The July meeting brought the election and installation of a new collection of officers for Chapter Five:
The weekend of July 28-30 brought a contingent of PRA5 folks to
Nevada's Black Rock Desert, a dry lake bed larger and closer than El Mirage.
A glance at the map shows an expanse six or seven miles wide, and about forty
miles long, only an hour and a half beyond Reno.
Troy Taylor had initiated preliminary liaison with a group of rocketeers
who conduct weekend launch programs to test their (unmanned) flying machines,
and it took little encouragement for him to organize a gyroplane weekend.
We didn't fly all weekend, of course: during the heat of the day most of us just lazed around or took a side trip to the launch site. There was sufficient energy to pose for a group photo (l. to r. Shawn Mathews, Troy Taylor, George Atkinson, Georgi Rumiansev, Joe Souza, and Gary Longmore). The early morning coolness was ideal for flying, and Joe provided the Saturday predawn overflight wakeup call to remind us that it was time to go aloft. Our gyros were soon buzzing about, checking out various desert campers, such as that pair of desert rats sleeping on the hood of their car right out in the middle of nowhere. A visit was paid to the rocket folks encampment about eight miles away, but some of them had expected to sleep in and were not pleased with the early morning circumnavigation of the launch site. Indeed, an hour later when George, Troy, and Joe flew over for a courtesy call, an upset individual hurried up to accost Joe and, like an angry chihuahua, berated him roundly, effing this and effing that. Joe (who was not involved with the earlier visit) just laughed at him. Except for the sorehead, the rocketeers were welcoming, and delighted to show their projects. Some of their rockets could rise as high as three miles, and a few punched through Mach 1 on their short trips.
After close of flying on Saturday evening, many of us drove back to
the rocket encampment
to view the night launches. Troy had the foresight
to bring along his GPS, else we might well have gotten lost on the way
back. [Some of us even got lost during the day, flying right past our own
camp.] In honor of the Burning Man celebration to be held the following
month on the Black Rock Desert, and because we wouldn't be returning for
that occasion, we built a burning man of firewood dowsed with avgas
and had our own dance-around-the-pyre. Sunday morning was short on flying
as we were busy with camp teardown and gyro stowage for the long drive
back to California in the middle of the I-80 gambler's return traffic.
All participants agreed that Black Rock Desert is the Northern
California counterpart to El Mirage, and should become at least a yearly
gathering for gyro enthusiasts.
During last year's visit to El Mirage I observed at first hand the downwind turn illusion, and understood the danger of orienting oneself to apparent ground motion instead of keeping an eye on airspeed. At Black Rock Desert I encountered another kind of deceptive ground motion that can lead an unwary gyro driver into the same quicksand.
This time it is vertical motion: the refusal of the ground to drop away smartly when climbing under full power. At an elevation of 3700 feet on a hot day, one expects reduced lift, and a long takeoff run. After making sure of a solid 55mph, I rise out of ground effect into the expected slower-than-usual climb. Full power sounds like full power, but minute after minute goes by while gaining only a hundred feet or so of altitude. Then the ground begins to rise noticeably. Rats, must've let myself slip behind the power curve. But no! Airspeed still 55, and ground still rising. The dry lake bed terrain is outclimbing me!
I think of the stories of gyro drivers in underpowered machines desperately dodging clotheslines in backyards while falling hopelessly behind the power curve. Resisting the temptation to add back pressure till safely back in ground effect, I land and ponder the lack of power. Air cleaner's not clogged with desert dust; engine sounds healthy; the accustomed climb rate just isn't there. Nor can the problem lie with downward-moving air in the lee of the nearby hills, for the effect extends right down to the ground.
Further flight tests confirmed what should have been obvious at the start: at some density altitude any machine will just refuse to climb, and I was close to the service ceiling. Adjustments had to be made. After a long downwind flight, for example, a turn back into the wind seemed risky without reserve power, and I didn't wish to settle onto a sideways-moving terrain; I landed downwind, turned the 180 in a wide arc, and lifted off again into the wind. Ah, the luxury of an open expanse of desert!
The whole weekend I never exceeded 800 feet AGL, or really needed to. Back at sea level, Boa performed with the old enthusiasm, eagerly rising 2000 feet in seven minutes. The lesson was clear: if I wish to fly mile-high, I should be planning real performance enhancement, not just re-jetting the carb and maybe changing the prop, but moving to a re-drive, and ...
Naw. I have a machine with great sea-level performance that's
a joy to fly. I'll do my sierra crossing in a fixed-wing and maybe
wave to Bill Clem on the way.
PRA Chapter 5 Newsletters are also available on-line at:
http://www.quiknet.com/~twitham/gyro/pra5/