The World From Your Airplane Window
A science writer's guide for the inquisitive air traveler.
- By Brian Clegg
- AirSpaceMag.com, February 07, 2012
Laurel F
One drink you might be served on board your flight could be a little disappointing—and not just because you might have to drink it out of a plastic cup. That’s a nice cup of tea. Tea enthusiasts like their tea made with boiling water—which means getting the water up to 100˚C [212˚F]. That’s never going to happen on a plane. Not because the cabin crew can’t be bothered to do it properly, but because it’s impossible to get water up to 100˚C on board the aircraft.
At the pressure of an aircraft cabin—the equivalent of being up to 8,000 feet above sea level—water boils at around 90˚C [194˚F], and that’s as hot as your tea is going to get.
Imagine if you had one of the water boilers from the galley on the wing of the aircraft. A cup of tea made with this water would produce a very unappetizing drink. With the reduced air pressure at around 40,000 feet, water boils at just 53˚C [127˚F].
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Comments (9)
Thank you for this very interesting and informative article. As a regular flyer myself, and a former student pilot, I would like to suggest adding some more information about what a passenger can see from the vantage point of sitting just behind the wing. I have had lots of fun looking at the control surfaces on the wing -- ailerons, spoilers, flaps -- and using what I see in the deflections of those surfaces, particularly the ailerons to deduce what the pilot is doing.
For example, on a landing approach, from my view out the left window just behind the wing, I see left ailerons deflected downward, indicating that there is a crosswind component from the right, causing the pilot to slip the airplane to the right to correct for the crosswind.
I have also seen pilots using spoilers to slow the airplane to safe turbulence penetration airspeed during straight and level flight, and also once, when there was a steep descent required due to traffic conditions on approach to a very busy international airport. That was a thrilling adventure as the pilot on that flight was also using thrust reversal together with spoilers in order to maintain safe airspeed.
Flaps of course, are quite obvious when landing or taking off.
I know, I have been verbose here, but if I could use some pictures, everything would be much clearer.
Thank you for considering this suggestion.
Posted by Gerard Pereira on February 8,2012 | 04:44 PM
Thrust reversers used in flight? No way, they are interlocked that they can not be used unless the plane is on the ground.
Posted by John Bell on February 12,2012 | 12:31 PM
@John Bell: Yes, many aircraft are certified for in-flight use of thrust reversers. The DC-8 is so certified. However, there are conditions of use which vary aircraft to aircraft...it is unusual!
Posted by Michael Bludworth on February 22,2012 | 05:38 PM
Maybe he meant speed brakes?
Posted by Robb Cole on February 22,2012 | 08:05 PM
When seated in a window seat near the wing leading edge or slightly aft, I have noticed several times the air density change, in certain atmospheric conditions, that allowed a normal shock wave to be visible in the vicinity of the engine nacelle intersection with the wing leading edge on a jet aircraft. This shock wave would be quite stable and proved that the gas dynamic textbook illustrations were accurate. The aircraft itself was not travelling supersonically but the air was being locally accelerated enough to approach or exceed sonic conditions.
Posted by Tom Lisec on February 23,2012 | 09:05 PM
Thanks for the snippet of information. Keep up the good work. My personal joy in flying is land use and geography / geology. Saw my first wind farm a year ago (Minnesota) and it took me a while to recognise the site and its minimal impact.
Posted by ErnestPayne on February 24,2012 | 08:26 AM
Was that steep approach into Washington National by chance? They tend to name it after the basic tool we know as the crowbar. I rode it in a USAIR Dc-9 once. Quite a ride, but I'm pretty sure he didn't use any reverse.
Posted by Markus on February 27,2012 | 11:53 AM
Would a runway facing due North be numbered 36 or 01?
Posted by Dave R. on February 28,2012 | 08:50 PM
A runway facing north is numbered 36. Approach it from the opposite end and it's numbered 18.
Posted by Auntie Analogue on March 23,2013 | 12:14 AM