RE: Composite-ARF Lightning Build Thread
 

staale, someone else will answer that question i am sure. a friend came up with the pictures. i have lots of other pics comeing will post soon.

m

RE: Composite-ARF Lightning Build Thread
 

Guys

I've been flying my Lightning just for 10 months or so with lots of flights.
World wide there are a lot flying and this is the first we have seen-so it's not common.
I know Composite ARF are looking at this issue VERY seriously, but rather than react without facts the were working on a possible improvement-just in case.
I am 100% confident in it's integrity, the spar is not just balsa-it has glass cloth either side. The tailplane skin adds a lot of strength, if I look inside all my composite aeroplanes they all have balsa spars keeping the skins apart-there is a lot of strength in the skins.
I think caution is a perfectly sane point of view, but some peoples methods of applying this need addressing.

I'm know there will be a response very soon from those that make decisions, it's been worked on for two days.

Dave Wilshere

RE: Composite-ARF Lightning Build Thread
 

Thanks for the reply, Dave.

I'll be looking forward to the response.

Robrow:
Sorry for your loss of the Lightning!
Why so quiet? Please let us know what happened in your eyes...
Was there any flutter involved prior to the loss of the stabs? What was the speed? Was the hatch secured pr. instructions as it gives strenght to the rear part of the fuse etc.?

Me and I'm sure others who owns Lightnings would appreciate it.

RE: Composite-ARF Lightning Build Thread
 

Despite his loss, Rob has kindly stated that he would not splash this news all over the forums bashing the product but is very professionally giving Comp-ARF time to answer the issues. As Dave said, there will be a response very soon.

The factory model has had over 500 HARD stress testing flights so hopefully, coupled with the fact that many other are flying without issue you will agree with Dave that this is not common!

For those who have PM'd etc expressing suprise that there "are no spars in the tailplane", please see the picture below ;)

Kind rgds,
Mark

RE: Composite-ARF Lightning Build Thread
 

Frankly, the way that this incident has been handled is as disappointing as the incident itself. Whilst of course, this incident is not nearly so serious as the loss of a critical component on a man carying machine, it could still have been fatal. In my view, based on a lifetime of operating jet aircraft, as soon as this incident occurred, there should have been an immediate world wide alert to the problem, requiring an immediate inspection of the stab. structure BEFORE further flight. It matters not one jot that the factory and others have a masses of flights on Lightnings, the fact is that THIS one came apart , in public, and as the construction process of this model is unlikely to be as careful as fullsize, with its regular approval ansd inspection processes, then the consistency of construction quality is NOT guaranteed. BOTH of my CARF models, a Mig 29 and Eurosport have BOTH required considerable attention to rectify construction defects, some critical, this Lightning loss may be a one off, of course it may be followed by others, who knows?

I have also had several other emails and PMs telling me of other structural failures and constructional quality problems of other C-ARTmodels, not just jets, including loss of tailplanes, so I am most certainly not alone.

And no, I have no hidden agenda, just an open one. If we are to secure the future of this branch of RC modelling and do our utmost to avoid a "big black eye" the we have to react to problems such as this, rapidly and with total objectivity. If anyone wishes to describe a serious flight safety issue such as this as "product bashing " then you have totally missed the point, and you have no idea of the culture and practices, built up over many years and with the experience of some very, very hard lessons, which exist in professional aviation, both civil and military. This hobby could , would, do well to follow their example.

Regards,

David Gladwin.

RE: Composite-ARF Lightning Build Thread
 

This is may Lightning,is not mayden.


saludos from spain (valencia)

victor sanchiz

RE: Composite-ARF Lightning Build Thread
 

I thought I had been rather harsh in my previous post and had intended to delete or modify it. However the large number of incredibly supportive emails and PMs I have had from US and UK led me to leave it, with just minor changes. Only one was in disagreement so let me make it absolutely clear that I do not agree that an urgent alert is in any way "product bashing", I call it real customer support.

Rob's loss is most regrettable and I am in no way critical of him, just the opposite, he has my sincerest commiserations and complete support. and I sincerely hope he will be fully compensated for his loss, absolutely NOT his fault in any way shape or form so far as I can see.

The problem is now in the open so I will sit back and see how C-ARF deals with the issue.

But may I ask just one question? Just what DOES have to happen before a manufacturer issues an IMMEDIATE airworthiness alert ?

Regards,

David Gladwin.

RE: Composite-ARF Lightning Build Thread
 

David,

OK, so maybe my use of the words "product bashing" were not wise in the circumstances. The point I was trying to make was that Rob was doing the gentlemanly thing and allowing C-ARF to resolve his problem before he came onto RCU and flamed everyone and everything. I think most level headed people will agree that it is only right to allow a company the right to reply before laying into them publicly. There are many threads that start that way only to be full of replies of "perhaps you should approach the company before coming on here..." etc

There will be an official statement from the factory made very soon which I will publish shortly as soon as I have had the opportunity to discuss it with Rob beforehand. I am sure you can understand that an issue such as this is NOT taken lightly and just glossed over. Instead, a certain amount of analysis has to take place. This cannot be done overnight.

I totally agree with you regarding the safety issues but I would hazard a guess that every manufacturer has had an airframe failure of some sort. Wasn't a very popular US sport jet suffering airframe cracks/failures fairly recently without a mass grounding of all existing aircraft? I am certainly not aware of there being a mass grounding of all aircraft due to a single, isolated, unexplained failure??

Rgds,
Mark

RE: Composite-ARF Lightning Build Thread
 

Factory statement as at 2pm 13/9/06....

"Since there is a risk of touching an unhedral tail plane to the ground during take off or landing, there is a chance of damaging the tail plane’s structure so that it can fail in flight. We had this very unlucky incident with one of our customers. This customer has been very professional, has given us the chance to carefully and completely investigate the incident and come up with a solution for all of you. The customer will be taken care off in privacy after full investigation is concluded.

Since not only the tips of the stab, but also the elevator control horns have a chance to hit the ground during take off and landing, depending on the surface structure of the runway, we have created a Kevlar skid which should be glued into the ventral fin to make sure that this skid will hit the ground first when the plane rotates, to protect the stab and the elevator control horns in case of overrotation. A servo gear damage caused by hitting the ground with the elevator control horn can result in elevator flutter which can create such huge forces on the tailplane that no reinforcement would make it stay together.

The case of enlarging the slots for the servo arms on the bottom skin of the stab (over the factory cut size) also can add to a possible risk of damaging the tailplane during take off further. Therefore we have quickly created a safety package of a nicely milled carbon fibre sheet, which is glued to the outside of the stab bottom skin in the area of the rear stab spar, to stiffen the skin in case any holes or slots have been added or enlarged. We remember a similar fix of a very popular twin boom trainer, where an additional carbon skin was glued to the surface of the booms. This was, and also in our case is, only a safety precaution for existing and flying airplanes.

Until last weekend we have not had a single structural failure of a Lightning, and we fly 5 airplanes in our factory team with many hundreds of flights on each of them. We know of at least 80 Lightnings already flying out of the almost 200 produced. So please don’t be worried about a general design problem or a manufacturing defect. But be cautioned to check your tailplane after every landing for damage, especially if you feel that you had hit the ground, and please contact your Rep so that he can send you the tail skid and additional carbon skin free of charge. This will be a piece of mind package for all who worry now.

Last but not least, we of course apologize to Rob that he lost his plane in that incident, we thank him that he stayed very very professional, and gave us a chance to investigate and comment, finally improving a product and its handling advices, where we all know that we are somewhat at the limit of the possible, boring 20 kg through the sky with 200 mph+. We are as glad as the pilot that nobody was hurt."

For existing customers, please contact the rep through whom you purchased your Lightning to ensure you get the precautionary safety package. Please contact your rep also if you have further questions.

Kind regards,
Mark

RE: Composite-ARF Lightning Build Thread
 

hear hear!!

Rob
since you purchased almost all MPX servo,s from me.
i can offer you new ones (if needed) for cost price or repair them for free or get you spare parts against cost price.
whatever you want.
i know when you lose a favourite model it is a real head banger when you lose it like this.
if you need anything else mail me (also got some merlin parts left).

i am just looking at my (mini lightning) flash and this one cant bang on the ground c-arf made indeed a bigger bump on the back to prevent this from happening.

RE: Composite-ARF Lightning Build Thread
 

Geez David, in this country, even the NTSB takes a few days to investigate an accident before delivering recommendations for inspections and such. It could well have been that the owner bumped the elevator against the side of the trailer taking it out, stripped a servo gear, and the resulting flutter in-flight took the stabilizer halves off. What good would an "immediate, world wide alert" (if there is such a thing for models) done if this was the case except panic everyone who owns Lightnings?

I don't believe you have a hidden agenda, but I do believe that you have somewhat of a different perspective on jet model aviation. Yes, I realize that we could be in trouble as a segment of the hobby if there is a serious accident, and yes want the flying of jets to be taken seriously, but this is a hobby, not "professional aviation" (which by the way, has its own problems - see the "Citation Jet Boat" thread). I think you should drop down just a notch and take into account that these are not commercial full-size aviation products being operated by "professional aviators" (which we all know is no guarantee of safety either) and sometimes, "stuff happens." IMHO, the manufacturer has outlined a probable cause in a timely manner and offered a solution for paying customers, so case closed...

Bob

RE: Composite-ARF Lightning Build Thread
 

I'm glad to see that the factory was so quick to address this issue. I'll contact my rep. reg. the upgrades.
Looks to be a solution that will give me some peace of mind.

Just a thought: Will C-ARF contact every customer who has bought a Lightning, or do they have to find out and request the upgrades themselves?
No problem here because there are just 3 Lightnings in the country. Two belongs to the rep., and one is mine..:)

Now that the factory has made a statement, isn't it time to tell the rest of us what actually happened to Rob's plane?
Did his stab tips/ control horns touch the runway on take-off, and was it flutter that ripped the stabs off?

I thought they changed the stabs to have less dihedral early in the production to prevent the tips possible touching the ground?
My rep has a early production one, and this one has more dihedral than his second Lightning (and mine).

RE: Composite-ARF Lightning Build Thread
 

Staale,

It will be a joint effort. All Comp-ARF reps should be contacting the customer who have purchased a kit through them and I would imagine several customers will be contacting their reps too.

I guess everyone should remember that if they have an u/c failure or belly landing etc to check their tail as a 40lb odd model sliding on the tips of the tailplane can cause damage that may lead to failure. This goes for any model that has to make an emrgency landing etc as the weight and inertia of these jets can put incredible stress on the airframe when landing/take offs do not go to plan.

It is also mentioned in the manual that a tail skid can be fitted to avoid stab strikes on rotation.

Rgds,
Mark

RE: Composite-ARF Lightning Build Thread
 

What a flimsy and lame excuse. COMP-ARF is not a paid RCU advertiser but will use this forum to promote their product or bash RCU members.

FWIW, because Comp-ARF is not a paid advertiser here, they are only allowed one product statement/announcement once every month. (That includes statements from their reps/shills)

If you want to use this forum to dissipate your information, sign up like other manufacturers did and become a paid advertiser. It cost a lot of money to keep this site up.

BTW, thanks David G for being the only lonely voice in the wilderness looking after the safety of this community. For those attacking you, all I could say is “How soon do we forget”. Was it not less than 6 months ago when a product manufactured by this company failed at an air show and killed a family?

RE: Composite-ARF Lightning Build Thread
 

I believe David was very very keen to see a statement regarding the issues/fix posted as soon as possible and rightly so. The post was made solely in the interest of safety which I am sure members will be more concerned about and would be more beneficial to them than the argument of paying to advertise?? I wouldn't exactly call this thread a product promotion.

This could quite easily be handled between the reps and customers only and wouldn't need a thread like this. Had this not been posted on the thread and left to the factory/customer/reps to sort we wouldn't be where we are now!

Re the RCU comment - I have amended the factory's statement accordingly. I agree that the point does not add any benefit to the statement made.

Rgds,
Mark

RE: Composite-ARF Lightning Build Thread
 

Hmmmmmmmmm!!!!!!!!........
Can you tell me how a person that bought the kit second hand will get contacted by factor or rep.

The bottom line is that we all benefit from this website so what is so wrong about supporting it?

FWIW, we fly a Lightning locally here and few months ago, we noticed cracks on both side of the bottom tail section. This was brought to the attention of a rep and he claimed that it was unusual for this to happen. He did not recommend any fixes and I do not know if he forwarded that information to the factory. My friend that owns the Lightning reinforced the area in question as a proactive measure.

RE: Composite-ARF Lightning Build Thread
 

I'm not responsible for the advertising budget :D

RE: Composite-ARF Lightning Build Thread
 

LOL.......I read you loud and clear my friend!

RE: Composite-ARF Lightning Build Thread
 

Thank you so much. More supportive mails were waiting when I got back tonight,

Just as Jackie Stewart did something to improve safety in Formula 1 someone needs to speak up, seriously, about safety in this hobby, and no I don't believe in a nanny state approach. I wont get it right for everyone, but by God I'm getting some support for speaking up about this issue. The best safety systems in the world are aviation and nuclear power, I passionately believe we should follow their example.

I aslo passionately believe it is far better to speak up BEFORE a big accident rather than try to get the horse back in the stable AFTER the event. Others may take a different view. .........................and please don't forget that this model crashed about 200 feet away from me , about 1.5 seconds flight time !

Regards, David Gladwin.

RE: Composite-ARF Lightning Build Thread
 

aaaa yes remember the famous talks

there was also one from mr watson

quoting:back then when racing was dangerous and s.e.x was safe now racing is safe and s.e.x is dangerous....
:D

RE: Composite-ARF Lightning Build Thread
 

Gents
I had the opportunity to examine the tail plane after the incident
I enclose photos showing my concern on this issue.
At the point of maximum load (where the tail plane leaves the support of the fuselage) the spar is notched to fit over the rib.
This left aprx. 6mm, 1/4" of spar to carry the load.
The remainder of the spar is butt jointed to the rib but unfortunately no glue appeared to be present on the butt face.
2 fillets of glue had been run down the sides but these were not very substantial.
in my opinion the spar should continue un cut with the rib parts butt jointed to the spar.

These appear to have failed which left the 6mm of balsa spar in free compression, You can see this on the photo.
This puts the top skin in compression and the bottom skin in tension.
The top skin has compressed and the bottom skin torn.......the tail plane failed.
You can see how the top skin is rippled and bent in the picture where as the lower skin is cleanly torn.
The most likely source of the start of the tear is the servo arm cut out in the lower skin.

I did not see any scrape marks on the tail plane halves indicating they had touched the runway on the one and only previous flight.

this represents my opinion only.
I am sure Comp ARF will take all necessary action to correct any safetey issues they feel exist.

RE: Composite-ARF Lightning Build Thread
 

Sir, Can hardly see any glue missing, however, I do see a servo screw missing? WHMC

RE: Composite-ARF Lightning Build Thread
 

yep your right it was the missing screw....

RE: Composite-ARF Lightning Build Thread
 

but why both sides?
seems like a unlucky event then?
seen many things fails , and flutter can do a lot of damage.
even if one would not be glued correctly , both at the same time?

RE: Composite-ARF Lightning Build Thread
 

Was it not less than 6 months ago when a product manufactured by this company failed at an air show and killed a family?

[/quote]

G.R.
Was that the incidet with the Pitts where the radio suffered iterference on the same frequency and locked out rarther than structural failure. If so how can C-ARF be responsible for that? Or is it one i have missed?

Trevor Skedge.