Expert: Malcolm Dickinson - 8/14/2007

Question
QUESTION: Dear Mr. Dickinson,
As a writer (not published yet), I find myself asking a lot of very specific or unusual questions.  Nothing about sailing a square-rigger here, though, of course!  (I have diverse interests.)
Some background: one of my current projects is a screenplay about...well, a lot of things, but it involves the Me.163 Komet rocket fighter.  In Mano Ziegler's excellent book, he explains that the rocket fuel ran out very quickly, so after the initial takeoff and crazy-fast steep climb, the "powered egg" basically became a glider.
Hence my subject line.  What wind direction, relative to a glider, will allow it to stay in the air the longest?
Carissa

ANSWER: If you are writing about the Me.163, you have (hopefully) already read the excellent article in the August 1997 issue of "Flight" magazine? It was written by Tom Atwood based on his interviews with Rudy Opitz, the Me.163 test pilot, who now lives here in Connecticut. The article gives an enormous amount of information, including pictures and technical data.

Rudy is an acquaintance of mine; we have flown together a few times. I presume you will want to interview him? I don't have his contact info, but if you want to reach him, you can do so by calling his friend, John Boyce, at 203-393-1225, explaining your project, and requesting to be put in touch.

Finally, to answer your question:
Gliders stay in the air the same amount of time regardless of which direction the wind is blowing. The wind has no effect on the duration of the glider's flight.

The only effect the wind on an aircraft in the air is that the "winds aloft" (that is, the wind speed and direction at 3000 or 6000 feet above ground) moves the aircraft along with it. It is not uncommon to have winds aloft of 30 or 40 knots.

So a glider flying east at 100 knots might be moving over the ground at only 60 or 70 knots if the wind is from the east; or might be moving over the ground at 130 or 140 knots if the wind is from the west.

---------- FOLLOW-UP ----------

QUESTION: I haven't read the article.  But I sure will now, if I can find it!  
I guess the question I really meant to ask is, what wind direction relative to the glider would allow it to cover the greatest distance?

Answer
I'm sure you can purchase a back issue of the August 1997 issue of FLIGHT magazine from the publisher:

Air Age Inc, 100 E. Ridge, Ridgefield CT 06877, http://www.airage.com Tel 203-431-9000, Fax 203-431-3000.

A glider will cover the most distance if the wind is behind it. That is to say, a tailwind allows a glider (or any aircraft) to cover more distance than a headwind or no wind.