Friday, February 2, 2007

L/D, Hype or Hysteria?

WHY DO perfectly sane pilots seem to go off their head every 18 months and chuck out the perfectly good wing they've just got used to, only to order a new one for a net gain of 0.168 L/D? What is 0.168 of advertised glide ratio exactly and can we believe these published figures?

That's right readers, time for some Pie testing. We read all we could on the subject, we called the experts at Tight-Schwirm, bought a tape measure & a new notepad, sharpened our pencils and decided to have a go.

We begged, borrowed & stole 284 of this years models within the DHV 1-2 class and headed off to Piedrahita. A 3000ft TTB with sprawling flatlands out front so we could get full use of the tape measure. Oh, and plenty of cheap beer for the post testing analysis. We flew all 284 wings off the top of Pena Negra at the exact same time, same weather, same altitude, same everything. We asked the pilots to remain motionless, not to touch a god-damned thing and to refain from any form of intervention including talking on the radio and farting. We also hand-launched a bag of potatoes in a harness as the control subject, King Edwards for the really curious.

Local expert, British pilot & all round red-head Steve Jamon-Serrano showed up as we were laying out and seemed quietly curious, "What the fuck are you wankers doing?", he asked in unusually direct language, "You won't prove a god-damned thing testing in these thermic conditions. Jesus wept, what next? Err, hey, let me get away first will you."

Well, we'll let the results speak for themselves. Varying distances were achieved with most wings hitting the dust within the expected, pre-determined distances between 2.1km and 14.8km from launch. We did have one or two surprises though. We felt the free beer for the night should have gone to the bag of potatoes which somehow thermalled it's way over the pass and landed on the far side of Avila for the flight of the day at 82.3km, and 15k over Steve's head.

Our initial test results clearly showed some of the manufacturers figures were a little off, in fact some could be said to be entering the realms of fantasy, but quite surprisingly the makers of the wing the potatoes were strapped under have been incredibly conservative with their estimates.

Desperately looking for input from any manufacturer, we contacted Crapco Aviation head, Natalie Coenstein. Speaking from his headquarters in downtown Ancient Judea, he told us, "What? Glide Ratios? We make them up, just like all the other players in this market. I mean. What did you expect? You call us up asking us questions, of course we get upset."

So, Glide Ratios then, Hype or Hysteria and do we really need to upgrade every 18 months?
Hype and Hysteria, and probably not. That's the concensus of the opinionated, self proclaimed experts here at Pie.

Oh, and the first $1000 cheque to arrive at the Pie offices will receive an email identifying the manufacturer of the wing the potatoes were strapped under.

Pie in the Sky
Funnier than the 1982 "Airplane II" sliding door scene