Buying a composite airplane with a significant damage history

[rk]

I am looking at this airplane to buy and turned out it sustained significant damages in a runway excursion back in 2005: https://planecrashmap.com/plane/va/N127X/

To quote from the NTSB report: A post accident inspection of the airplane revealed that the composite structure had sustained multiple cracks, tears, and punctures. Further inspection also showed that the nose wheel landing gear, as well as the right main landing gear, had separated from the airplane. Additionally, the firewall was bent and portions of the exhaust system had separated from the #4 cylinder...

Initially I decided to back out of the purchase due to this history, but the salesperson is telling me that composite repairs are different from metal repairs since unlike metal, once the repair is done in a composite it will be like new. I found that a bit odd, because to my limited knowledge small cracks or other internal damages are hard to find in composite, so it's more likely that something might have gotten missed during the initial repair.

What do you folks think? If two airplanes have similar damage histories - one composite and the other is metal, which one would you be more comfortable flying after the repair?

 

[Daleandee]

"but the salesperson is telling me that composite repairs are different from metal repairs since unlike metal, once the repair is done in a composite it will be like new."

I know little about composite repair but that sounds like "salesperson gibberish" to me. Like new is very dependent upon who, where, when, & how it was repaired.

"If two airplanes have similar damage histories - one composite and the other is metal, which one would you be more comfortable flying after the repair?"

I have repaired/built fabric and metal airplanes so I'd feel much better about inspecting a metal aircraft. The amount of damage reported for that particular aircraft would make me walk run away ...

 

[Stewartb]

One of the advantages of composites is that a good composites guy can make repairs that are every bit as good as the original. You just need to find the right guy.

 

[nauga]

I wouldn't buy any airplane of any construction method with a history of substantial damage without a thorough investigation into the repairs - who, what, where? The accident was in 2005, what's been done to the airplane in the meantime, to include additional repairs and flight time?

Nauga,
who would also deal with a different 'salesman'

 

[nauga]

One of the advantages of composites is that a good composites guy can make repairs that are every bit as good as the original.

...and one of the difficulties is that it's next to impossible to tell if they were successful. Short of replacing entire components it's difficult to make repairs without either (a) reduced structural margins/altered load paths, or (b) increased weight. While it's trivial to see if they managed (b), assessing (a) is very difficult, particularly without special tools, time, and money.

Nauga,
and more than a tap test

 

[TCABM]

A post accident inspection of the airplane revealed that the composite structure had sustained multiple cracks, tears, and punctures. Further inspection also showed that the nose wheel landing gear, as well as the right main landing gear, had separated from the airplane. Additionally, the firewall was bent and portions of the exhaust system had separated from the #4 cylinder. Both propeller blades had been bent approximately 90 degrees rearward, and each blade exhibited chord wise scratching.

That takes some force; hard pass in my book.

 

[Stewartb]

There's nothing on an airplane that can't be repaired. All it takes is money. In this case it was somebody else's money. That's the best kind.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-214A.pdf

 

[Bell206]

but the salesperson is telling me that composite repairs are different from metal repairs since unlike metal, once the repair is done in a composite it will be like new.

This part is BS. Both composite and metal repairs, when performed, properly, will meet or exceed the original design limits. Thats regulatory. Any repair meeting a lesser standard would be an unairworthy repair.

If two airplanes have similar damage repair histories - one composite and the other is metal, which one would you be more comfortable flying after the repair?

FTFY. As to which one I'd fly in either one. Regardless, whatever repair history an aircraft has and what would be acceptable is very subjective to that individual. From my background of performing major composite and metal repairs I see no difference in the structural integrity of the aircraft whether repaired or not. The key is in the method of repair and how it is documented that counts.

 

[kmacht]

You are both right. Composites can be repaired to act and look like new but it is also very hard to detect damage, delamination, internal cracks, etc to a composite structure. Unless he has pictures of all the damage and repairs, a structural analysis showing how all the repairs will restore the structures strength, and not inspections (ultrasonic, x-ray or similar) of all areas that could have sustained sub surface damage I would make it a hard pass. Even if the plane is structurally would would you still feel comfortable flying it?

 

[Racerx]

Even if the plane is structurally would would you still feel comfortable flying it?

Yes, With the caveat of who did the repair and how

 

[robin ardoin]

Properly performed structural composite repairs (glass or carbon reinforced plastic) as mentioned can be just as strong as the original structure. Learn all you can about the original damage and what repair station performed the repairs. How many hours on the airframe since the repairs? Is there any paint cracking in the vicinity of the repairs? Any dull area on percussion? My experience is limited to boats (glass/polyester) and race cars (carbon/epoxy). In our formula cars any potential structural damage to the monocoque (tub) or wings could only be repaired, per the series director, by two shops (one in Atlanta, one in Toronto). Carbon fiber repairs, in order to attain the original strength, need to be effected with the proper repair design, materials and equipment/conditions. A thorough understanding of the operational stresses of the area under consideration for repair is paramount in designing the repair. I would consider buying a significantly damaged airframe only if the complete damage/repair history and competency of the repair station are known.

 

[PilotRPI]

Composite damage can be harder to detect in some instances, but composites can also be repaired. The accident sounds pretty significant. I would want hyper-detailed information on what the damage was, who repaired it, how it was repaired, etc. The salesman sounds like he is spouting pure BS to make a sale, well that is his job.

 

[Bell206]

The one thing people tend to forget is that composite structure damage and their associated repairs fall under a different category than equal metal structure damage and repair. In general, composite repair has more limitations and requires a higher level of OEM and FAA involvement than similar metal repair requirements. In the case of the OPs Diamond DA40 all the repairs performed required repair schemes approved by the OEM and the FAA. So as I've stated in other threads, damage/repair history is strictly a subjective topic for the buyer and basically has nothing to do with the structural integrity of the aircraft when properly repaired. And yes the are ways to ensure it was properly repaired for both composite and metal structures.

 

[Dan Thomas]

The one thing people tend to forget is that composite structure damage and their associated repairs fall under a different category than equal metal structure damage and repair. In general, composite repair has more limitations and requires a higher level of OEM and FAA involvement than similar metal repair requirements. In the case of the OPs Diamond DA40 all the repairs performed required repair schemes approved by the OEM and the FAA. So as I've stated in other threads, damage/repair history is strictly a subjective topic for the buyer and basically has nothing to do with the structural integrity of the aircraft when properly repaired. And yes the are ways to ensure it was properly repaired for both composite and metal structures.

Yes.

The manufacturer will have a structural repair manual, and the one doing the repair should have some training and maybe certification in it. It's not a boat, and a failure means a lot more than getting wet.

I took the Cirrus maintenance course. It showed me that this stuff is far different from repairing tubing or fabric or sheet aluminum, and a lot different than repairing boats, which I have done.

 

[NoHeat]

https://planecrashmap.com/plane/va/N127X/

To quote from the NTSB report: A post accident inspection of the airplane revealed that the composite structure had sustained multiple cracks, tears, and punctures. Further inspection also showed that the nose wheel landing gear, as well as the right main landing gear, had separated from the airplane. .

It's a DA40.

I don't know about Diamond, but Cirrus factory engineers have gotten involved in drawing up the plans for a local shop to make major structural repair to the composite. It would make me less worried if I knew exactly how factory engineers were involved.

Also, there are shops that do a lot of major composite repair. For example Midwest Aircraft Refinishing in Hibbing MN repairs a lot of Cirri after chute pulls. Typically the owner doesn't want to wait for the repair, so Midwest buys the plane, fixes it, paints it, and then sells it. That particular shop does so many of these that it would give me more confidence if the work was done there.

Additionally, the firewall was bent and portions of the exhaust system had separated from the #4 cylinder..

I wonder if the firewall is composite in a DA40. I wasn't expecting to see the word "bent."

 

[nrpetersen]

Damage of primary structure or major attachments of a composite airframe probably requires access to an autoclave to be assured of a full strength repair - something that only the manufacturer is likely to have created or have access to. Minor damage to non-critical structures maybe using heat lamps etc, but the description here doesn't sound like it. There are many more experts and even reasonably competent amatuers that can evaluate damaged metal, than can evaluate damaged composites.

No.

 

[FORANE]

It's a DA40.


I wonder if the firewall is composite in a DA40. I wasn't expecting to see the word "bent."

Not familiar with a Diamond, but composite experimentals have a protective metal firewall attached to the composite structure.

 

[Bell206]

I wonder if the firewall is composite in a DA40

From what I read the firewall is stainless steel with a ceramic matting.

probably requires access to an autoclave to be assured of a full strength repair - something that only the manufacturer is likely to have created or have access to

Autoclaves are mainly used during the manufacture process. For repairs there are specialized cure blankets that provide both heat and vacuum for the repair process.

There are many more experts and even reasonably competent amatuers that can evaluate damaged metal, than can evaluate damaged composites.

For the most part even the evaluation part is pretty limited. In my experience usually anything beyond a structual deep scratch or a full panel puncture exceeding a 3 inch circular repair requires OEM assistance. On the metal side I can evaluate and legally repair an entire legacy aircraft under AC 43.13-1B.

 

[Doc Holliday]

 

[mondtster]

I don't know about Diamond, but Cirrus factory engineers have gotten involved in drawing up the plans for a local shop to make major structural repair to the composite. It would make me less worried if I knew exactly how factory engineers were involved.

As far as I know, the Cirrus engineering department prescribes the repair procedure for all structural repairs and also provides the components to complete them. The intent is to minimize the amount of "field engineering" involved in those repairs. I expect that Diamond would take a similar approach although I don't have first hand experience with structural repairs on Diamonds.

Because of this approach by the OEM I'd venture to guess that the average quality of repair to a type certified composite aircraft with composite damage would be higher than that of a metal or fabric aircraft where there is less factory involvement. Regardless, I wouldn't lose any sleep over flying or owning a properly repaired aircraft of any construction type.

 

[Ventucky Red]

Damage of primary structure or major attachments of a composite airframe probably requires access to an autoclave to be assured of a full strength repair - something that only the manufacturer is likely to have created or have access to.

No.

Maybe some vacuum curing/bagging at the least to suck the air out. Even then, one must know what they are doing with regard the the layup pattern.

 

[Omalley1537]

I think the key word (when considering the credibility) is “salesperson”…

 

[Stewartb]

Sounds to me that the salesperson knew what he was talking about.

A friend had his 185 tied up when a storm beat the bottoms of his Aerocet floats to pieces on rocks. Those floats got repaired (major reconstruction) locally and it was impossible to find any flaws. They were literally as good as new. Very impressive.

 

[Dan Thomas]

A friend had his 185 tied up when a storm beat the bottoms of his Aerocet floats to pieces on rocks. Those floats got repaired (major reconstruction) locally and it was impossible to find any flaws. They were literally as good as new. Very impressive.

It's the flaws hidden within the matrix that would concern me, and those won't be visible on any surface.

The same thing applies to aluminum structure. Flaws such as cracks and corrosion can be hidden within layers of the metal. Eddy current inspection is one way of finding them; you'd never see them otherwise. The corrosion of the C177/C210 carrythrough spars is a good example of that; deep pits with almost no surface indication might be there. The splicing laminations in the wing spars of the strutted Cessnas is another; corrosion has been known to form within them, and often by the time someone spots it, it's pretty serious. One has to look really hard at annual time. Another one is cracking from the rivets at each end of the Cessna wing struts; only eddy current spots most of those. I've seen that.

A coworker found serious denting in a C185 vertical stab. It had been filled with body filler, very "professionally," and the airplane painted. The stab spar beneath it was deformed and thoroughly compromised. The stuff some people do is appalling.

 

[Stewartb]

WTF does any of that have to do with composite repairs? You don’t know what you don’t know, but you might not be too old to learn!

 

[WDD]

Just an observation. What you didn't say is as interesting as what you did say in the original post.

The salesperson gave you information. But you didn't mention any independent pre buy inspection done by your own person.

 

[Brad Smith]

The extra money you’ll pay for an aircraft with NDH buys peace of mind, something you’ll never have with the purchase you’re considering.
https://www.newscientist.com/article/dn12951-composite-aircraft-may-hide-dangerous-flaws/

 

[Dan Thomas]

WTF does any of that have to do with composite repairs? You don’t know what you don’t know, but you might not be too old to learn!

Maybe you missed this post I made yesterday?

I took the Cirrus maintenance course. It showed me that this stuff is far different from repairing tubing or fabric or sheet aluminum, and a lot different than repairing boats, which I have done.

 

[Jeff767]

What do the logbooks show? Without that info no one can provide real help.

 

[Rockymountain]

The Diamond is a very strong airframe, and you can fix composite as good as new. BUT, it has to be done really well by an expert in the field, with sign off from the factory engineers before repair. People that make composite aircraft have very elaborate factories, vacuum, ovens, processes and technicians that are more like artists than technicians doing the work, and they do it all day long. I, personally, would be a hard pass on a heavily damaged composite plane repaired in the field. That is due to the fact that you can't see and measure how well the composite, glue, heating, layup, quality control of materials, and everything else involved in the repair was done. Plus if you buy a used NDH diamond, you will likely be able to sell it for almost what you bought it for, when time to sale comes around. Going to have a real challenge selling a DH aircraft if you ever decide to sell or move up.

 

[RudyP]

It comes down to (as others have mentioned) the quality of the repair and how well you buy it.

I owned a repaired CAPS deployment SR22 for many years and ~1000 hours of flying. I was 100% confident in the repairs and the airframe (the engine is a different story but that applies to all Continental singles IMO). In my case, the repairs were performed by arguably THE most reputable experts in this area and fully signed off by the manufacturer (Cirrus) who oversaw the repairs. I also bought it well which mitigated the valid point that Chuck makes above. If you buy it well, you should be able to sell at fair market value for a damage history plane without any financial impact. You will have a smaller pool of potential buyers and no one will want to pay price comparable to an no damage history plane so you have to acknowledge that. But I'd actually argue you can do pretty well on it as a buyer because you have so much less buyer competition and that is good in what is still a seller's market. Make sure you buy it at a substantial discount and when you come to sell, you've actually helped reduce the damage impact somewhat since a freshly repaired, mostly untested airframe warrants a bigger percentage reduction for damage history vs. one where the damage was repaired many years and successful hundreds of hours ago. I'm not the only one to have done pretty well on airplane ownership from 2014->2020 but I made some money on my ownership of my airplane.

But again, it all comes down to doing your diligence so that you are 100% certain the repairs were done correctly and then buying it at the right value and with eyes open on what that means for resale down the line.

 

[weilke]

Composite gliders have been around for 60+ years. It is not uncommon that tails get twisted off or landing gear is torn off during landings on unimproved surfaces. These aircraft are routinely repaired. There are approved inspection methods etc.

So if the repair was done by a appropriate shop and the price reflects the major damage history, I wouldn't dismiss it outright.

 

[Bell206]

would be a hard pass on a heavily damaged composite plane repaired in the field. That is due to the fact that you can't see and measure how well the composite, glue, heating, layup, quality control of materials, and everything else involved in the repair was done.

So how would you "see and measure" the same items with a new aircraft from the OEM?
FYI: a field repair follows the same processes as the manufacturer uses and requires the same results as well. That's as factual as it gets.

 

[WDD]

What may not be factual is that a field repair person did what the factory told him/her. How would you know?

I think you can have a reasonable confidence that the factory - if they’ve been making planes for a while - is putting things together as they should.

 

[Bell206]

I think you can have a reasonable confidence that the factory - if they’ve been making planes for a while - is putting things together as they should.

Continental recently had an AD issued against it that affected 1000s of engines simply because the factory... didn't check the engagement of a circlip. And they've been making engines for how long?

If you truly understand how the field maintenance is complied with on a daily basis you'll find discussions of field work vs factory work don't hold much water in the context being discussed. And just because the topic is composite repairs doesn't change the narrative over say major metal repairs or engine overhauls. Regardless, in the real world most major composite repairs are performed at the field level as it is the exception rather than the norm for the OEM to send someone onsite or even provide that service. However, if you lack confidence in your field mx level providers then perhaps its time to change providers.

 

[benyflyguy]

“A review of the student pilot's training records indicated that at the time of the accident he had accumulated approximately 38.7 total hours of flight experience, all of which were in the accident airplane make and model.”

bet he still brags how soon he solo’ed

 

[WDD]

Continental recently had an AD issued against it that affected 1000s of engines simply because the factory... didn't check the engagement of a circlip. And they've been making engines for how long?

If you truly understand how the field maintenance is complied with on a daily basis you'll find discussions of field work vs factory work don't hold much water in the context being discussed. And just because the topic is composite repairs doesn't change the narrative over say major metal repairs or engine overhauls. Regardless, in the real world most major composite repairs are performed at the field level as it is the exception rather than the norm for the OEM to send someone onsite or even provide that service. However, if you lack confidence in your field mx level providers then perhaps its time to change providers.

I guess it's a matter of probability. There are (not yours or mine) people who will use bondo to repair vertical stabilizers, sign off on a plane (Cherokee) that is so corroded it is unsafe to fly, and other unscrupulous activity. I believe comments have been made about how a good inspection could pick up if a bad metal repair has been made, but can't detect if the field repair on a composite was good or not.

So... how do you know if the composite repair was done correctly? That is the key question that I've not yet read a reply that gives a path forward for the OP to know this.

 

[Bell206]

So... how do you know if the composite repair was done correctly?

In the context of the OPs situation, it starts with the record entry on the repair(s) performed. A corresponding check on the aircraft is made to verify the record entry and perform any localized tests/checks like resistance checks of the lightning protection system.

If I still wasn’t satisfied or for certain extensive repairs, I would have further NDT tests performed of the repair areas. And since most major composite repairs require additional inspection requirements as part of the repair, I would review those inspection entries as well.

Then I'd make the call the repair is good or not. And to add even sheetmetal repairs can be just as problematic to review as a composite repair. Regardless, its no different than checking/accepting an overhauled engine or helicopter transmission from a 3rd party shop or installing a rebuilt wing. As a side note, you’ll find that a failed or improper composite repair is usually found using a simple tap test.

 

[WDD]

As a side note, you’ll find that a failed or improper composite repair is usually found using a simple tap test.

OK - you have an interested audience! A tap test? 1) What exactly is that, and 2) that seems to go against the other positions that a composite repair is hard to examine vs a metal one. I take it that isn't the case?

 

[Bell206]

that seems to go against the other positions that a composite repair is hard to examine vs a metal one. I take it that isn't the case?

For those who understand composite construction and have experience with composites its not the case. I've found those who push that narrative have limited composite experience or just aren't a fan of composite structures. Some bring up points like how do you know if the fibers are orientated properly or if the bonding process is correct which I usually counter with a metal repair quandary how do you know if all the rivet holes have been deburred or if all the metal was bend 45 or 90 degrees to the grain. At some point you need to trust the system at certain levels. Regardless, I can still have a composite repair x-rayed for fiber orientation and ultrasonically tested for bonding integrity if needed. But that would not be the norm.

A tap test? 1) What exactly is that,

In general, you basically take a coin, washer, special tapping hammer, etc and lightly tap the area you are inspecting while listening for a change in tone or dullness when you tap the surface. There are a number of variations on this depending on OEM but the test has been around for eons and used by many industries with composite structures or bonded panels. Below is a section right out of the DA40 mx manual. And the link below that shows a tap test on a glider wing.