The last several months have
seen the CAFE Foundation devote a huge effort to create a sophisticated new system for
evaluating homebuilt aircraft. This EAA funded and sponsored program will be announcing
some real breakthroughs in aeronautical understanding in the coming months. This has been
helped in large part by major contributions from Fluke Corporation, Aircraft Spruce &
Specialty Company, Terra Corporation, and B&C Specialty Company.
Perfecting the zero thrust glide (ZTG) test method, about which CAFE Board member Jack
Norris has contributed the article this month, has spurred much of these advances. ZTG is
proving to be an exciting and elegant new way to get the truth about an aircraft's
performance.
EAA Headquarters in Oshkosh has generously provided a used 32' motorhome to serve as an
all weather data processing center and ready room for the CAFE flight test crews. Heated
and air conditioned, the interior is being outfitted with a wall of radio and computer
video/electronic analysis equipment for year 'round use. It doubles as a great place for
on-site meals, thanks to Vice President Larry Ford, the designated and now acclaimed chef.
We have officially named it "Larry's CAFE Cafe" and his cooking has been a major
draw to keep the CAFE engineers working on into the night on busy weekends. Antennas are
being fitted to the motorhome for aircraft com, GPS, and, in the future, telemetry for
data.
Several other major donations have been made to the CAFE Foundation in the last few
months, giving the non-profit group the tools they need to round out the increasingly
sophisticated test program. The Fluke Corporation donated a portable digital storage
oscilloscope/meter which is a powerful and sophisticated instrument for analyzing
real-time trends from various flight test sensors. This marvelous instrument gives the
CAFE group the ability to get a clear understanding of several aspects of airplane
performance while flying. It allows the study of laminar flow, exhaust system back
pressure, static port turbulence, torque oscillations and many other detailed subjects.
The Aircraft Spruce & Specialty Company has donated an ICOM handheld aircraft
transceiver to aid in conducting flight tests and to serve as a backup to installed
aircraft com sets. Jim Irwin, president of Aircraft Spruce, has been a constant strong
supporter of CAFE activities for over 14 years. His unhesitating generosity to the CAFE
Foundation attests to his steady and honest efforts to improve the world of homebuilt
aircraft.
Terra Corporation donated a TX-10 Base Station Aircraft Communications Transceiver which
has been a great help to the ground crew. It has the power needed to reach out to the test
aircraft when they are flying over the ocean. This ability proved a great help when, on a
recent flight, the onboard computer program crashed and the flight crew was talked through
a successful step-by-step reprogramming to get it started again and avoid aborting the
flight. Sitting at the workstation in the motorhome, Ed Vetter was able to mirror the
computer display in the cockpit as he talked them through it.
Bill Bainbridge of B&C Specialty Company in Newton, KS has donated one of his
excellent lightweight alternator systems for use on the test aircraft. Since the zero
thrust glides must be flown without an alternator belt, the resulting total loss
electrical system meant shorter test flights and delays in the hangar while recharging
batteries. The B&C alternator is the perfect solution to this problem because it is
driven off the vacuum pump pad of the Lycoming engine and thus imposes no axial loads on
the crankshaft during zero thrust glides.
Another exciting development is an invitation from NASA at Ames Research Center for the
CAFE team to present their findings on Jack Norris' new ZTG flight test method. Placing a
test mule Cessna 152 into NASA's full-scale wind tunnel would allow comparing its drag
results there with those from the zero thrust glide flight test program. This may also
provide some spin-off studies of things such as sheared wingtips, laminar flow wheel
pants, alternative cowl shapes, etc.
Work is now underway to complete a full Aircraft Performance Report on the popular Bushby
Mustang II in a future issue of SPORT AVIATION. This report will be the most
thorough yet completed and will be followed by reports on the Rutan Long-EZ, Questair
Venture, Glasairs, and many others.
The CAFE Foundation enjoys the tremendous benefit of customized flight test weather
forecasts from expert meteorologist Jim Mathews at the National Weather Service in
Sacramento. Jim is capable of using NWS modeling, balloon soundings, Doppler Radar and
Satellite photos to predict when the most favorable atmospheric conditions will prevail
over the CAFE's headquarters in Santa Rosa. His help has thus far been right on target and
this has provided for much higher quality flight test data.
The CAFE scales are being re-calibrated with special 1,000 lb. test weights that will be
certified by the California State Department of Weights and Measures. An upgrade to the
scales circuitry and programming will then be made to further improve their renowned
accuracy. Conveniently located flush in the test hangar's concrete floor, these scales
have been the basis for much of the aerodynamic insights recently obtained. Otis Holt is
fabricating special high-strength dollys to allow moving the test weights onto the scales
to confirm accuracy at any time.
CAFE Board member Crandon Elmer, an expert in scales and applied load cell technology, has
been transferred from his job in Santa Rosa to a new position at Weightronix in Fairmont,
MN. The CAFE team wishes him the very best at his new job there and hopes that all the
EAAers in Fairmont will give him a warm welcome.
(CAFE - Comparative Aircraft Flight Efficiency, Inc., is a non-profit, all volunteer,
tax-exempt educational foundation sponsored and funded by the EAA. CAFE headquarters is
located at 4370 Raymonde Way, Santa Rosa, CA 95404, 707/526-3925, 707/545-CAFE
(hangar/weekends), FAX 707/544-2734.)
