Interesting Facts: add them here

[matthew1]

The Tsar Bomba was detuned from 100MT to 50MT by project manager and physicist Andrei Sakharov himself in the weeks before its detonation* when he realized it would have spewed simply too much fallout into the atmosphere. In other words, the political downsides would have outweighed the gains from this Khrushchev muscle flex**.

It was a three-stage weapon, where the first stage (like all multi-stage weapons) was a traditional, friendly fission reaction, an "atom bomb". That detonation compresses the second stage: lithium gas (or whatever fusion reaction material you want, there are choices here). These multi-stage weapons cause atoms not to just split, but also to combine -- fusion. These are known as hydrogen bombs, or "the H-bomb". They far eclipse the power of the more simple Hiroshima-style single stage weapons, which are theoretically capped at about 500KT, or .5MT yield.

In the Tsar Bomba and some US weapons, the second stage in turn gets multiplied by the third stage. Theoretically it is possible to chain many more stages together, to end up with a 4-, 5- or 6+-stage weapon. However the utility of this design goes down as fast as the MT goes up. Quite simply, there is not enough atmosphere to make 50MT+ weapons useful because the fireball exceeds the thickness (10 miles) of the Earth's atmosphere, and any extra yield is mostly vented into space.

Some weapons designers have said it's possible to make a 1000MT weapon using many stages.

The Tsar Bomba was detected via earthquake monitor stations, and when the size was calculated and delivery method considered, it caused a great deal of alarm in D.C. A simulated airburst over the center of D.C. at 4k feet -- ideal detonation height for this size weapon -- would have caused a total of 3.5 million eventual deaths, estimated. In 1961 this was TWO PERCENT of the American population of 180 million.


*Still, he estimates it caused 500k cases of cancer, and it wasn't even close to a groundburst. Rather it was detonated at 15k feet, which kept the fallout to a minimum.
** It was bad enough to push both Khrushchev and Kennedy to sign the atmospheric test ban a year later.

[jblackburn]

I love WWII aircraft, so this was something I stumbled across recently.

War Emergency Power

WEP in WWII aircraft

Maximum normal power would be limited by a mechanical stop, for instance a wire across the throttle lever slot, but a more forceful push would break the wire allowing extra power. In normal service, the P-51H Mustang was rated at 1,380 hp, but WEP would deliver up to 2,218 hp. In the P-51D Mustang, the model most produced and used during WWII, the WEP increased the HP from 1490 to 1720. The Vought F4U Corsair, not originally equipped for WEP, later boasted a power increase of up to 410 hp (17%) when WEP was engaged. Several methods were used to boost engine power by manufacturers, including water injection and methanol-water injection. Some earlier engines simply allowed the throttle to open wider than normal, allowing more air to flow through the intake. All WEP methods result in greater-than-usual stresses on the engine, and correspond to a reduced engine lifetime. For some airplanes, such as the P-51D, use of WEP required that the engine be inspected for damage before returning to the air. 5 hours use of WEP on the P51D required a complete tear down inspection.
British and Commonwealth aircraft could increase power by increasing the supercharger boost pressure. This modification was common by the Summer of 1940, with the widespread availability of 100 octane fuel. Raising supercharger boost pressure from 6lb to 12lb increased the Merlin III engine rating to 1310hp, an increase of over 250hp. Pilots had to log the use of emergency boost and were advised not to use it for more than 5 minutes continuously.

The German MW50 system methanol-water injection system required additional piping, as well as a storage tank, increasing the aircraft's overall weight. Like other boost techniques, MW50 was restricted by capacity and engine temperatures and could only be used for a limited time. The GM 1 nitrous oxide injection system, also used by the Luftwaffe, provided extreme power benefits of 25 to 30 percent but required cooling on the ground and added significant weight. One of the few German aircraft that could be equipped with both systems, the late war Focke-Wulf Ta 152H high-altitude fighter, could attain a velocity of some 756 km/h (470 mph) with both systems used together, reportedly as Kurt Tank once did in using both boost systems simultaneously when he was flying a Junkers Jumo 213E-powered Ta 152H prototype fitted with both MW 50 and GM-1, to escape a flight of P-51D Mustangs in April 1945.

Modern times

Perhaps the most dramatic WEP feature was found in the MiG-21bis fighter jet. This late variant of the standard Soviet light fighter plane was built as a stopgap measure to counter the newer and more powerful American F-16 and F/A-18 fighters until the next-generation MiG-29 could be introduced to service.
The MiG-21bis received the upgraded Tumanski R-25 engine, which retained the standard 42 / 65 kN normal and forsazh power settings of earlier R-13 powerplants, but added a new super-afterburning system. Use of this "diamond regime" provided a massive 97.4 kN of thrust for no more than 3 minutes in actual wartime use. Use of this temporary power gave the MiG-21bis slightly better than 1:1 thrust-to-weight ratio and a climbing rate of 254 meters/second, equalling the F-16's nominal capabilities in close-quarters dogfight.
In air combat practice with the MiG-21bis, use of WEP thrust was limited to 1 minute, to spare on the engines' 800 flight hours lifetime, since every second of super-afterburner use counted as several minutes of regular power run due to extreme thermal stress. When WEP was on, the MiG-21bis's R-25 engine produced a huge 5 meter long blowtorch exhaust - the six or seven brightly glowing rhomboid "shock diamonds" visible inside the flames gave the emergency-power setting its "diamond regime" name.

I want something like this for passing

[Ben850]

I do production work for functions at the Yankee Air Museum here in Ypsilanti Michigan. You would probably love to visit this place.

This is where the B-24s were built. My father incidentally flew 52 missions in a B-24 in WWII. I will likely donate his bomber jacket and flight suit to the museum.

My Dads Bomber Squadron

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Flying Tigers were his escorts. Shoulder patch.

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Some audio and visuals for a NASA exhibit, and a Gala reception dinner celebrating the B-17.

A coworker flies large scale remote control planes as a hobby, (almost as expensive as Volvo as a hobby). He has a B-17 and a couple Mustangs among many others.

RC B-17

P-51 Mustang

[ThinAir]

The first food eaten by a U.S astronaut in outer space was applesauce.

[abscate]

Ben..I actually stumbled across an old Jumo 004 (?) jet engine in the basement of MIT

This was the first jet engine in the Me262 of course. I hope they didn't throw it away...

Thx for your family service. My Dad was fighting on the other side....ok, RAF actually. Later was Concorde chief engineer for structural dynamics.

Aerospace was always talk of the house growing up.

[matthew1]

Later was Concorde chief engineer for structural dynamics.

Coool. Please tell us some stories / experiences about him and his work.

[Ben850]

Paul Newman was a qualified pilot willing to serve in the U.S. Air Force, but was turned down due to color blindness.

[jimmy57]

I love radial engines for their weird science-ness. That is a P&W Wasp in the photo isn't it?

I think working on one of those would make any of long for the toughest DIY Volvo repair you've ever done.