For some time now, Captain Steve, a pilot with a major U.S. airline (and one of the nicest humans you’ll ever meet), has been answering your questions about flying. He has commented on everything from cabin air to maintenance problems and ticket prices. It’s been a while since we had him here, however, and since there’s no shortage of airline headlines — including an eventful winter for weather interruptions — we thought it was time to bring him back for another round of questions. So fire away in the comments section below, and we’ll post his answers shortly thereafter. I’ll prime the pump with a question of my own:
Steve, not long ago, I had occasion to fly into Hong Kong International Airport and, well — wow. It’s a very good airport in many ways but, to me, what’s most impressive is how it sits on an island outside the city, the product of a land-reclamation project, and how it therefore handles massive traffic by auto, bus, and rail without ruining traffic in the city itself.
On this blog, we’ve discussed the crowded New York airspace, and how closing LaGuardia might in fact alleviate that problem. So let’s blue-sky for a moment. What would happen if — against all existing political and financial obstacles — such an airport could be built offshore to serve New York? Talk to us about what such an airport would look like, what it would accomplish (or fail to), how large it would need to be to handle existing and future New York air traffic, etc. And most of all: what would such an airport be like from a pilot’s perspective?
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. You can also watch it on 
Another source for flying information is Ask the Pilot (http://www.salon.com/technology/ask_the_pilot/index.html).
Looks like these two “Ask” blogs complement each other very well.
Aircraft are designed and maintained so well, it seems that gross human errors or mischief play a role in many disasters. But a PBS “Nova” episode on Air France Flight 447 suggests that safe flight is only possible in a very narrow speed range. “At high cruising altitudes, the speed range that all commercial aircraft fly inside gets very narrow…. If Flight 447 speeds up or slows down by as little as 10 knots, it could suffer a potentially lethal condition known as a stall.”
I don’t see how excess speed could cause a stall, but there must be a maximum safe speed. Is the range really so narrow that unreliable airspeed indicators could, on their own, pose a danger?
Why do the wings on civilian airliners tend be attached to the bottom of the fuselage while the wings on large military aircraft (like the B-52, C-5, and C-17) are usually attached to the top of the fuselage. The obvious exceptions are the KC-10 and KC-135, but they’re both military adaptations of civilian aircraft.
Military planes, specifically transports, are designed for taking on and discharging cargo, including paratroopers. The KC-10 and KC-135 are tankers, which actually do carry some non-fuel cargo, but their primary mission involves their payload being pumped, not hauled, aboard.
If I remember correctly, you have to have wings up high if the tail section is raised as it is on military transports, for aerodynamic reasons.
The primary reason military transports have high wing mounts is to provide additional clearance for the engines off the ground. Miltary aircraft are designed to land at less than ideal airstrips and debris could easily enter the engine nacelle or damage the prop during takeoff or landing. By raising the engines, you reduce the risk to the aircraft and its crew.
There are many reasons why the wings are raised on millitary transports.
Engine clearance is one, especially in the C-17 and C-130, which were designed to land on unimproved fields (also: every Soviet-era Russian transport aircraft).
Another is aerodynamics, but many planes have high tails and low wings, the placement is due mostly to the main wing spar. There’s one backbone that runs from the tip of one wing to the tip of the other. Obviously it has to pass through the fuselage somewhere. On a civilian jetliner, the idea is to maximize passenger space, so the wing spar is placed at the bottom, where the cargo is stored around it (this is why commercial jerliners have forward and aft holds). On a millitary aircraft, the idea is to have the load floor as low as possible, to facilitiate loading of vehicles and other large cargo. Thus, the wingspar is placed above the cargo hold. In fact, many trnasports place the wing spar in a hump atop the fuselage, and the plane literally hangs from it, which gives maximum cargo room for a given size aircraft.
Bombers and cargo planes put, well, bombs and cargo in the bottom of the fuselage. Having a large wing structure running across the bottom of the tube would disrupt the aircraft’s ability to do its mission. So, the designers of heavy lift military aircraft run the wings across the top of the tube. Tankers don’t have this issue, because liquid fuel can flow around a low-mounted wing.
Why do pilots’ uniforms look the way they do?
After hearing about the extensive efforts to find the ‘black boxes’ from flight Air France Flight 447, something occurred to me: When gigabits of memory can fit in something as small as an iPod, why not, in addition to the traditional black boxes, have a dozen little iPod-like recording devices distributed throughout the aircraft? This redundancy would allow a better chance of finding at least one of the recordings. Studying past crash debris could determine what part of the plane is most often recovered; one of these recording devices could be installed there. Not all of them would need to survive a crash, only one would do. But for a relatively low cost, there would be a dramatic increased chance of recovering a recording of what happen in the event of an airline accident.
I think you will find that each black box is not as small as an ipod, mainly because in each one there are is a whole range of redundant instrumentation already. Where possible, analogue and digital records are kept and just about everything that has any relevance in a place is stored in there. Furthermore they need to be able to store all this data at speeds that are on par with the rate the large amounts of data that are generated and often state-of-the-art processors are used as well as many forms of memory to make sure at least 1 survives (magnetic drives such as those in most ipods could easily get damaged by the increase in radiation at high altitudes, eeprom and flash memory such as in USB sticks is prone to malfunctions in high humidity such as would happen should the black box fall into water, etc)
The bottom line is everything i have listed so far accounts for only a tiny fraction of the VERY dense and precise especifications a critical device such as a black box has. The problem lies not in how much memory/processor you can get in to a black box/ plane, but rather how many different ways can you protect that data.
Finally, unless im wrong, most airplanes today use anywhere from 3-5 black boxes per aircraft. Adding more redundancy without a reasonable increase in the effectiveness of the black boxes as a system is just wasting money since you are reducing cargo capacity and increasing weight, both bad things since black boxes do not pay anything to ride on that plane.
have u seen Michael Moore’s movie Capitalism: a love story?- in it, he reports on the plight of training pilots, some of whom make minimum wage, sleep in cars, work other jobs, etc- what is your opinion on the way the industry treats the next generation of pilots, and do you think they should unionize?
Since radiation is in the news, is there any strategy for pilots and flight crews to mitigate the health risk from increased exposure to solar and cosmic radiation at cruising altitudes? Flight crews generally are exposed to much more radiation per year than nuclear industry workers. This periodically hits the news from time to time when the latest study showing increases in leukemia, etc. comes out. Is this something flight crews seriously think about, some background risk that everyone consciously accepts, or some nebulous far off threat people just don’t really take very seriously?
Why is the quality of loudspeakers so poor in all planes? Majority of PAs are either horribly loud giving a heart attack to napping passengers, and invariably so unclear it’s like someone is blowing to the mic (often in some other language than your own). There should be no echo in the cabin, there is cloth (seats, carpets) to diminish it. One would enjoy listening to PAs every now and then, and of course it’s necessary in emergencies.