Primarily for general aviation discussion, but other aviation topics are also welcome.
  • 1
  • 28
  • 29
  • 30
  • 31
  • 32
User avatar
By MichaelP
FLYER Club Member  FLYER Club Member
#1876882
Josh wrote:The video doesn’t explain it well Michael, I recommend reading the full report if you’re interested exactly what went wrong and why:

PDF here


Thanks Josh,
A quick scan and a read of the main bits is interesting, with a parallel report on a UK 737-700 incident.

In test flight mode we should adhere to altitude recommendations and be careful observers of our instrument indications, i.e. airspeed and pitch angle in this instance.

Unlike aircraft with similar tailplane systems (such as Piper Super Cubs) it doesn’t seem that full forward stick is sufficient to overcome the full nose up trim and full thrust effects in some configurations.

Such tests are done to establish whether a system works with an expectation that it might not!
So when the airspeed dropped below the actuation indicated airspeed the test should have been noted as a failure and the aeroplane returned to normal flight, and thence to maintenance.

On my first flight in the Pup I looked down to note the airspeed soon after takeoff. The aeroplane was climbing like a T21 on a winch launch, but the controls felt firm and responsive. The ASI read nothing, so here I am in a new type with no airspeed indication... No problem, fly the aeroplane, fly attitude and power.
Switched the engine off and glided in for a very gentle three point landing.
As an instructor I gave my students circuit sessions with the ASI covered, and never had any problem with control.
Often raising the sticky during climbout showed the correct airspeed as the student had already learned the correct attitude for the power and the performance required.

Unlike the 737-Max the A320 relies on five computers with two different operating systems.
But unlike the human pilot these do not see, they rely only on the sensors.
Pilots rely on their indications to their peril, but they have the ability to see and to feel.
If we follow an attitude indicator following vacuum failure we go to the turn and slip and ignore the artificial horizon... This is tiring and so we go find some VFR as soon as we can.

On base leg in an AA5 the owner pointed out that we were doing 100, we were not!
I tapped the panel, and the ASI dropped to 70 where it should have been.

The fundamentals you learn as student pilots are important to your future habits as airline pilots.

In my opinion the Airbus accident would have been avoided if correct procedures were followed.
When doing test flights in controlled airspace I’ve stated what I wanted to do and requested a block of airspace.
The Airbus crew should have done likewise.

Never assume an aeroplane will perform without snags after maintenance. After maintenance is the most dangerous time to fly an aeroplane, why there are specific procedures to be followed when test flying

The A320 accident is not closely related to the trouble with the Max.
The system in the Max fights for control with the pilot.
The Airbus releases its grip to allow the pilot to sort out a situation that exceeds the normal law.
But you’d better know how to fly.
#1876958
As an ex Boeing (707 and 747) and Airbus (310,320,330) pilot I don't agree with much that has been said here.

The stab trim sytem on the 737 is substantially the same as that on the B47, 707 and 727. Uncommanded stabiliser movement was always trained in the simulator, the effect of the stab trim cutout switches was known, and the procedure to recover pitch control well trained. On the 707 it involved 'splitting' or isolating inboard or outboard spoilers or flaps and using their position on the sweepback to apply pitch. There could be many reasons for stab trim problems: motor runaway, mechanical failure, clutch failure, mach trim malfunction. MACAS might have been misunderstood but its effect was easily isolated.

As for the Airbus, it is generally true to say that with few exceptions (eg AA 587) every aircraft that has crashed has been fully airworthy at the time of impact. The reason for the crash was the pilots not understanding or acting on the Flight Mode Annunciator - the 5 windows above the Primary Flight Display that show the status of the thrust, pitch, roll and autopilot systems. You don't fly an Airbus, it flies you, and will do safely providing you understand its interface...
  • 1
  • 28
  • 29
  • 30
  • 31
  • 32