http://www.spartacus.schoolnet.co.uk
http://www.azcentral.com/arizonarepublic/local/articles/0313clay0313.html
It's not easy to shoot from old biplanes
Mar. 13, 2006 12:00 AM
Today's question:
I was watching an old movie recently, and it had the old biplanes flying around, shooting their machine guns. I am wondering how they don't shoot off their propellers? My wife thinks I'm silly for worrying about this, but it's now driving me crazy since I can't figure it out.
I agree with your wife, but if it will give you some peace of mind, I'll answer the question anyway. advertisement
When airplanes were first used as weapons of destruction, the strategy was pretty simple. One guy flew the plane, and another guy shot at people with a handgun or a rifle or dropped grenades on them.
Finally, it occurred to somebody that this wasn't a very efficient plan, so they gave the second guy a machine gun and fixed him up in a safety strap so he could stand up and blaze away.
Later the French started experimenting with firing through the propeller. This didn't work very well until in 1915 when a French pilot named Roland Garros fixed his propeller with steel deflector plates to turn away the bullets that hit the blades.
This turned out to be a swell idea, and Garros shot down five German planes in two weeks.
Unfortunately for Garros, one day some guy on the ground took a potshot at him with a rifle and managed to cut his fuel line. Garros crash landed behind enemy lines and tried to burn his plane, but the Germans showed up and put out the fire and threw Garros in the clink.
Then they sent the plane to a Dutch designer named Anthony Fokker, who had an airplane factory in Germany. Fokker studied on the deflector plates and thought really hard and eventually came up with a plan for a single-seat fighter plane that synchronized the machine gun and the propeller blades.
I'm not sure I understand this very well, but what he did was invent an interrupter doohickey with a cam connected the engine crankshaft in line with each propeller blade. When the blade was in a position where it might get hit by bullets, the cam set off a pushrod which in turn set off a series of linkages that stopped the gun from firing.
You can look that up at www.spartacus.schoolnet.co.uk and see if you can understand it better than I can.
How do those microorganisms they find at vents on the ocean floor get any oxygen?
They don't. They breathe hydrogen sulfide, which doesn't sound like much fun to me, but there you have it.
Reach Thompson at clay .thompson@arizonarepublic .com or (602) 444-8612.