Correct me if I'm wrong, but isn't there two altimeters, one 'manual' and one which uses electricity; so if the electrical one went off, then the manual one is the one that he pilots looked at. If there's two altimeters, then shouldn't there be two speed, one manual (if that's possible) and one power by electricity?
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Air France plane lost over Atlantic
- Thread starter arkitect
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The overspeed came first, the stall warning (if they got one) came second. If you over speed an airplane too much the wings might rip off. This could provoke the wrong reaction in a pilot. A lot of things were probably going on. Did they get a stall warning (which would have come later in the event)? And what was the FMS (flight management system) doing with the throttles? In a normal flight mode, the throttles are automatic. You select an airspeed and the throttles set the power to maintain what you've selected, however in an over speed, the throttles may reduce, but how much I don't know.
This kind of airspeed issue in the past has been the purpose for having a separate stall stick-shaker system based on angle of attack readings vs pitot static readings in case your primary system is getting bad data. If they did get a stall speed warning, the proper reaction would be to blow off the over speed, manually move the throttles up if the FMS (flight management system) had them rolled back, and lower the nose.
But stick shakers are just one approach and the Airbus has more than a primary system for airspeed indication, it has two primaries and a backup emergency system.
I'm not familiar with the big Airbus that crashed, but it's systems are very similar to the smaller Airbuses I am familiar with, which have 3 separate systems that manage airspeed indications, one for the Captain, First Officer, and a standby emergency system. I'm not sure exactly if there are two pitot-static systems or 3. The emergency system might share with one of the others. Now that they have the black boxes, they may know exactly what each of these 3 systems were doing during the event. I've not read the report nor do I know if the report has been released to the public. I do believe they had false airspeed readings (overspeed) due to malfunctioning pitot static system, but the speculation is did they have conflicting readings on the different systems?
It is easy for me to say in the calm of my office
, but the key when a warning like this goes off is to take a minute and evaluate before rushing to fix it by putting the aircraft into an abnormal attitude. For example what if the Captain's airspeed showed an over speed, but the FO's showed normal? What if the both showed overspeed, but the standby system showed normal? To reemphasize, there is no reason an aircraft in level cruise flight should suddenly find itself deep into the red over speeding. If ice is slowly building up within the pitot tube and/or static port, it would reach a point of blockage where the airspeed indications would start moving much quicker than the airplane can accelerate. Suspicion would be warranted not haste.Most of the time we cruise at an airspeed that is very close to redline and an event like mountain wave can nudge your airspeed up just over the redline and the alarms go off. BTW the redline is set conservatively. It's not the point where the wings are actually going to fall off.
Selecting a lower airspeed corrects the problem and when an external reason for the over speed (mountain wave in my example) is past, airspeed can be selected back to a normal setting. The aircraft is at a normal airspeed, stable cruise flight, power has been set for a long time and seconds later airspeed is 100 kts into the red, but the pilot does not notice until alarms are going off, something is amiss. The airplane does not have the ability to accelerate like this, and there is no physical reason for this to happen, so for this situation, evaluation versus rash action should be the approach.
Normally the backup altimeter is purely a static mechanical system. But in this type of accident it's not the altitude readout that is the culprit, it's the over speed warning that is provoking the wrong reaction and at some point, depending on the pilot(s) if they have latched onto the wrong solution, even if it's not working, analytical thinking may cease. That is what happens with people sometimes.
Example: Cruising along happily and suddenly the overspeed warnings sound and the airspeed shows 500 kts (overspeed). What should you do?
1. Maintain level flight, pull back the throttle to 2/3 normal power and see what the airspeed does. If it appears stuck, discount the airspeed. Fly known attitudes and power settings.
2. In a knee jerk reaction you try to slow down by climbing, throttles may be at idle, but airspeed is not decreasing, and you may or may not get a stall warning, but now you are now falling out of the sky watching the altimeter unwind. Continuing with back stick, even full back stick, is not going to salvage the situation. Although this was the wrong approach, it could still be recoverable. The aircraft has stalled, there is inadequate smooth air over the wings to support the airplane so it is descending possibly in a stalled condition.
Recognition is 9/10 of the battle. I guarantee if you have good airspeed indications with the nose up, the airspeed will slow. If it is not slowing, you must blow off the airspeed reading, lower the nose, "feel" you are getting your speed back, if the stall warning was sounding, hopefully it goes away, and then nudge the airplane back towards level flight well before you hit the ground, then fly known attitudes and power settings. If the pitot system was frozen over, hopefully at the lower altitude it will unfreeze and airspeed will come back.
With pitot heat applied no properly designed pitot static system should ever freeze over at least I don't think it should.
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I recently talked to someone who knows more about this than I do. In my previous posts, I've kind of overlooked they flew into a thunderstorm. Word has it, they lost all of their instruments. The Airbus is equipped with a standby gyro so I'm not real sure about that aspect. With the kind of failure they had, there is a way to restore an altitude and wing attitude indication, but you have to know how. I just got a brief on it.
But you know everyone tries like hell to avoid flying into a tstorm.
But you know everyone tries like hell to avoid flying into a tstorm.
Unless it's above their ceiling of operation, yes.
Would be interesting to program a flight simulator, with the black box info, and see how an instructor would handle it.
But without prior warning, naturally.
My whole family has been in the flight business for years. Waitress, pilot and Air Traffic Controller... we have it all! We talked about this during diner a few days back. It turned out that the plane had started giving erroneous speed calculations (saying it was going at cruise speed when it was going slower). They lost lift and the plane slowly kept going down. Amidst a thunderstorm, they also lost radio contact.
It is also said the pilots were arguing in the cabin. In any case, if something ever goes wrong in a plane, remember it is ALWAYS the pilot's fault, sometimes even if it's technical (new aircrafts have systems to warn against, etc., which some pilots deliberately ignore).
It is also said the pilots were arguing in the cabin. In any case, if something ever goes wrong in a plane, remember it is ALWAYS the pilot's fault, sometimes even if it's technical (new aircrafts have systems to warn against, etc., which some pilots deliberately ignore).
Unless it's above their ceiling of operation, yes.
Would be interesting to program a flight simulator, with the black box info, and see how an instructor would handle it.
But without prior warning, naturally.
If I understand you, you especially don't want to fly into a TStorm if it's above your aircraft's ceiling. Flying though a thunderstorm is not an option unless if is the only choice as in run out of gas if you don't. We took off out of Minneapolis for the East Coast one night and flew straight South along a line of thunderstorms for 300 miles before we found a hole and could turn East. Fortunately we had extra gas in anticipation.
Would be interesting to program a flight simulator, with the black box info, and see how an instructor would handle it.
But without prior warning, naturally.
The problem here is that when you sit any pilot in a simulator, he/she is primed and ready for failure after failure. I get nervous in the simulator if I'm flying around without anything wrong - it makes me think I'm missing something.
But up at cruise in the real thing, it's a lot easier to be caught off guard. A pilot should know the appropriate way to properly handle instrumentation failure (Huntn explained it very well above). In the heat of the moment it's difficult to force yourself to mentally slow down, but you've gotta do it - the consequences of misdiagnosing the problem are dire.
Whatever happened up there, it was certainly a crappy situation the crew found themselves in.
this horrible, my heart really goes out to those that lost family members.
You know this happened over 2 years ago, yes?
PM article
There's a new Popular Mechanics article about this flight, which reconstructs a lot of what happened based on the flight recorder data. I'm surprised none of the aviation buffs at MR have commented on this yet.
There's a new Popular Mechanics article about this flight, which reconstructs a lot of what happened based on the flight recorder data. I'm surprised none of the aviation buffs at MR have commented on this yet.
^^
Thanks for the link.
If I remember correctly, this has happened before (the tubes freezing up / being covered by maintenance).
Thanks for the link.
If I remember correctly, this has happened before (the tubes freezing up / being covered by maintenance).
There's a new Popular Mechanics article about this flight, which reconstructs a lot of what happened based on the flight recorder data. I'm surprised none of the aviation buffs at MR have commented on this yet.
Thanks for that link. It makes for some chilling reading. Basically the pilots weren't educated enough about the systems and capabilities of their aircraft and flew a perfectly serviceable aeroplane into the sea.