For those of you who don't read NTSB reports as a hobby, know that Preliminary reports generally do not assign probable cause or list contributory findings. They're usually just full of basic, factual information like the date, time, location, weather, info about the aircraft and pilot, and so on. So don't go into the PDF thinking you're going to learn the cause of the crash.
While this is generally true and having read this report I do not believe it to contain any new material information related to the probable cause, it continues to paint the picture of the captain making a pretty big series of mistakes.
It really sucks that the FO could not intervene further as he clearly identified the problem and articulated the solution.
I certainly doubt there will be a satisfying ending to this one.
> It really sucks that the FO could not intervene further as he clearly identified the problem and articulated the solution.
First officer could have easily intervened, all they needed to do was call for a go-around. If the captain wouldn't initiate a go-around(AFAIU typical airline policy from my understanding is that if either pilot calls for a go-around then they must initiate a go-around) after being called for by the FO they should have initiated one themselves. The events from the CVR show only the captain ever called for a go-around after it was too late.
> According to Automatic Dependent Surveillance-Broadcast (ADS-B) Out and FDR data, flight 7598 was about 105 ft above ground level (agl) at a groundspeed of 177 kts as it crossed the threshold of runway 30. The accident airplane touched down about 3,750 ft past the threshold at a groundspeed of 160 kts.
Runway is 9360 ft long, so touchdown 40% down the runway.
> winds were from 190° at 19 kts with gusts to 22 kts
So, that's strong crosswind from slightly behind - not great.
> 1:42 [1 min 42 sec before end of recording]: The captain called for flaps to be set to 20 degrees, and the FO cautioned they were too fast. The FO made additional comments regarding the airplane’s excessive speed throughout the remainder of the recording. There was not a consistent verbal response to the comments about speed.
> 00:31 Sounds similar to the airplane touching down.
> 00:15 The captain called for a go-around.
> 00:10 Sounds similar to the airplane departing the paved surface.
Looks like they landed way too long and fast, without deploying speed brakes and thrust reverser. Should have gone around. Then there was a go-around attempt that came way too late and was aborted.
> The landing gear weight-on-wheels (WOW) parameter intermittently switched between “air” to “ground” for about 7 seconds. The WOW parameter switched to ground for the remainder of the recorded data when the airplane had about 2,730 ft of runway remaining. The FDR data showed the speed brakes remained stowed and the thrust reversers did not deploy during the landing and subsequent landing rollout.
> Wheel brakes were manually applied at a groundspeed of 146 kts. The brake pedals for wheel braking were subsequently released about 8 seconds later at a groundspeed of 120 kts and the throttle resolver angle for both engines increased to go-around thrust values; the airplane had about 930 ft of runway
remaining.
> About 4 seconds later, the throttle resolver angles for both engines reduced to idle values at a groundspeed of 117 kts, when wheel brakes were reapplied; the airplane had about 415 ft of runway remaining.
> without deploying speed brakes and thrust reverser.
I don't think they were able to, since their aircraft never really touched down firmly enough to satisfy the weight-on-wheels interlock system. The aircraft won't allow the crew to reverse thrust until it settles into a "ground state" which we have today because some past guys managed to crash airplanes that way. Also, these guys commanded go-around power when they should have been hitting the brakes, so there's no way the flight systems were going to open the reverser.
It really sucks that the FO could not intervene further as he clearly identified the problem and articulated the solution.
I certainly doubt there will be a satisfying ending to this one.
First officer could have easily intervened, all they needed to do was call for a go-around. If the captain wouldn't initiate a go-around(AFAIU typical airline policy from my understanding is that if either pilot calls for a go-around then they must initiate a go-around) after being called for by the FO they should have initiated one themselves. The events from the CVR show only the captain ever called for a go-around after it was too late.
Though that's as a lay-person; I am not a pilot but would love to hear if the seemingly obvious issue is the likely root cause.
Touching down 2/3rds of mile down the runway at around 25 knots over Vref. That was never going to go well.
> According to Automatic Dependent Surveillance-Broadcast (ADS-B) Out and FDR data, flight 7598 was about 105 ft above ground level (agl) at a groundspeed of 177 kts as it crossed the threshold of runway 30. The accident airplane touched down about 3,750 ft past the threshold at a groundspeed of 160 kts.
Runway is 9360 ft long, so touchdown 40% down the runway.
> winds were from 190° at 19 kts with gusts to 22 kts
So, that's strong crosswind from slightly behind - not great.
> 1:42 [1 min 42 sec before end of recording]: The captain called for flaps to be set to 20 degrees, and the FO cautioned they were too fast. The FO made additional comments regarding the airplane’s excessive speed throughout the remainder of the recording. There was not a consistent verbal response to the comments about speed.
> 00:31 Sounds similar to the airplane touching down.
> 00:15 The captain called for a go-around.
> 00:10 Sounds similar to the airplane departing the paved surface.
Looks like they landed way too long and fast, without deploying speed brakes and thrust reverser. Should have gone around. Then there was a go-around attempt that came way too late and was aborted.
> The landing gear weight-on-wheels (WOW) parameter intermittently switched between “air” to “ground” for about 7 seconds. The WOW parameter switched to ground for the remainder of the recorded data when the airplane had about 2,730 ft of runway remaining. The FDR data showed the speed brakes remained stowed and the thrust reversers did not deploy during the landing and subsequent landing rollout.
> Wheel brakes were manually applied at a groundspeed of 146 kts. The brake pedals for wheel braking were subsequently released about 8 seconds later at a groundspeed of 120 kts and the throttle resolver angle for both engines increased to go-around thrust values; the airplane had about 930 ft of runway remaining.
> About 4 seconds later, the throttle resolver angles for both engines reduced to idle values at a groundspeed of 117 kts, when wheel brakes were reapplied; the airplane had about 415 ft of runway remaining.
I don't think they were able to, since their aircraft never really touched down firmly enough to satisfy the weight-on-wheels interlock system. The aircraft won't allow the crew to reverse thrust until it settles into a "ground state" which we have today because some past guys managed to crash airplanes that way. Also, these guys commanded go-around power when they should have been hitting the brakes, so there's no way the flight systems were going to open the reverser.