Why Airbus is called scarebus?
Firstly all traditional jet aircraft until it came out in 1986 were controlled in the traditional sense from the control yoke back via cables and pulleys through to the hydraulic or electrical servos that activated the flight controls.
On the Airbus A320, the control inputs are via a side stick controller to a flight control computer, which determines how much control is actually needed. So, rather than reliance upon the cables and pulleys, all the signals are digital and hence run through more of wiring. Hence the term 'fly by wire;.
What this also allows Airbus to do is to do program a set of flight control laws for tha A320 and all other Airbus aircraft from then onwards, so they would feel to fly the same despite differing sizes and configurations ie an A320 will feel the same as flying the A330/A340 and soon A380.
Now, with the flight control software, Airbus has imposed hard limits - that being that automation has the final say in aircraft control. For example, the pilot cannot bank the aircraft past 67 degrees in roll, 30 degrees nose up and 15 degrees nose down.
There are also other inbuilt protections that override pilot controls such as alpha floor and alpha max. Alpha floor kicks in when the aircraft senses it's about to fly into the ground (ie no gear or flaps extended at extremely low altitude) sending engine power to maximum continuous thrust and pitching the nose up to attain a maximum climb angle. Alpha max kicks in when the aircraft senses it's about to hit maximum operating speed, again overriding pilot controls, by reducing engine thrust and pitching up to slow down.
Airbus claimed that the A320 was "so easy to fly that even a fifteen year old could fly it" and that, with all the automation and in-built protections it was deemed the "uncrashable plane".
In 1986 when Air France put on an an extremely low altitude flyover display over Habsheim, the aircraft crashed into the trees (remember the footage?) not far off the end off the runway it flew over. Pilots were expecting the Alpha floor function to kick in if the aircraft got too low. However, this only works when the aircraft is gear and flaps up, they had gear and flaps fully extended such that the 200' pass ended up being a 40' pass over the runway, and well, I won't go into too much specifics into what happened afterwards.
The second A320 to go down happened in Strasbourg not long after, this time with Air Inter. This aircraft crashed short of the runway it was supposed to land on. A confusing and poorly designed mode on the Flight Control Unit (read: autopilot) was a contributing factor to this one. Instead of dialling in 3.3 degrees of glide slope angle for the landing, an incorrect 3,300 feet per minute descent rate was dialled in. On the FCU this simply reads as "3.3" the only difference being highlighted in the Primary Flight Display (read LCD screen).
The third A320 to go down happened at Bangalore, when an Air India aircraft crashed short of the runway, again under similar circumstances. It was found the training syllabus for the A320 required a thorough analysis. Airbus claimed that with automation, less training was required, but in fact more
training was required, particularly with the use of automation itself.
The fourth A320 crashed in Bahrain, this time a Gulf Air example - this one crashed into the sea just short of the runway. Again under very similar circumstances as with the Air India accident.
Now I will go back to an earlier example, this time with an Air Chine A300-600R that crashed at Nagoya. The aircraft was being hand flown by the first officer for the landing, accidently engaging the go-around mode (read: abort landing, increase power and try again). With the Airbus system - the go around mode overrides
the pilot, increasing power and adding nose up pitch. The crew found themselves fighting for control of the aircraft, the aircraft reached an excessively high nose up angle (read: almost vertical) stalled (not as in engine stall, but not enough speed to maintain airflow and hence lift from the wings) and crashed onto the runway killing all onboard.
Now in recent times, Airbus thought it had its fly by wire flight control software sorted, until in 1997 when on a test flight the prototype A330 crashed killing Airbus' chief test pilot. It was found there was a "hole" in the programming, when the pilot took off and simulated an instantaneous single engine failure after takeoff.
Under ordinary circumstances the A330 has a pretty massive rate of climb (as with any twin engined jet that has to be 100% overpowered in case one engine fails). When the chief pilot reduced thrust to idle on one of the engines, the automation hadn't quite catered for reducing the rate of climb to compensate and attain the dialled in level out altitude. Hence the aircraft kept pitching up, and up and up until it reached an extreme nose up attitude, the aircraft dipped one wing and stalled from a position the chief pilot couldn't recover from.
Now, with the Boeing design philosophy, the pilot has the final say in the orientation of the aircraft, and hence provides soft protections that being aural warnings, buzzers and lights warning the pilot, rather than simply taking over.
(Read: If it's not Boeing, Darky ain't going!)
I'd much prefer to fly in the B767, although the -200 series was a bit of a dog and was underpowered, the -300ER was the best of the bunch - it was the best handling of all the B757/B767 family, had plenty of range and grunt! Yeap, 61,500 lbs of thrust per engine (Read: QF spec GE CF6-80C2B6.....mmm.....love those GE's) pushing bugger all of weight to New Zealand would be pretty cool for the take off (except these are getting less fun these days as they are pretty much all derated to keep the airline bean counters happy).
I've had the pleasure of riding the jump seat for the take off on a flight to Honolulu (aircraft almost fully loaded) and still remember how quickly the numbers reeled off the airspeed indicator, and how much of a scalded cat the B767-300 was off terra firma at that weight.
Now I'm starting to get off topic, but anyone seen the wing snap tests that get done? That's pretty cool!
Oh, and I might also add I have a habit of reading about air disasters in-flight.