Video of Miami Crash

[Publishers]

The video is hard to see exactly where the separation is but I would point out that the engine here is on top of the wing at the wing root. An uncontained engine explosion would have an extremely negative effect. You also would have a prop that is spinning and would separate and by centrifical force may well do sustantial damage to the wing root. Fire would or could complete the job and disable control.
This senario would have little to do with the age and more to do with the design. We will be able to get some info on this realtively quickly as the aircraft remained largely in tact.

 

[AnimalMother]

Age isn't necessarily relevant...but speculation is the halmark of unprofessionalism. One should be ashamed of guesswork; it belies everything we do in this industry.

We don't guess at performance numbers, we don't guess at anything we do. We know.

Sounds like Donald Rumsfeld babble. Do you write his speeches?

 

[hindsight2020]

I agree with Publishers, it is not totally off left field to suggest that a catastrophic engine failure would have induced sufficient damage to deteriorate the integrity of the wing root assembly to the point of failure; at least the video catches enough to see that wing failure, in fact, happened.

The NTSB will be able to ascertain the particular timeline of this event (was there fire on the engine first, did it explode and then caused the wing to fail, or did the wing fail first and then the engine/assembly on that side ignited etc, etc) and be able to pinpoint contributing factors and probable cause.

Now, the following is my opinion (and a little bit of a soapbox regarding aging aircraft), based on pure academic experience and operational testing that doesn't transcend the laboratory; my Aerospace Eng. Master's concentration was fracture mechanics and aging aircraft.

I am not disagreeing at all with those that have suggested that the age of the aircraft may have little to do with the cause of the accident. There is certainly plenty of scenarios that would have put that airframe in a damage condition that would have caused failure even if the wing assembly had been built yesterday. Do I think that deems it negligible? Absolutely not. My point is that EVEN IF that wing assembly suffered damage that would have rendered a brand spanking new assembly in catastrophic failure as well, we NEED to re-evaluate how we tackle the issue of our ever increasing aging aircraft population.

I am not suggesting at all that the MX on the Mallard's case was shoddy, but I will submit that the inspection and NDT evaluation schedules are getting ever more stringent and expensive. Human factors compound the problem with these old airframes, and I don't care how diligent you say your MX team is and more importantly,how appropriate your MX BUDGET is, flying these birds for 40+ years is just asking for trouble. Hell, we have the Air Force tap dancing around their little C-130 wingbox "problem" and their KC-135's WFD "problem" and how at the end of the day it all revolves around an ECONOMIC constraint, not one of engineering issues.

I know I'm pipedreaming about this topic, C-172's will still be 200K brand new and aging aircraft inspections will continue to become more expensive, but we can't continue to vouch for our safety on a cake of optimism sprinkled with a little bit of science icing on top, to put people at ease. When you operate an extremely old airframe, there comes a point where inspection schedules, meticulous modular approach to limited-life parts replacement, and honest and meticulous NDE/NDT technology implementation is not going to make you safe, not to mention too great of an opportunity cost when considering re-manufacturing.

I give the FAA a little due, I don't think they are trying to screw anybody, but I do feel that the economics of this business have become such that the FAA doesn't have much of a choice in their ability/willingness of alleviating the economic constraints that 1)keep people operating aging aircraft and 2)seriously and economically undermine the operator's ability/willingness to conduct inspection and maintenance that suffices for the age and operating cycles the aircraft has seen. Cycles which by the way, keep going up and up and up like a ticking bomb.

It will be yet another wakeup call for the FAA if this NTSB report comes back listing corrosion-assisted cracking as the culprit, or even an aggravating factor, in the inability of the wing assembly to remain functional after damage from an engine failure. Even worse, if the wing failure had everything to do with corrosion or other cracking mechanism, and the engine had nothing to do with it. We certainly could make a whole new thread on the economics of the matter, it is such an elephant of an issue.

My condolences are with the crew of the aircraft, I sincerely hope I can say at the end of my time that I pursued my life doing something of consequence, benefit and relevance to me and those around me. I hope and wish that in the end that was also true for those individuals in the cockpit. My condolences are also with the passengers and their loved ones, these accidents always hit a deep core, and we as pilots almost always feel just a little bit "there too", since we share and contribute to this aviation passion of ours.

Let's keep it safe and fun out there folks.

 

[agpilot34]

I have my doubts that this had anything to do with a catastrophic engine failure. The old round motors that these birds used to have were much more prone to fly apart, and I cant recall one ever taking a wing with it. I've looked at the video a bunch of times so far, and it looks to me like the wing separated inboard of the engine, which would hold true with the fact that there apeared to be no fire or smoke trail following the fuselage... only the wing section. At any rate, my prayers go out to the familis of the crew and passengers.

 

[Publishers]

It did look like the wing separated inside the engine and the prop appeared to still be in tact. Still, the suddeness of what appears to be an explosion near the engine leaves it a real possibility. The fire went with the wing and the engine so that to looks to be material.

 

[Mud Eagle]

CNN reporting this morning that there was an existing fatigue crack nearly all hte way through the spar.

 

[Publishers]

That is what the initial report is. I cannot recall another case of this in an aircraft flown normally. We have had several that occured in fire fighting aircraft like the C130 that came apart, and, the small trainer that was used in unusul attitude and spin recovery, but those were all high stress situations.

This could be the combined age/salt water/ sea plane impact (slightly different than landing on land and tires all the time).