(Please see update below.) Thanks for a slew of messages and queries on the two unrelated air-safety items in the news today. These involve an episode two years ago in Singapore, and one today over the Gulf of Mexico. The main points:
1) OK, Now I See How a Mobile Phone Could Be Dangerous in Flight. This case, from 2010, is easier to explain but harder to understand. According to Australian news reports, the crew of an Airbus A320 had to abort a final approach, and "go around" just before landing, because its captain was distracted by beeps on his mobile phone -- and didn't notice that he had failed to put the landing gear down. The flight was on Jetstar, the discount sibling to Qantas, and went from Darwin to Singapore. FWIW, my wife and I had gone on that very Jetstar route not long before.
The account in Australia's The Age, based on an investigation by Australia's counterpart to the NTSB, is fairly dramatic:
Somewhere between 2500 feet and 2000 feet, the captain's mobile phone started beeping with incoming text messages, and the captain twice did not respond to the co-pilot's requests.
The co-pilot looked over and saw the captain "preoccupied with his mobile phone", investigators said. The captain told investigators he was trying to unlock the phone to turn it off, after having forgotten to do so before take-off.
At 1000 feet, the co-pilot scanned the instruments and felt "something was not quite right" but could not spot what it was.
At this stage the captain still did not realise the landing gear had not been lowered, and neither pilot went through their landing checklist.
At 720 feet, a cockpit alert flashed and sounded to warn that the wheels still hadn't been lowered.
At 650 feet, the captain moved the undercarriage lever "instinctively" but then a "too low" ground-warning alarm sounded as the plane sunk through 500 feet, indicating the landing gear was not fully extended and locked.
This is easy to "explain" in the same way a texting-while-driving car crash would be. Every pilot who has trained in a retractable-gear plane has heard a zillion warnings and reminders about the constant danger of forgetting to lower the landing gear. (One reason the kind of plane I fly, the Cirrus SR series, has "fixed" landing gear is precisely to avoid this source of risk.) As the old chestnut has it, there are two kinds of retractable-gear pilots: Those who have forgotten to put the gear down, and those who will.
Precisely because of this danger, there are countless drills, mnemonic devices, cockpit alert systems, "flow checks," and other safeguards meant to increase the likelihood that you will have "three green" before landing. These are three green lights showing that the wheels on the nose and the right and left wings are all down and locked. I've never been in an A320 cockpit during a fight, but here's more or less the idea of how the three-green indicator would look in an A320. Those green triangles would be glowing and hard to ignore.
And of course all pilots are supposed to use checklists -- above all two-person crews of professional airline pilots. They obviously didn't do so in this case, and that obviously looks bad for them and the airline. At least they recognized the problem before it was really too late and went all the way down for a "gear up" landing. These need not be fatal, or even dangerous, but they certainly mess up the airplane and cause a lot of trouble.
And, of course, the incident had nothing to do with a passenger using a Kindle or other "device with an on-off switch" while in flight. I'm sure the captain is the first to admit that: he should simply have ignored the phone and any other distraction while he was landing, and of course both pilots should have used the checklist. In the end, they were embarrassed and may be disciplined, but no one was hurt.
2) The Crash in the Gulf. As reported in the Atlantic Wire and elsewhere, a twin-engine Cessna 421 circled over the Gulf of Mexico, with its pilot apparently unconscious, until it apparently ran out of fuel and landed in the water. It appears that the plane sank before the pilot, reportedly the only person aboard, could be rescued.
A lot about this crash is yet to be explained, but two graphics from the indispensable Flight Aware -- the same service that was censored from showing the track of the Space Shuttle Discovery's ceremonial flyby over Washington DC -- are suggestive. The first is the plane's course across the Gulf, before descending into the water:
This suggests that somewhere over the water the pilot, for some reason, was no longer in control of the plane's course. Maybe he had a heart attack or similar medical problem? Maybe, as in the crash of Payne Stewart's jet back in 1999, the plane suddenly lost its pressurization, and the pilot quickly lost consciousness in the thin air and frigid temperature at high altitude? It appears that the autopilot somehow got set for a steady turn to the right. The corkscrew tracks keep moving further toward the east, as the plane was pushed that way by the prevailing winds.
The graph shows the plane's altitude:
The significant points: the plane was very high, at an airliner-like "flight levels" altitude of around 30,000 feet, where the pilot could not have remained conscious and active for long in a decompression. The autopilot was clearly set to hold altitude, and the (relatively minor) excursions in airspeed could be explained in a way I'll get to another time. And the airplane appears to have descended relatively slowly, which would be consistent both with the idea that it eventually lost power and began gliding because of fuel exhaustion, and with the reports that it floated for a while after hitting the water.
The turns shown on the map, over a period of hours, are clearly auto-pilot driven, with no one awake at the controls, rather than the spiral-descent of "stall-spin" accidents or cases like the John F. Kennedy's crash. I'll explain this another time too. For now sympathies to all affected.__
Update A friend who is an avid pilot sends this annotation:
First, after initially making a big right turn, it looks like the plane got set up for making a steady LEFT turn resulting in that corkscrew pattern seen on the Flightaware track.
Second, while I don't know the details of the autopilot [or much else for that matter] on the C421, it doesn't seem that the altitude hold was working. Shortly after leveling off at FL280, the altitude varies to as much as FL328 or so.
And last, the Flightaware altitude/speed chart shows GROUNDSPEED, not airspeed, which may explain the more-or-less sinusoidal variation in speed as the plane flew in circles with a prevailing westerly wind.
The last point, especially, makes obvious sense. At the stage in each corkscrew when the plane was turning into the wind, its groundspeed went down. When it circled around to be going with the wind, the groundspeed naturally picked up. Should have mentioned that before.