By continuing to use this site, you agree to our use of cookies. Find out more

Structural failure

In Flight Failure

All Topics | Latest Posts

Search for:  in Thread Title in  
PETER BRUCE - Eastchurch Gap23/04/2012 15:24:36
avatar
856 forum posts
112 photos

I was doing my usual video again and caught this...

Edited By Steve Hargreaves - Moderator on 23/04/2012 15:26:01

Olly P23/04/2012 15:38:22
avatar
3215 forum posts
181 photos

whoops....

fly boy323/04/2012 15:44:36
avatar
3784 forum posts
22 photos

Probably lack of glue, good skills to get it down in one piece. said this before ,love your videos, keep em coming . Cheers

Edited By fly boy3 on 23/04/2012 15:45:17

PETER BRUCE - Eastchurch Gap23/04/2012 16:03:46
avatar
856 forum posts
112 photos

Thanks for the kind comment - We inspected the failed recovered sections afterwards and it looks like its just been yanked off but to be fair this was in a flat-out spiral dive. The wing section was a fully balsa sheeted section so it was just lucky that Dave was using two servos on the elevator as if only one was being used the model would have been a bin liner job... A decent hardwood spar at the design stage would have been a good idea but its not something you can see thats needed on a finished model.

Just an interesting thing I managed to video again (because I dont like crashes)... Regards Peter

Josip Vrandecic -Mes23/04/2012 16:29:19
avatar
2993 forum posts
260 photos

Hi Peter,I'm delighted by the competent pilot....thumbs up

Cheers

Jo

Terry Walters23/04/2012 17:12:57
avatar
1829 forum posts
1068 photos

Impressed! Very pleased that the outcome wasn't terminal - phew!

Makes you think about things doesn't it?

Terry

Martin Harris23/04/2012 17:25:48
avatar
9594 forum posts
258 photos

Unusual approach manouevre bearing in mind the structural problem - nice to see it down without further mishap though!

Paul Marsh23/04/2012 17:48:58
avatar
4112 forum posts
1245 photos

I second the twin elevaotor/servo setup. At least one's still got partial control - enough to get back safely. I find now if building or assembling an airframe above a certain size/performance, use two servos, rather than either using one, or linking them together from one servo.

Suppose these emergencies keep one on their toes...

Did you find the elevator half?

PETER BRUCE - Eastchurch Gap23/04/2012 18:00:05
avatar
856 forum posts
112 photos

Hi Martin. The unusual approach manouevre was made to keep the speed up as the model was not responsive at a slower speed this together with keeping the model over the patch promted the strange approach to the landing. Right or wrong it was the pilots choice and it was his hands on the sticks...

Richard Harris23/04/2012 18:00:49
avatar
2223 forum posts
2054 photos

ARTF at its very finestsecret

I will third the twin servo set up, I would hate to think what could have possibly happened if it were just a single servo elevatorcrook

Top marks to the pilot, excellent judgement and calmnessthumbs up

Rich

Martin Harris23/04/2012 18:05:26
avatar
9594 forum posts
258 photos
Posted by PETER BRUCE - Eastchurch Gap on 23/04/2012 18:00:05:

Hi Martin. The unusual approach manouevre was made to keep the speed up as the model was not responsive at a slower speed this together with keeping the model over the patch promted the strange approach to the landing. Right or wrong it was the pilots choice and it was his hands on the sticks...

And all was well in the end. It wouldn't havebeen my choice though!

Peter Miller23/04/2012 18:49:56
avatar
11593 forum posts
1393 photos
10 articles

Don't you just love ARTFs. You can always trust the builder. He is so concerned about the quality......Well, at least concerend about earning another bowl of rice before kncoking off.

PETER BRUCE - Eastchurch Gap23/04/2012 22:31:46
avatar
856 forum posts
112 photos

Tend to agree with what you say...

Big Bandit01/06/2012 10:17:59
avatar
2436 forum posts
947 photos

I agree with the twin servo for elevators and that was some really cool flying considering the situation. It just goes to clearly show the potential problems with ARTF's.

Cheers,

Chris.

Alan Cantwell01/06/2012 16:18:45
3039 forum posts

PLEASE dont brand all models the same, to many, artf models have been a godsend, not all out there are peter millers, ive seen a LOT of tat at flying fields that have been shabbily built by folks who should not bother, ive also seen good quality artf kits put together by folks who really should not bother, now, i m going to watch this video

Alan Cantwell01/06/2012 16:30:56
3039 forum posts

RIGHT, watched the vid, i thought from the comments it was the wing that failed, i see its the taiplane, now then, i have seen this SO many times, a lot of the time, we have proved its the builders fault, cutting the film away from the fus fitting bit, and scoring the sheet, even scribing with a pen, or pencil can create a shear point, great care should be taken when removing this film from the area to be glued, i use a soldering iron, and melt the film away, i also brace the tails with carbon rod and a brass ferrule, 10 minutes work, and no trouble--ever, bad design can happen, not saying it cant, YT had a batch of kits from a supplier, everyone that broke did it in the same place, halfway along the tailplane, we issued a brace, and no more trouble, the next batch where fine, cos we had the construction altered, what caused it? the leading and trailing edge had a slot cut into it, for the cross beam, and it failed, but most i have seen have been builders fault, so much so, that we put an amendment in every kit about how to cut the film away, no trouble since--touch wood

PETER BRUCE - Eastchurch Gap07/06/2012 11:56:12
avatar
856 forum posts
112 photos

I published the video and when the plane landed we went over it with a very fine tooth comb. We observed that the tailplane had no structural spar (at the fuz point) and strength was due to the tailplane being sheeted. All the failed parts were recovered and examined closely and the sheet balsa was found to be extreamly wide grained, soft, and pliable - with the higher power plant installed in the plane and the the high G stunts which were being performed the tail section (in my own humble opinion) was not strong enough to take the strain. If a spar had been incorporated into the tailplane design the problem would never have surfaced or perhaps if a harder Balsa sheet section had been used on the tail that may have prevented the failure. The points made in the comment box above about failures which can be caused by even the dig of a pencil line at a stress point are all valid and like everything something will break if its pushed too far. The video was published here to promote debate and not debase ARTF models which have been a blessing and a curse depending on what time you have for our hobby.

Alan Cantwell07/06/2012 17:34:05
3039 forum posts

there is deffo an issue with material quality control, looked at the vid again, there certainly seems a lack of any substance regarding a spar, there is what looks like a thin vertical thing, combination of a leading edge, trailing edge, and the sheet should have kept it together, it just sounds like the material choice could have been suspect, i hope you have been in contact with the importer, and discussed the damage, good job on the landing, by the way,

Stephen Grigg07/06/2012 18:31:58
avatar
8691 forum posts
1128 photos

Very impressed with the pilots skills shown and his decision to land in that way was obviously the right one as landing was very successful.Very good video congratulations to both experts.

Frank Skilbeck07/06/2012 19:10:28
avatar
4868 forum posts
107 photos

Did this plane have twin elevator servos or was it just the side without the servo that broke off. If it was a twin servo version then the elevator would still have been connected to the servo (unless that broke away at the same time) which may have made handling more interesting.

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
CML
electricwingman 2017
Subscribe now
Sussex Model Centre
Slec
Advertise With Us
Sarik
Latest "For Sale" Ads
NEW POLL - has the pandemic altered your event safety perceptions?
Q: Has the covid pandemic deterred you from attending shows and events in 2021?

 No, I'll be attending just as many as I usually do
 No, but I'll choose my event with greater care
 Yes, I'll attend fewer events going forward
 Yes, I wont attend any where previously I have

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!