Anatomy of a homebuilt aircraft failure 

+BetterAircraftFabric I think RC airplanes are a good start for a basic know how. Altough small airplanes and heavy airplanes behaves in a different way. Minor unimportant mishap on small airplane could be fatal on big one. As you told. There are amateur aviation asociations with professionals from aircraft industry which offers guidelines, help, inspection not as part of their profession but a hobby. Sometimes for a bottles of good wine or schnaps:) Building is about learning. If you are not willing to learn, you are doomed.

This is what killed this guy: you cannot use model airplane construction techniques and apply to them full size airplanes. Just because it works on a model does not mean it will work full size. Discontinuous spar caps and crappy plywood won't do.

PDZ1122 Totally agree! Sometimes the project is good, the plans are easy to understand, and even the constructor is skilled enough to carry on the project with no problems, but using poor materials, like non-aeronautical grade wood, or wrongly cut, or just by using inappropriate type of glues could lead to disaster.

PDZ1122; You are sure right with these two comments...No question... Building a wooden airplane requires far more skill and care than bolting together and kitplane or ultralight of the metal kind. Attention to "detail" is a total must with wooden structures...

@@BetterAircraftFabric i bought an avid speedwing and amd starting lessons soon. And i have 100% faith in it. But no way wpuld i buy or try to build or design a wooden airplane. Also luan plywood is a horrific choice

Maybe he watched "Flight of the Phoenix" once too often...

Even RC airplanes don't use this type of wing. All RC planes whether they have a tube joiner or not will have a full length spar, the tube is bonded to the spar and connects both spars from each panel together.

However, it looks like the failure did NOT occur at the point where the spar is glued to the sheer web. It would have been helpful if they would have shown a picture where the break occurred.

I guess you would not like to fly in a Bellanca Viking. Speaking static load tests, look at the load test done on the Viking wing. By the way, aluminum develops defects, it's called corrosion.

With you right up to the bit about the building a stronger spar if the wing bends. Wings on airliners bend. They are designed to flex somewhat. If they are too rigid they will be brittle and then when overloaded they would simply snap all at once. All that really matters is if the wing is damaged.

Wood is a very effective aircraft building material. Has been for a century, and still is. Some of the best aerobatic aircrafts use wood. Any material has defects, but wood has distinct advantages such as very good bonding capability, easy to work with, durable in time if well protected, and overall, good strength to weight ratio with low density allowing large sections, just strong enough, without weight penalty. Most metallic designs are not designed for strength but stability (buckling).

Honesty Counts If you are referring to destructive test procedures for Boeing a/c type certification per FAA then you are mistaken.

There are several kit airplanes with exposed foam ribs. Including Spacek SD-1 Mini Sport, Luciole MC-30. They simply glue 1 to 3mm plywood skins onto the foam. Even the ailerons and elevators are made this way. You can find Extruded Polystyrene (XPS) insulation foam boards with compressive strength from 15psi to 100psi. The cheapest pink foam at home depot is Owens "Foamular 150" which is the lowest end of the spectrum, and not an aircraft grade material by any means. (Im sure Owens would agree). That being said, the Burt Rutan designed Quickie Q1 utilized 2lb.ft^3 Polyurethane foam, which has a compressive strength around 20psi and was even weaker than XPS 15psi foam. Used PU foam, as it was easy to carve into a sleek fuselage shape. Those Q1s seem to hold up at least 30+ years. But also have 1-3 layers of fiberglass over the foam. There are several SD-1 and MC-30 with hundreds of hours. But I would not count on them lasting 30+ years.

Excellent comment.

I don't care if a person designs and builds and crashes his own aircraft. But it does affect us all in the experimental aircraft world the faa/government will get more involved. And this guy sold his other aircraft.

Strongly disagree....everything we do affects others and in particular in aviation. If you die through ignorance or stupidity....you may be gone but others suffer the effects from your bad decisions...so..as a responsible adults..it is our RESPONSIBILITY to exercise our rights and freedoms with thought to others.

WarPig's Busted Knuckle Garage No, that would not happen because the FAA wouldn't allow you for a couple of reasons. Number 1, you say that you would not kill anyone. How would you know that? The truth is that before you fly your plane there is no certainty that no one would die which is why the FAA makes sure all aircraft are safe and that the pilots are safe. Number 2, the FAA would nit approve a brick plane. It's your rights to own an airplane and follow the rules, not to do whatever you want and put other people's lives at risk.

Erich Hartmann Absolutely agree in spades. I was told by a well respected inspector that he would give an airworthiness certificate to a broom stick with an engine if someone is crazy enough to fly it....however the test period would be huge and the area very restrictive...even with that...ones life is not ones for the taking. Others are involved with ones problems after a decision leads to their demise. Common sense dictates and if there is none...stick with model cars...please.

No one cares if you die, but you just might take an innocent person with you when your poor design falls out of the sky onto someone else's house or car or person.

Testing by jumping up and down on it is nuts..as in using luan plywood thats literally garbage. If i designed a plane id test it to 4 or 5 g's just off the top of my head. Youre landing at 40 to 80 mph and may drop from 10 feet to 0 in a half second. Im betting thats 3gs minimum. And you do a hard banking turn and the wrong wind gust hits a wing/s.... This guy was nuts

You mean, Moron!

Kitfox's and avids anongst others have fantastic reputations. Your concerns would be the quality of the welds and making sure they didnt take shortcuts . if you sat in, examined my avid youd be impressed w the strength .

2Phast4Rocket, properly maintained older airplanes are safe. The key word being properly.

A lot of false premises there.

Youre risking ypur own life. Why should we have to get approval from some dude w a certificate? Per ypur implied mindset we wouldnt have planes or automobiles because their inventors wouldnt have been allowed to build them. There are a LOT of experimental that far outclass their commercial counterparts in every way. Google DRACO stol. The best stol aircraft on the planet. Experimental. Designed from scratch by a hobbyist who routinely radically changes it

Has to do with some of the inane defects in the Professional Engineering laws in many states. (I am A P.E. btw.) You have to have signed and sealed drawings for a residential air conditioner installation, but a car, airplane, refrigerator, or hair dryer is a “manufactured item” and is exempt.

Peter Pasieka The airplane does not appear to have a N-number. In order to be a certified experimental airplane and have an N-number the builder must submit a build log with photographs, expense report, etc. to prove that he or she built more than 50% of the airplane themselves. The more documentation you have, the easier it is to get Federal Aviation Administration certification. At that point you generally have at least a Sport Pilot's, and probably participate in the EAA and other enthusiast groups. There is the possibility that it's a FAR 103 compliant ultralight, which do not require such certifications. Kits and designs generally get certified anyways as a selling point, but individual ultralights do not as they are not legally considered aircraft, being originally motor powered hanggliders and needing to be built with fuel tank of less than or equal to 5 US gallons and a range of less than 60 statue miles at cruising power, flying in unurbanized areas of the US to minimize the risk to others.

The hard landing sped up the failure time. That wing was inadequately designed and would fail soon. Look closely at the presentation and the design calculations. A steep turn, 60 degree bank, which is a normal aircraft maneuver would stress that aircraft above it's design limit.

It may not have been approved for flight or issued an N number. I have read several accident reports of home jolts that crashed that were never registered. I have also read of several homebuilts that were built and flown off of farm strips and have never been registered, but have also never flown anywhere but around the owner's property.

You can't really believe that he got this plane inspected and approved by anyone from the FAA do you?

I didn't do the math myself, the presenter did. However, there is a really great book called "Stress Without Tears" that shows exactly how to do this type of math. It is very easy to read, requiring only high school math to understand.

Johnny Tobifour good UN... I was thinking more like put sandbags you knew the weight of on the wings while you were safely on the ground until they failed. I know crazy right? What was I thinking. Much more fun to pull the G's

+Johnny Tobifour Sorry, but you're talking nonsense. The reference to a 60° bank (coordinated) producing 2Gs of load on the craft is talking about how steeply the aircraft is banked (a line drawn through the wingtips would be 60° from level). The G-loading on the aircraft increases on a curve and approaches infinity as the angle of bank approaches 90°. If you rotate the craft beyond 90° then it's actually inverted and it is impossible the achieve a coordinated bank with positive G forces. So really hope you were kidding.

There is plenty of knowledge accessible in the world online and otherwise to build a plane that is flight worthy. A postmortem is meant for learning to try and not repeat the same failures. Post mortems are done when an airliner goes down whether it is pilot error, design problem or maintenance problem. But judging by the things this builder did, he was just a hack trying stuff until he got himself killed without adequately educating himself. Blame game and lawyers....so here is a question...which country is known throughout the world for the blame game and lawyers?

If the information from the inspectors is available then there is no fault except the builder. We pay our hard earned tax money to feed these inspectors so we should receive something for our money beside criticism.

There is considerable information on aircraft design and construction available online from the FAA. There is an excellent, nearly boundless, resource through the EAA to it's members. (Membership is $40 per year).

Ryan Taylor - no inspection if under far 103.

Thank you for the info, I checked the FAA web page regarding FAR 103. I find this amazing, since it means that someone with ZERO experience, and ZERO knowledge of aircraft design can slap anything together (providing it is within the specs. of an ultralight for speed, and weight), and basically build their own coffin. I'm not a big fan of government regulation, but aircraft have the potential to kill not only the pilot but anyone unlucky enough to be in the impact zone.

Drone registration is currently not required, for private 'model aircraft' category units. Fought in Court and the 2012 federal law exempting model aircraft signed off on during the Obama administration won out over the FAA requirement (May 2017 case). This was primarily for tracking ones used in illegal locations that crashed & were recovered. More useful as a reminder to legal users of the rules they sign off on when registering and that they may be caught if violating them than for any prevention of intentional illegal use.

I don't see a Registration number on the aircraft , the builder may not have had the required inspection. He built it and he flew it.

Under current FAA Regs, an individual can design/build an aircraft from scratch with very few regulatory requirements. In this case, with no inspection covers, a DAR had no way to inspect the structure as finished. The required builders log might have given a clue but even then the nature of the spar design may not have been apparent. Incredibly, even engineering calculations are not required. TLAR, that looks about right, is acceptable. The EAA is a tremendous resource for anyone interested in anything from a powered parachute to a super sonic jet. Everything from first hand experience in fabrication to design expertise. And for the most part, it costs almost nothing. Unfortunately, some folks insist on their independence and get into trouble. One I’m familiar with is a fellow that plans built a beautiful amphibian out of wood. First rate wood working. The DAR asked what adhesive was used. The answer, “Elmer’s.”(That’s a common water based general purpose glue.) The DAR thought it was a joke. It wasn’t. This builder had attended one local EAA chapter meeting, brought something for “Show and Tell,” that was below par workmanship wise. Some fellows tried diplomatically to show him the problems but he wouldn’t hear it. Spent six years building a one to one scale model of an airplane designed to operate on water with a water based glue. The DAR told the guy to take a chain saw to it. You got to admire the passion but even the Wright Brothers got outside help when they needed it.

They are promoting aviation. Do you think they should stay silent about bad construction practices?

You would indeed be endangering others when the airplane, RC or full scale flew, unless of course, you are flying over a completely isolated area which is unlikely.

They don’t let you operate just anything with an engine and wheels on a road. It has to meet certain safety standards and guidelines. The same goes for aircraft. The pilot built His plane with, evidently, zero regard to basic structural integrity.

Yeah not a huge fan of regulation but I don't want you flyin over my house in a POS like this either. People building junk like this are exactly how and why the government gets control to regulate, because SOME people wont regulate themselves and kill others in the process.

No, the government controls and regulates things because they are no longer bridled by the constitution. Scope creep has brought us into a hyper regulatory illegal-everything world. And we have people like jones here, and jose batista, and john smith, and rotorheadv8, who "internalize" and "normalize" the illegal-everything world they grew up in, and champion more of the same. Thank God we got Trump to tamp down the government as much as he can in 8 years. God help him stack the Supreme Court so it will stay tamped down for most of the rest of my life, at least.