 Here is an ingenious method for mechanically
generating properly proportioned ribs for wings that are not rectangular - including
sing and double straight tapers and even elliptical planforms. Of course today you
can print out a perfectly dimensioned set of ribs to accommodate any planform and
root-to-tip thickness taper profile. In 1960 when this "'Simplex'
Airfoil Templates" article appeared in the 1960 Annual issue of Air Trails
magazine, such conveniences were in the purview of universities and government research
facilities. Even if you have no need of cutting ribs for tapered wings, it is worth
your time to read this brief article about the mathematical principle - logarithmic
(aka equiangular) spirals - behind the scheme. There are no formulas, so don't be
scared off ;-)
 "A second
B−21 bomber is now under construction at Northrop Grumman's facility in Palmdale,
California. The B−21 is expected to make its inaugural flight next year. Randall
Walden, director of the Air Force Rapid Capabilities Office, told Air Force Magazine
that while the fifth-generation stealth aircraft hasn't yet reached final assembly,
it is 'really starting to look like a bomber.' B−21 Number Two has a slightly different
purpose than the first. 'The second one is really more about structures, and the
overall structural capability,' Walden explained. 'We'll go in and bend it, we'll
test it to its limits, make sure that the design and the manufacturing and the production
line make sense.' Capable of carrying both conventional and nuclear weapons, the
Air Force expects the B-21 to enter service in 2026 or 2027. The Congressional Budget
Office estimates the cost of developing and buying the first 100 aircraft to be
$80 billion..."
 As
mentioned in an earlier post, a while back I bought a box full of vintage Old
Farmer's Almanacs (OFA) at a yard sale, figuring there would be a bunch of
good items to post here on RF Cafe and on my
Airplanes and Rockets
hobby website. Chief amongst the postworthy features is the Mathematical Puzzles
section. They are a fair challenge to an engineer's cerebration, contemplation,
and deliberation. These particular mathematical posers appeared in the 1974 issue
of OFA. #10, while rated a difficulty of 4 (where 5 is most difficult),
is really not even a mathematical challenge when you think about it (hint - it's
an old riddle you've probably seen before). Enjoy!
 The
Peppy Trainer
control line (C/L, or U−C) model airplane was designer with multiple factors in
mind - low cost, easy construction, easy to fly, ability to perform basic stunts,
light weight, and ruggedness for withstanding beginner's mistakes. Lower cost was
achieved by specifying only easily obtained, standard components - like using sheet
balsa parts for the wing leading and trailing edges rather than pre-formed types.
Its built-up 28" wingspan, flat−bottom airfoil, with a solid balsa fuselage and
tail surfaces is pulled along by a .09 engine. Construction and rigging is kept
simple by not using wing flaps. The author also suggests 17 commercially available
C/L trainer kits that are roughly the equivalent of the Peppy Trainer...
 "It's almost the end of the line for one
of the most famous names in business aviation, or in aerospace altogether, with
the news that manufacturer Bombardier is bringing production of the
Learjet to an end this year. It's a blow for the company's 1,500-strong Wichita-based
workforce, which will be cut back as a result, and it also brings the curtain down
on what's perhaps the world's most familiar bizjet. 'With more than 3,000 aircraft
delivered since its entry into service in 1963, the iconic Learjet aircraft has
had a remarkable and lasting impact on business aviation,' said Éric Martel, Bombardier's
president and chief executive officer, in a statement today. 'However, given the
increasingly challenging market dynamics, we have made this difficult decision to
end Learjet production..."
 1976
is the year I was emancipated (aka graduated) from high school, and this issue of
The Old Farmer's Almanac (OFA) happens to be from that year. For as long as I can
remember, the OFA has included a set of Mathematical Puzzles in its annual publication. They range in
difficulty from 1 (very easy) to 5 (sometimes quite difficult). Having been a faithful
buyer and reader of the OFA for as long as I can remember, I have spent many hours
toiling with some of the more challenging examples. In fact, there were a lot which
I never did figure out and needed to look up the answers in the back (come to think
of it, I experienced the same dilemma with my college engineering textbooks). Because
quite a few of the Mathematical Puzzles are worthy of an engineer's cerebration,
contemplation, and deliberation, all I have will be eventually posted here on RF
Cafe. Enjoy!
 This is the February 8, 1942, "Flyin'
Jenny" comic strip. The Baltimore Sun newspaper, published not far from where
I grew up near Annapolis, Maryland, carried "Flyin' Jenny" from the late 1930s until
the strip ended in the mid 1940s, so I saved a couple dozen from there. The first
one I downloaded has a publication date of December 7, 1941 - that date "which will
live in infamy," per President Roosevelt. Many Americans were receiving word over
the radio of the Japanese attack on Pearl Harbor while reading this comic at the
breakfast table. I expect that soon there will be World War II themes. "Flyin'
Jenny," whose real name was Virginia Dare (what's in a name?), was a test pilot
for Starcraft Aviation Factory who divided her time between wringing out new airplane
designs and chasing bad guys. She was the creation of artist and storyteller Russell
Keaton...
 "Joby Aviation has selected the Garmin G3000
integrated flight deck - which first debuted in 2009 - for its
eVTOL aircraft, bringing proven avionics into the program to develop commercial
operations - which it expects to launch by 2024. The G3000 avionics suite was selected
in part for its lightweight, adaptable architecture and high-resolution displays.
Garmin anticipates future development in the urban air mobility space, and the Joby
platform will allow the company to proceed with further work in creating communications,
navigation, and flight sensor solutions as UAM progresses into more advanced phases..."
 These are some really great action photos
from the
23rd Annual National Modelplane Championships held in Chicago. Considering it
was from a time when auto-focus, auto-exposure, auto-f-stop, auto-shutter-speed,
and other modern features were not available on cameras, photographer John W.
Schneider did an incredible job of obtaining shots with one one chance of getting
each instance. The F4U Corsair take-off is a prime example. Most events were held
at Chicago's Glenview Naval Air Station, compliments of the U.S. Navy. Some
free flight events were held at the Chicagoland Airport, while indoor flying took
place in Chicago's 132nd Infantry Armory. The quality of construction and finishing
is apparent, even in the grainy, black and white photos. Coverage of the event appeared
in the November 1954 issue of Air Trails magazine. Do you recognize any of the names
and/or faces here?
 "It's developing what it calls its Cassio
series of hybrid-powered four- to 10-seat aircraft, two of which are aimed at the
air taxi, charter, and utility markets.
Hybrid power systems make sense because they use both batteries and gasoline-burning
internal combustion engines (ICEs). This can provide benefits beyond system redundancy
and higher power ratings. Battery and ICE power can be teamed up for takeoffs, or
for high-speed cruising. When low-noise takeoffs and landings are priorities, battery
power alone can drive any electric motors. And after an electric-only takeoff, ICEs
can be fired up to both recharge batteries and boost en route speed and range. VoltAero's
concepts use sleek fuselages, forward canards, straight wings, and twin-boom tails
supporting wide-span horizontal stabilizers..."
 Flying in a contest with 35 mile per hour
winds is hard to imagine, but that was the case at the 1954 Nats FAI Free Flight
semi-finals. Fortunately, on the day of the actual event the winds had calmed down.
I would never consider flying even an radio-controlled model airplane in 35 mph
winds, much less a free flight. Howard Timlin was the designer, builder, and flyer
of this beautiful "Saturn,"
which appeared in the November 1954 issue of Air Trails magazine. It sports a wingspan
of about 60 inches with a Goldberg G-10 undercambered airfoil (same as the Carl
Goldberg Viking free flight model). Although not specified, I assume this is a Class
A model since the F1C class allows up to 0.15 cubic inches (2.5 cc). Howard
had another successful contest design - the 50" wingspan ½A "Solar"...
 Most
people familiar with the history of
radio control (R/C) airplanes credit twin brothers Walt and Bill Good for the
first truly successful R/C airplane, which they dubbed "Big Guff," in 1938. Interestingly,
this YouTube interview with the Good brothers mentions, as does Mr. Isberg
in his 1939 article in Radio News magazine article, the first sanctioned R/C contest
where the Good's model was the only one to fly. Ross Hull and Clinton DeSoto were
two other prominent early R/C'ers. Transmitter operators were licensed Hams who
designed and built their own equipment at 56 MHz, unlike modern turn-key R/C
systems operating in unlicensed ISM bands. Vacuum tubes were used in the transmitter
and the airborne receiver. Lead-acid batteries often provided power for the receiver
and control surface actuators (pseudo-servos) in the airplane, which unfortunately
would burst during a crash...
 "Astronomers have confirmed that a small
object temporarily captured by Earth's orbit is the
Centaur upper-stage rocket booster that helped lift NASA's ill-fated Surveyor
2 spacecraft toward the moon in 1966. The object, designated 2020 SO, was initially
detected by the Panoramic Survey Telescope And Rapid Response System, which monitors
near-Earth objects such as asteroids that might pose a threat to Earth. Upon closer
examination, scientists at the Center for Near-Earth Object Studies (CNEOS) realized
that this was no ordinary asteroid. Typically, the orbit of an asteroid is more
elongated and tilted relative to Earth's orbit. However, before 2020 SO was captured
by this planet's gravity, it was orbiting around the sun in a near circle and in
an orbital plane that almost matched Earth's. Adding to the mystery..."
 When this article appeared in a 1949 issue
of Air Trails magazine, the
Jetex engine
line was relatively new to America. It had just been introduced in England in 1947
by Wilmot, Mansour & Company Ltd., of Southampton, consisting of Wilmot brothers,
Charles Mandeville Wilmot, John Wilmot, and Joseph Naimé Mansour. In 1950, American
Telasco became the U.S. importer and distributor of the Jetex line of motors, fuel,
and model airplane kits. Henry Struck's "Jetex Job" uses the Jetex 100 engine,
which was bigger and more powerful than the Jetex 50 model. Tailless airplanes
were popular because the lack of a vertical fin minimized the influence of wind
on flight since weathervaning was less pronounced. Jetex Job is a fairly large model
with a 21" wingspan, but you can see how lightweight the construction is. The fuselage
uses a formed 1/16" balsa tube in the rear engine...
 How
come nobody told me about this? With all the articles I've read about the Perseverance
rover recently landed on Mars, none come to mind which mentioned a
message
on the underside of the parachute used to lower the atmospheric entry spacecraft
and its load to the point where retrorockets took over just above the surface. It
only took a moment to figure it all out - much simpler than Carl Sagan's team's
cryptic message on the Pioneer 10
and 11 interplanetary explorer, but a bit more tricky than "We come in peace for
all mankind" on Apollo 11's
Eagle lunar module. Très cool, IMHO.
 "The Perseverance
rover's
Mars Helicopter (Ingenuity) will take off, navigate, and land on Mars without
human intervention. Tucked under the belly of the Perseverance rover that will be
landing on Mars in just a few days is a little helicopter called Ingenuity. Its
body is the size of a box of tissues, slung underneath a pair of 1.2m carbon fiber
rotors on top of four spindly legs. It weighs just 1.8kg, but the importance of
its mission is massive. If everything goes according to plan, Ingenuity will become
the first aircraft to fly on Mars. In order for this to work, Ingenuity has to survive
frigid temperatures, manage merciless power constraints, and attempt a series of
90 second flights while separated from Earth by 10 light minutes. Which means that
real-time communication..."
|
-
