BeechTalk - BT

Username Protected · **Posted:** 12 Jan 2015, 14:48

Any idea where the chute is living inside the SF50? Trying to figure how they store/launch it without getting in the engine's way.

Username Protected · **Posted:** 12 Jan 2015, 15:10

Username Protected wrote:

Any idea where the chute is living inside the SF50?

In the nose.

http://cirrusaircraft.com/static/img/vi ... safety.jpg

Mike C.

Username Protected · **Posted:** 12 Jan 2015, 15:57

Looking at those drawings, I wonder why the aircraft doesn't descend and impact in a nose-high attitude. I would think it would be a less violent impact that way, with more structure to crumple behind the cabin than below it.

Username Protected · **Posted:** 12 Jan 2015, 16:09

Username Protected wrote:

Looking at those drawings, I wonder why the aircraft doesn't descend and impact in a nose-high attitude. I would think it would be a less violent impact that way, with more structure to crumple behind the cabin than below it.

That's an interesting suggestion.

I bet it would cause violent whiplash either during initial chute deployment or at impact.

Seats and seat belts are made for forward or downward impacts, not from the rear. Even if nose high was better, you could be looking at creating all new seats standards to deal with it.

Mike C.

Username Protected · **Posted:** 12 Jan 2015, 16:10

Username Protected wrote:

Looking at those drawings, I wonder why the aircraft doesn't descend and impact in a nose-high attitude. I would think it would be a less violent impact that way, with more structure to crumple behind the cabin than below it.

Likely weight. The engine and tail are heavier and therefore if they hit first, you get a more gradual energy release for the remainder of the impact.

Think about paratroopers. They have the heavy sack hanging by a rope below the legs, the sack impacts, then chute has less weight to flight rapidly slowing the trooper down reducing the impact the paratrooper must disperse on landing.

Tim

Username Protected · **Posted:** 12 Jan 2015, 16:54

Username Protected wrote:

Think about paratroopers. They have the heavy sack hanging by a rope below the legs, the sack impacts, then chute has less weight to flight rapidly slowing the trooper down reducing the impact the paratrooper must disperse on landing.

Tim

Username Protected · **Posted:** 12 Jan 2015, 16:59

Username Protected wrote:

The key there is the rope. It ensures there are two separate impacts - the first doesn't affect the second - it's different with a rigid body.

Airplanes are designed to withstand much greater g-forces on the nose with a crumple zone that makes the body less rigid and more energy absorbent. The problem with landing on the nose is what happens next. It wouldn't be good if the airplane came to rest inverted. I've always thought that was reason why the Cirrus was suspended level from the parachute. Backs might be damaged, but egress will be easier, and the descent less frightening.

Ashley

It still applies, it spreads out the energy. That is the goal.
The SR series lands left wheel first. If you ever do martial arts and do a fall where you stick out your arm and slap the ground. You dramatically reduce the impact on the remainder of the body.

Tim

Username Protected · **Posted:** 12 Jan 2015, 17:21

My point was that, with a rigid body, the energy is not spread out like it will be for a parachutist with a load hanging beneath. It's interesting to learn that one wheel is designed to touch first. There is a lot of flexibility in landing gear which will absorb energy and spread the deceleration as you suggest.

It's generally preferred that the passenger cabin remains rigid. Maybe the structure behind the passengers in the SF50 could be designed to crumple?

Ashley
PS. Having belatedly looked at the drawings, it looks like, though the parachute is in the nose, the airplane is designed to be suspended in way similar to the SR22.

Where is the parachute going on the SF50