I have been watching the Band of Brothers on the History Channel which chronicles some US paratroops from the D-Day invasion through the end of the war in Europe. I have some questions:
Why did the planes fly so low? It seems this made them easier targets for anti aircraft guns? Were military planners taking a gamble on planes hit in order to get more troops to the proper drop zones/greater accuracy of deployment? Was the idea to not have the troops in the air as targets too long? In retrospect, it seems like it would have made more sense to jump from an altitude beyond AA range.
How do flak cannons work? How do the gunners know how high the planes are, and how do they adjust the flak explosions if the planes increase altitude?
Why did the troops jump with so much gear? Obviously, they needed it, but couldn’t they have dropped the gear as cargo with a separate chute? Based on the weight of hte gear - 80 - 100lbs, I would expect many men were injured from the jump alone, and this was exacerbated by the high speed and low altitude of the planes.
Just the opposite. A low flying aircraft crosses the visual field of an AA gunner much faster, decreasing time for targetting and increasing the movement necessary to track it, resulting in less accuracy. The only downsize is a slightly larger target, but the cumulative benefits of low flight make it safer.
Just a tactical preference on the part of the U.S. Army for ensuring that its paratroopers had their heavy gear with them when they hit the ground. German paratroops dropped their heavy weapons in separate containers, which I imagine could be awkward in the case of a widely scattered drop.
The planes couldn’t really fly higher than the AA and still see where they were going, and if they dropped the troops from too high they’d land really spread out.
WWII-era AAA shells had a simple time fuse, so they detonated a certain time/distance after firing; the gun captains pretty much guessed the altitude (I’m sure they had the usual altitudes for bombers, cargo planes, etc. written down somewhere) and tried it, and set the next batch higher or lower, depending on results. It helps to have a lot of guns and cover a range of altitudes.
If they dropped their gear seperately, it’d be too easy to get seperated from it. Most of the gear goes in a bag on a rope that you drop when you’re about halfway down, and it dangles ten feet below you on its rope; that way, it hits the ground first, so you’re not landing with 100 pounds extra on your knees. The planes were flying pretty slow, and the altitude doesn’t matter (as long as it’s above a couple hundred feet) – once the chute opens, you fall at the same speed no matter how high you started. The parachute is opened automatically by a line attached to the plane. If you land right, you won’t get hurt. If you land wrong, you can break an ankle, but they wear tall, stiff boots to help prevent that sort of thing.
Low flying is needed to avoid scattering the troopers. And it is a tradeoff. If you drop from high altitude the troopers are exposed to ground fire longer and the enemy has more time to prepare to greet them as they land.
Anti aircraft gunners in WWII had either optical or radar range finders. The shells have fuzes that are set to explode at a certain time after firing. WWII troop carrier aircraft could not change altitude very quickly. A reasonable rate of climb for a formation of C-47’s or C-46’s would be about 500 ft./min.
They didn’t jump with any more that was thought necessary. They carried small arms and ammunition. You can’t count on the equipment and the troopers being in the same place on landing if they are dropped separately. If you haven’t reat The Longest Day by Cornelius Ryan do so (don’t go by the movie of the same name). Ryan gives a good account of just how scattered out the 82nd and 101st Airborne troopers were.
The Normandy drops were in the dark. A lot of heavy equipment was dropped separately and was never recovered. Quite a bit of the heavy stuff was landed in gliders and much of it was also never used because it wasn’t found in time.
C. Ryan’s book “The Longest Day” gives several incidents of planes deliberately flying so low to avoid AA that the jumpers’ chutes didn’t have time to fully open- with ensuing deadly effects.
Flying as low as possible without hitting hills has been a useful strategy for a long time. It is still in use with modern stealth craft which use computerized systems to guide the craft thru notches in ridges and such. But they don’t carry paratroopers.