How long does it take to fall from the sky?

As a retired Naval Aviator, we were required to don oxygen masks at or above 10000 feet. Not that we could not survive higher but the flight physiologists determined that some cognitive impairment could begin at the atm pressures of 10000 ft.

Flying with hypoxia (oxygen starvation) is like driving DUI. It's a cheap drunk and no hang over after. Wouldn't do to have "drunk" pilots. So we put on the oxygen masks at 10K ft.

Pressurized cabins, like on commercial aircraft, are set to roughly 8000 ft above sea level. Which is why we don't wear O2 masks when flying much higher.

If a hapless pilot bailed out at 10K ft only to find he'd forgotten to strap on his chute, his fall would look like this:

SUMMARY OF RESULTS

Object mass (M) = 100.0000 kg or a nominal 220.462 lbs

Coefficient of drag (Cd) = 0.700

X-section area (A) = 0.800000 meters^2

Starting altitude H = 10,000.00 feet or 3,048.00 meters

Starting speed U = 0.00 mps

Impact or Terminal V = 120.30 mph or 53.78 mps

Time to impact T = 55.599 seconds or 0.927 minutes <NOTE the time to fall from 10000 ft through air.

Maximum V = 138.92 mph at 7,851.00 feet

Altitude lost to reach Max V = 2149.00 feet or 655.02 meters

Impact Forces*

dS cushion interval = 3.0000 meters or 300.00 centimeters

dT cushion time = 0.1116 Seconds

Impact force (w/o weight) = 48,200.790 Newtons or 10,835.97 lbs

Impact force (w/o weight) = 5.418 Tons or 10,835.971 lbs

Gs = 4915.113 or 48,200.790 m/s^2

Impact force (with weight) = 49,181.455 Newtons or 11,056.43 lbs

Impact force (with weight) = 5.528 Tons or 11,056.434 lbs

Gs = 5015.113 or 49,181.455 m/s^2

*NOTE: Impact forces are highly dependent on the impacted material (e.g., soft vs hard) [Proprietary computer program.]