mightynimbus
Well-Known Member
How many times have they folded up?
Fire Fighting - Two Fatal in AZ
- Thread starter fholbert
- Start date
How many times have they folded up?
Pilot Fighter
Well-Known Member
A ten second search revealed:
"From approximately 1961 to 1993, 24 aircraft crashed when spar failures caused the loss of the wing in flight.[18] Thirty-five more spars were found cracked during inspections.
mightynimbus
Well-Known Member
thank you for saving me 5 seconds !!!
FlyingAccountant
Well-Known Member
Nah, Matt worked for a flight school/charter outfit out of FFZ. The guy you’re talking about appears to be a medevac guy down south.
fholbert
Mod's - Please don't edit my posts!
Turbo Commanders. Why they don’t call them Turbine Commanders, I don’t know.
Space Monkey
Arbitrariness replaces reason with authority.
'Cause the Jet
Turbi??
G-money Commanders?
Asking that is like asking how many licks it takes to get to the tootsie-roll center of a tootsie-pop.
Last edited:
knot4u
Repeat Offender
As an academic I'm sure you're aware of the term "economy of language". The point is to to use the least amount of words possible and still provide a concise description or opinion. This also seems to translate to ones post count on any message board, each post made seems to dilute any credibility from an overly vocal contributor, especially so when that person seems to think it's their duty to educate the other members. Knock it off.
ahw01
Well-Known Member
Awesome steed. I'd love to fly one
Space Monkey
Arbitrariness replaces reason with authority.
Do you have a crush on me? C'mon... admit it. I really love all your attention, but you're not my type. (heart emoji)
FlyingAccountant
Well-Known Member
It looks like the docket for this one was published in November. Nothing terribly groundbreaking. The left wing was found intact almost a mile away from the main crash site. The materials analysis suggests the wing spar fractured from fatigue as the result of overstresses experienced in its lifetime.
data.ntsb.gov
RIP, Matt.
NTSB Docket - Docket Management System
RIP, Matt.
DE727UPS
Well-Known Member
I didn't read all that but did they render an opinion on if there was cracking that should have been seen during routine maintenance? I think they use those as lead planes and I can see how they could get beat up. Thanks for posting. I've always wondered what happened with that one.
FlyingAccountant
Well-Known Member
I don't see that, but there were no shortage of inspections and repairs done to the spars over the course of the airplane's life, including a repair that was made to the left wing spar cap that failed just three months before the incident, which seems sort of susp. I don't claim to be an A&P, but I am also curious how this was missed given they were in there and working on that location of the aircraft only three months before the incident.
Murdoughnut
Well sized member
It looks like the docket for this one was published in November. Nothing terribly groundbreaking. The left wing was found intact almost a mile away from the main crash site. The materials analysis suggests the wing spar fractured from fatigue as the result of overstresses experienced in its lifetime.
NTSB Docket - Docket Management System
RIP, Matt.
I'd say the groundbreaking piece is Textron looking at the inspection photos and telling them they needed to replace the spar, and them not doing it. They won't, but someone should be behind bars for that.
Roger Roger
Bottom of the list
Wait what….guess I need to look at that docket now
Murdoughnut
Well sized member
Let me know if I'm reading it wrong - from the Factual Report ...
FAS submitted a structural damage report and service request detailing the crack indication to the Textron Aviation structures group on April 12, 2021 and followed up with photos of the hole location on April 13. Textron Aviation responded to FAS on April 14 that the crack indication necessitated the replacement of “the center section forward spar cap, center section forward lower fittings and both outboard main spar assemblies”. The email response from Textron Aviation to FAS also included the warning below from SIRM 57-13-01 (in part).
WARNING: A crack in the center section lower forward spar cap necessitates the replacement of all lower forward inboard fittings, the lower forward spar cap on the center section, and both outboard forward wing panel main spar assemblies.
FEA and FAS elected to repair the wing spar at BL 29.27 instead of replacing the spars and contracted with a FAA Designated Engineering Representative (DER) at Callahan Aircraft Services, LLC for the design of the repair. The repair involved oversizing the affected fastener hole to 0.328 inch and installing an external doubler around the hole location. The repair was installed and signed off on May 24, 2021, with an FAA Form 337 Major Repair and Alteration and included a FAA Form 8110-3
Roger Roger
Bottom of the list
That’s actually really common. GA Manufacturers don’t want to deal with drawing complex repairs so they’ll just tell you to replace everything. As a mechanic and IA, or an operator, if I have data from a DER and a repair competently accomplished per that data my hands are clean. I’m not a structural engineer and it’s not on me to check their work other than glaringly obvious stuff. The DER should absolutely be in hot water though.
FlyingAccountant
Well-Known Member
I missed the factual, but that was the impression I got from looking at the maintenance records, but wasn't completely sure. That certainly seems to be the case.
According to the report, the DER claims he wasn't aware of Textron's recommendations, although Falcon Exec claims otherwise. Interesting.
Roger Roger
Bottom of the list
OK so after reading more….the crack was in an area that is under an AD and that is where the “replace such and such parts if a crack is detected” comes from. I don’t know how much authority a DER has to get around that and if end-running the AD by a DER is common in the king air world. It definitely would put me on alert.
Also, a peek at the Callahan site is….interesting.
Also, a peek at the Callahan site is….interesting.
inigo88
Composite-lover
Yep - this is the scary part of being a DER. There are lots of ground rules and assumptions that go into designing a repair like that, well above the AC43.13 “make your doubler look kinda like this” diagrams. Aluminum has no minimum fatigue strength so as soon as a metal airplane rolls off the assembly line and lifts off the runway for the first time the clock starts on the number of cycles the structure can take before it dies. And while the economics of aviation push everyone involved towards designing complicated repairs, sometimes the parts are a lost cause and have to be removed and replaced.
The DER might have absolutely messed up, but they may also have assumed the airplane didn’t have a history of a bunch of yahoos over-Ging it and then lying about it. There’s no amount of math that can fix that part.
Edit: Still don’t know enough to Monday morning QB but if the repair was contrary to the manufacturer’s recommendations and an AD… seems bad.
FlyingAccountant
Well-Known Member
They made an interesting comment in the materials analysis about one major overstressing event that happened 100 or so cycles before the accident based on the metallurgy that they should have been able to correlate back to the logbook, but no mention was made around the time in question.
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