The pitot tubes were certified in iceing - I don't remember the exact combination of events and atmospheric conditions in which they froze up. Making things worse was it was a night flight and they were over open ocean, and if I remember correctly there was a storm (not sure of the weather part). I think there was a redesign of the pitot tube, but all of them are heated even ones on small airplanes.
Read Air France Flight 447 - Wikipedia for the details.
As is typical of air disasters, a number of "little" things which together doomed the flight. It is very rare that a single event leads to a crash.
Well, usually, but not always. And think here... Time is short, or may be short, you have a number of instruments, some redundant such as the attitude indicator which many large aircraft actually have 3 of - Which is right? Which is wrong? This is another "it's simple to say" thing. Like I have said - In a simulator, or on a training flight, everything is in control so it's simple to say "...if this happens, do this...".
I remember one check flight I had where the instructor did an engine failure, he throttled the plane to idle and instructed me "handle it". We were over farm fields, I lined up with the rows, gear down, full flaps, and was all set. I was young and cocky, and the check pilot was a guy I didn't particularly like. He had told me "do NOT touch the throttle until I tell you OK". So, I took him at his word. I'll bet I wasn't 50 feet AGL when he freaked out and said "what are you doing?" and opened the throttle to full power. I had been taught the check pilot's word was that of god. By reaching 100 feet AGL he should have said something like "OK - Full throttle - Good job", but hadn't. He said nothing until his freakout. I was ready to set the darn plane down in a soybean field in Missouri.
The flight was a "qualify in type" check ride. He didn't even have to pull that check, but he decided to.
Ah, the good old days. Back then it wasn't even a big deal to land a smaller plane in places like St. Louis or Kansas City. These days that's pretty much a no-no unless there's an emergency. Back then I was doing some charters and "mail" runs between Cincinnati, KC and Omaha. I usually hit St Louis for fuel and sometimes KC. I remember one night coming into KC - Middle of the night, a somewhat foggy night and I had spilled some coffee. I couldn't spot the runway - So many city lights. I was talking with KC approach control - We were both tired and cranky. I was close, maybe 10 miles out. I asked him to turn up the runway lights. He did a bit but I still couldn't make them out. I asked a couple times again. Finally he was frustrated and turned them on full. That runway stood out like a sore thumb. I will say all the various controllers I worked with, so to speak, were wonderful people. Helpful, professional and just great people.
