Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Doctor Gollum]

https://web.archive.org/web/20240104064946/https://www3.nhk.or.jp/nhkworld/en/news/backstories/2948/

Well that seems pretty definitive...

[LC0112G]

It's seemed fairly obvious to me from early on that the Dash8 entered the runway without clearance, and that ultimatley is the root cause. Not that there aren't other contributory factors of course.

However, what's done is done, and the important thing is what lessons can be learnt. Couple of things that strike me as being in your immediate area of expertise are....

1) Evacuation of the A350 didn't start till 8 minutes after the aircraft came to a halt. It then took 10 minutes to complete. Now I understand the reluctance to disgorge 360+ PAX from a 'safe' environment inside the aircraft to outside when there is fire on the ground and engines are still running - but once the fire brigade turn up and start hosing foam everywhere - I think 18 minutes to get everyone out starts to look a little suspect.

2) Nose wheel failure/collapse isn't *that* uncommon. It appears this renders the rear emergency slides basically unusable - the aircraft's ar5e is so high in the air the slides are hanging not far off vertical.

3) There needs to be a way for ground based fire and rescue to cut the fuel from a free running engine. This was a problem in QF1 at SIN, and it was a problem with the starboard engine here. Having an engine run on - even at idle power - whilst PAX are running about like headless chickens won't end well. It also reduces the number of useable emergency exits dramatically.

4) Allowing the airframe to burn out - hmm. In an emergency it is drummed into you that you leave all hand luggage behind. Yet we regularly see PAX (in the west anyway- though not in this case) ignoring this and walking away with their hand luggage. So you're held on the aircraft for 8 minutes - you've got valuables in your hand luggage - and you know they'll let the plane burn to the ground. Like it or not - PAX will modify their behaviour in light of this. I already keep passport, keys and wallet in my pockets on flights for this very reason.

[Doctor Gollum]

To answer most of your questions are you familiar with CCOM as a concept? Basically it will save a chunk of background explaining as I address your questions

And yes the A350 is one of my licenses.

[LC0112G]

To answer most of your questions are you familiar with CCOM as a concept?

Not an FLA that I'm familiar with, and google doesn't help. I assume it's summut to do with Command and Managment. Trouble is PAX that haven't read the emergency card certainly won't have any knowledge of CCOM.

[Doctor Gollum]

To answer most of your questions are you familiar with CCOM as a concept?

Not an FLA that I'm familiar with, and google doesn't help. I assume it's summut to do with Command and Managment. Trouble is PAX that haven't read the emergency card certainly won't have any knowledge of CCOM.

Basically, each aircraft has a comprehensive 'user manual' Airbus is the Cabin Crew Operating Manual, and Boeing is the Flight Attendant Manual. These are aircraft/type/config specific and are additional to the airline operating procedures. CCOM/FAM are pretty universal due to regulations but have detailed variables according to customer specification... Each variant of equipment has its own instructions within the manual. Airline procedures are more generalised and include things like operating parameters for the flight crew or the process for dealing with an emergency. So in this case the Airline procedures would somewhat dictate a course of action, but the CCOM would specifically detail the actual operation.

Think of CCOM/FAM as the owners handbook on a company car, and the Airline Procedures as the parameters of use of that company car... Speed restrictions always using lights and pre journey checks and responsibilities and such like.

With that summarised, I will address your questions as best I can based on what I know of the A350 and what I might have done based on my training. Also I may answer each point as a separate post for clarity.

[Doctor Gollum]

#1. The delay in beginning the evacuation may in part have been a cultural point. Respecting the chain of command to the bitter end.

The interphone system appears to be functioning from the internal footage. But if everyone is trying to call everyone else at the same time it will jam up.

The evacuation was ultimately initiated from 4L and eventually the front of the aircraft caught on. It is reasonable to get your bearings and establish what the immediate environment is doing both in and out. And if conditions become such that you need to leave, then that's what you do and we're trained to make that decision independently. Basically wait for it to stop, then get a grip on your faculties and go from there. The angle of the cabin would have been a clear indicator that further movement was unlikely.

With that in mind, you look out of the window. If it's safe you open the door and deploy the slide (it should be automatic but there are technical reasons as to why it might not deploy so you pause a beat to check and deploy it manually). Keep checking the conditions outside. If a fire spreads you block the exit or if it clears then you open it. Lots of shouting of clear, concise commands. Without the front fans the idle thrust of those engines wouldn't have been a threat to the R4 slide, I would probably have opened that door.

Doors 2and 3 wouldn't have been opened in those conditions.

So, the evacuation should have been started at least 8 minutes sooner and using another slide would have taken significantly less time. Once all the pax are believed to be off, you systematically search the cabin. And then leave. I would expect the crew to be a couple of minutes behind the pax.

[Doctor Gollum]

#2 'dangle berries'. Basically 

Pan Am 845

I suspect this had a bearing on future legislation.

But everything 'we' operate is specifically equipped for all slides to be useable subject to two conditions... 1. It's actually safe to deploy the slide, (fire/ground equipment etc); and 2, the aircraft is basically the right way up.

Any combination of gear/engine/belly is within the operating parameters of the slides. In this case the angle of the D1 slides was more beneficial than the alternative 8' drop. Likewise whilst the L4 slide was steeper than you might be comfortable with, the alternative is a 23' drop.

The point is to expedite the evacuation not make it fun.

The are specific variations on certain types for ditching scenarios based on technical system limitations, but that wasn't the case here.

[Doctor Gollum]

#3 Without the front fan and running in such a poor manner, the idle blast from what was left of the right hand engine would have been significantly reduced. What you can see out of the window would serve as guidance to making that decision.

Deployment of the R4 slide may have been a dice role* but an extra slide would have made the evacuation quicker.

*An exit may or may not remain useable throughout an evacuation as conditions change. Incidentally the slides can still be used even if they don't inflate but you have to direct the first passengers to assist those following and if needs be, holding the foot of the slide and keeping it taught should it deflate.

[Doctor Gollum]

The following may seem a bit extreme and some of it is written a bit lighter, but non compliance might actually kill people so consider that as you do what you do.

#4 Generally agree with all of this. But...

Keys may cause damage to the slide in the same way that high heels can. Not to mention cause injury if you smack into something/someone. Be a shame to get to the slide only to stab yourself in the femural artery with your Omega key.

Wear your coat, but do it up fully.

Basically the logic is simple. Anything that delays your exit or cause you to delay someone else getting off either in person or byway of discarding items* in the aisle is to be avoided. This is also why your seat must be upright with the table stowed... It maximises the amount of space you have to get into the aisle.

Not being allowed any loose items on your lap or floor in an exit row means you're less likely to trip on something on your way out and you/your stuff won't be sprawling on the floor opposing up everyone else's chance to get off pronto.

And always wear your shoes for taxi, take off and landing. This way they'll be on your feet when you need them and not five rows away causing chaos whilst you dick about looking for them as people break their ankles tripping over the damn things.

* I would include overhead lockers in this list on certain configurations. Smack your head into one, from any angle, and ask me why

[Doctor Gollum]

Oh and if you want a meal choice, pre order it at least a week ahead.

[LC0112G]

#1 - I understand and accept all your points. I can understand why the crew may want to keep the PAX inside the aircraft whilst external fires are dealt with by the fire crews - which may explain the initial 8 minutes before first doors open. However, 10 further minutes to clear the cabin via 3 of the 8 exits? IATA specs are 90 seconds through half the available exits. Obviously 3 is less than half, but still, 10 minutes?

AIUI there was a failure of the internal intercom so crews were communicating through megaphones. The front crew (1L/1R) were taking instructions from the cockpit. The rear crew (4L/4R) couldn't hear that, and were basically waiting for instructions.

Anyway, whether the evacuation decisions and delays were 'acceptable' will no doubt form a large part of the accident investigation report, and thankfully in this incident they don't appear to have had any adverse effects.

[LC0112G]

#2 - Yes if a plane ends up resting on it's engine nacelles rather than main undercarrage it's likely to tip backwards (particularly B737!). Similarly older planes (B707) had a habit of doing it on the ground, and KC-135's still have a ground prop inserted under the tail when parked.

But that's really not the point. With these very long fuselages if the plane ends up nose high or tail high then 1L/R or 4L/R ends up a very long way above ground. Yes it's still better to jump onto a slide inclined at 60 ish degrees (rather than a more normal 45 deg), but quite severe injuries are going to result. The PanAM case says 6 serious back injuries, and there are also a few injuries in this A350 case (although accepted it's unclear if they were from using the rear slide).

I would be disappointed if the regulators didn't at least look at extending the length of the 1L/R and 4L/R slides on this and similar long fuselage planes. IMV we got lucky with this crash If 90+ PAX (one quarter of them) had been forced to use the 4L slide in 90 seconds I reckon we'd be looking at a lot more injuries - some very serious.

[LC0112G]

Oh and if you want a meal choice, pre order it at least a week ahead.

Funny you should say that. LHR->VCE next weekend on BA. Can't see the caviar and salmon starter with Wagu beef main option in my scum class booking though.

[Doctor Gollum]

 

All that bonging as the plane came to a halt was the interphone alert. I can't immediately find the footage, but there's a point in something I saw a couple of days ago that showed a glimpse of the exit sign above the aisle at Doors 3. These signs have the various call indicators along the bottom edge. The middle one was illuminated (red/pinkish). This is an interphone call indicator (along with the bongs... Different tones for different things) and it sounds like at least three crew tried calling within a couple of seconds of each other. It was functional at the point the aircraft came to a stop, but how much longer it remained so would be speculation. Certainly it may have just been long enough to place a priority PA from any handset. Again if we feel it is prudent we can independently initiate an evacuation. Pressing the evac command switch at any crew seat triggers the whole aircraft but also records and highlights the origin.

If the -900 has 4 crew at D4, then you can be pretty self sufficient but CRM needs to be 100%

BA2276 whilst different circumstances, was a textbook evacuation using reduced number of slides. https://youtu.be/AOSLxHgOXnw?si=gOEGq5WNznUmi3y7
For comparison purposes.

Megaphones are typically one each end of the aircraft, at L1 and R4 on the 350, and I can't speak for the -900 or the JAL specific procedures.

It's going to make this years recurrent sessions a bit more interesting.
 

[Doctor Gollum]

#2 - Yes if a plane ends up resting on it's engine nacelles rather than main undercarrage it's likely to tip backwards (particularly B737!). Similarly older planes (B707) had a habit of doing it on the ground, and KC-135's still have a ground prop inserted under the tail when parked.

But that's really not the point. With these very long fuselages if the plane ends up nose high or tail high then 1L/R or 4L/R ends up a very long way above ground. Yes it's still better to jump onto a slide inclined at 60 ish degrees (rather than a more normal 45 deg), but quite severe injuries are going to result. The PanAM case says 6 serious back injuries, and there are also a few injuries in this A350 case (although accepted it's unclear if they were from using the rear slide).

I would be disappointed if the regulators didn't at least look at extending the length of the 1L/R and 4L/R slides on this and similar long fuselage planes. IMV we got lucky with this crash If 90+ PAX (one quarter of them) had been forced to use the 4L slide in 90 seconds I reckon we'd be looking at a lot more injuries - some very serious.

The A350 handling and maintenance manual is publically available but only gives basic information re the slides. For obvious reasons, I can't share our CCOM, but suffice to say it gives the angles and sill heights for all doors however the aircraft might reasonably end up on a flat surface and I can guarantee that even on the significantly longer -1000 all 8 slides are designed to be safely (as opposed to comfortably) subject to the two primary conditions I mentioned previously. Preservation of life shouldn't be confused with injury free.

Following the instructions on the safety card will mitigate any effects from going down the slide. As your feet get to the end use your momentum to stand up and almost jog away. Riding it to the end would almost certainly result in a broken arse. And keep your arms crossed to your shoulders.

Definitely questions to be asked/answered, and I hope the answer wasn't that people were queuing to get off. It should be a constant flow of people.

[Doctor Gollum]

Oh, A320 will tip enough to jam the doors onto the steps, and load/unload a 321 without care and it will sit on its arse all day long

Ask me how I know

[Doctor Gollum]

Oh and if you want a meal choice, pre order it at least a week ahead.

Funny you should say that. LHR->VCE next weekend on BA. Can't see the caviar and salmon starter with Wagu beef main option in my scum class booking though.

I don't think even First get Wagu beef

You should now get a choice of sweet or savoury complimentary snack and a napkin. There's a choice of sandwiches/hot handheld snacks available to be pre-ordered. Pre ordering is better than waiting to see what's on board.

[LC0112G]

Oh and if you want a meal choice, pre order it at least a week ahead.

Funny you should say that. LHR->VCE next weekend on BA. Can't see the caviar and salmon starter with Wagu beef main option in my scum class booking though.

I don't think even First get Wagu beef

You should now get a choice of sweet or savoury complimentary snack and a napkin. There's a choice of sandwiches/hot handheld snacks available to be pre-ordered. Pre ordering is better than waiting to see what's on board.

Which tastes better - the sweet/savoury snack or the napkin?

[Doctor Gollum]

Not operated short haul for a while so wouldn't like to say

Try your luck at check in and see if you can sneak forward

[LC0112G]

Ok. Airbus figures.... https://www.airbus.com/sites/g/files/jlcbta136/files/2021-11/Airbus-Commercial-Aircraft-AC-A350-900-1000.pdf

So worst case - the dash1000 - front slide length 10.25m, rear slide length 9.35m  (2-8-0 Page 2) . Front sill height 5.05m, Rear sill height 5.29m. (2-3-0 Page 10) So angle of dangle when standing normally on all U/C is 30 degrees front and 34 degrees rear.

Nose wheel is 32.5m ahead of the MLG, 4.63m behind the nose and about 2.9m tall.(2-7-0 Page 13)
D4 is 59.53m behind the nose, and therefore 22.4m behind the MLG. (2-7-0 Page 5)

If the nose wheel 'fails' and the thing ends up nose down arse up, I think the trigonometry says the rear sill ends up roughly 2m higher - or about 7.29m up - assuming it's still on it's MLG. For a rear slide of 9.35m that's an angle of dangle of 51 degrees.

More difficult to calculate for a nose up arse down, but I'd be surprised if it's much better.

[omega2018]

Where's STEMO when you need him?

[Doctor Gollum]

A further update and interpretation from Blancolirio's channel...

https://youtu.be/U1VuXT7Twyc?si=segpZw-GyxwEzSmj

Reiterates much of what was suspected initially.

[Doctor Gollum]

To your Man maths...

All gear down. D1 5.09m, D4 5.2m, inclination 0°.
Nose gear collapsed. D1 2.54m, D4 6.99m, inclination -4.74°
Main gear collapsed. D1 4.98m, D4 2.9m, inclination +2.37°.
All gear collapsed. D1 5.4m, D4 2.24m, inclination +3.55°

Figures for the -1000 of a particular configuration, and assumes a flat level surface... (a base line can't account for every what if).

And in the video of the evacuation from outside, L4 appears to be perfectly useable as demonstrated by people using it and walking away

[Doctor Gollum]

A further update and interpretation from Blancolirio's channel...

https://youtu.be/U1VuXT7Twyc?si=segpZw-GyxwEzSmj

Reiterates much of what was suspected initially.

Although, contrasted to Boeing, these shiny new Airbuses use touch screen panels for ALL the controls including the Evac command button, although anyone can initiate it, it needs to be functioning and in a smoke filled environment a double press of a touch screen is potentially alot less reliable than a hard switch.

[LC0112G]

To your Man maths...

All gear down. D1 5.09m, D4 5.2m, inclination 0°.
Nose gear collapsed. D1 2.54m, D4 6.99m, inclination -4.74°
Main gear collapsed. D1 4.98m, D4 2.9m, inclination +2.37°.
All gear collapsed. D1 5.4m, D4 2.24m, inclination +3.55°

Figures for the -1000 of a particular configuration, and assumes a flat level surface... (a base line can't account for every what if).

Ok, so worst case D1 is 31.5 degrees. Worst case D4 is 48.4 Degrees. If they put a 10.25m slide (same as D1) on D4 then the angle comes down to 42 degrees - still too high IMHO but a lot better.

There must be some ICAO figures somewhere for slide lengths vs height - probably calculated from injury statistics for various angles/heights. If not, then what not have 80 degree slides to save weight on a rarely used item?

And in the video of the evacuation from outside, L4 appears to be perfectly useable as demonstrated by people using it and walking away

One of the videos I saw showed someone late in the evacuation - perhaps the captain? - basically dropping down the rear chute and landing on the tail end of it like an airbed. Try that with 100+ people in 90 seconds and you'll end up with people soup. Other reports (which may or may not be correct) were that the rear cabin crew were sending people to the front door slides because of the steepness of the drop. Will be interesting to see how many people used the rear slide versus the front two, and why. That info may be in the final report.

[Doctor Gollum]

A couple of points there.

On the A350, the D1 slides are single lane slides with width restrictors to prevent excessive flow, whereas the rest are all dual lane*. At some point you have to trust the equipment you're given. One reason it took 8-10 minutes to evacuate (when they finally started) might have been due to the percentage of people sent forward. Had they used L4 slide to better advantage, and possibly R4 as well, the total evacuation time would have been alot nearer 90 seconds.

* There are packaging reasons for this, the D1 area is narrower due to the taper of the nose and it saves a couple or four inches of space each side. Besides, the front of the forward cabin may only have 12-18 seats (2 rows or less in economy terms). For example Our -1000 is configured with 44 suites between D1 and D2; 12 suites, 56 Prem seats and 49 economy seats between D2 and D3; and 176 seats between D3 and D4.

A high density -900 is still going to be arse heavy in terms of pax per door.

I would suggest that the final person leaving D4 did so with a degree of panic. You need to go with enough aplomb to keep momentum out of the door, but it's not some Hollywood movie looking for style points. Also CRM and pax management comes into play here. Delegate 2-4 people to support the slide as people come down it. Also required if the slide fails to inflate... Pull it taut and it will still serve its primary purpose. Delegation of certain actions to Able Bodied Pax is part of the preplanning process in an expected/planned emergency, ideally someone next to your crew seat. If they say no, swap them for someone who is prepared to do what's asked of them. Not so easy in an unexpected/unplanned situation, but still a useful tool in an emergency.

Similar documentation for the A380 suggests that the respective door sill heights on the main deck are comparable to the A350.which suggests a legislative requirement. Don't forget also that the slides double up as liferafts and so are a  certain size to accommodate more than their share of the pax capacity (the opposite of the Titanic).

[TheBoy]

and load/unload a 321 without care and it will sit on its arse all day long

Ask me how I know

My last A321 flight, the pilot was carefully telling passengers which rows to get off from to keep the plane level, as the ground staff never brought any steps to the rear....

[Doctor Gollum]

https://youtu.be/LNmeTHY1m5g?si=_n4e8DgD7-6U7HlO

Found the footage I was looking for. Attendant clearly holding the handset either waiting for an answer or actually using it. The pinkish light in the exit sign above her is illuminated suggesting a connection between that handset and another.

[LC0112G]

https://youtu.be/LNmeTHY1m5g?si=_n4e8DgD7-6U7HlO

Found the footage I was looking for. Attendant clearly holding the handset either waiting for an answer or actually using it. The pinkish light in the exit sign above her is illuminated suggesting a connection between that handset and another.

And that video also shows the L4 exit slide at time 2:50. Yes sliding down that is better than simply jumping out the door and hitting the ground 7m later, but I maintain you can't evacuate 25% of the pax down that slide in 90 seconds without causing significant injuries and possibly deaths. And as you rightly say the back of the plane is usually more packed with scum class pax so in a similar future evac L4/R4 will be the closest "usable" door for the majority of the PAX.

Yes given no other choice I'd use it, but that's not to say we shouldn't learn from this and at least think about how things might be made (even) safer.

[Doctor Gollum]

If they'd made it to the water, they'd have had time to do a bar round and still be off in 18 minutes.

Where the aircraft ended up wasn't a perfect flat surface, rotated slightly to the right and down a slight bank. You can't plan for every aspect of every scenario.

The A380 has an extension to the D1M slides that deploys if it is arse down, but they are under the door in the fuselage so have a bit more space to play with.

I suspect the question will be is it possible to make the slide another metre or two longer and still fulfill it's function as a raft and fit in into the bustle along with the extra gas required to inflate it and remain practical to use at a shallower angle and keep it portable... (This is potentially something that affects every aircraft and on some the slides can be removed and moved to another door). Personally I think the answer will be no.

This is a secondary concern to why it took so long for the evacuation to be initiated and completed (cabin layout is possibly another factor*) and why the #2 engine failed to stop if commanded to. Also the AFRSs only just arrived as the pax were evacuating and why did they not foam the #2 engine as a priority? There's no visible fire by L2 in that clip, so the conditions changed and that's another dual slide that could have been used...

* For an aircraft labelled as XWB, there's not much room  in the aisle,.and every time the aisles pass from one cabin to the next, it's offset... With seats overhanging the lavs etc.

Be interesting to see what the FDR has to say regarding communication on the A350.

[Doctor Gollum]

Not to mention the CVR

[LC0112G]

I've read elsewhere that this is the 8th time a FADEC engine has failed to shut down (or respond to commands to shut down) during an incident. Basically the engine control electronics tries to keep the engine going in the last commanded state in the event of lost coms. In the QF1 Singapore A380 event, it took the fire brigade 3 hours to eventuallly 'drown' the engine in water/foam before it stopped.

There is now some doubt about the evacuation timings. There is onboard video of PAX in the rear cabin running forwards through empty front cabins as the fire brigade foam the wing/engine/fuselage areas. Initial reports were that the first fire appliance arrived about 6 minutes after the plane stopped. If that's correct it's far too long - The last survivor from the Manchester 737 was carried out (by a fireman) at about 5:37 from the alarm being raised. My understanding is/was that airport fire services are supposed to reach the scene of an on-airport incident in 3 minutes.

Also AIUI the CVR and ADR have not yet been found. Another problem with letting the aircraft burn to the ground. They are very very rugged devices, but may not survive 5-6 hours in an intense fire. Worrying.

[Doctor Gollum]

The Mancchester fire raised alot of issues regarding fire retardation and materials.

When we do our drills, if the exit is blocked, you have to keep checking outside but it's easy to get task focused moving people forwards and forget to look out of the window. A fluid situation requires a fluid process to manage it.

As to FADEC issues, the A350 has form

[Doctor Gollum]

Also, my mind keeps returning to an incident in the Middleish East involving a widebody aircraft that had an emergency landing due to a fumes event in an AC pack and they taxied off the runway and stopped. Everyone on board was asphyxiated but had they shutdown and evacuated as soon as they stopped everyone would have survived

Damned if I can remember the specifics though...

Point being, as soon as it becomes more dangerous to stay, you need to be out the door.

[LC0112G]

Also, my mind keeps returning to an incident in the Middleish East involving a widebody aircraft that had an emergency landing due to a fumes event in an AC pack and they taxied off the runway and stopped. Everyone on board was asphyxiated but had they shutdown and evacuated as soon as they stopped everyone would have survived

Damned if I can remember the specifics though...

Point being, as soon as it becomes more dangerous to stay, you need to be out the door.

Saudia 163. https://en.wikipedia.org/wiki/Saudia_Flight_163

[Doctor Gollum]

That's the one