Sunday, December 13, 2009

And Now Back to Our Regularly Scheduled Programming

Whatever that was.

I felt a lot like my boat lately when they opened me up and took various bits out of my back, then sewed me up again, all in the name of better performance. On the whole I am improved, but hoping not to repeat the experience any time soon. The boat won't escape a second trip to the operating room, I'm afraid. But that's progress.

The local fleet is going strong, thanks to strong commitment and efforts on the Chinchillazilla and Black Pearl sides of the fleet. They were in Dago over the weekend so one hopes we will see some photos of the action. It rained cats and dogs in LA on Saturday but apparently things were not as hopeless further south.

Lately mothing has been confined to messing with spreadsheets, which are lots of fun actually. I have been trying to figure out how much vertical immersion one typically sails with upwind and down; from Bora's vids on U-tube it looks like 10-12 upwind and I would expect less offwind in flatter conditions - perhaps eight inches?

I plug these various scenarios into the spreadsheet and convert them into torque, in hopes of me, the boat and the planet all staying attached to one another no matter the sea state. I imagine it is sort of like designing a building to cope with wavelike fluctuations in the strength and direction of gravity, only in this case the building has to jump up and down in time to a conductor's wand.

When I was a kid in South Dakota, Ronald Regan funded these ridiculously cool supersonic nuclear-capable bombers called B-1s. Their main mission was to sneak in below Russian radar and annihilate everyone with cruise missiles loaded onto a carousel rather like a thermonuclear gatling gun in the bomb bay. In order to do this the plane was given seriously capable radar-controlled autopilots, allowing it to fly near supersonic at altitudes of about 300 feet. One of the best places to test this capability is over Eastern Montana, which is fairly close to my home town of Rapid City, SD. But then everything is pretty close when you are flying an air-refueling-capable supersonic bomber, and in fact pilots would not infrequently tell tales of flying to England for lunch and being home for dinner. But I digress.

The radar seemed to work well enough, but as in foiling, the margin for error is pretty slim when flying near an interface with another form of matter: birds, the airborne equivalent of the plastic bag, occasionally blasted through the wing leading edges and severed all hydraulic lines, and crews occasionally appeared to stuff the avionic equivalent of the foiling gybe, crashing into the ground out in the middle of nowhere for no apparent reason. But then typically none of them ever survived to tell their sides of the story.

I don't know what all this proves except to say that Moths are hardly the first craft to have problems flying at extremely low altitudes. The prototype B-1A had so much airframe flex from the rapid pitch adjustments during low level flight that they had to add little canards to the front of the aircraft to avoid making the pilots throw up. The canards are actuated by little accelerometers that kick in to limit the vibration of the airframe whenever it jiggles too much. This is of course the origin of the term "getting jiggy with it".

On a personal note, I like the B-1 for its all-moving tailplanes, which remind me of my mainfoil, except that the two sides can move independently of one another to induce roll (!). Pretty sure I am not ready for that feature.