Toronto place crash 2

[LittleInch]

A Delta plane appears to have touched a wing tip during landing, ripped the wing off then promptly flipped over onto its back.

As they were on the airfield and this time didn't run into anything or catch fire, everyone is alive, though not surprisingly some injuries.

All passengers survive crash landing as plane flips at Toronto airport

Eighteen of the 80 people on board were injured after the Delta plane overturned on landing.

www.bbc.co.uk

This video https://www.dailymail.co.uk/news/article-14407855/delta-plane-crash-toronto-fireball-footage.html makes it look like a very hard landing - no visible flare

 

[Alistair_Heaton]

I am with tug. Zero flare. Hit the ground doing 700-800 ft per min.

There seems to be a point around 3g landing where the main spar gets permanently deformed on most aircraft types.

Below that there is a series of escalating inspections starting at 2.1g load index landing for the A220.

 

[thebard3]

I don't know if there is a single scenario where the outcome will be improved by having the wings come off, other than to have a reduced fire risk due to fuel. That plane hit the runway hard, and even so, it's not easy to understand how the wing to fuselage connection failed.

 

[btrueblood]

In the second video above, the plane transitions from a normal nose-up approach to a more level or even nose-down approach, just a the plane crosses the a-pillar of the vehicle. May be a pilot response to a sudden gust?

 

[Alistair_Heaton]

Most aircraft the main spar and wing root are used as a fuel storage area or at least one wall of the fuel tank.

If the gear which is normal attached to the main spar causes it to fail or split then it will release fuel.

To be honest I really don't see this as an engineering failure if there were no fatalities.

 

[LittleInch]

I agree more of a semi disaster.

I suppose it wouldn't have made much difference if there had been an engine under the wing to slide down the runway. At the end of the day, I suppose most landings are manual and you are at the mercy of pilots and their ability to deal with very rapidly changing situations.

The cabin and seat integrity does seem to be very good.

 

[Sym P. le]

Landing video posted on Facebook and on X. The video confirms wind directly from the west, landing aircraft crabbing into the wind, right wing low.

 

[DirteJoe]

It's more of an engineering triumph seeing as everyone survived.

thebard3, once the wing contacted the ground hard it had nowhere to go aside from bending/breaking at connection points. Once lift was lost on that wing and the other was still making lift, it only added more force to the damaged area and is what initiated the roll most likely.

 

[TugboatEng]

Maybe it was a Navy pilot.

 

[Sym P. le]

Once lift was lost on that wing and the other was still making lift, it only added more force to the damaged area

The issues compounded very fast. It's surprising how fast the aircraft flipped and also how fast it came to a stop. I wonder if I could still land a Cessna that short.

 

[DirteJoe]

Has it been stated how short of a distance it was before they came to a stop yet?

 

[Alistair_Heaton]

No but PAPIs to the other runway crossing point on Google maps will give you it.

 

[Sym P. le]

Data posted on PPRuNe Forums (or here for all the posts) indicates ground speed on approach at 103 kts so it's not an unlikely stopping distance given the ground assist.

ADS-B data analysis shows last IAS reported as 152 kts, ground speed 103 kts

 

[GregLocock]

Here's the transcript. I see it is being whitewashed, he probably misspoke in the heat of the moment. I'd love to see the cost benefit analysis/FMEA of exploding bolts holding the wing on

SOUCIE: Yes, if they haven't reported any souls, any fatalities, then they're saying that we've accounted for them, we have them, they're off the aircraft. So that's a really good sign. And again, it's testament to the fact that the engineering that goes behind these airplanes, you notice that both of the wings are off of the airplane right now.

And that's by design. They have breakaway explosive bolts that hold those wings on so that if the aircraft does go sideways, and it does hit the wing, if that wing was too stiff, it would tear the fuselage apart and dislodge the seats and damage the fuselage. But it's designed to allow that when it's a huge impact on the wing to strip those wings off. And then that aircraft can continue to move and come to rest safely.

So there's so many examples now that we know we don't have fatalities. We have this opportunity now to show exactly all of the things that have happened in the past that we've learned from as Peter Goetz brought up the 16G seats, and then also these breakaway bolts on the wings.

 

[SWComposites]

There is NO way any sort of explosive bolts holding commercial aircraft structure together will ever get certified. None. Its just stupid to even contemplate; can you imagine those bolts going off at 35,000 ft? Sorry for being blunt. I've worked aircraft structures for decades, and there is no requirement nor design goal for the wings to completely separate in a a crash. There are crashworthiness requirements, and fuel tank survivability requirements. But exploding bolts? in an aircraft that has to be maintained for 20+m years in a difficult operational environment, and which must be 100% safe for not exploding in-flight? Not happening.

 

[DirteJoe]

Just trying to imagine the torquing and safety wiring process on breakaway bolts on a wing boggles the mind.

Imagine being in a high G recovery for what ever reason and your system blows the wing fasteners because the data is at or above loading of a wing vs tarmac.

Sorry for the derail. I've been involved in the manufacture of aerospace components for quite some time and have never heard a (former) airframe mechanic and FAA safety advisor/accident inspector say such nonsense before.

 

[Brian Malone]

CNN bio for David Soucie:
-------------------
David Soucie is an aviation safety analyst for CNN. He has traveled the world in the interest of improving safety awareness. He’s worked in the cockpit, on the hanger floor, within the aviation boardroom, and inside the Washington D.C. beltway. He’s seen death up close and personal and is committed to preventing loss of life in catastrophic accidents.

Soucie has recently been elected to the World Aviation Forum in Washington D.C, where he will be the Publishing and Press Focal Point. He is the author of Why Planes Crash: An Accident Investigator’s Fight for Safe Skies (2001) and Malaysia Airlines Flight 370 (2015).
‐‐-----------------
I have no knowledge of the exact structure of aircraft and found the concept of the wingtips shearing by design to be quite amazing, though surprising for the reasons mentioned. So CNN's av-expert has added some false info and the fortunate situation of the fuselage remaining intact was the result of general good engineering and construction and good luck?

 

[sunnysky]

Looks like pilot error without a flare landing and excess vertical speed.

 

[Tomfh]

There is NO way any sort of explosive bolts

Chinese whispers most likely. Someone has probably heard that wing bolts will shear off before ripping the wing box and fuselage to pieces, and it's been confused as explosive bolts designed to trigger in the event of a crash.

 

[GregLocock]

Breakaway bolts do work - if you drive a FE RWD then the chances are the front subframe is held on with a breakaway feature for crash so that the engine submarines under the floor rather than saying hello to the occupants' legs.

 

[DirteJoe]

I don't think anyone is doubting they work. Airplane wings are just not the appropriate application.