On Thursday, September 22, 2016 at 9:10:35 AM UTC+12, Ian wrote:
On 21/09/2016 03:24, Tom Kelley #711 wrote:
On Tuesday, September 20, 2016 at 7:01:26 PM UTC-6, Soartech wrote:
or fantasy of flight?
On page 52 of the September issue of Soaring magazine Jim Payne is listed as having flown an out and return course of 300 km at an average speed of an amazing ground speed of 189.62 MPH ! Can someone please explain how he did this when the Vne of the Arcus M is 174 MPH. It seems to me the only way to do this is to somehow fly (at Vne the entire flight),downwind, on both out and return legs.

Wave and altitude kick. Remember the higher you fly your TAS increases. That"s why speed and distance folks fly the great basin. Crusing at 16-18 thousand gets you a 30 Kt kick in TAS. Here's his story from the OLC. Best. #711.

Pilot:
Co-pilot Miguel Iturmendi.
Mission was to fly a declared 300 km out-and-return between Inyokern and Big Pine.
The forecast said the wave would be weak early with winds and lift increasing in the late afternoon.
During the first lap, the wave was not good between Cindercone and Manzanar...the turn was covered in cloud.
During the second lap, the lift was better...the speed was 278 kph.
By the third lap, the lift was ripping and the clouds much better...the speed was 305.12 kph (189.62 mph)...
Late in the day the Antelope Valley was overcast. We descended through a large hole in the overcast near California City.
Had a Sage 2 clearance to FL290 in R-2508.
For photos see www.tumblr.com/SoaringBlog.
Thanks, Cindy for coordinating the Sage 2; Joshua for the outstanding service; and Doug T, Greg, Beth, & Jackie for crewing.

Hats off to the pilots for their performance. But the above looks a bit
extreme. So I did some checking. Google found me a copy of the "Flight
Manual for Powered Sailplane, Arcus M" at

http://www.schaenis-soaring.ch/filea..._M_AFM_ENG.pdf

Around page page 38 of that document is a table listing Max permitted
speed verses altitude. I listed 3 points in their hight band below and
used my old circular flight computer to find the TAS at each of the
altitude.

Altitude (m) VNE (km/h) TAS (km/h)
7000 220 318
8000 207 320
9000 195 318

There is obviously a pattern above. To achieve an average cross country
speed of 305km/h must have required operating right on the edge of the
envelope for the entire flight.

Ian

The police won't come knocking on your door if you exceed the "permitted" speed.

They're designed to 40% (?) above Vne and test flown to 20% (?) over.

Yes, exceeding the Vne printed in the manual makes you a test pilot. That's part and parcel of world record flying. Don't try it at home.