Where did you hear that information? I'm still not seeing an NTSB prelim.
Damn...loses both wings, fuselage drops like a rock from thousands of feet altitude and there's a survivor?
If you lose lift on one side the only way to balance the rolling moment is to lose an equivalent amount of lift on the other side. If you lose *all* of the lift on one side then the math is pretty simple. "Compromised" may not mean losing the entire wing, and until there's some kind of substantiation this is hearsay anyway.
Give some credit to the meat servo. The 'famous' one that lost the big chunk of wing was not FBW. (much) Later models are.
Several new variants of the F-15 are FBW.
It will be interesting to know what maneuvers they’d been doing, if the plane had recently been through any botched recovery from maneuvering (over-G), how the convection was (a thunderstorm was building and the sky was quickly getting very dark - I live five miles south) and if the maintenance was really done by the book or if the logs were just pencilwhipped.
I was trying to guess this from the ADSB track. Huge grain of salt with that data but none of the speeds seemed crazy.
Just read about that one...wow.
Yes, but the two entries have vastly different TIS and factored hours. Is the top (later) entry implying 1200 factored hours *since* the ECI in 2021? That would be 600h/yr which is possible. The interim AD is one-time, though, so this doesn't really make sense either.
See https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID159830425420221019132116.0001
It was at a flight school, so 600 factored service hours per year would be totally possible. Honestly if it was flying daily I would expect more than that. If it flew 1000 hours per year (20 hrs/week), and had 10 100-hr inspections that year it would equate to 1000 factored service hours.
My thoughts exactly. It's easy to jump to conclusions on the spar bolt hole because there's an AD, but if the wing is going to fail that's (one of) the first place it will. If we trust the metalurgical conclusions (no fatigue), then that would seem to imply the airframe was overstressed. It's a little annoying the preliminary report didn't include more images, e.g., of the fracture through the spar bolt holes.
Given they were compliant with the initial AD requirements, my guess is they were proactively repeating the AD requirements on a new 5000 TIS clock. Using the AD as a reference for the 2nd time track one method of doing this. Have seen similar rechecks at the 135 levels.
Same here. However, its mainly the picture of the uniformly distorted center main spar box that I think is very telling. And the fact its mentioned no visible signs of fatigue cracking at the breaks. The 2018 Piper wing failure center spar box was not deformed and I believe it only lost one wing vs both in this accident.
It had the eddy current on the main spar done. But perhaps that forward attach fitting was compromised 20 years ago?
I wonder if these would have made it to the next ECI?
Pretty likely that due to the TBI and extreme mental stress of the crash, he really doesn’t remember it accurately.
In my experiences with structural failure reports and analysis, yes those fatigue cracks would have made it to the next test and beyond. In general, fatigue anomalies tend to manifest over a long period of time and progress at a specific rate. In some cases they can actually count the of cycles at the granular level and calculate when the fatigue started. The factored services hours in the AD are one offshoot of this fatigue tracking. Over-stress is a completely different failure and has its own track to follow. And just as the report stated, the fatigue cracks did not contribute to the over-stress failure. Its rather an interesting science when you get down to the granular level of investigating cracks and other failures.
I’m saying that that with what we’ve seen multiple times from that particular school’s instructors and students, it’s likely that aerobatics - or attempts at it - was not a one-time occurrence. I’ve witnessed repeated examples of deliberate bad decisions from them - doing S-turns at 600 feet across final to a paved, marked, charted runway, doing a simulated engine failure to the same runway with a right hand pattern and downwind approach, and go-around head-on with a plane doing a low pass and max performance climb (which was making multiple trips around the pattern and making all the radio calls), entering the pattern opposite direction to traffic (experienced it with them at two different airports).
