The FAA has released their report on the Zodiac 601XL

[mcjon77]

The FAA released their special report on the zodiac 601XL and what deficencies they perceive in the original design and testing of the aircraft. Overall, I found the report interesting and informative. The report makes it clearer (for me anyway) how the chain of small miscalculations could collectively lead to some of these accidents.

The first issue in the report was something that I had not heard before. According to FAA analysis, the wings were 20-25% weaker than the minimum ASTM standard for a plane with a gross weight of 1320lbs.

Wing structure: FAA analysis of the aircraft showed that the loads used by the
manufacturer to design the wing structure did not meet the ASTM standard for a
1,320 lb aircraft. FAA analysis estimated that the wing design loads were 20 to 25
percent too low. Static structural tests completed in the Czech Republic, and testing
done as part of an investigation by German authorities support this conclusion. Those
tests revealed that the wing structure could not sustain the original design loads
developed by the manufacturer for compliance to the ASTM standards for a 1,320 lb​

airplane.

There were also issues with how the company calculated their manuvering speed, as well as how the ASI was calibrated in individual planes. The net result (as I understand it) is that the manuvering speed listed in the POH was higher than it should be, while the ASI might indicate that the aircraft's speed was lower than it actually was. This could collectively result in a pilot imposing more stress on the wing than it was capable of taking. There are several other issues that the FAA found, but these are the one's that stood out to me. Overall, there was lots of interesting stuff in the report and food for thought.


Direct Link to the FAA report.
Direct link to the Apendix for the report.

 

[jesse]

Hmm. I suspect that report won't be helping the resell value.

 

[dmccormack]

Wow..so much for blind faith in the POH....

 

[Dean]

Hmm. I suspect that report won't be helping the resell value.

Whats the price of scrap aluminum these days? Your next pop can may be made from an old Zodiac.

 

[Trapper John]

Perhaps the person who posted recently about being unable to obtain financing on a used Zodiac is feeling lucky today.


Trapper John

 

[mcjon77]

Perhaps the person who posted recently about being unable to obtain financing on a used Zodiac is feeling lucky today.


Trapper John

IIRC, that person was trying to buy a 601HD or HDS. The HD/HDS have completely different wings from the 601 and have a good safety record.

 

[tonycondon]

this doesnt help the 'self certifying' trust factor between the FAA and manufacturers on the LSA ASTM standard. bummer deal for 601XL owners.

 

[steingar]

I feel especially bad for the Tron Guy. He'd probably make more from his aircraft by ripping out the avionics and selling the airframe for scrap.

 

[Geico266]

It looks like the "rumors" I heard (coming from a source close to the investigation in another country) in the light sport world about the Zodiac were correct. That being the wing was not structurally sound enough to have added a flap arrangement. It is just sad that this was not "discovered" before people died, including a good friend of mine. Gary left behind 3 kids and a wife.

I would still like to know why after the NTSB wanted these planes grounded in March or April of '09, why it took another death, and until November for the FAA to take action.

 

[Geico266]

I feel especially bad for the Tron Guy. He'd probably make more from his aircraft by ripping out the avionics and selling the airframe for scrap.

I would think that after the wings are rebuilt the plane would be safe to fly, and the market would be there in a few years.

The RV-3 had a similar problem way back when. Three planes lost their wings after doing aerobatics, most (it was reported) in the 8-10G range. Just about took Vans out of the kit plane business, but he persevered and came up with a spar fix, and a better understanding of aircraft and home builders. The rest is history.

The market now for RV-3a (a' models as they are called after the fix) is really strong. I owned one and it was a hoot to fly, although I limited my aerobatics to 3G's.

 

[tonycondon]

I would think that after the wings are rebuilt the plane would be safe to fly, and the market would be there in a few years.

The RV-3 had a similar problem way back when. Several planes lost their wings after doing aerobatics, most (it was reported) in the 8-10G range. Just about took Vans out of the kit plane business, but he percivered and came up with a spar fix, and a better understanding of aircraft and home builders.

The market now for RV-3a (as they are called after the fix) is really strong. I owned one and it was a hoot to fly, although I limited my aerobatics to 3G's.

the 601 is not similar to the RV-3. the 601 has had in flight breakups while seeming to have been flying within the designers stated limitations. I have a hard time believing that Van designed the original -3 for 8-10 Gs of aerobatics.

 

[Geico266]

the 601 is not similar to the RV-3.

I was responding to the post about market value of a plane with a structural history. The RV-3 and the Zodiac are similar in that regard. Only time will tell if the market will be there for the Zodiac, and if history can tell us anything by looking at the RV-3 the value will come back.

It was not immediately known the planes were being flown at 8-10 G's, just like it was not immediately known that there was a structural defect in the Zodiac.

 

[bbchien]

We have a builder here who has taken his wings apart. Despite the kit being only ~$850, it's MANY hours of work and creates a few non-inspectable spaces near the wing roots. When you drill out the rivets, you ruin the holes in the ribs ~30$ of the time.

Ruh Roh, Rorge.

 

[Keane]

IIRC, that person was trying to buy a 601HD or HDS. The HD/HDS have completely different wings from the 601 and have a good safety record.

I think you guys are referring to me. I was looking at the HDS (trying to save up the cash before it sells) which have totally different wings.

However, I saw on barnstormers a few people who are willing to do the repairs to the wings for $5k, which isn't terribly bad when one owes a 50k+ plane like Jay does.

 

[Geico266]

However, I saw on barnstormers a few people who are willing to do the repairs to the wings for $5k, which isn't terribly bad when one owes a 50k+ plane like Jay does.

I'd buy one cheap and have it repaired, fly it for a while. Might be a good investment. Glad to see someone trying to save the airplanes from the scrap heap.

While I hate them for killing my buddy, he was a dealer for them, and loved the dang things. To him there was no better plane, other than an RV.

 

[steingar]

A $5K repair isn't bad, but prove it fixes the problem. And please don't tell me its because the manufacturer says so, since they're the ones who bolluxed it in the first place.

 

[Keane]

A $5K repair isn't bad, but prove it fixes the problem. And please don't tell me its because the manufacturer says so, since they're the ones who bolluxed it in the first place.

Won't the FAA/NTSB do tests on it to make sure that it reasonably fixes the problem before allowing them to be ungrounded?

 

[tonycondon]

Won't the FAA/NTSB do tests on it to make sure that it reasonably fixes the problem before allowing them to be ungrounded?

doubt it. LSA is completely self governed under the ASTM standards. FAA doesnt dip their finger in certification. We (Collective) wanted cheaper airplanes, and we got them. Saved all that money in expensive FAA certification costs.

 

[steingar]

The Zodiac CH601 has been around long before LSA was conceived, 1984 to be exact.

Wasn't until the whole LSA thing that they started routinely falling out of the sky, if I'm not mistaken.

 

[Geico266]

Wasn't until the whole LSA thing that they started routinely falling out of the sky, if I'm not mistaken.

If you look at the wing skeleton there are only 5 ribs outboard of the walkways. If I remember right the RV-12 has 10-12 ribs. Somewhere along the line Zeneth added flaps to this wing, but did not strengthen the rear spar or increase the number of ribs. The added twisting of deploying flaps weakened the rear spar and over time and caused it to fail, or develop flutter. Don't shoot me, that's what I was told.

Personally, in a weird way, it is gratifying to me to know there was something wrong with the design, and not my buddies flying. There is speculation he hit a flock of birds, we'll never know. In any event, he was a hell of a bush pilot in AU, he made Crocodile Dundee look like a weenie.

 

[mcjon77]

Won't the FAA/NTSB do tests on it to make sure that it reasonably fixes the problem before allowing them to be ungrounded?

No they won't. In fact, if you read the report, the FAA has recomended a series of test for the aircraft with the new modifications. From what I understand, Zenith has already come out saying that they do not intend to do additional testing (particularly the more expensive testing) because they feel that their modifications go beyond what was needed, and that the FAA's calculations were extremely conservative. Time will tell.

 

[jmaynard]

I'd comment on this, but I don't think I'd be treated equally or fairly in replying to the inflammatory comments already made. I see no reason to bother.

 

[tonycondon]

i thought the discussion so far was quite civil

 

[mcjon77]

Jay, if you have additional information or insight, please share it. I'm sure this thread can continue without any personal attacks. If you feel that there is misinformation in this thread, I have found that the absolute best way to confront it is with facts. Factual statements and careful analysis tend to sway more minds that personal attacks and hyperbole.

 

[jesse]

I'd comment on this, but I don't think I'd be treated equally or fairly in replying to the inflammatory comments already made. I see no reason to bother.

Could you speak to what those inflammatory comments are?

 

[Geico266]

We have a builder here who has taken his wings apart. Despite the kit being only ~$850, it's MANY hours of work and creates a few non-inspectable spaces near the wing roots. When you drill out the rivets, you ruin the holes in the ribs ~30$ of the time.

Ruh Roh, Rorge.

Drilling out rivets is an art. Most builders just get into too big of a hurry. If you use a drill .002-3 smaller than the original size drill you can usually punch out the rest (after snapping the manufacurers head off) leaving the rib untouched..... hopefully. In the event a hole is enlarged by the drill "walking" there are "OPPS" rivets. Aptly named in case you pull an OPPS! In which case you over size drill the hole and use these.

http://www.aircraftspruce.com/catalog/hapages/othersizerivets.php

They do "set" different than the smaller ones, but they do work great for OPPSes. (Of course, I personally have never have had to use them. ) Hopefully, the builder doing the repair has a good A&P or EAA Tech counselor looking over his shoulder. Before he closes up the area you cannot see I would have an A&P sign off that he has inspected this area, and make an entry in the log book.

 

[SteveinIndy]

i thought the discussion so far was quite civil

+1. It was quite civil, especially given the often polarizing stances people take on topics such as this. All I will add is that I wish it had not cost a lot of good people there lives for this problem to be taken seriously and remedies- even a complete grounding of the type as heavy-handed as it might be- to be implemented.

 

[jmaynard]

Could you speak to what those inflammatory comments are?

Both comments are still present in the last thread on the Zodiac, even after the MC review.

The most offensive, and the one most in violation of the rules of conduct that call for all participants to respect each other, is "Seems to me the only dumb pilots were the ones to keep flying them after the NTSB recommended grounding them." I don't think I'm a dumb pilot, and I doubt those who have flown with me would think so either, but I continued to fly my Zodiac literally until the day the FAA and AMD issued the grounding order. (The last flight in my logbook is dated 6 November 2009, 0.6 and 5 landings in N55ZC.)

This issue is loaded with emotion, and yet only one side's emotional responses are supported and allowed to remain by the MC. I'm not about to invest more of my time in contributing to a place where my contributions are so devalued.

 

[Trapper John]

Both comments are still present in the last thread on the Zodiac, even after the MC review.

The most offensive, and the one most in violation of the rules of conduct that call for all participants to respect each other, is "Seems to me the only dumb pilots were the ones to keep flying them after the NTSB recommended grounding them." I don't think I'm a dumb pilot, and I doubt those who have flown with me would think so either, but I continued to fly my Zodiac literally until the day the FAA and AMD issued the grounding order. (The last flight in my logbook is dated 6 November 2009, 0.6 and 5 landings in N55ZC.)

This issue is loaded with emotion, and yet only one side's emotional responses are supported and allowed to remain by the MC. I'm not about to invest more of my time in contributing to a place where my contributions are so devalued.

Yeah, I guess until you get to be the board censor, you'll have to settle for the victim role...


Trapper John

 

[Geico266]

Both comments are still present in the last thread on the Zodiac, even after the MC review.

The most offensive, and the one most in violation of the rules of conduct that call for all participants to respect each other, is "Seems to me the only dumb pilots were the ones to keep flying them after the NTSB recommended grounding them." I don't think I'm a dumb pilot, and I doubt those who have flown with me would think so either, but I continued to fly my Zodiac literally until the day the FAA and AMD issued the grounding order. (The last flight in my logbook is dated 6 November 2009, 0.6 and 5 landings in N55ZC.)

This issue is loaded with emotion, and yet only one side's emotional responses are supported and allowed to remain by the MC. I'm not about to invest more of my time in contributing to a place where my contributions are so devalued.

Jay, with all due respect, and IMHO, continuing to fly an airplane that was recommended to be grounded by the NTSB is "not smart" until the known needed repairs were completed. As the owner of a Zodiac 601 it was your call, you survived, good on you. Was that a good decision? Are you proud of that decision? Would you come to the same conclusion now? Everyone here will have opinions on your decision making concerning a life and death matter.

In this thread I have been trying to shed some light on the fact that an airplane can come back from the "scrap heap" if proper repairs are made, and if the flying public buys into it. Would you rather have me run the plane down more?

I lost a good friend needlessly that was flying this airplane, Jay. His kids and widow grieve every day. If I get testy about it I would hope you can understand why. I have a dog in this fight.

 

[steingar]

Both comments are still present in the last thread on the Zodiac, even after the MC review.

The most offensive, and the one most in violation of the rules of conduct that call for all participants to respect each other, is "Seems to me the only dumb pilots were the ones to keep flying them after the NTSB recommended grounding them." I don't think I'm a dumb pilot, and I doubt those who have flown with me would think so either, but I continued to fly my Zodiac literally until the day the FAA and AMD issued the grounding order. (The last flight in my logbook is dated 6 November 2009, 0.6 and 5 landings in N55ZC.)

This issue is loaded with emotion, and yet only one side's emotional responses are supported and allowed to remain by the MC. I'm not about to invest more of my time in contributing to a place where my contributions are so devalued.

Jay, your opinions are valued by the participants of this site, as least by the ones I know personally. However, I can find no fault in the comments you've referenced. If I had a good friend perish in an aircraft model that the NTSB declared unsafe, my comments would be far more vitriolic than those you've referenced.

I understand your point of view. You've put a lot of resources into an aircraft that has performed well for you. I just hope that the fix solves your own problems and allows you to fly or dispose of the aircraft in a satisfactory manner.

I try very hard not to quibble with the MC even when I don't like their decisions. I like to think that I am sufficiently mature to realize that someone has to make decisions, it involves work, is unpaid, and that someone is a human being prone to error.

Of course, show that mature comment to my Mrs. and she'd have a good laugh...

 

[TMetzinger]

Do you see the difference between "not smart" and "dumb"? I feel that there is one.

 

[jesse]

Both comments are still present in the last thread on the Zodiac, even after the MC review.

The most offensive, and the one most in violation of the rules of conduct that call for all participants to respect each other, is "Seems to me the only dumb pilots were the ones to keep flying them after the NTSB recommended grounding them." I don't think I'm a dumb pilot, and I doubt those who have flown with me would think so either, but I continued to fly my Zodiac literally until the day the FAA and AMD issued the grounding order. (The last flight in my logbook is dated 6 November 2009, 0.6 and 5 landings in N55ZC.)

This issue is loaded with emotion, and yet only one side's emotional responses are supported and allowed to remain by the MC. I'm not about to invest more of my time in contributing to a place where my contributions are so devalued.

I see no problem with either post. I don't see Larry blaming "dumb pilots". I hope this doesn't end your participation in the community and I would love to see you at Gastons.

 

[SteveinIndy]

"Seems to me the only dumb pilots were the ones to keep flying them after the NTSB recommended grounding them."

It is a little heavy handed to call someone 'dumb'. Perhaps it's a very short-sighted and risky decision ("poor aeronautical decision-making" to quote the ASF and NTSB) but it does not make a person stupid. Now continuing to fly AFTER a major problem is identified and especially AFTER an agency known for dragging its feet until a sufficient amount of blood has been spilled speaks up and says 'Hey, there is something seriously wrong', that crosses the line between ignorance and stupidity that I had drilled into my head when I was younger. Jay, that is why I am so happy you decided to stop flying after the ground order was issued. I know several pilots who chose not to do so.

Honestly, I think the comments by Skyhog and others on the previous thread blaming the pilots for these crashes when it was quite clear even at that point that it was a problem with aircraft (the EAA at that point was up in arms trying to convince the FAA to take action...that should say something) was one of most telling statements about pilots and their attitudes towards safety: the greatest resistance one encounters surprisingly comes from those at the greatest risk. Many of us are so loathe to admit that a popular design has serious issues- be it a homebuilt or one of the models from a popular manufacturer- that anything else is blamed first and even with a lot of evidence that something is wrong, you can't convince people that the aircraft has a major problem. As Dr. King was famous for saying "There is nothing in this world quite so dangerous as sincere ignorance and conscientious stupidity". He may have been speaking about race relations, but he might as well have been talking about the blinders that so many of us choose to wear when it comes to safety issues.

This issue is loaded with emotion, and yet only one side's emotional responses are supported and allowed to remain by the MC

I can't speak to that, but I can tell you it's not much fun being on the "Something's not right here" side either. If you could see the nasty PMs I've received (and deleted) on the subject, it would probably be a good indicator that it is not quite as one-sided as you might think. My mother's virtues have never been questioned more than by some of those I've crossed on here.

I hope this doesn't end your participation in the community

If it does, I will be extremely upset. Jay, you're one of my favorite members on here and losing your input on here- even as much as you and I butted heads on a lot of things in the chatroom- would really make this a far less interesting and fun place to visit. For crying out loud man, I used to include you specifically in my prayers until I heard you had stopped flying after the grounding order because I was worried for your safety as a friend.

I would love to see you at Gastons.

Likewise, you're always welcome here in Indy. Our door is always open to you Jay as it is for all PoA members.

 

[jmaynard]

I see no problem with either post. I don't see Larry blaming "dumb pilots". I hope this doesn't end your participation in the community and I would love to see you at Gastons.

Haven't you noticed my absence? It's over this very issue. The MC, by allowing the cited attacks to remain while removing my responses to those attacks, told me I am not welcome. I'd love to make some of the fly-ins, but I see no way to make it possible, and there are some people whose attendance would make me unwilling to exert the effort required to make the trip.

Would you rather have me run the plane down more?

Your every word drips scorn and contempt for those who own and fly Zodiacs. Trying to respond to you nearly got me thrown off the system; I will not, especially, repeat that error.

I can't speak to that, but I can tell you it's not much fun being on the "Something's not right here" side either.

The ironic thing about all this is that I've been one of the staunchest defenders of ZBAG, the group that performed the independent analysis, in the Zenith community. Considering some of the vitriol that's been flung my way in that community, to be called an apologist for the design is extremely inaccurate.

If it does, I will be extremely upset.

As I mentioned to Jesse, it already has.

 

[jesse]

Haven't you noticed my absence? It's over this very issue. The MC, by allowing the cited attacks to remain while removing my responses to those attacks, told me I am not welcome.

The MC never told you that you weren't welcome. It seems as though you've told yourself you're not welcome. I'm sorry that you feel that you were being attacked - but I feel otherwise. There are times where the MC must rule in a way that someone does not agree with. It's absolutely absurd to think that we're telling that person they aren't welcome here.

Believe me, the MC has ruled on issues in the past that I didn't agree with. But, I didn't leave the community because of it.

Not a single person is saying you shouldn't be a part of PoA. Nor do I see a lot of people feeling you were attacked. If you consider that, it seems as though the right decision was made.

 

[Everskyward]

I'd comment on this, but I don't think I'd be treated equally or fairly in replying to the inflammatory comments already made. I see no reason to bother.

I'm curious what you think is wrong about the report.

 

[Geico266]

I would think that after the wings are rebuilt the plane would be safe to fly, and the market would be there in a few years.

The RV-3 had a similar problem way back when. Three planes lost their wings after doing aerobatics, most (it was reported) in the 8-10G range. Just about took Vans out of the kit plane business, but he persevered and came up with a spar fix, and a better understanding of aircraft and home builders. The rest is history.

The market now for RV-3a (a' models as they are called after the fix) is really strong. I owned one and it was a hoot to fly, although I limited my aerobatics to 3G's.

I was responding to the post about market value of a plane with a structural history. The RV-3 and the Zodiac are similar in that regard. Only time will tell if the market will be there for the Zodiac, and if history can tell us anything by looking at the RV-3 the value will come back.

It was not immediately known the planes were being flown at 8-10 G's, just like it was not immediately known that there was a structural defect in the Zodiac.

I'd buy one cheap and have it repaired, fly it for a while. Might be a good investment. Glad to see someone trying to save the airplanes from the scrap heap.

While I hate them for killing my buddy, he was a dealer for them, and loved the dang things. To him there was no better plane, other than an RV.

(Talking about Geico) Your every word drips scorn and contempt for those who own and fly Zodiacs. Trying to respond to you nearly got me thrown off the system; I will not, especially, repeat that error.

My every word drips scorn for the Zodiac? In my posts I said I would buy one, fix it, and fly it. I also give my experience and professional opinion the value will improve as it did with other aircraft with structural defects. Yep, that's scorn all right.

 

[Geico266]

Do you see the difference between "not smart" and "dumb"? I feel that there is one.

It is a little heavy handed to call someone 'dumb'.

The use of the word "dumb" was not started by me, it was carried over from the comments from someone else and a post that was deleted by the MC. The word dumb was being associated with my friend that was killed in AU and I took offense to it. I was defending the dead, his minor children, and his widow in a public forum where it is entirely possible they could read this.

I did not start it, nor was I referring to Jay specifically. Jay took offense, and got his feeling hurt, posted several posts that contained vulgarities and those posts were deleted.

 

[Dr. O]

Awwwright guys... No kicking, biting or eye gouging, and definitely no flicking boogers at each other...

denny-o