Delta crash at Toronto

[JimPghPA]

No ( or not enough ) flair to provide that nice soft initial touch of the mains we all like. I wonder what the airport and landing runway looked like from the pilots view. Was there too much snow on the runway combined with snow blowing around close to the ground combined with anything else reducing the pilots ability to judge height? Maybe a total white field of snow on aproach also added to the pilot not being locked into exactly where the aircraft was with respect to ground.

Not likely, but not a zero chance, might the wings have been somewhat iced?

If significant snow was on the runway, it would have added shear force as the wheels plowed through it. But that does not look to be the case.

I wonder if a long stretch of all white on the ground before the airport might have reduced depth perception for the majority of final aproach leg? That should not cause a great pilot to not properly flair, but only add to the work load. Still, if that was a contributing factor, it may have been one more hole in the Swiss cheese, to plug up for future similar setups.

I can see it now, miles of heated dye sprayers set up to collor snow covered areas before airports where that could be a concern, as if lights are not enough. Not likely, but hay, any port in a storm. Or any easy to see ground refference in a storm.

 

[mk378]

that B737 with the defect that caused the gear to go through the wing.

Wasn't that the MD11? Several of those had a wing break off from landing hard on the wheels, which leads to a deadly spin and flip on the ground. The new design much like the engine mounts is for landing gear to collapse and/or break away before it transmits enough force to break the frame it is attached to.

 

[edyvw]

One condition you can find yourself in wind driven snow events are depth perception whiteouts for lack of a better term. Kind of like landing on a lake with glassy water you lose some of your reference for actual height off the deck. Not saying that's what took place here but could be another hole in the Swiss cheese model that lined up...

Best to test that is ski chair. Take a ski chair in winter and than summer. In summer you actually realize how high it is.

 

[Just a civilian pilot]

Wasn't that the MD11? Several of those had a wing break off from landing hard on the wheels, which leads to a deadly spin and flip on the ground. The new design much like the engine mounts is for landing gear to collapse and/or break away before it transmits enough force to break the frame it is attached to.

The MD11 has a truly extreme hard landing , bounced, and the pilot caused oscillations ( porpoising ) which no plane can handle causing the wing to come off.

No mechanical problems , just pilot error with the MD11.

The B737 that had the gear though the wing was not pilot error and was caused by a defective part on the landing gear causing it to break ( even though the landing wasn’t hard ) and go through the wing.

The landing gear isn’t supposed to go up through the wing ( where the fuel tanks are ….fire hazard ) , no matter how hard the landing is.

 

[hemioiler]

This 35 second amateur video seems to show the approach and first few seconds of landing up until roll-over from someone in a vehicle at the end of the runway. I didn't see it posted, but I didn't watch the longer youtube videos so I apologize if it was.

If I could figure out how to delete the written comentary and still reference source I would. Sorry.

This is the original post on X:

 

[Jimmy_Russells]

Looks like ~500 foot descent rate just before touchdown

 

[Pelican]

Saw a video that clearly showed the right undercarriage collapsed as soon as the whole A/C/ weight was on it.
Impossible to say what was the cause, possibly mechanical or hydraulic failure, but it will come out during the investigation.
Edited: The Video I saw was the one posted by Hemioiler above.

 

[dbias]

In the mid 80’s my flight from San Antonio to Pittsburgh landed like a rock in Pittsburgh during a pretty good snowstorm. It hit so hard that several of the seatbelt signs and air vents above our heads detached and landed in our laps. Several people were assisted off the plane by EMS. Didn’t make the connection flight to HTS in a smaller plane seem very appealing lol

 

[Just a civilian pilot]

Looks like ~500 foot descent rate just before touchdown

With the strong headwind component, and low calculated landing speed ( if they flew the correct speed ) , the rate of descent to stay on the ILS glide slope, and PAPI below minimums on the approach ( even pilots see the runway way above IFR approach minimums , they fly the approach down to minimums, then transition to the PAPI lights normally until the flare ) would have been about what Juan Browne showed on the video.

Hard to believe that even not flaring with a descent rate around 525 FPM would do that to a plane.

 

[ArrestMeRedZ]

In watching that video, that was hard, right wing down, landing. No flare...

I see exactly the same thing. You beat me to the punch.
The right wing down at the last moment put all the landing weight on the right main. Combined with the high sink rate that poor plane stood no chance. It's a testament to the engineers the fuselage remained intact.

 

[Astro14]

With the strong headwind component, and low calculated landing speed ( if they flew the correct speed ) , the rate of descent to stay on the ILS glide slope, and PAPI below minimums on the approach ( even pilots see the runway way above IFR approach minimums , they fly the approach down to minimums, then transition to the PAPI lights normally until the flare ) would have been about what Juan Browne showed on the video.

Hard to believe that even not flaring with a descent rate around 525 FPM would do that to a plane.

I am hearing that the sink rate at touchdown was closer to 1100 FPM - well past the airplane's design limit.

Put all that load on one half of the structure designed to handle it, and you're asking for material failure.

I don't know where Juan, or anyone else, is getting 525 FPM at touchdown.

The whole point I am trying to make is that they had too high of a descent rate at touchdown - not during the approach. That ADS-B data isn't entirely accurate - it is a snapshot well prior to touchdown.

Watching the video linked - the mishap aircraft goes from about the fuselage length above the runway, to contact with the runway, in under 4 seconds.

So, from over 100 feet, to zero feet, in 4 seconds, is an average sink rate of 25 FPS - which is 1500 FPM.

Even if my perspective in that video is a bit off, this was a very high sink rate landing. Nothing close to 525 FPM. the fact that they landed so short on the runway is further evidence of excessive sink rate. A constant sink rate, and staying on glideslope, would have had them hitting the runway about 1,500 feet down.

But they landed just past the numbers, and the only way that could happen is if they left the proper vertical profile with an increased descent rate.

This crew fixated on something - to the detriment of their vertical profile and sink rate/power management - they landed short, they landed hard, they landed right wing down.

Were they looking at the blowing snow? Worried about centerline?

They didn't flare - and they set up an excessive sink rate - and that broke the airplane.

 

[Patman]

When a pilot is involved in an incident like this do they generally ever fly again or are they too rattled to get in there again? (Or would these pilots actually be terminated if they are found to be the root cause of the crash?)

 

[andrew_j]

Snow was a potentially saving factor , the plane was full engulfed in video and appears to mostly self extinguish on roll over in snow off runaway as it plows gently slowing it.

 

[JimPghPA]

Some bug smashers can handle abuse like that but not something that heavy.

 

[Just a civilian pilot]

I am hearing that the sink rate at touchdown was closer to 1100 FPM - well past the airplane's design limit.

Put all that load on one half of the structure designed to handle it, and you're asking for material failure.

I don't know where Juan, or anyone else, is getting 525 FPM at touchdown.

The whole point I am trying to make is that they had too high of a descent rate at touchdown - not during the approach. That ADS-B data isn't entirely accurate - it is a snapshot well prior to touchdown.

Watching the video linked - the mishap aircraft goes from about the fuselage length above the runway, to contact with the runway, in under 4 seconds.

So, from over 100 feet, to zero feet, in 4 seconds, is an average sink rate of 25 FPS - which is 1500 FPM.

Even if my perspective in that video is a bit off, this was a very high sink rate landing. Nothing close to 525 FPM. the fact that they landed so short on the runway is further evidence of excessive sink rate. A constant sink rate, and staying on glideslope, would have had them hitting the runway about 1,500 feet down.

But they landed just past the numbers, and the only way that could happen is if they left the proper vertical profile with an increased descent rate.

This crew fixated on something - to the detriment of their vertical profile and sink rate/power management - they landed short, they landed hard, they landed right wing down.

Were they looking at the blowing snow? Worried about centerline?

They didn't flare - and they set up an excessive sink rate - and that broke the airplane.

Thanks.

Just about to check in for work, more later.

Where did you hear the plane was descending at 1100 FPM ( not saying it wasn’t )?

I enjoy these discussions despite the fact that we are all speculating based on 2 videos and the latest Juan Browne video ( where he says it was not an unstable approach based on the data he provided ).

For me, based on looking at those two videos ( one isn’t very clear ) and the data Juan Browne provided, I just find it very hard to believe that much damage could be done unless the sink rate was A LOT higher than it appears.

I could be wrong but I am suspicious about other factors.

Visually, from that cockpit video, it didn’t seem that hard but maybe it did.

We had an Airbus ( Captain disconnected the auto thrust ) come over the threshold , unstable, very low IAS, high sink rate and slammed into the runway just past the threshold and the “ only “ damage was to replace something in the gear ( will check later but I don’t think they had to replace the entire gear ).

IIRC, a CRJ had a hard landing in YYZ in 2005 and the gear collapsed and I am pretty sure there was some sort of defect ….will confirm tonight. Sure, it landed hard but the defect with the gear , IIRC, caused it to collapse.

Looking for award to the discussion.

I better flare heading to Mexico today

 

[SC Maintenance]

If you look at the X video that several have posted. The contact is at about 8 seconds. So if 500 FPM is the max allowed descent, then your saying at this point the plane is 67 feet in the air at most. Looks like more to me? Of course this assumes a somewhat linear descent which of course it may not be? But even at 4 seconds they look a lot more than 33 feet off the ground?

 

[MolaKule]

Juan brings up a good point in that "Crabbing" requires extra power for this maneuver, so it brings up the question, "was suffcient power applied before landing?"

One retired Delta pilot (I am paraphrasing) said "Crabbing would have been proper given the direction of the winds in this case; the procedure would have involved landing on the right landing gear first and keeping the right wing down into the crosswind before settling on the left main gear followed by the nose gear for a full touchdown..."

In my view, the actual sink rate is still in question.

Another question involves the right landing gear; if the sink rate was proper, was there metal fatique somewhere in the assembly or attachment points that resulted in failure?

Most landing gear primary structural components are of Titanium 6Al4v, a very tough material. However, the top of the gear has attachment points to either a wing root structural member or a frame component that is dimensionally smaller. In addition, the wheel spindle(s) are attached at a right angle which represents a very high stress point.

I am hoping the Safety Board in charge will examine those landing gears and the attachments with a fine-tooth comb. Below is a CRJ-900 landing gear.

 

[JimPghPA]

There is SPECULATION of wind gust, and even down draft.

I was thinking that a rear engine jet had more of it's fuslagage ahead of the wings to help balance the engines weight aft. And aproaching in a crab then transitioning to align with the runway requires a lot of rudder forces being applied. And even more so with the extended version that that aircraft was. With a lot of rudder comes a lot of drag, causing loss of forward energy, slower speed, and faster sink rate. All of this still probably was not enough to cause such a hard landing, but may have been a contributing factor.

The short main landing gear because it did not have engines under the wings, and long wings, meant that there is less room for roll angle during touchdown, wing tip strike can happen easier. Shorter main gear probably also mean less shock absorption travel built into those mains.

Did the right main give before wing strike?
Or at the same time as wing strike?
Or after wing strik?
Or not at all, and it was wing strike alone that ripped that wing off?

And maybe it's not that important to know what gave first because the sink rate at touchdown was way beyond design.

Some comment that the initial force of touch was on the right main only. That also contributes.

It would be nice to see that on a large slow video.

 

[Just a civilian pilot]

On break between flights….

The main point I am making is, there is no way the landing gear would collapse or wings come off just because a pilot didn’t flare and cause a hard landing on a stabilized approach.

In order for the landing to be that severe, the approach would have to be unstable.

 

[Just a civilian pilot]

When a pilot is involved in an incident like this do they generally ever fly again or are they too rattled to get in there again? (Or would these pilots actually be terminated if they are found to be the root cause of the crash?)

I used to fly with a Captain ( another airline ) who survived a serious crash ( he was FO ) where people were killed. He was a nervous wreck.

I am aware of two other pilots who never came back.