Posted on 07/06/2012 9:19:28 AM PDT by Olog-hai
The Air France Flight 447 crash, considered one of the worst aviation disasters in history, could have been avoided, a top-ranking aviation safety expert said.
"Absolutely, this accident didn't have to happen," said William Voss, the president and CEO of the Flight Safety Foundation.
BEA, the French government's official accident investigators, conducted a three-year investigation into the crash, which killed all 228 people on board, including one married couple from Louisiana, when the Airbus A330 slammed into the Atlantic Ocean off the coast of Brazil in 2009.
In the agency's final report, which was released today, investigators determined that a combination of technical failures and mistakes made by inadequately trained pilots was responsible for the crash. They recommended that pilots be better trained to manually fly commercial aircraft at high altitudes and called for stricter plane certification rules.
According to the report, a speed sensor on board the plane, called a pitot tube, stopped functioning after becoming clogged with ice at high-altitude while the plane was flying through a thunderstorm. This caused the auto-pilot to disengage and shift the controls back to the pilots. While flying in heavy turbulence, the pilots failed to properly diagnose the severity of the problem because the pitot tube, a critical piece of equipment to the aircraft, was sending inaccurate data to the cockpit, the report said. The pilots put the plane into a devastating stall and it fell rapidly from the sky, before pancake-ing into the ocean.
"Despite these persistent symptoms, the crew never understood that they were stalling and consequently never applied a recovery maneuver," the report said.
(Excerpt) Read more at abcnews.go.com ...
On 31 October 1999, the Boeing 767 operating the route crashed into the Atlantic Ocean, about 60 miles (97 km) south of Nantucket Island, Massachusetts, killing all 217 people on board"
No error here.
"If two air-speed sensors on same aircraft give different readings, the prudent master will hastily investigate."
Learned later from someone I knew who was on the flight, and sitting in the back, that the tail was slewing back and forth violently. Some passengers were barfing and others were literally praying aloud.
Hey that happened to me once in a complex Piper - wasps!
We were in IMC but I did have a pilot in the right seat so we figured the pitot was non functional and ignored those indications.
I can’t believe they ignored stall warnings - kind of a clue that the AC is falling out of the sky
I’ve done that a few times but I don’t think I would try that in an Airbus!
I would request a different runway :)
Correct about pitot heat. You may be surprised, however, to know that pitot heat can be deferred on aircraft, provided temps and visible moisture do not conspire to create icing conditions. In fact on some aircraft (part 121 certified) all of the anti-icing equipment can be deferred..
I’m not a pilot, but in other threads that have discussed this issue, those in the know say that GPS will only give you ground speed. And ground speed is very much different than airspeed. Airspeed is the key. It lets you know how much air you got passing over the wings. With a strong tailwind, your GPS will show great ground speed, but if you’re not passing enough air over the wings to create lift (airspeed), you’ll stall.
Stupid question but why didn’t they just keep the plane level and not change airspeed?
Been on one of those flights where the plane is going, “I think I can”, the passengers are going, “I hope you can” and the pilots are going, “I got 10 bucks that says the lady in 12C throws up.”
In gusty conditions the airspeed will change whether the pilot wants it to or not.
2 out of 3 pitot systems on this Airbus do not have pitot heat IIRC. Poor design is being adressed aledgedly. Not the first time for this scenario. Pitot system is interpreted by computer making the aircraft do strange stuff.
Watch this 747 landing in Hong Kong, and this one here
***...called a pitot tube, stopped functioning after becoming clogged with ice at high-altitude***
Those on our B-52s KC-135s in the military were electrically heated.
“No error here.”
I thought that was intentional. Unless that’s what you meant.
“Sorry,I’ve fixed the link Blocked Pitot Tube”
Thanks for the link
From the article:
” Experts believe the most likely culprit is a species called the black and yellow mud dauber wasp, well known by pilots flying in the Dominican Republic. The aircraft had not flown in 25 days during which time the pitot tubes were not covered, giving the wasps an opportunity to build nests in the tubes. “
Like I always say, you leave a pitot tube uncovered for 25 days in a place infested with black and yellow mud dauber wasps,...well, you’re just asking for trouble.
The tail was found 30 miles from the rest of the airframe. This means it broke off first. Fully composite tails without metal clips to strengthen stress points (a Boeing feature!) is a design flaw with some Airbus planes. I believe 5 planes have gone down in this way. Remember the Airbus that went down in NYC about ten years ago in the draft of a 747? The tail broke off. Air France pilots are offered extra pay for flying these planes but generally they won’t. I worked as a contract engineer for both companies (Airbus and Boeing) for over 20 years and have watched this drama carefully. Solution: sell the planes to third world countries (I am not sure of this but I highly suspect).
during the summer of 1959, I was taught to fly without the airspeed indicator....
It had to be MORE than one bad speed sensor, because the Triple Modular Redundancy could handle one failure without problems.
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