Heavy Damage to Alaska B738 at KSNA During Tropical Storm
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Heavy Damage to Alaska B738 at KSNA During Tropical Storm
An Alaska 738 made a "heavy" landing during Tropical Storm Hilary at KSNA. The left main looks like it pushed through the wing box.
https://www.radarbox.com/blog/alaska...g-at-santa-ana
https://aviationsourcenews.com/incid...-in-santa-ana/
https://www.radarbox.com/blog/alaska...g-at-santa-ana
https://aviationsourcenews.com/incid...-in-santa-ana/
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Having peered into the 37 wheel well many times that's hard to believe...Joked a few times about "at we didn't drive the wheels thru wings" but didn't think it could actually happen...In the cabin left side video the touchdown "seems" pretty benign...
Not your usual scene from the window... but, not that nasty, the breaks will be interesting examinations.
The loading of the gear that is certified is a symmetric loading § 25.473 (a)(1) Landing load conditions and assumptions. § 25.479 Level landing conditions.
the main gear are assumed to touch symmetrically, the OEM goes beyond that, but a high sink rate, or with a roll rate developing, can be ugly, recall the MD11/11F's at [take your pick... but Narita is still pretty impressive]. The auxiliary spar giving up here is probably a best alternative on the day. Going to need a fair bit of bondo filler for it to RTS though.
The loading of the gear that is certified is a symmetric loading § 25.473 (a)(1) Landing load conditions and assumptions. § 25.479 Level landing conditions.
the main gear are assumed to touch symmetrically, the OEM goes beyond that, but a high sink rate, or with a roll rate developing, can be ugly, recall the MD11/11F's at [take your pick... but Narita is still pretty impressive]. The auxiliary spar giving up here is probably a best alternative on the day. Going to need a fair bit of bondo filler for it to RTS though.
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The summary at Aviation Safety Network states, “The aircraft was able to vacate the runway via taxiway E and came to a full stop on the taxiway.”
The flight crew chose to taxi an aircraft in that condition? And with a 90-degree right turn no less. Or was the aircraft towed? There is a photo of the aircraft parked on taxiway E with the tail clear of the hold bars.
The flight crew chose to taxi an aircraft in that condition? And with a 90-degree right turn no less. Or was the aircraft towed? There is a photo of the aircraft parked on taxiway E with the tail clear of the hold bars.
The summary at Aviation Safety Network states, “The aircraft was able to vacate the runway via taxiway E and came to a full stop on the taxiway.”
The flight crew chose to taxi an aircraft in that condition? And with a 90-degree right turn no less. Or was the aircraft towed? There is a photo of the aircraft parked on taxiway E with the tail clear of the hold bars.
The flight crew chose to taxi an aircraft in that condition? And with a 90-degree right turn no less. Or was the aircraft towed? There is a photo of the aircraft parked on taxiway E with the tail clear of the hold bars.
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It's hard to believe that the aircraft could taxi with the left engine dragging on the pavement.
Before everyone assumes that the accident was caused by heavy landing forces alone, there has been speculation about an underlying defect in the gear, either metallurgical or related to prior maintenance procedures as a cause or a contributing cause.
Runway 20 at KSNA is only 5700 feet long. Throw in tropical storm rain and a gusty crosswind and one can easily understand a desire to get those mains on the ground. More data will be helpful.
Before everyone assumes that the accident was caused by heavy landing forces alone, there has been speculation about an underlying defect in the gear, either metallurgical or related to prior maintenance procedures as a cause or a contributing cause.
Runway 20 at KSNA is only 5700 feet long. Throw in tropical storm rain and a gusty crosswind and one can easily understand a desire to get those mains on the ground. More data will be helpful.
Perhaps similar to the December 2019 gear collapse of a UAL 737-800 at Denver. Cause was a faulty overhaul of the main gear resulting in failure of the aft trunnion pin. Aircraft was repaired and returned to service.
N87513
N87513
From another website,
Narrative:
• Flight departure was delayed about 45 minutes out of SEA. Crew called Dispatch to see about an extension for the curfew at SNA and it was extended until 2330 PDT.
• Ran SNA Rwy 20R landing performance Flaps 40, AutoBrakes 3.
• Aircraft flew ILS to Rwy 20R. Stable approach, aircraft fully configured prior to FAF. Before Landing Checklist Completed. Aircraft broke out about 800’.
• SNA ATCT was closed.
• CA flying, touched down firmly on purpose just pass the 1000’ marker but prior to LTP. CA and FO both stated it was a firm landing, but nothing that alarmed them.
• CA felt what he described as "the tire popping” and noted the green light for the Left MLG was gone but no red light. Other two LG lights were still showing green.
• Aircraft pulled a bit to the left, but CA got it back to center line with rudder.
• Turned left off Rwy 20R onto Taxiway E and stopped. It was then that the airplane really started listing. After landing flow done.
• CA opened window and looked out and saw left wing resting on the nacelle and a wheel.
• Electrical source was transferred to APU and shut down engines. Did not pull fire switches.
• Called SNA Ops to send maintenance out.
• SNA Airport CFR heard the flight advise CTAF that they thought they had a gear collapse. SNA CFR came out and assessed the situation. Advised no visible fuel leak and that airplane was basically resting on the left engine cowling and one of the tires. Wing tip not touching ground.
• Ground crew initially planned air stairs on left side of airplane for deplaning through L1 door. Mechanics came on the intercom and suggested deplaning from R1 door to avoid further collapse and instability. Crew agreed and passengers deplaned from R1 door.
• Passengers were pretty calm. Took about an hour to get all the passengers off and to the terminal. Had passengers stay seated until everything was set for them to deplane. It was 30-45 minutes until they started deplaning and 60 minutes or so until everyone was off the airplane.
I’m also hearing that the plane went thru some maintenance on the gear and they suspect that some bolts weren’t put back in.
Narrative:
• Flight departure was delayed about 45 minutes out of SEA. Crew called Dispatch to see about an extension for the curfew at SNA and it was extended until 2330 PDT.
• Ran SNA Rwy 20R landing performance Flaps 40, AutoBrakes 3.
• Aircraft flew ILS to Rwy 20R. Stable approach, aircraft fully configured prior to FAF. Before Landing Checklist Completed. Aircraft broke out about 800’.
• SNA ATCT was closed.
• CA flying, touched down firmly on purpose just pass the 1000’ marker but prior to LTP. CA and FO both stated it was a firm landing, but nothing that alarmed them.
• CA felt what he described as "the tire popping” and noted the green light for the Left MLG was gone but no red light. Other two LG lights were still showing green.
• Aircraft pulled a bit to the left, but CA got it back to center line with rudder.
• Turned left off Rwy 20R onto Taxiway E and stopped. It was then that the airplane really started listing. After landing flow done.
• CA opened window and looked out and saw left wing resting on the nacelle and a wheel.
• Electrical source was transferred to APU and shut down engines. Did not pull fire switches.
• Called SNA Ops to send maintenance out.
• SNA Airport CFR heard the flight advise CTAF that they thought they had a gear collapse. SNA CFR came out and assessed the situation. Advised no visible fuel leak and that airplane was basically resting on the left engine cowling and one of the tires. Wing tip not touching ground.
• Ground crew initially planned air stairs on left side of airplane for deplaning through L1 door. Mechanics came on the intercom and suggested deplaning from R1 door to avoid further collapse and instability. Crew agreed and passengers deplaned from R1 door.
• Passengers were pretty calm. Took about an hour to get all the passengers off and to the terminal. Had passengers stay seated until everything was set for them to deplane. It was 30-45 minutes until they started deplaning and 60 minutes or so until everyone was off the airplane.
I’m also hearing that the plane went thru some maintenance on the gear and they suspect that some bolts weren’t put back in.
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That makes sense that it's probably mechanical given the robustness of Boeing gear....Not nearly as serious but had a tiller not steer (737-300) on landing roll out...Cleared the runway but had to get towed to the gate...Mech took a peek and said a linkage bolt was missing...Maintenance had been done on it at our dep arprt...Obviously fell out sometime after I stopped using the tiller on dep...
certainly didn't look like they "dropped" it from the utube vid. Not as hard as some of the carrier style landings at the old Singapore airport to avoid the bounce on the runway ridge
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This type of failure has happened multiple times and is usually due to improper maintenance during overhaul. Here is one from 2015 that clearly shows a sheared trunnion pin. Repairs are not difficult and the plane usually returns to service.
http://www.b737.org.uk/incident_vt-jga.htm
http://www.b737.org.uk/incident_vt-jga.htm
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AvHerald is reporting that a failure of the aft trunnion shear pin cause the failure, not a hard landing.
Accident: Alaska B738 at Santa Ana on Aug 20th 2023, gear punched through wing
Accident: Alaska B738 at Santa Ana on Aug 20th 2023, gear punched through wing