YRP
June 12, 2025, 12:44:00 GMT
permalink Post: 11899171

Quote:

Originally Posted by bnt

According to Aviation Safety Network, this is the first hull loss of a B-787. Both previous incidents involved damage incurred on the ground that was repairable,

The battery fire aircraft were both repaired? Interesting, for some reason assumed they hadn't been, that the damage was too great.

Subjects: None

YRP
June 12, 2025, 13:00:00 GMT
permalink Post: 11899183

Quote:

Originally Posted by FullWings

How horrible. From what has surfaced so far, it does appear that the aircraft became airborne and got to a reasonable height and groundspeed, within parameters for a normal takeoff. The video with RAT-like audio and the snapshot from another video showing hints of RAT deployment seem to be the biggest clues so far: flaps and gear are a minor issue compared with a serious power loss, although loss of electrical power would trigger the RAT if it uses the same logic on the 787 as earlier Boeings.

That you can hear the RAT on the video over what should be engines at takeoff thrust at that point adds credence to the theory, as does reports of a MAYDAY.

The audio is not great and kind of whiny. Even at the end when the crash happens, it does not sound robust.

Likely: this is not the RAT sound; it is just poor audio pickup.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY Parameters RAT (All) RAT (Deployment)

YRP
June 12, 2025, 18:42:00 GMT
permalink Post: 11899587

Quote:

Originally Posted by ManaAdaSystem

A mayday call will normally contain information about the nature of the emergency.
The flaps instead of gear is based on the landing gear being down throughout the whole emergency. It\x92s just weird. I get that it may be overlooked in a stressful situation, but when they had time for a mayday call?
So, someone said the 747 will have an early thrust reduction if you retract flaps too early, is this also the case with the 787?

This was my thought. tf were they doing making a radio call in that situation.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY

YRP
June 12, 2025, 19:13:00 GMT
permalink Post: 11899627

Quote:

Originally Posted by Bratchewurst

My understanding is that Boeing believes that it\x92s better to allow the PF to fly right to the edge of a stall and provide ample warning that a stall is imminent. Airbus believes that it\x92s safer to never allow a stall, even at the price of limiting the PF\x92s ability to maneuver right to the ragged edge. Obviously (AF 447) that doesn\x92t always prevent stalls either.

Pretty sure AF447 went into alternate law with protections disabled once the airspeed sensor failed. Even so, a high altitude zoom climb might be beyond what the protections were capable of handling.

Subjects: None

YRP
June 12, 2025, 19:25:00 GMT
permalink Post: 11899642

Quote:

Originally Posted by The Nutts Mutts

In that video there's a large puff of dust as they become airborne... from that I'd assume they were very close to the end of the runway if not slightly past it. It looks like they barely had enough speed to get airborne, and what little speed they did have didn't take them very far. The big question is why they barely climbed... performance issue, engine failure, birdstrike? No idea.

That looks like wing tip vortices, spreading out after rotation/liftoff, picking up some dust from beside the runway well behind and below the aircraft.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Engine Failure (All)

YRP
June 13, 2025, 20:58:00 GMT
permalink Post: 11900895

Quote:

Originally Posted by Seamless

SLF, so probably stupid question: Why don't companys like Airbus or Boeing integrate scales in their planes? Not to make calculation of lift of weight of calculations are wrong? Why don't they integrate systems that hinder you from retracting flaps in the first 20 to 30 seconds after the landing gear lost contact to the ground etc?

What I am trying to say: There are pretty simple logics that could be integrated that would presumably kill many discussions held here.

The difficulty is making the sensors and control systems reliable.

Your simple logics can make the situation worse in failure modes. E.g. someone mentioned MCAS, simple simple logic that fixed a minor problem but brought down two airplanes when the sensors failed.

Other examples: there was an A340 into Quito (?) a while back that landed hard, breaking the WOW sensors. Interlocks wouldn\x92t let ground spoilers, reversers, etc deploy. Aircraft unable to stop, went off the end with fatalities. Yet those interlocks do save lives in other situations, eg AC DC8 crash in Malton in the 1960s.

Simple sounding systems are not nearly as simple as imagined. Design engineers have to work out every conceivable combination of faults/failures and what would happen. Fixing one situation often opens up another one.

Subjects: None

YRP June 12, 2025, 12:44:00 GMT permalink Post: 11899171	Quote: Originally Posted by bnt According to Aviation Safety Network, this is the first hull loss of a B-787. Both previous incidents involved damage incurred on the ground that was repairable, The battery fire aircraft were both repaired? Interesting, for some reason assumed they hadn't been, that the damage was too great. Subjects: None
YRP June 12, 2025, 13:00:00 GMT permalink Post: 11899183	Quote: Originally Posted by FullWings How horrible. From what has surfaced so far, it does appear that the aircraft became airborne and got to a reasonable height and groundspeed, within parameters for a normal takeoff. The video with RAT-like audio and the snapshot from another video showing hints of RAT deployment seem to be the biggest clues so far: flaps and gear are a minor issue compared with a serious power loss, although loss of electrical power would trigger the RAT if it uses the same logic on the 787 as earlier Boeings. That you can hear the RAT on the video over what should be engines at takeoff thrust at that point adds credence to the theory, as does reports of a MAYDAY. The audio is not great and kind of whiny. Even at the end when the crash happens, it does not sound robust. Likely: this is not the RAT sound; it is just poor audio pickup. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY Parameters RAT (All) RAT (Deployment)
YRP June 12, 2025, 18:42:00 GMT permalink Post: 11899587	Quote: Originally Posted by ManaAdaSystem A mayday call will normally contain information about the nature of the emergency. The flaps instead of gear is based on the landing gear being down throughout the whole emergency. It\x92s just weird. I get that it may be overlooked in a stressful situation, but when they had time for a mayday call? So, someone said the 747 will have an early thrust reduction if you retract flaps too early, is this also the case with the 787? This was my thought. tf were they doing making a radio call in that situation. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY
YRP June 12, 2025, 19:13:00 GMT permalink Post: 11899627	Quote: Originally Posted by Bratchewurst My understanding is that Boeing believes that it\x92s better to allow the PF to fly right to the edge of a stall and provide ample warning that a stall is imminent. Airbus believes that it\x92s safer to never allow a stall, even at the price of limiting the PF\x92s ability to maneuver right to the ragged edge. Obviously (AF 447) that doesn\x92t always prevent stalls either. Pretty sure AF447 went into alternate law with protections disabled once the airspeed sensor failed. Even so, a high altitude zoom climb might be beyond what the protections were capable of handling. Subjects: None
YRP June 12, 2025, 19:25:00 GMT permalink Post: 11899642	Quote: Originally Posted by The Nutts Mutts In that video there's a large puff of dust as they become airborne... from that I'd assume they were very close to the end of the runway if not slightly past it. It looks like they barely had enough speed to get airborne, and what little speed they did have didn't take them very far. The big question is why they barely climbed... performance issue, engine failure, birdstrike? No idea. That looks like wing tip vortices, spreading out after rotation/liftoff, picking up some dust from beside the runway well behind and below the aircraft. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Engine Failure (All)
YRP June 13, 2025, 20:58:00 GMT permalink Post: 11900895	Quote: Originally Posted by Seamless SLF, so probably stupid question: Why don't companys like Airbus or Boeing integrate scales in their planes? Not to make calculation of lift of weight of calculations are wrong? Why don't they integrate systems that hinder you from retracting flaps in the first 20 to 30 seconds after the landing gear lost contact to the ground etc? What I am trying to say: There are pretty simple logics that could be integrated that would presumably kill many discussions held here. The difficulty is making the sensors and control systems reliable. Your simple logics can make the situation worse in failure modes. E.g. someone mentioned MCAS, simple simple logic that fixed a minor problem but brought down two airplanes when the sensors failed. Other examples: there was an A340 into Quito (?) a while back that landed hard, breaking the WOW sensors. Interlocks wouldn\x92t let ground spoilers, reversers, etc deploy. Aircraft unable to stop, went off the end with fatalities. Yet those interlocks do save lives in other situations, eg AC DC8 crash in Malton in the 1960s. Simple sounding systems are not nearly as simple as imagined. Design engineers have to work out every conceivable combination of faults/failures and what would happen. Fixing one situation often opens up another one. Subjects: None

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