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

 

[LittleInch]

Looking at that picture in your post #103, it looks more probable to me that the locking arm actually did its job but either a compressive or axial force big hit as it smacked into the runway with a fair bit of sideways force somehow damaged a structural element of the wing which with the wing still generating large quantities of lift was enough to snap it off.

An interesting failure for sure and I've noticed that its when there is some semi decent video footage or reliable information that we can make some sense of this.

 

[DirteJoe]

Phone screenshot is the best I can manage right now.

 

[Sym P. le]

I believe this Airworthiness Directive is about adding some line items to the Maintenance Requirements Manual (MRM)

Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

This service information specifies new or revised tasks to detect cracks in the principal structural elements of the fuselage and wings.

Published format - https://www.govinfo.gov/content/pkg/FR-2024-03-05/pdf/2024-04557.pdf

Originating document, Transport Canada Airworthiness Directive CF-2022-35 : Time Limits / Maintenance Checks – Airworthiness Limitations – Tasks Revision

53-41-115 Overwing Longerons, Bottom Flanges

Terminology from ScienceDirect re: Longerons / Flanges / etc.

see also MHIRJ Service Bulletin

 

[Sym P. le]

Wing root and right main gear diagonal brace (snapped off at the gear connection)

 

[Sym P. le]

A better crop of the brace

 

[Garbage1]

Correction. Damage to gear end of lateral brace indicates it may have failed as wing tore away, and perhaps not from initial axial compressive load.

Image of CRJ900 Wing structure during manufacturing, to compare to wreckage photos above.

 

[Sym P. le]

Notwithstanding its appearance in the image in post #103, the left gear diagonal brace may also be detached. The diagonal brace may not be the primary weakness that led to the wing failure.

 

[Sym P. le]

When the aircraft lands hard, the weight of the fuselage, including the engines, passengers and luggage, can punch through the wing assembly. This has an interesting affect which is visible in the animated landing gif. In Frames 5 and 6, the right wingtip is unusually low, even though the aircraft is levelling out putting down the left gear. If I'm correct, it's because the right gear twists the wing giving it a negative angle of attack which sucks it down. As soon as the aircraft puts all of its weight on both main gear, my earlier scenario takes effect and the weight of the entire aircraft whips the right wingtip upwards, Frame 7, at a rate the video struggles to capture.

The diagonal brace would break with the wingbox shearing. This would allow the right gear to assume any random configuration though apparently, the net forces kept it under the wing for at least a small fraction of time.

They might have to ground the fleet.





(CRJ-700 as an example)

 

[LittleInch]

When the aircraft lands hard, the weight of the fuselage, including the engines, passengers and luggage, can punch through the wing assembly. This has an interesting affect which is visible in the animated landing gif. In Frames 5 and 6, the right wingtip is unusually low, even though the aircraft is levelling out putting down the left gear. If I'm correct, it's because the right gear twists the wing giving it a negative angle of attack which sucks it down. As soon as the aircraft puts all of its weight on both main gear, my earlier scenario takes effect and the weight of the entire aircraft whips the right wingtip upwards, Frame 7, at a rate the video struggles to capture.

The diagonal brace would break with the wingbox shearing. This would allow the right gear to assume any random configuration though apparently, the net forces kept it under the wing for at least a small fraction of time.

They might have to ground the fleet.

View attachment 5643


View attachment 5645
(CRJ-700 as an example)

That's a great find,. I've been looking everywhere for details of the wing structure and not found anything.

So what's the actual connection mechanism at that shared connection at the back?

Rivets or bolts?

When I look at those photos it looks like the rear spar sheared off? The red circle? Or did the rear connection frame for the wheel go first and just bent this one?

 

[Alistair_Heaton]

It looks like a mixture of both on the cs300.

 

[DirteJoe]

It should be a combination of 13-8PH hi-loks, rivets, and 13-8PH or Inc718 lockbolts on the structure for the wing and gear.

 

[Garbage1]

Here is the short PR mfg video I found for information.

Very impressive collabration effort!

 

[mfgenggear]

according to the information from AI and other sources. which is confusing to me.
some of hardware is designed to break
or blow on impact. any one has conformation.

 

[Sym P. le]

No $*#!@ way the wing spar is designed to break apart. Unless they're a turkey after the feast, they're full of stuffing. I talked to the chef.

IOW There isn't much meat on those bones!

 

[SWComposites]

some of hardware is designed to break or blow on impact

AI is again COMPLETELY WRONG.

 

[Sym P. le]

Does anyone recognize this part? I'm curious about the structure aft of the landing gear bracket. The flap system likely requires some robust support.


Youtube

 

[SWComposites]

Kind of looks like an actuator for the MLG assembly.

 

[LittleInch]

More likely the flap mechanism.

 

[GregLocock]

The pyro bolt/breakaway bolt was misinformation put out by a TV expert. As I said the FMEA/CBA on that would be fun. At the same time the basic point that the wing is weaker than the wing root/fuselage section seems accurate at least in this instance.

 

[GregLocock]

Grabbed from pprune.