Re: RANS S-9 Chaos loses a wing

[Gemini]

On 2010-08-21, brian whatcott > wrote:
> On 8/20/2010 11:59 AM, Gemini wrote:
>> On 2010-08-20, brian > wrote:
>>> At least one type suspends the aircraft tail down when the chute is
>>> deployed.
>>> This is probably the optimum energy absorbing method, with abvious
>>> benefits in crushing the tail first, and keeping a high wing from
>>> dropping into the cabin. The disadvantage is the possibility of whiplash
>>> on the neck.
>>>
>>> Brian W
>>
>> I get having that distance from the tail to crush, like a crumple
>> zone, but wouldn't that add some significant dangers, such as:
>>
>> If the plane is 20' long, and only crushes 5', wont you then be
>> ~15' in the air when it tips, w/o the benefit of the parachute?
>>
>> Also, landing on the tail, wont you also have the engine, which is
>> most of the airplane weight, still above you? That's a lot of
>> potential energy that could cause it to collapse more, and
>> put an engine in your lap.
>>
>> I'm still relatively new - 15hr Student Pilot, so there may be
>> some things I'm overlooking; but those things sorta jumped out
>> at me as potential additional hazards.
>>
>> Regards,
>> Scott
>
> The tail down approach hangs the chute off the engine mount - a hard
> point in any plane. when the tail touches down, that starts taking some
> of the load, so the chute slows the remainder better....
>
>
>
> Brian W

I agree that having the attachment to a hard point like an engine mount
is good - and that the tail would make a great crumple zone, but
I wonder if having that extra weight of the engine above you, and still
pressing down would cause more trouble. I also wonder, that, once
the tail hits, and starts absorbing the impact, the parachure will
actually "deflate" and continue to fall, likely faster than the
crumpling, and fall off to the side, so that when the plane falls
over, there will be nothing to slow it down.
Since there will be wind, it will likely not fall straight down, and
will hit with some lateral motion, thus increasing the risk of it
toppling with more energy. Know what I mean? I'm not sure if I'm
accuratley describing my concerns.

Regards,
Scott

[a[_3_]]

On Aug 23, 2:39*pm, Gemini > wrote:
> On 2010-08-21, brian whatcott > wrote:
>
>
>
> > On 8/20/2010 11:59 AM, Gemini wrote:
> >> On 2010-08-20, brian > *wrote:
> >>> At least one type suspends the aircraft tail down when the chute is
> >>> deployed.
> >>> This is probably the optimum energy absorbing method, with abvious
> >>> benefits in crushing the tail first, and keeping a high wing from
> >>> dropping into the cabin. The disadvantage is the possibility of whiplash
> >>> on the neck.
>
> >>> Brian W
>
> >> I get having that distance from the tail to crush, like a crumple
> >> zone, but wouldn't that add some significant dangers, such as:
>
> >> If the plane is 20' long, and only crushes 5', wont you then be
> >> ~15' in the air when it tips, w/o the benefit of the parachute?
>
> >> Also, landing on the tail, wont you also have the engine, which is
> >> most of the airplane weight, still *above you? That's a lot of
> >> potential energy that could cause it to collapse more, and
> >> put an engine in your lap.
>
> >> I'm still relatively new - 15hr Student Pilot, so there may be
> >> some things I'm overlooking; but those things sorta jumped out
> >> at me as potential additional hazards.
>
> >> Regards,
> >> Scott
>
> > The tail down approach hangs the chute off the engine mount - a hard
> > point in any plane. *when the tail touches down, that starts taking some
> > of the load, so the chute slows the remainder better....
>
> > Brian W
>
> I agree that having the attachment to a hard point like an engine mount
> is good - and that the tail would make a great crumple zone, but
> I wonder if having that extra weight of the engine above you, and still
> pressing down would cause more trouble. I also wonder, that, once
> the tail hits, and starts absorbing the impact, the parachure will
> actually "deflate" and continue to fall, likely faster than the
> crumpling, and fall off to the side, so that when the plane falls
> over, there will be nothing to slow it down.
> Since there will be wind, it will likely not fall straight down, and
> will hit with some lateral motion, thus increasing the risk of it
> toppling with more energy. Know what I mean? I'm not sure if I'm
> accuratley describing my concerns.
>
> Regards,
> Scott

There have been a number of actual deployments on SEL airplanes
(Cirrus, c172, c182), in a number of cases the airplane was not
totaled, and it appears that the chances of walking away or at least
living through a descent under a rescue parachute is greater than
trying to fly the airplane down.

The likelihood of being in a circumstance where one needs to deploy
the chute seems pretty small but if you need it that it is available
would be nice. It's an expensive insurance policy, expensive to
install and expensive to use. If I remember this correctly one had not
been used, according to some of the references, because of an engine
failure. I would have thought that was the most probable use!

..

[Gemini]

On 2010-08-23, a > wrote:
> On Aug 23, 2:39*pm, Gemini > wrote:
>> On 2010-08-21, brian whatcott > wrote:
>>
>>
>>
>> > On 8/20/2010 11:59 AM, Gemini wrote:
>> >> On 2010-08-20, brian > *wrote:
>> >>> At least one type suspends the aircraft tail down when the chute is
>> >>> deployed.
>> >>> This is probably the optimum energy absorbing method, with abvious
>> >>> benefits in crushing the tail first, and keeping a high wing from
>> >>> dropping into the cabin. The disadvantage is the possibility of whiplash
>> >>> on the neck.
>>
>> >>> Brian W
>>
>> >> I get having that distance from the tail to crush, like a crumple
>> >> zone, but wouldn't that add some significant dangers, such as:
>>
>> >> If the plane is 20' long, and only crushes 5', wont you then be
>> >> ~15' in the air when it tips, w/o the benefit of the parachute?
>>
>> >> Also, landing on the tail, wont you also have the engine, which is
>> >> most of the airplane weight, still *above you? That's a lot of
>> >> potential energy that could cause it to collapse more, and
>> >> put an engine in your lap.
>>
>> >> I'm still relatively new - 15hr Student Pilot, so there may be
>> >> some things I'm overlooking; but those things sorta jumped out
>> >> at me as potential additional hazards.
>>
>> >> Regards,
>> >> Scott
>>
>> > The tail down approach hangs the chute off the engine mount - a hard
>> > point in any plane. *when the tail touches down, that starts taking some
>> > of the load, so the chute slows the remainder better....
>>
>> > Brian W
>>
>> I agree that having the attachment to a hard point like an engine mount
>> is good - and that the tail would make a great crumple zone, but
>> I wonder if having that extra weight of the engine above you, and still
>> pressing down would cause more trouble. I also wonder, that, once
>> the tail hits, and starts absorbing the impact, the parachure will
>> actually "deflate" and continue to fall, likely faster than the
>> crumpling, and fall off to the side, so that when the plane falls
>> over, there will be nothing to slow it down.
>> Since there will be wind, it will likely not fall straight down, and
>> will hit with some lateral motion, thus increasing the risk of it
>> toppling with more energy. Know what I mean? I'm not sure if I'm
>> accuratley describing my concerns.
>>
>> Regards,
>> Scott
>
> There have been a number of actual deployments on SEL airplanes
> (Cirrus, c172, c182), in a number of cases the airplane was not
> totaled, and it appears that the chances of walking away or at least
> living through a descent under a rescue parachute is greater than
> trying to fly the airplane down.
>
<snip>

I was referring to having a parachute in the front; so the
plane would land on the tail, rather than nose first or flat.

Regards,
Scott