Pea soup
The first fully automated landing of a passenger-carrying commercial aircraft was in
- 1929
- 1965
- 1977
- none of the above
Answer: B. on June 10, 1965, at London’s Heathrow airport. (1929 would be a tad early, but that’s when Jimmy Doolittle made history’s first take-off and landing by the use of instruments alone.) An ILS Category IIIc is an approach procedure which allows a landing without a decision height minimum and without a runway visual range minimum. The motivation behind this event was that BEA and other European airlines were losing revenue due to frequent weather days, so BEA decided to develop an automatic landing system. Prior to this, autopilot systems worked only in cruise. Autoland could fly down to 12 feet on a CAT-3B landing without the pilot touching the controls. The first such passenger flight was in June of 1965. Choice C represents the year of the first test landing of the Space Shuttle Enterprise. (The first landing of STS-1, after a return from orbit, was in 1981.)
That’s okay; I still have my other ear…
The noisiest aircraft of all time, during takeoff, is (was)
- a B-1 in full afterburner
- Concorde
- the XB-70 Valkyrie supersonic bomber
- the SR-71
Answer: C. Takeoff noise levels of 136 dB were measured, with perceived noise levels 10 dB higher than this in the 125 to 250 Hz frequency range (from NASA Technical Memorandum X-1565, April 1968). The approximate noise level of the B-1B at similar distances is 120 dB. The effective perceived takeoff noise level (EPNdB) of Concorde is actually not too bad, relatively speaking (almost 120 dB), although not quite as stealthy as a 747. (According to Advisory Circular 36-1G, “Noise Levels For US Certificated And Foreign Aircraft”, the early 747 models ranged between about 105 to 109 dB, although some later -400 series can get below 90.) To give you some relative reference, a chain saw at normal operating distances puts out about 110 dB, and a very loud rock band perhaps 120 dB. (Keep in mind that the scale is logarithmic, and not linear.) Anything over 130 dB risks an actual excitation of structural component resonances. (Can we say “Jericho”?)
Highway tolls
In general, it is more expensive to fly distances of up to a very few hundred miles than it would be to make the same trip by car. For trips of more than this, it is much more efficient to fly there, in terms of fuel and energy expended per passenger-mile. From the following choices of the percentages of the world’s transportation energy budget that is consumed by air travel, and that which is needed for highway travel, which comes closest to reality? (Note: the two will not add up to 100%, as there are other forms of transportation, such as over water, which are not considered here.)
- air, 25%; highway, 40%
- air, 20%; highway, 50%
- air, 15%; highway, 60%
- air, 10%; highway, 70%
Answer: D. It’s actually more like nine percent and about 72%, respectively. So even though over 40% of the initial weight of that 747, in which you and a few hundred other folks are zipping along at maybe 500 knots, is just from fuel, and perhaps only five percent of the weight of your car is due to the gas you had to pump into it, flying is still cheaper (at least on a demographic usage level) overall.
