Toronto place crash 4

[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]

To me the wing root fails before the other wing derotates and stops flying.

So there isn't even full load on that gear. And there can be rotation to unload.

To be honest I have seen what looked to be much harder landing contacts. Which yes have required lengthy inspections afterwards with damage. But haven't resulted in a fast fracture complet failure as with this one.

 

[DirteJoe]

It appears there have been service bulletins from 2015, 2016, and 2018 on /700/900/1000's to inspect the main landing gear.

"There have been reports of damage to the protective coating and/or corrosion on the piston/axle of the Main Landing Gear (MLG). The damage to the protective coating was caused by friction between the inboard axle sleeve and the axle thrust face. If not corrected, this condition can cause the axle to separate from the piston/axle [and consequent collapse of the landing gear during ground maneuvers or upon landing]."

"It is possible for the orifice support tube (OST) of the Main Landing Gear (MLG) to break. If the OST breaks, it is possible that the shock absorber will not operate correctly. This can cause damage to the aircraft structure and/or the MLG to collapse."

I'm sure this will be getting looked into in detail. There's not much in the change of the design of the components. CRJ900's being given about a 30,000 flight cycle limit on the main gear struts.

 

[LittleInch]

Not withstanding all the comments, views and thoughts, I'm with our pilot here when he says people have smacked aircraft into the tarmac much harder than this and the airframe has survived, possibly with some damage or bending.

So this points to either a weakness in this design, this aircraft or unpredicted failure of some important strut or component. These aircraft get some pounding and high number of landings on runways with cold, corrosion and fatigue all in play here.

I'm not sure why airports don't routinely video take off and landings from the end of the runway or track them on final descent with reasonable resolution cameras, which can be highly automated?

 

[Alistair_Heaton]

I really don't think it's a problem with design.

There would have been more events like this and they would have occured earlier in the life span of the aircraft type.

Either manufacturer material issues, some strange fatigue profile or corrosion in a hard to access boroscopae cheap D check item.

 

[Garbage1]

Not withstanding all the comments, views and thoughts, I'm with our pilot here when he says people have smacked aircraft into the tarmac much harder than this and the airframe has survived, possibly with some damage or bending.

So this points to either a weakness in this design, this aircraft or unpredicted failure of some important strut or component. These aircraft get some pounding and high number of landings on runways with cold, corrosion and fatigue all in play here.

I'm not sure why airports don't routinely video take off and landings from the end of the runway or track them on final descent with reasonable resolution cameras, which can be highly automated?

Or dissolving bolts that attached wing root to fuselage. An example of this loss of strength over time is coated steel screws/nails/fasteners in the EPA neutered pressure treated wood used to build wood decks that are exposed to the environment. As the steel corrodes it loses strength, until.........

 

[Alistair_Heaton]

You can actually get that.

Mercury can be involved.

Also toilet leaks can seem to cause extreme rapid degrading.

 

[RobWard]

 

[DirteJoe]

Rubber debris not cleaned off can cause pitting and errosion to the structure and fasteners as well, especially with salt in use. Poor NDT practices can miss that.

 

[Garbage1]

It is impossible to follow that one, but here goes...........nothing..........

Perhaps our pilots could address on these short pond jumper flights that receive lots of landing cycles in a very short time period. How consistent are landings on same runways in same direction with prevailing winds from the same direction and with similar thermal cycles based upon short repetitive routes?

What I am getting at, is could one side of air plane be exposed to touching first based, upon same prevailing winds and environement, a lot more often than the other side? Thus cycle stress accumulates faster on one side versus other? We may need Elon's AI to dig into this?

Along with DirteJoe's comments on maintenance, I read that in 2018 FAA extended maintenance intervals on CRJ's, even though they are known as maintenance whores according to the article. Lots of these planes are much older in 2025 than they were in 2018, and Bombardier sold to Mr. Bishi in 2020? So lots of things and focus can change under new ownership, as these planes are direct competitors to their MRJ's, and are likely on a phase out path as they age?

 

[mfgenggear]

one method to attachment of wing to fuselage

https://www.reddit.com/r/StructuralEngineering/comments/v8hsql/how_are_lug_joints_used_to_connect_wings_to_the

 

[DirteJoe]

I never took the job with Mitsubishi during that 2020 hand off, but I do remember their main focus only being on servicing the powerplants with other work being sublet to independent certified maintenance and overhaul shops. They likely have very little to do with anything these days with the actual work and inspection performed.

We saw more abuse on the shorter jump flights mostly due to hard landings with newer pilots getting their hands wet with larger planes. A lot of old smaller plane habbits like full stall landings and forcing them down were quite often. Hard landings, to the point of bouncing, would also largely go unreported by the pilots. There's been a few instances of cabin crews reporting their concerns to the new crew coming abord on shift changes after the outgoing FOs and Captains refused. More often than not was on crews with combined low hours on type.

 

[Alistair_Heaton]

I agree with the above opinion about regional bus route operations.

Also there are some funny characters dealing with training and flight standards.

 

[Sym P. le]

YesI watched the video several times, I just have a different interpretation than you.

What I love to hate about this forum. You can't just expect everyone to go along with good arguments let alone flimsy ones. Why can't ya'll just agree?

To me the wing root fails before the other wing derotates and stops flying.

There is good evidence of that. I think the video shows some upper surface wing deformation before the tip disappears. Not that the tip disappears, there is a faint trace of it through the other frames.

In keeping with this I modified the gif. The first frame is tipped for 0.5 degrees of roll, as data indicates approximately that for the final landing orientation.

 

[Garbage1]

Landing was at some angle, whether .5 degrees or more, thus the outer tire took more load initially. With all that landing load on landing gear, I have a hard time with the frictionless movement laterally of the tires on the tarmac. Rather I see the landing gear locking arm pushing back towards the wing root, as wing root is failing.

 

[Sym P. le]

The diagonal brace doesn't push into the spar though, it pushes/pulls off the fuselage, well towards the centreline of the aircraft. I'm thinking the wing damage was in the space between the fuselage and landing gear mount, not the brace. The landing patch is likely somewhat greasy from the temperature build up of near instantaneous acceleration of the rubber. Hence the rubber build up and runway maintenance requirements.

 

[waross]

the front gear has the hinge at the back and what you're looking at I think is the steering mechanism.

I agree. I have heard several comments on the "locking gear" that I think meant the steering link or toggle.

 

[Garbage1]

The diagonal brace doesn't push into the spar though, it pushes/pulls off the fuselage, well towards the centreline of the aircraft. I'm thinking the wing damage was in the space between the fuselage and landing gear mount, not the brace. The landing patch is likely somewhat greasy from the temperature build up of near instantaneous acceleration of the rubber. Hence the rubber build up and runway maintenance requirements.

Agree that diagonal brace likely pushes/pulls directly off fuselage, and that push actually would inject more force on the wing root bolts/lugs/connections perhaps pushing wing away from fuselage on initial landing angle.

 

[waross]

I don't think that this was just a hard landing as far as the gear was concerned.
With the crosswind, the plane was probably crabbing and a hard landing with the tire not in line with the direction of travel may have put extreme side pressure on the gear in addition to the hard landing forces.
With too much down force to allow skidding something had to give.

 

[LittleInch]

What I love to hate about this forum. You can't just expect everyone to go along with good arguments let alone flimsy ones. Why can't ya'll just agree?


There is good evidence of that. I think the video shows some upper surface wing deformation before the tip disappears. Not that the tip disappears, there is a faint trace of it through the other frames.

In keeping with this I modified the gif. The first frame is tipped for 0.5 degrees of roll, as data indicates approximately that for the final landing orientation.


View attachment 5555

OK, that video clip is a bit opaque, but I can see where you're coming from that it looks like the right wing fails as the landing occurs, which kind of makes sense as both wings had a fair amount of lift still so it is certainly a key point I'm sure they are looking at to try to see what happened very quickly in what order. That wing tip was difficult to see. I wonder if the original full video clip has a bit more definition and I hope they have it.

Does make you wonder still why it's not standard to video all commercial flight landings at decent definition.

 

[Sym P. le]

I have the advantage of working on the individual frames prior to gifing. They're just a touch better. I wasn't expecting great things but the earlier gif was a bit lacking so when I saw the better quality video, I took a closer look. I was trying to identify some of the attifacts in the poorer video and was surprised by what I found. I was really trying to find the wing plowing onto the ground.

Now if the diagonal brace was broken off (at either end) by the lateral force of impact, the gear would then provide extra leverage to crank on the wing in addition to the vertical force. I wonder if they will find broken stuff closer to the touchdown point.