Like Boeing, Airbus doesn't display the Calculated Angle of Attack anywhere on the pilot's display. Nor does Airbus have any light or indicator if the two AOA sensors in the AIDRU disagree, even though this is one of the factors that can automatically disengage the auto-pilot and reboot the three flight computers.
It will be interesting to see if any of Boeing's or Airbus customers decide they want this information added to their display, which Boeing is willing to do and I'm sure Airbus would as well. The complaint most frequently heard is the information displays are nefariously overloaded with information not directly useful to the pilot.
Once co-pilot Pierre Cedric Bonin was flying the Air France flight 447 under Alternate Flight Law, he seemed to get the completely wrong idea. Each time the Stall Warning sounded, he should have pitched the nose down, like an MCAS would, but he never did. An MCAS would have been done for him even with the flight computers out of service and everyone onboard Air France 447 would have been saved.
Instead, every time the Stall Warning sounded, Bonin pitched up the maximum bringing the aircraft's speed below 125 mph, shutting off the warning because it assumed he was trying to land.
Roughly 20 seconds later, at 02:12 UTC, the Bonin decreased the aircraft's pitch slightly, airspeed indications became valid, and the stall warning sounded again; it then sounded intermittently for the remaining duration of the flight, but stopped when the pilot increased the aircraft's nose-up pitch.
From there until the end of the flight, the angle of attack never dropped below 35 degrees. From the time the aircraft stalled until its impact with the ocean, the engines were primarily developing either 100 percent N1 or TOGA thrust, though they were briefly spooled down to about 50 percent N1 on two occasions. The engines always responded to commands and were developing in excess of 100 percent N1 when the flight ended.
First officer Robert said to himself, "climb" four times. Bonin heard this and replied, "But I've been at maximum nose-up for a while!"
Captain Dubois realized Bonin was causing the stall, causing him to shout, "No no no, don't climb!"
The aircraft was now too low to recover from the stall. Shortly thereafter, the Ground proximity warning system sounded an alarm, warning the crew about the aircraft's now imminent crash with the ocean.
Bonin, realizing the situation, said: "Fuck! We're going to crash! This can't be true. But what's happening?" Sorry dear, no MCAS safety feature on an Airbus.
The final data showed the Airbus 330 Air France flight 447 hit the water falling vertically at 124 mph, and moving forward at a mere 123 mph, all because they had no MCAS.
What Knave would fail to install an MCAS on such an advanced and costly aircraft. It could have saved everyone? |
