Question: How old is the block of special use airspace in downtown Washington DC which is known affectionately as P-56?
- Ancient. It was established by Congress on December 18, 1903.
- Nah, not THAT old. But it IS old. It’s been around since just after World War I, though it has changed shape somewhat. It used to cover just from the White House to the Capitol building, and also included the US Naval Hospital (before it was moved to Bethesda MD).
- C’mon! It’s STILL not THAT old! P-56 (A) was initially set up under an Executive Order in June of 1938. P-56B (the Naval Observatory and the Vice President’s residence) was established in May of 1950.
- It was initially established in January of 1959.
The correct choice would be #3. (That’s my final answer.) View the evolution of the Prohibited area around the “White House”.
Subject: On autorotation in a Robinson R-22:
Question: How long do you have to enter autorotation after an engine failure in an R-22?
- a little over one second, or you’re history
- just under four seconds at minimum power speed of 60 knots
- six seconds at 60 knots, eight at 85 knots
- Hey, no sweat! There’s a HUGE moment of inertia swinging around up there at a few hundred miles an hour, and you have about 10 seconds while you slowly and gently sink back to earth.
The answer is #1: Jack be nimble, Jack be quick, or Jack be day-ed. Robinsons are great, the engines are de-rated and almost never fail, but you can get carb ice… And unfortunately, they’ve got very LOW rotor inertia. Once you get below 70 to 80% rpm (altitude-dependent), it’s over. And the rate of decay below that is much more rapid.
Subject: Inorganic chemistry; (and why not?) Lithium: No, not my medication, but the fact that it’s the lightest metal.
Question: Lithium is the lightest metal — much lighter even than magnesium. It’s extremely light (though not quite buoyant), with an atomic number of just THREE — the next lightest element being helium! So why don’t they make aircraft parts out of it?
- It isn’t strong enough. With the tensile strength approaching halvah, or maybe torrone, anything made of it would collapse on itself under its own weight.
- It’s too expensive. Aside from being the lightest solid element (and paradoxically having the highest specific heat of any solid), it’s just too dear even to make airplanes out of (though it IS alloyed with other metals).
- Being an alkalai metal, it’s extremely reactive–like, with water. As soon as you flew into rain, your entire airplane would explode.
- all three
The answer is (mostly) #1 and #2. Sodium is the alkalai metal that ‘burns’ in water.