Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.
51

It's an airspeed indicator for ultralights. The pitot inlet is at the bottom and the pitot air pushes a little red plastic disc up and down on a central rod, with a calibrated clearance between the edge of the disc and the walls of the tube. They are very sensitive and are good down to 10 MPH or less. You'll also see them on hang gliders. See here: ...


48

He's using the angle of his legs to control the attitude of the platform (and as a result, the direction he's flying in). So he can't take a relaxed pose, he's standing with his knees slightly bent the whole time.


46

When you fly gliders you discover it's quite common to run into air that's descending at 1-200 fpm, or "sink" in soaring-talk. Descending air next to a thermal, or air descending due to downsloping terrain. It's a lot more than that at times, but a couple hundred fpm is typical. On a day where there's any convection (with rising air, there is always ...


41

This is what he said after the 1st attempt "When you fly with your body, even your hands affect the direction you want to go in. You feel the turbulence and the air through your fingers," Zapata told CNN. "It's like becoming a bird. But it's also very hard. I have to fight against the wind with my legs so there's pain too. It's not as peaceful as it ...


27

Pretty simple, powered parachutes fall under the ultralight vehicle category, which is 14 CFR 103: 14 CFR 103.15 Operations over congested areas.: No person may operate an ultralight vehicle over any congested area of a city, town, or settlement, or over any open air assembly of persons. And Also: 14 CFR 103.17 Operations in certain airspace. No ...


24

There is another bit of information worth mentioning in the CNN link in CrossRoads' answer The flyboard looks like a chunky skateboard and is powered by five small engines. It is fueled by kerosene, which Zapata carried 104 pounds [47 kg] of in his backpack. I believe that carrying a 50 kg backpack and balancing on a jet powered air skateboard ...


22

It looks as if they rotate in opposite directions. This eliminates prop torque, which should improve handling, especially at low speeds. On the other hand, you are right with your impression that it adds complexity, but at least it is not completely useless. Asymmetric prop failure is indeed an issue and will markedly reduce handling qualities, and for ...


21

It works in a half-assed way but the key word is half-assed. You'll always be skidding around the sky since sideslip is required to obtain and maintain any rolling moment. Control response can be somewhat laggy, since you have to induce a skid and wait for the roll, depending on how much dihedral you have. So to have something approaching snappy control ...


21

I've examined a Lazair, and actually taxied one around on the ground once, and yes there are two throttles. Two reasons: In any twin engine airplane you want to minimize or eliminate single-points-of-failure (especially with engines as unreliable as little 2-stroke water pump motors) and this means you want the keep each power plant completely mechanically ...


20

FAA Advisory Circular AC 103-7, Paragraph 19 has this to say: MAXIMUM FUEL CAPACITY OF A POWERED ULTRALIGHT VEHICLE. The maximum fuel capacity for a powered ultralight vehicle is 5 U.S. gallons. Any powered ultralight with fuel tank(s) exceeding this capacity is ineligible for operation as an ultralight vehicle. a. Determination of ...


20

Keeping too much speed in an approach in any airplane can be risky depending on how much runway you have as it all has to bleed off before you can stop. It's a great way to end up in a hedge. Extra airspeed means you'll either float in ground effect for a very long time, or if you somehow manage to get the wheels down you won't get much braking action as the ...


17

It is essentially two propellers stack on top of each other. You can see it in this picture of a Lazair. As for why they were chosen for the Lazair, Many have asked why Ultraflight opted for double propellers stacked in a biplane fashion. This is a very unique setup and draws lots of attention. Apparently when Ultraflight changed over to the Rotax ...


16

This answer assumes that "GA" means "little piston planes." Aluminum (or non-fabric) aircraft tend to "hold up" better against the elements. I would not store a Stinson 108 outdoors but would not think twice about storing a 172 (or Cirrus) on an open air tiedown. The fabric covering requires a great deal of care compared to the metal (or composite) skin ...


15

This image would suggest it had two throttles, located in the usual position on the pilot's left side:


14

It's indeed an airspeed indicator. Here's one at Oshkosh 2018, with me blowing about 27 knots into it.


12

Ultimately the decision of whether or not a pregnant woman should be piloting an aircraft is between her and her doctor, and you shouldn't take the commentary of strangers on the internet as medical advice ("I am not a doctor, and even if I were I am not your doctor"). That said while I'm not sure what EASA has to say on the subject I know the FAA does ...


12

I could not find a definite definition of congested area. As mentioned here: [...] neither the FAA nor the NTSB has ever provided [...] a precise definition of [...] a "congested area." Rather, a "congested area" is determined on a case-by-case basis. According to the Board, "the determination must take into consideration all circumstances, not ...


12

Basically it allows the benefits of multiple propellers with a single engine. At low powers increasing the number of engines decreases power-to-mass ratio. Additionally, the builder might simply have had only one engine available or affordable. Removal of prop torque, as mentioned in the accepted answer, is a clear benefit. Probably relevant for this ...


12

The jury (i.e. FAA) is still out on this question as of early June 2014. FAA has indicated it will not give a gasoline "fuel allowance" to be credited against weight for batteries. Given that fuel weighs 6 lbs. per gallon, or 30 lbs. for the maximum legal gas an ultralight can carry, it would be a somewhat negligible, but certainly welcome, allowance for ...


12

Yes, under FAA regulations, ultralight vehicles are considered to be aircraft. 14 CFR 1.1 states: Aircraft means a device that is used or intended to be used for flight in the air. Ultralights are used or intended to be used for flight in the air, so they are aircraft. 14 CFR Part 103 defines the term "ultralight vehicle" and describes the rules for ...


12

I don't see an ASI in the panel. I am unable to confirm this guess, but it could be an airspeed indicator (ASI). Google Dwyer Wind Speed Indicator. The Dwyer is plastic, wider at the bottom, and works by having the wind push a ball up a tube that gets progressively wider near the top. As the airflow pushes the ball up, more air can leak around the ball. ...


12

The bungee is just a bidirectional spring that tends to hold the elevator at position x, and if you move the stick you are stretching the spring in one direction or the other. They are used in the elevator control circuit to provide an adjustable centering force for trim purposes, and on gliders with all flying tails, a measure of stick free static ...


11

Those are wing fences and they prevent airflow perpendicular to the direction of travel. This isolates the portions of the wing and allows the inner wing to stall independently of the outer wing. Since the wing uses flaps, the inner portion will create more lift and stall (separation of airflow on the upper wing leading to loss of lift) at a lower angle of ...


11

You can, in theory, fly a faster landing speed than the default Vref of 1.3*Vso. But it’s wasteful in the round out and potentially very dangerous on short field landings. When an airplane lands, the pilots needs to enter the round out with only enough energy to arrest the descent and establish the airplane in the correct attitude for touchdown approx 1-2 ...


10

NOTE: This answer was originally given based on a conservative interpretation of available interpretations of the regulations. New guidance may shed new light on the issue. The interpretation presented here may be superseded; see the discussion and other answers. Short Answer within the lateral boundaries of the surface area of Class E airspace ...


10

Most aeroplanes are designed with the Centre of Gravity being ahead of Centre of Lift, so when the aeroplane's wing cannot produce sufficient lift anymore -- due to a high Angle of Attack, the nose will drop, therefore, it will decrease the AoA and as the gravity pulls the aeroplane towards earth, the speed will increase which in combination with the lower ...


9

This should be understood as a supplement to @acpilot's excellent answer. All his points are valid and correct, and I just want to add a few more. Fabric covering is easy to build and hard to maintain. In the early days, when engines were heavy and less powerful, a wooden airframe with fabric covering was the fastest, lightest and easiest way to get ...


9

A simplified analysis of column buckling shows that the axial load required for buckling is directly proportional to the second moment of area of the column's cross section: $F=\pi^2EI/(KL)^2`$`, where F is the buckling load, E is the elastic modulus of the material, I is the second moment of area, and KL is an effective column length based on the geometric ...


8

what causes a weight-controlled microlight to tumble There seem to be several mechanisms. One is an excessively sharp nose-down control input after entering or approaching a stall. and is it possible to stop it from tumbling once it starts? Not without an external safety device (presumably a throwable parachute or something similar) The tumble mode ...


8

It means you have to stay outside the cloud while flying. You're expected to use your own good judgment (remember it is illegal to fly into the cloud, and if you don't have proper instruments and know what you're doing, it's downright deadly) but there is no minimum clearance as there is at other times, so if you really felt like a daredevil you could reach ...


Only top voted, non community-wiki answers of a minimum length are eligible