve intended to do for some time: monitor the background radiation flux as the plane changed altitudes. I brought along a QuartaRAD RADEX RD1706 Geiger-Müller counter which detects beta particles (high energy electrons) and photons in the x-ray and gamma ray spectra and displays a smoothed moving average of the radiation dose in microsieverts (μSv) per hour. The background radiation depends upon your local environment: areas with rocks such as granite which are rich in mildly radioactive thorium will have more background radiation than those with rocks such as limestone.
One important component of background radiation is cosmic rays caused by high energy particles striking the Earth’s atmosphere. The atmosphere is an effective radiation shield and absorbs many of these particles before they reach sea level, but as you go to higher altitudes, fewer particles are absorbed and you experience a higher background radiation dose from cosmic rays. Background radiation at sea level is usually around 0.10 to 0.13 μSv/h. At Fourmilab, at an altitude of 806 metres above mean sea level, it usually runs around 0.16 μSv/h.... [Read More]