Crash after 3D printed air intake collapses. Good heads up for us kit builders

[skippydiesel]

Random thought;

 

Given that the "melted" part was designed to conduct cool/external air and cooled by the same, the undercowl temperature of this aircraft must have been extreem to overcome the cooling effect of the fresh air. 😈

[facthunter]

It's a  Pusher isn't it? They are harder to cool. Nev

[danny_galaga]

2 hours ago, skippydiesel said:

Random thought;

 

Given that the "melted" part was designed to conduct cool/external air and cooled by the same, the undercowl temperature of this aircraft must have been extreem to overcome the cooling effect of the fresh air. 😈

Not random at all. I wondered if there might have been a small engine fire

[facthunter]

It would show on other Parts I reckon.  Nev

[danny_galaga]

57 minutes ago, facthunter said:

It would show on other Parts I reckon.  Nev

Probably.

[Thruster88]

Looks like this aircraft had  rotec? Throttle body injection also called a pressure carburetor. I think they can suffer from carburetor ice so it is possible carburetor heat was in use during the low power decent for landing.

[sfGnome]

Depends on the material used (apologies if the actual material was discussed earlier). My son printed some proof-or-concept items for me, and they distorted when left in his car. I can imagine the under-cowl getting hotter than that. 

[danny_galaga]

44 minutes ago, sfGnome said:

Depends on the material used (apologies if the actual material was discussed earlier). My son printed some proof-or-concept items for me, and they distorted when left in his car. I can imagine the under-cowl getting hotter than that. 

Yeah, I linked to a useful article, but its in the previous page. Here it is again 

 

https://hackaday.com/2025/12/10/failed-3d-printed-part-brings-down-small-plane/

 

[danny_galaga]

2 hours ago, Thruster88 said:

Looks like this aircraft had  rotec? Throttle body injection also called a pressure carburetor. I think they can suffer from carburetor ice so it is possible carburetor heat was in use during the low power decent for landing.

Lycoming 0360. Not sure how you came up with Rotec 😄

[Thruster88]

6 hours ago, danny_galaga said:

Lycoming 0360. Not sure how you came up with Rotec 😄

Yes the data plate says o-360 and it would have left the lycoming factory with an updraft Marvel-Schebler carburetor bolted directly to the sump, just like the one in my RV6a, however the picture clearly shows that was no longer the case unfortunately. 

 

Edited December 13, 2025 by Thruster88

[sfGnome]

11 hours ago, danny_galaga said:

Yeah, I linked to a useful article, but its in the previous page. Here it is again 

Yep, definitely not ABS. With a glass transition of 52C, it has to be PLA. Someone got distracted and put the wrong reel on the machine (I can’t believe that it was intentional). Moral of the story? If you buy a 3D printed part, put it in the oven for a while (ie anneal it) and watch what happens. 

Edited December 13, 2025 by sfGnome
Fixed error

[Blueadventures]

On 05/12/2025 at 11:05 AM, danny_galaga said:

Plane totalled, landing short of runway.Pilot only minor injuries. A good reminder I guess that it gets toasty under the hood!

 

https://www.bbc.com/news/articles/c1w932vqye0o

On a side comment it doesn't look like the gascolator bowl securing has been safety wired to prevent loosening.

[facthunter]

I can't see how it's Totalled either. The rear and Motor is undamaged.   Maybe the Photographer doesn't know how the Plane LOOKS undamaged. That Lycoming runs the air/mixture through passages in the alloy sump which cools the Oil and heats the fuel Mixture. It also causes sludge Build up on the cooled surfaces.

  That Floatless Carb is Made by Rotec. Nev

Edited December 14, 2025 by facthunter
more content.

[danny_galaga]

8 hours ago, Thruster88 said:

Yes the data plate says o-360 and it would have left the lycoming factory with an updraft Marvel-Schebler carburetor bolted directly to the sump, just like the one in my RV6a, however the picture clearly shows that was no longer the case unfortunately. 

 

That was the point of that air duct. They had fitted a new induction system, presumably replacing the carby.

[facthunter]

It has NO floats and is probably a lot cheaper and More available than the Schebler. Having no venturi, It's Probably LESS prone to Icing but I know a bit of fuel sometimes drips on the ground when starting.  I'd be happy with the Mechanical Injectors and the GAMI treatment on the 360. It's NOT a troublesome Motor..   Mounting the Carb directly to the Hot Sump (as original) Probably Means Icing is not  a great Issue. Power off approaches with a Hot Muffler as a heat source can't be relied on.   Nev

[Blueadventures]

 

[Thruster88]

So the part had been in service for some time. I think the lesson here is just because you fit a part a part and it seems to work fine doesn't necessarily mean much.

 

The Lycoming 320, 360 carburetor or fuel injection engines have been in service unchanged for at least 65 years now. The very few parts that have caused problems have been the subject of an Airworthiness Directive, AD.

[sfGnome]

Highly misleading title on that video. It wasn’t the fact that it was 3D printed that caused the crash; it was the material that caused it. It would be like using cardboard for spars, and then after a crash implying that you should never have spars…

[facthunter]

Or non waterproof glue on a sailing boat.. Nev