Originally Posted by
Ex Douglas Driver
One of the photos doing the rounds shows the MLG doors are open, suggesting at the least, a green hydraulic system failure.
Media comment from Korean and local authorities said a hydraulic failure causing a brake failure, and the high speed off the end also suggest a further brake system failure beyond a G sys failure and its reversion to B sys alternate brakes.
The pax tweet about a landing under emergency conditions indicate that the crew were aware of an extended landing distance prior to the final approach.
They may have had a double hydraulics failure (Green and Blue). Comments about lack of reverse thrust (only 1 side?), could be because of the additional B hyd fail. The second hyd fail would have had to have happened while they were previously configured as the slats are in the extended and gapped position and require G or B hyds to extend.
B+G hyd fail leads to Accumulator braking with no ABS (at least 7 full brake applications through pedals, pilot limited to 1000psi with the possibility of blowing tires or under braking), #2 Reverser only, reduced flap (depending on where the slats are locked) and higher approach speeds, only 2 spoilers per wing operative, and limited diversion opportunities due no gear and slat retraction.
That would put them in a bad position without doubt.
Both T/Rs appear to be stowed, which is odd. The main doors if they are open is definitely indicating a Green system failure which is going to be a pain, but would have been manageable, assuming that the BSCU was working, and there were no other failures. The blue and yellow are the TR powers respectively for Left and right engines... and as they are not extended, on an overrun, and a very slow deceleration, that suggests the guys had a compound problem. The fact they landed on an airport suggests that it wasn't loss of all 3 hydraulics... so am thinking Green + BSCU (G/A Sensing failure) which gives open inner gear doors, no T/R's, no ground spoilers, and alternate brakes only without anti-skid. That would put the aircraft in the weeds in most cases, outside of maybe Edwards.
Losing a HYD and another sensing system may suggest that the second landing was less than stellar, but, if no one died in this, am gonna give some latitude to the guys. The second landing may have some echoes of Iberia's -600... Going to be interesting to get the full report.... except it is CAAP land. KCASA will have more on it probably.
