Even as the airplane does wild things, it can seem perfectly normal inside, as Bob Hoover demonstrates below.
Posted on 07/29/2011 10:38:19 AM PDT by magellan
Even as the airplane does wild things, it can seem perfectly normal inside, as Bob Hoover demonstrates below.
I can only imagine someone had to notice the backup altimeter not showing a climb.
I suspect they were confused by the slow airspeed indications, which seem odd considering pilots are trained from day one to understand the symptoms and take proper actions.
Combine slow airspeed indicators, a nose high attitude, and full throttles and a pilot could think they just had to be climbing regardless of the altimeter, instead of thinking they might be in a stall and that altimeter is correct.
I always start by assuming the altimeter and attitude indicator are correct but the air speed indicator might be incorrect due to the pitot being frozen or clogged by debris or a bug. Also, the GPS system will give ground speed even if indicated airspeed is suspect. I mean, if the GPS says I’m flying at 450kts ground speed I can’t help believe that is well beyond stall speed and good enough to keep flying with the proper attitude. Toss in power settings and attitude indications and a pilot could fly just fine.
Maybe it’s just me, but... from the attitude of the aircraft, it’d be rather obvious that we were in trouble. In that circumstance, I’d rather have the pilots working to get us out of trouble than having them expend effort notifying us that we’re in trouble. I fail to see why notifying the passengers is such a big issue.
Welcome to mishap investigation procedures 101.
Which is why the basic flight instruments should never, ever be capable of being overridden by computer and they should always be part of emergency procedures and flight recovery procedures.
If a crew suspects flight computer errors that endanger an aircraft I evangelize that that there must always be instruments that can be trusted. Instead, we get these "cool" electronic displays that are fed by software. I only fly small airplanes but even they have analog instruments that I can trust when the flat panels fail, and they do fail.
Here is one instrument panel of a plane I fly and notice it has the analog instruments at the top. Nice and sweet. When those G1000 displays go blank or the flight computers get confused those round dials work just fine. It is a rude awakening to be flying at night near the mountains and have those panels go blank and reset.
That wouldn’t surprise me. Seeing the history of structural problems on the A380 (failed tests on the eve of full production that caused Airbus to have to install wing stiffeners, fuselage stiffeners, and re-design a more beefed-up tail), I wouldn’t put any more trust in their avionics.
Freeper NittanyLion theorized the pilot hit the q-corner
Yeah. I was raised on the flight line at a Marine Corps airbase.
Thanks for the information. Computers are nice. However I remember a problem and lecture in my College Algebra Class(many years ago) where the Professor, an engineer, had us calculate the probability of failure for electronic circuits of ever increasing complexity. In short, the more bells and whistles the greater the odds of something going wrong.
“had us calculate the probability of failure for electronic circuits of ever increasing complexity”
For primary avionics systems there is a similar calculation that states only so many errors are allowed in the system. It is a pretty small number but how those calculations are a human derived figure and extremely optimistic.
Yes they are.
However they use the pitot-static input and since that was iced over they read wrong.
To all you other naysayers
THIS IS NOT A DESIGN FLAW. It is Physics. It has nothing to do with the fly-by-wire. The pitot static system works the same way they always have. If the pilot was too poorly trained to know how they back systems worked under adverse conditions they are to blame (or their trainers are).
This is like someone crashing a car because they were so use to anti-lock brakes they did not know how to stop a car on ice that did not have anti-lock. You can’t blame the brakes. You blame the person that got behind the power curve in an aircraft they did not know how to fully operate.
Pitots have nothing to do with altimeters. See the following chart of a basic Pitot-Static system. Only the air speed indicator uses the pitot. The Altimeter uses the static ports.
The problem was based upon actual failure rates of various parts.The rates were derived empirically I never forgot what he taught us. I’m not an engineer but it did give me a healthy skepticism towards electronic circuits. I loved science and math but unfortunately they did not reciprocate my love. I had no aptitude for them and worked 10 times as hard as the kid with an aptitude to get the same grade.
” do feel certain that were you to spring this scenario on pilots in a simulator without warning less than half of them would have a successful outcome. Safely flying the 320, 330 and 340-series Airbus requires something of a non-pilot mindset.”
An interesting, although anecdotal, experience is that when non-pilots are given control in a simulator for most aircraft with electronic displays, and especially the Airbus with stick control, they do better in unexpected situations than pilots. I suspect it is due to their not having this large set of information in their heads about the airplane and can quickly focus their attention on level flight. They also don’t have that muscle memory to go on so they react by stick-to-indicator results. I’ve often had non-pilots remark, “This is easy, what’s so hard about that?” Of course, flying a plane properly according to regulations is very difficult and takes lots of practice and stick landings are not as easy as they think. Landings usually do them in on the simulators, and they have no clue about flying an actual route of any kind.
As someone that is suppose to know something about flying you should know you mostly really are worried about airspeed when you are recovering from a stall.
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