https://www.npr.org/sections/health-...here-s-a-catch

Research published in a major medical journal concludes that a parachute is no more effective than an empty backpack at protecting you from harm if you have to jump from an aircraft.

But before you leap to any rash conclusions, you had better hear the whole story.

The gold standard for medical research is a study that randomly assigns volunteers to try an intervention or to go without one and be part of a control group.
Now if you haven't read the rest of the story, please don't jump on Bo.

They started by talking to their seatmates on airliners.

"We'd strike up a conversation and say, 'Would you be willing to be randomized in a study where you had a 50 percent chance of jumping out of this airplane with — versus without — a parachute?' " Yeh says.

Only a few people said yes to this outrageous invitation, and they were excluded for reasons of questionable mental health.

The scientists had much better success asking members of their own research teams from Harvard, University of California, Los Angeles (Where Yeh's brother is a surgery professor), and University of Michigan (where a buddy works) about volunteering to participate in the experiment on other aircraft.

In all, 23 people agreed to be randomly given either a backpack or a parachute and then to jump from a biplane on Martha's Vineyard in Massachusetts or from a helicopter in Michigan.
23 would do the test.

Relying on two locations and only two kinds of aircraft gave the researchers quite a skewed sample. But this sort of problem crops up frequently in studies, which was part of the point Yeh and his team were trying to make.

Still, photos taken during the experiment show the volunteers were only too happy to take part. "I think people are laughing all of the way to the ground," Yeh says.
The missing item:
Oh, there's one important detail here. The drop in the study was about 2 feet total, because the biplane and helicopter were parked.
This explains it all;....Nobody suffered any injuries. Surprise, surprise. So it's technically true that parachutes offered no better protection for these jumpers than the backpacks.


So quit jumping to conclusions.