Category Archives: Accidents
I got the greatest e-mail of all time today. But I’ll get to that in a moment. A while ago, Business Insider published an article detailing the “Most Dangerous Airlines.” This piece was in my opinion a hack job twisting facts to meet conclusions with only a limited basis in reality.
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A body fell from Air France flight 547 on approach to Niamy, Niger before continuing on to Paris. The Airbus 330-200 originated from Ouagadougau, Burkina Faso. The person, a presumed stowaway, had most likely hidden in one of the wheel wells and fallen when the gear opened for landing. As the flight was only 261 miles long, it highly likely that the individual was still alive at the time of his fall. Most stowaways freeze to death due to the extreme cold from long periods of high altitude flight. Unfortunately, this event is not uncommon and happens several times a year from flights originating in Africa. A post flight inspection of the aircraft discovered blood on one of the wings and the plane has been grounded pending a more thorough inspection.
I really wish events like this didn’t happen, but they do. Events like this only serve to reinforce the idea that something needs to be done to help the developing world.
As my normal signature would seem trite, I will only say be well.
H/T Aviation Herald.
Several weeks ago Asiana flight 214 crash landed at San Francisco International Airport. Of the 307 people on-board there were only three deaths. Of those three that died, 16 year old Ye Mengyaun died from essentially being run-over by a fire truck enroute to the scene.
Airport personnel frequently practice fire rescue on commercial airplanes. Those fire trainers, often repurposed airliners, are frequently visible in some disused corner of the airport. Due to the nature of their training, personnel do not have a large number of people running around to really simulate an airplane crash. Thirty years ago this made sense, back then the prospect of surviving an airplane crash was slim-to-none. Now however, if the airplane makes to the airfield, or never left, the probability of survival is quite high. The highest it has ever been actually. If a plane crashes on an airfield, rescue crews can expect to see large numbers of both ambulatory and nonambulatory passengers. So training for both ground staff and and aircrews needs to change.
Aircrews are currently trained to get the passengers off the plane as quickly as possible. The rule is that any commercial aircraft of any size has to be evacuated within 90 seconds. However, as far as I know there is no training for the next 90 seconds. After the evacuation there is now a large number of people panicking and rescue crews showing up who are just as amped up as the passengers. That alone is a recipe for disaster.
The solution to this problem isn’t easy. Every crash is different. However, aircrews should be expect to provide some crowd control after evacuation, and tell passengers move to the back, front, port, or aft. There should also be pre-arranged ways of communicating this to the rescue staff. This would insure the passengers do not interfere with rescue personnel and prevent future deaths.
On June 1, 2009 Air France flight 447 from Rio to Paris fell from the sky over the Atlantic Ocean killing all 228 passengers and crew. Today July, 5th 2012, the final report on the accident was released by the BEA the French aviation authority. This report containing numerous recommendations represents the final word on what happened.
What happened? Well if you have seen the Nova film on the matter, then you have a good idea. If you haven’t you should. I’ll do my best to explain.
Cruise flight in a modern aircraft occurs at high altitude. Makes sense the higher the altitude the less air, the easier it is to move the aircraft through space. The downside is the aircraft has to be going fast enough to move enough air over the wings to generate lift.
Thus, infinite speed infinite altitude right? No.
At those speeds going though air is like going through soup. The aircraft causes disruptions in air. Too fast and these disruptions break the flow of air over the wings causing a high speed stall. Too slow, it stalls, too fast it stalls. The speed in-between is called the coffin corner. 20-30 knts either way at altitude and the aircraft stalls.
How do you measure speed. Well, at cruise flight speed is a function of pressure. The aircraft needs to know how much pressure is pushing against the front of the aircraft. They use pitot tubes. The measure pressure.
In this case the pitot tubes iced over. Thus the aircraft was unable measure pressure. So AF447’s electronic brain concluded that the pilot should fly the plane.
Ok, so if you don’t know the speed, you eventually stall and then you die.
No. If that were true there would be a lot fewer planes around. Airbus built in a setting where the aircraft will be airworthy. 85% power and 5 degrees nose up and the pilots will be able to control the aircraft.
If this is true why did AF447 crash? Well the pilots didn’t fly the aircraft. Imagine this.
You’re a commercial pilot, you’re 3hrs in to a 10hr flight. The flight is going smoothly, systems seem ok, dinner was just finished, and through a combination of food, stability, and slight tiredness, you’re not as alert. You know the majority of incidents happen on takeoff and landing, so there is not much to worry about. Oh and it is pitch black outside and inside. Then all hell breaks lose. Lights are now flashing on the control panels, audio alarms are going off proclaiming multiple emergencies, and you have no idea why all of this is happening.
The purpose of these alarms were to draw the attention of the pilot. The pilots of AF447 were both fairly junior. The senior pilot was having a rest. This is standard procedure for all international airlines. However, here the situation went from fine to catastrophic in a matter of seconds. The pilots did what anyone would do, panic.
Panic is something good airline crews plan for. It’s called crew resource management. Step one of the plan is secure oxygen. Step two is fly the plane. Step three is assess the situation. Step four is take appropriate steps to remedy the problem. Granted this is an over-simplification but it works here.
The crew on AF447 didn’t fly the plane. They got so caught up in alarms, systems, and other things, they panicked and forgot how to fly the plane. Nova showed what to do, set power and trim, fly the plane, then listen to the alarms.
Wait listen to the alarms is last? Yup, the pilots have to fly the plane. But the pilots are not all to blame here. (Though I think they are ultimately responsible)
Airbus shares a lot of the blame. People talk about the pitot tubes and that it was a parts failure. I call bull on this. Planes are designed to fly after an engine explodes, a pitot tube failure should not bring down a Cessna 152 (Do Cessna 152s have pitot tubes?) much less an Airbus 330.
Let’s take an engine explosion. Qantas Airbus 380 flight from Singapore to Sydney had an engine compressor explosion after leaving Singapore. Plane returns safely to Singapore, no fatalities. In documentary about this flight one comment the pilot made interested me a great deal. He mentioned having to go through an acknowledge pages of alarms on his data screen as well as the rest of his control panel. He stated that he spent a lot of the emergency not dealing with the emergency but acknowledging that there was a problem. As if he didn’t know from the engine explosion.
I think Airbus is overloading pilots in emergencies. Rather then encouraging the pilot to focus on flying the plane they are providing the pilot with too much information about the situation. I want my pilot flying the plane, no acknowledging a system prompt in the first few moments of the emergency.
Where the line is between too much and too little information, nobody knows. However, with fewer alarms would the AF pilots been able to save the flight, I think so.
Whatever happens now and in the future this sad chapter in aviation history closed.