A guy was killed here last year by a turbine engine from a C130 ( but without the prop fitted ) . He was a trained tech , working for a well known company , with the engine mounted in a proper teast rig . Most people were in disbelief that such a small engine could ” bite ” , but it did !
What some of the videos posted here portray is little short of Russian Roulette ( with nothing but ear muffs for protection ) ! Still , I had a good chuckle at a few of them . Thanks .

I was simply guessing that it was wood rot, but my ultimate point, which remains valid, is that it didn’t matter what color you painted the airplane. The glue did not weaken with heat, as does epoxy.

Whilst I make no claim to having any specific knoledge , is it worth pointing that not all epoxy’s are not created equal ? In my profession I glue a lot of ” hot grips ” to motorbike handlebars . If you use 5 minute epoxy , they last about a day . If you use 24 hour epoxy ( the only glue recommended ) , they generally wont come off – even if you try . I know that the techinical specs ( such things as strengh and heat range ) are available for comercial glues , and in fact I have seen a well known suppemarket brand , repackaged for aviation use ( by including such specs on the packaging – same glue ) .
Im just saying that the generalised term ” epoxy ” is perhaps a bit misleading , and nobody would use it ( whichever sort they chose ) for aircraft use without being satisfied that it was suitable for the application .

They actually used filler on the leading edges and around the first 25% of the wing cord, before painting in a dull silver finish.

My understanding was that the finish on the wing was important to preserve the benifits of the ” laminer flow ” , in much the same way as a dimpled golf ball flies better than a smooth shiny one .

I remember reading that the majority of piston light aircraft engines are actually old designs, tweaked here and there.

Because the red tape involved in ” new ” designs is simply too expensive to make them viable . Thats why there are so many cool options in the ” experimental ” catorgory

Okay , so after thinking a bit , and reading Al’s post , I think my first response was wrong . On reflection most of the valve combinations I have seen do indeed have the cupped valve is the intake , not the exaust . So a very quick Google latter and I found this http://www.enginebuildermag.com/Article/2371/engine_valve_designs.aspx . The first few paragraphs seem to explain things pretty well .

I’m no aerodynamicist but:

Increasing the speed of an aircraft does indeed increase lift. However that is for a given angle-of-attack. What they are saying here is that the increasing lift is countered by decreasing the a-o-a, i.e. raising the tail slightly, which in practical terms is true.

In a conventional aircraft the tailplane produces a downforce to counter the forward pitching tendency of the mainplanes. In this case all we are doing to keep the lift at a constant value is decrease the a-o-a but it doesn’t make the tail any lighter. It only reduces the pitching moment (down force) of the tail about the c of g.

Weight is mass multiplied by the local gravitational acceleration. This is a constant value in this instance.

Anon.

Think thats about right . In normal flight the most forward noteworthy piont is the COG , behind that is the centre of lift , meaning the lift of the tail is in a downward direction to balance the other two . It has to be like this to ensure that if lift is lost ( stall ) , the nose will fall and enable recovery . The closer the COG is to the centre of lift , the faster a plane will go ( partly because the tail doesnt need to create so much downward lift to balance things ( lift = drag ) , and the more manourable it will be .It also causes a plane to become uncontrolable , to the piont that modern jets often cannot be flown without computer assistance . I fly RC planes and there is a common saying – ” Nose heavy aircraft fly poorly , tail heavy aircraft fly only once ” .

or run the oxy/acet carburizing flame over it to turn it black, then add Oxy & burn off the soot. Same result.

The soap trick works quite well for bent castings.. motorcycle levers spring to mind.

I dont bother with soap , or soot , for motorcycle levers , just hold the base in a vise , apply pressure to the end ( about half as much as you would need to bend the lever cold ) ,then apply heat to the bent area and it will start to straighten when its hot enough .Works a treat with quality original equipment forged levers , but a waste of time with cheapo die cast ones .