[Glen Akins] had a WW2-era aircraft engine cowl flap indicator lying around (as you do) and thought it would make a jolly fine USB-attached indicator. The model in question is a General Electric model 8DJ4PBV DC Selsyn, which was intended for four-engined aircraft. For those not familiar with the purpose [Glen] explains in his detailed writeup, that piston-engine aircraft of that era were air-cooled, and during conditions of maximum engine power — such as during take-off — flaps on the side of the engine cowling could be opened to admit additional cooling airflow. These indicator dials were connected to a sender unit on each of the flap actuators, providing the pilots an indication of the flaps’ positions. Continue reading “Interfacing An Old Engine Cowl Flaps Indicator To USB”
Rubber Band Behemoth Winds Its Way Toward World Record
Egged on by adoring fans who demanded more aircraft videos, [ProjectAir] has decided to break the world record for rubber band powered aircraft… despite having never built a rubber band powered aircraft. Why rubber band power?
Before little two stroke motors became affordable, and long before electric motors and batteries were remotely possible, there weren’t a lot of options for powering your model aircraft. One technology that really took off was that of rubber band power. By winding a rubber band, it could store enough energy to turn a propeller for a short duration. With a 10 foot model taking the current world record, as you can see in the video below the break [ProjectAir] decided to see if he could beat it.
Starting with a successful free flight aircraft made of foam board, [ProjectAir] simply scaled it up to an eleven foot wing- one foot larger than the ten foot world record holder. Since there were now eight rubber band motors, a mechanism was created to release the propellers in sync, but this was problematic. Eventually a slightly heavy but solid solution was found.
[ProjectAir] did more testing, more problem solving, and through rapid iterations, he eventually was able to have a successful flight under radio control. His personal goal of a 12 second flight was exceeded, and then Guinness called! They’re interested in certifying his attempt as long as his plane can fly for at least 30 seconds- almost double his current ability. What will he do? Check the video, too, for [ProjectAir]’s challenge to the community to join him in trying to beat the world record. Sounds like fun!
Aside from powering world record attempting radio controlled aircraft, did you know that you can build a rubber band powered refrigerator? It’s true!
Continue reading “Rubber Band Behemoth Winds Its Way Toward World Record”
Ugliest Airplane Ever Built Predicted The Future
The airplane that many called “the flying barrel” is also widely considered the ugliest plane ever built. However, [Dark Skies] in the video you can see below argues that the Stipa-Caproni was the direct predecessor of the turbofan engine. Either way, it is an interesting and unique part of aviation history.
The plane was built in the days when inventors were experimenting with many different ways to improve aircraft utility and performance. In this case, the inventor built an “intubated propellor” which used a prop to draw air through a venturi tube in an effort to improve engine efficiency. The 570kg vehicle had a wingspan of just over 14 meters and was a bit more than 6 meters long. It could reach about 72 knots and climb to over 3 km.
Continue reading “Ugliest Airplane Ever Built Predicted The Future”
Is There A Simpler Aircraft Than This Electric Paramotor?
The dream of taking to the air has probably ensnared more than a few of us, but for most it remains elusive as the safety, regulatory, and training frameworks surrounding powered flight make it not an endeavour for the faint-hearted. [Justine Haupt] has probably delivered the simplest possible powered aircraft with her Blimp Drive, a twin-prop electric add-on for her paragliding rig that allows her to self-launch, and to sustain her flights while soaring.
It takes the form of a carbon-fibre tube with large drone motors and props U-bolted to each end, and a set of brackets in the centre of laid carbon fibre over 3D-printed forms to which the battery and paraglider harness are attached. The whole thing is lightweight and quiet, and because of the two contra-rotating propellers it also doesn’t possess the torque issues that would affect a single propeller craft.
We’re not fliers or paragliders here at Hackaday, so our impression of the craft in use doesn’t come from the perspective of a pilot. But its simplicity and ease of getting into the air looks to be unmatched by anything else, and we have to admit a tinge of envy as in the video below the break she flies over the beach that’s her test site.
If you recognise Justine from past Hackaday articles, you’re on the right track. Probably most memorable is her rotary cellphone.
Continue reading “Is There A Simpler Aircraft Than This Electric Paramotor?”
New Engines Could Propel The B-52 Beyond Its 100th Birthday
First taking to the skies in April 1952, and introduced into the US Air Force in 1955, the B-52 Stratofortress has since become a mainstay of American air power. Originally developed as a nuclear bomber to carry out the critical deterrence role, changing realities saw it delivering solely conventional munitions in actual operations.
Of 744 B-52s originally built, 76 remain in service with the Air Force and Air Force Reserve. This fleet is set to go on flying beyond the type’s 100th birthday, into 2050 and beyond. To reach that milestone, a new engine package will be key to keeping these birds in the air.
Continue reading “New Engines Could Propel The B-52 Beyond Its 100th Birthday”
Quiet Wings, With Shape Memory Alloy
It’s a fact of operating an aircraft, that the make noise. If you’re an aviator you might want to quiet your craft to avoid annoying people nearby, or you might even want to operate in stealth mode. It turns out that there are different sources of noise on a plane depending upon the phase of flight. A NASA study found that when landing, a gap between the wing and leading edge slats causes air to cavitate causing unnecessary noise. Blocking that hole would allow for quieter landings, but there was no material suitable for both normal flight and the landing. That is, until Texas A&M researchers devised a way to use a shape memory alloy to do it.
In addition to two different shape memory alloy configurations, the study looks at a more conventional fiberglass composite, although this would only work for a limited number of wing configurations.
Aircraft Compass Teardown
We didn’t know what a C-2400 LP was before we saw [David’s] video below, but it turned out to be pretty interesting. The device is an aircraft compass and after replacing it, he decided to take it apart for us. Turns out, that like a nautical compass, these devices need adjustment for all the metal around them. But while a ship’s compass has huge steel balls for that purpose, the tiny and lightweight aviation compass has to be a bit more parsimonious.
The little device that stands in for a binnacle’s compensators — often called Kelvin’s balls — is almost like a mechanical watch. Tiny gears and ratchets, all in brass. Apparently, the device is pretty reliable since the date on this one is 1966.