P-47

2 Articles

Bogey Six O’clock!: The AN/APS-13 Tail Warning Radar

October 31, 2024 by 20 Comments

Although we think of air-to-air radar as a relatively modern invention, it first made its appearance in WWII. Some late war fighters featured the AN/APS-13 Tail Warning Radar to alert the pilot when an enemy fighter was on his tail. In [WWII US Bombers]’ fascinating video we get a deep dive into this fascinating piece of tech that likely saved many allied pilots’ lives.

Fitted to aircraft like the P-51 Mustang and P-47 Thunderbolt, the AN/APS-13 warns the pilot with a light or bell if the aircraft comes within 800 yards from his rear. The system consisted of a 3-element Yagi antenna on the vertical stabilizer, a 410 Mhz transceiver in the fuselage, and a simple control panel with a warning light and bell in the cockpit.

In a dogfight, this allows the pilot to focus on what’s in front of him, as well as helping him determine if he has gotten rid of a pursuer. Since it could not identify the source of the reflection, it would also trigger on friendly aircraft, jettisoned wing tanks, passing flak, and the ground. This last part ended up being useful for safely descending through low-altitude clouds.

This little side effect turned out to have very significant consequences. The nuclear bombs used on Hiroshima and Nagasaki each carried four radar altimeters derived from the AN/APS-13 system.

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Retrotechtacular: Field Assembling Airplanes Like Wartime “Ikea”

December 21, 2017 by 29 Comments

Imagine it’s 1943, and you have to transport 1,000 P-47 fighter planes from your factory in the United States to the front lines in Europe, roughly 5,000 miles over the open ocean. Flying them isn’t an option, the P-47 has a maximum range of only 1,800 miles, and the technology for air-to-air refueling of fighter planes is still a few years off. The Essex class aircraft carriers in use at this time could carry P-47s in a pinch, but the plane isn’t designed for carrier use and realistically you wouldn’t be able to fit many on anyway. So what does that leave?

It turns out, the easiest way is to simply ship them as freight. But you can’t exactly wrap a fighter plane up in brown paper and stick a stamp on it; the planes would need to be specially prepared and packed for their journey across the Atlantic. To get the P-47 inside of a reasonably shaped shipping crate, the wings, propeller, and tail had to come off and be put into a separate crate. But as any reader of Hackaday knows, getting something apart is rarely the problem, it’s getting the thing back together that’s usually the tricky part.

So begins the 1943 film “Uncrating and Assembly of the P-47 Thunderbolt Airplane“ which has been digitally restored and uploaded to YouTube by [Zeno’s Warbirds]. In this fascinating 40 minute video produced by the “Army Air Forces School of Applied Tactics”, the viewer is shown how the two crates containing the P-47 are to be unpacked and assembled into a ready-to-fly airplane with nothing more than manpower and standard mechanic’s tools. No cranes, no welders, not even a hanger: just a well-designed aircraft and wartime ingenuity.

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