Is there any way to prevent this?

[Bob Moore]

I maiden my number two Wot 4 in the week with a brand new Irvine 40 and had a couple of dead sticks, possibly because I was running too rich out of caution for this engine, which had only had 4 tanks of fuel thru it. Or as I just discovered, possibly because the kerplunk was jammed forward.

Two dead sticks resulted in landing in the field, though the last was a heavy one and broken prop.

The final dead stick was low and although I turned back to the field I mis judged it's distance off, clipped a hedge, took of the u/c and landed in an adjacent field. Luckily missed the tarmac road 2 meters away, or it would have been bin bag job.

Wing still remarkably in one piece, engine unharmed, though fusi in two pieces. Fortunately the mid-wing section with the servos and rx was very intact. The fusi is back in one piece, I have stuck the jigsaw of bits back together, and I'm just in the process of glueing doublers on each side of the fusi. Should be as good as, if not stronger, than before within a couple of days. (This Wot only cost me £12, and I sold the engine it came with for £17 on e bay. Purchase price - £5. A few new servos and a bit of a rebuild but it flies beautifully. Not pretty, but at least I didn't crash my new artf Wot 4 or I would have cried!)

Anyway to cut to the chase as they say, I just removed the fuel tank to sort the u/c and found the kerplunk jammed forward. It may well be that this was the cause of the last dead stick? Or maybe all of them?

My question...

Is there any way to stiffen the fuel feed tube in the tank so that it does the job, but won't go forward in the case of a heavy landing?

PS This was the second maiden of this wottie. The first was a few weeks back and also suffered dead sticks with an old engine. Two good landings and one bad one in adjacent field, with small damage. Hence I bought a new engine! It was like Groundhog day

PPS When the engine was running (which it did for a few minutes) the power was impressive. Climbing almost vertically and great speed. Can't imagine what a Wot would be like with an engine bigger than a 40!

[r6dan]

The problems normally arise when the clunk tube is too long and gets stuck mid tank,it isdefiantlythe right length?

Good luck on the re-build!!

[Alan Cantwell]

you can place a piece of aluminium tube in the clunk line, but i just use thicker wall tubing, as for the wot with a bigger engine, my lad s one had an irvine 53, and a genesis throttle pipe--perfect!!

[001]

Bob,you shouldn't need to stiffen up the fuel tube. If you have a hard landing the clunk will go to the front of the tank. You then hold the plane vertically nose up and shake it. hard. You should hear the weight hitting the sides of the tank. You should really also check that the brass tubing hasn't cut the silicone tubing inside the tank.

Also check everything else. That might have been damaged, loosened or gone out of adjustment.

Edited By Richard Bond on 21/01/2011 18:02:04

[001]

I knew somebody who put a Laser 80 on a Wot 4 with flaps. To teach himself to fly!

You can guess what happened.

[Biggles' Elder Brother - Moderator]

Richard's right, a good shaking usually sorts it.

If its really bothering you then slip a second length of, slightly wider,fuel tubing over the main tube - just adds a little extra stiffness.

BEB

[Bob Moore]

Thanks for all the prompt responses. It's definitely not too long. And I did shake it free when I found the problem, though I've found this doesn't always work if the kerplunk has jammed itself into the filler and pressure pipes.

Trouble with jammed kerplunks is that the problem doesn't manifest itself until the tank fuel level goes down a bit, and /or you climb hard.

I might try the stiff outer tube idea. Thanks.

Incidentally , I think the reason I misjudged the distance off was because I have been flying the little depron Edge quite a lot lately and I'd flown it just before flying the Wot. It's almost half the size. Switching to this larger model when I turned back towards the field I was surprised to find the model was way behind the 50 foot tree on the edge of the field. I'd intended to be well this side of it. (Luckily I didn't go into that.)

I had totally misjudged it because of difference in scale. I was most surprised. Something to watch out for, though I'm not sure how to avoid the problem?

[Martin Harris - Moderator]

Do you do a proper nose up check? Not the quick blip that many do as a token gesture, but 10 - 15 seconds at full throttle close to vertical - if the clunk has stuck at the front it will almost certainly cough and die in this time.

[fly boy3]

Good advice Martin, I see a lot of fliers who never do this test, others with a nominal 3/4secs. FB3

[Lindsay Todd]

Spot on Martin, I see this time and time again

[Bob Moore]

I must admit mine is a pretty brief nose up check, but I was just thinking as I walked back from the pub, it makes sense to do a longer one.

Thanks for mentioning it as well! If the clunk was stuck it could have saved me a lot of work. At least it elimates one source of problems as well.

[winchweight]

You can stiffen it by cutting the tube and inserting a length of brass tube into the tube inside the tank. But make sure you trim it so it won't get stuck at the back of the tank and moves freely to all the corners.

[David perry 1]

I echo Martin's advice.

I hold mine vertically up and then give the plane a good shake to really chuck the thing around (not hooligan violent here, just shake it!).

The best advice though, cough cough, is learn to land. A heavy landing is the description used by ourselves when we arent happy with the landing. So be critical and really nail those landings. Get instruction if needs be, don't be ashamed. And go and stand by "good landers", see how they set it up.

The best advice I had, years and years ago, and which really transformed my flying from below average clubman to instructor / examiner was this: I was standing next to a really good flier when he landed it short in the rough. I thought, blimey, it happens to the best of us , and I said "oh bad luck Tony". His reply? The reply from this God? "No, bad flying".

That was my epiphany.

David

[Martin Harris - Moderator]

Posted by David perry 1 on 22/01/2011 08:56:01:

 

I echo Martin's advice.

 

 

Likewise!

 

Acceptance that you could, and should, have done better is the key to becoming a better flier. True bad luck is extremely rare.

 

Another old chestnut, which is extremely valid is the advice to never land from a bad approach. If you have fuel in the tank, it's always better to accept that it's better to go around and set yourself up better - the landing from a good approach in reasonable conditions should be a simple speed control exercise with very few other corrections needed.

Edited By Martin Harris on 22/01/2011 09:58:37

[Alan Cantwell]

Posted by Shaun Chant on 22/01/2011 08:06:05:

You can stiffen it by cutting the tube and inserting a length of brass tube into the tube inside the tank. But make sure you trim it so it won't get stuck at the back of the tank and moves freely to all the corners.

can i refer the honorable gentleman to my similar post futher up, and respectfully suggest that brass is NOT used, as the fuel attacks brass over time, leaving it oxidised, and very brittle, have you guys ever stripped a tank with brass pipes, and witnessed this?

[Alan Cantwell]

ooer whats with the black print? wasnt me officer

[Bob Moore]

My 'hard landing' was a result of a dead stick, which doesn't necessarily give the time for a nice approach, or going around again! (Not saying I don't occasionally mess up though, as I am quite a beginner at this. Only got my A last year.)

The last dead stick happened after I did a low slow pass I was doing to get used to the glide angle of the Wottie, it was as I opened the throttle and pulled away I had a dead stick. Not a lot of chance of recovering when low out in front. I turned back towards the field, but with not a lot of height, and tried to make a downwind landing as there was little wind. But didn't have enough height. l tried to make the slope on the edge of the strip, but misjudged the distance off (as said.)

Re the brass tube corrosion , I have indeed witness that effect. Very brittle.

I should have done a shake rattle test? It would have told me if the kerplunk was free.

Anyhow, the good news is the model is at the recover stage. Not really pretty, though once covered won't be obvious, and if anything, stronger than before.

 

PS This was my first ever 'major' repair so it's been a good learning experience. The wing and fusi are true, no twists, but I think the model is a one mm or so longer!

 

 

From this

to this

Edited By Bob Moore on 22/01/2011 11:52:12

[NigelH]

Here's a very easy way to avoid that sort of problem

 

http://www.falconsrcs.co.uk/

http://www.brchobbies.co.uk/

 

[Myron Beaumont]

Bob

Take no notice . You can't repair a pile of ash can you ?

Myron (Hope your thumb is healing OK)

[winchweight]

Posted by Alan C on 22/01/2011 10:17:51:

Posted by Shaun Chant on 22/01/2011 08:06:05:

You can stiffen it by cutting the tube and inserting a length of brass tube into the tube inside the tank. But make sure you trim it so it won't get stuck at the back of the tank and moves freely to all the corners.

can i refer the honorable gentleman to my similar post futher up, and respectfully suggest that brass is NOT used, as the fuel attacks brass over time, leaving it oxidised, and very brittle, have you guys ever stripped a tank with brass pipes, and witnessed this?

 

 

Blimey.... that's me told then. I have used brass and never had an issue, but then I bow to your not inconsiderable experience.

 

So perhaps you should use another metal, but the tube thing works for me..

[Andrew Jarvis 1]

As other have said, use thicker fuel tubing on the clunk and make sure it's not to long, Also, your Irvine 40 should hold full RPM after 4 tanks, never run an ABC engine rich thinking you are erring on the safe side, you will damage the engine.

[Bob Moore]

Thanks for that Andrew. I have read than running too rich is just as bad as running too lean. Won't be able to fly for a bit though having almost chopped my thumb into two parts in a very sharp fast running apc prop! Sliced like a knife through butter, as mentioned in another thread. Stainless pin comes out in 3 weeks, but don't know how long till it's fully mobile.

 

 

[Myron Beaumont]

Re the clunk issue

I use a length of brass tubing from halfway down the length of the tank to the clunk .Simples-No probs & it probably doesn't float around as much as a silicone tube all the length

[Bob Moore]

I do think that's the best solution Myron (other than perfect landings every time that is!)

[Myron Beaumont]

BOb

Ah- but All I read about on here is crashes & mishaps !! By the way I run in my engines (no matter what sort ) in the air would you believe after an initial bench run .Simples-Again -Phew!