Montycosmos racer
the life of thread ? (not brian!)
i have two wings, the original 12m chronos , 1993, and a 15m northwing maverik, appx 200hrs. i,m flying the maverik on my cosmos echo here in arizona, where i winter ( ain,t i a lucky bastard!). i have to tie it down here in the desert , my home-made wing covers (made from some $1 per yard cotten, ) over the wings. i hang empty plastic milk jugs all arround the edges to keep the covers on. i used to put water in 'em but with the covers frequently wet with dew the extra weight wasn't needed. (till the wind blows!). even though the material is soft it still seems to abrade the stitches (aided by the dust). some of which show fraying. i paint the leading edges of both wings black and yellow, plus the two outer wing panels, partly for visability, partly 'cos yellow is the fastest color! the paint stiffens the maverik leading edge panel and it SEEMS to climb better, that could be the yellow too! i use water based latex which dries very quickly, covers well ,sticks like shit to a blanket, and adds very little weight. sometime ago i built a 'bettsywhanger wing rippa'and tested my 'test panels' stitched to the rear of the wing. couldn't rip it, but i lack the 'gonadia' to try it on my stitches! (especially the 'wounded' ones). i don't have any parameters to compare it to. i'm sure the 'purists' out there will castigate any moron that would fly with 'frayed' anything, and maybe i'm overplaying the 'wear and tear' on the stitches. i do look at the 'worn ones', as well as 'kicking the tires before 'most' attempts to aviate, and not much change is apparent to the fraying. i'll stick my scrawney neck out and ask " why not paint the UV damage - prone top surface when new with some kind of protective 'paint' that would delay the UV onslaught? the weight would be significant, but on a 100# wing wouldn't be a dealbreaker, though the passenger seat warmer might have to go! i'm thinking more of single surface 'dacron' not the 'high budget' fast wings out there, obviously they 'ain't covered with 'bed-sheet' cloth! my 12m chronos, although celibrating its 23rd birthday is still 'stiffer than a wedding dick', and when i tried my 'wing-rippa on it all that happened was the needle hole stretched a bit, no ripping. i believe it is 'trilem' or something like that, i think it's used to make french chastity belts .i haven't, (and won't ) tried to rip the stitching after all what would i achieve with out 'factory' figures to compare to. i have no idea what wing stitch material is, it well could be cat-gut for all i know! if any one out there in trike-land, oops! flex-wing-dom, has tried painting his wing, results? replacement ain't gonna happen, i'll run what i brung, (unless theres an abandoned revo, (low hours) out there somewhere! (preferably yellow). hugs and farts, monty (not python!)
Comments
thanks boss, you done did it, hugs, farts and cuddles, monty
come to think of it even the most expensive wings are stitched together so the thread is probably the 'achiles heel' and would fail before the material. haven't read much about wings 'coming undone' . i would expect that it would have been reported in trike wrecks we've been aware of. if stitches were to fail in flight i would hope! that a 'corner' of a wing panel would start 'fluttering' causing the pilot to 'set her down' to 'check it out'. i've seen some fabric covered planes tied down and neglected and obviously faded beyond ''flyability', yet the stitching was still 'hanging' on. ??????
Searching around I found only a weed hopper accident that was blamed on the fabric. not on the thread per se. Have you seen a thread caused accident reported?
Niet ken, the Whitman accident was due to his fabric ripping off (at 200 mph!). I don't know of stitch failure being the cause of any wrecks. I could see a fabric panel ripping at the stitch line, those stitches seem to create 'enlarged' holes in fabric, so that could conceivably initiate a 'rip' line, but i'd say that 99% of trike wrecks are 'pilot' initiated, not equipment failure, so i'll quit worrying , monty
:) I'm guessing the weed hopper in question wasn't doing 200.
Looks to me like he had a series of maintenance shortcomings - here is the incident report
Accident occurred JUL-11-93 at PORT ARTHUR, TX
Aircraft: WEEDHOPPER B, registration: NONE
Injuries: 2 Fatal.
THE UNREGISTERED AIRPLANE WAS SEEN TO MAKE A HARD LEFT TURN AND ENTER A VERTICAL DIVE FROM AN ALTITUDE OF BETWEEN 100 AND 150 FEET. AT AN ALTITUDE OF ABOUT 75 FEET, THE FABRIC SEPARATED FROM THE RIGHT WING AND THE WING FAILED. POST ACCIDENT INVESTIGATION DISCLOSED THE RUDDER CONTROL CABLE WAS FRAYED, HAD BROKEN, AND WAS OF THE WRONG SIZE. THE WING FABRIC WAS DETERIORATED, HAD BEEN PREVIOUSLY PATCHED, WAS OF THE WRONG TYPE AND WEIGHT, AND BORE SPANWISE TEARS. THE WING SPAR HAD FAILED AT A POINT WHERE PREVIOUS REPAIRS HAD BEEN MADE. ADDITIONALLY, THE WING RIBS WERE OF THE WRONG TYPE. THE PILOT HAD CONVERTED WHAT HAD BEEN A SINGLE PLACE ULTRALIGHT VEHICLE INTO A TWO PLACE AIRPLANE BY USING PARTS FROM WRECKED ULTRALIGHTS, CAUSING THE EMPTY WEIGHT TO EXCEED THE MAXIMUM ALLOWABLE.
Probable Cause
THE FAILURE OF THE WING FABRIC AND WING SPAR. FACTORS WERE: THE IMPROPER DESIGN CHANGE, MAJOR REPAIR, AND REBUILDING OF THE AIRCRAFT BY THE PILOT IN COMMAND.
holy moley, there wasn't much correct on the plane. i bet the wing failed THEN it dived vertically. i put 50+ hrs on my weedhopper, 1984 vintage, but i didn't molest it like this guy did! sounds like he was on a suicide mission, but no SAKE! oh well, as has been said many times, aviation is unforgiving of mistakes , and mistakers! too bad he, the 'pilot' took an innocent' guppy' with him.
Monty. I havnt heard of one iether,but i have heard of it happening with hang gliders. But if i can remember the gliders were quite old. Like i said before a pilot i knew flew into a anvil head and was taken to the top of it for quite some time around 5 or 6hours in lightning ,hail, and severe turbulance. This happened in the early 80s. Bob was found hanging in a cottonwood tree in corrales NM. They
brought his glider into american aerolights where i had a chance to inspect it.The flying wires were scorched by lightning strikes. The sail cloth was ripped to shreds chord wise. But the stiched seams held. F-16s dont even fly into anvil heads so if that aint a testiment to the stiching i dont know what is. If i remember correct the case of stiching failure i heard about was due to the use of a solvent cleaning agent used to clean the pilots wing deteriated the thread strength. I worry much more about uv damage.
http://www.upi.com/Archives/1981/06/26/An-Albuquerque-hang-glider-pilot-who-took-off-from-10678-foot/6152362376000/ALBUQUERQUE, N.M. -- An Albuquerque hang-glider pilot who took off from 10,678-foot Sandia Crest during a thunderstorm was killed in a crash in Corrales, about 10 miles west of the crest.
Police said Bob Abbott, 26, an experienced hang-glider pilot, died late Thursday.
A friend, Chris Horn, said he and Abbott took off about mid-afternoon, but he landed at the base of the mountain because of the storm.
'I landed on purpose because of the storm,' Horn said. 'I took off right behind Bob just as the storm was coming in.
'I went down to avoid the storm. The last time I saw Bob, he was over Albuquerque, flying at about 10,000 feet.'
Police said Abbott apparently was caught in an updraft as he left the crest, and was carried into the mass of storm clouds.
A witness who saw the craft come down in Corrales, about 45 minutes after he left the crest, said the hang-glider appeared to have been disabled before coming straight down.
Police said he was covered with ice when found at the crash site, and said he was probably unconscious due to hypothermia at the time of the crash.
Gosh jeff i cant believe that was 1981. Chris horn was a friend we flew at tatilla peak. I think it came out later that bob may have committed suicide. Chriss told me that he spun out of the suck. Chriss said he never even saw bob try to spin out of it. Not sure but i think bob had just broken up with a girlfriend. Still sad after all these years. But dam good ground lesson for those who need to understand cloud suck?