h a l f b a k e r yQuis custodiet the custard?
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Systems already exist for 60K (pounds) Low Velocity Airdrop System [link]. Put a version of one of these systems on smaller airliners, for emergency landings.
Example of maximum weight on a regional airliner: Bombardier CRJ700 series ER: 34,019 kg (75,000 lb) - ER: 41,640 kg (91,800 lb)
Most light
transport aircraft probably carry considerably less weight.
60K Low Velocity Airdrop System
http://www.globalse...ystems/60klvads.htm
[4and20, Sep 12 2014]
Landing gear #2
http://247wallst.co...rplane-accidents/3/
[4and20, Sep 12 2014]
36% of accidents on landing
http://www.1001cras...lg-2-numpage-3.html
[4and20, Sep 12 2014]
Hajile
http://en.wikipedia.org/wiki/Hajile
"Elijah in reverse ..." [8th of 7, Sep 14 2014]
Normal people + tank
http://www.core77.c...n_russian_24304.asp
Russians [4and20, Sep 15 2014]
[link]
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hmm, well, aicraft safety is taken pretty seriously by
people like the NTSB and the AAIB. They are actually a
pretty wonderful example of learning from mistakes,
made institutional. They do a pretty good job at working
out why airliners, regional or otherwise, crash. I'm sure if
you asked them how to improve safety, they'd just pull
the most recent list marked: "how to increase aircraft
safety". They'd probably say things like "retire aircraft
type x" and "don't fly aircraft type y in icing conditions".
Parachutes for regional airliners are going to be big and
bulky. Also, some regional aircraft are jets, deploying a
parachute when you're doing 400 KIAS will probably tear
the aircraft apart. Also, where are you mounting it? it's
not like aircraft have super tough hard points on the top. |
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It might work for Cirrus, but they're small and mostly
slow. Best to keep knocking the most dangerous things off
the top of the list. I'd go with "regional aircrew get the
same rest and pay as regular aircrew". |
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A high wing, the main spar is right there, so it's easily'ish doable from an engineering POV. |
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Perhaps the poster would care to go over the safety record of high wing regional transport(s) and see if the proposed system might have mitigated any of the accidents. |
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(I'm gonna guess the situations are limited to "all engines andor all control surfaces completely stopped working at a high altitude over very rough terrain) |
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The Bombadier CRJ700 mentioned is low wing. Also, it
cruises at 500 knots. To deploy a parachute, you'd have to
slow it down to <200 or so. Which is going to require all your
control surfaces. If your control surfaces are working why
deploy the parachute? |
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// Perhaps the poster would care to go over the safety record of high wing regional transport(s) // |
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I'm glad you asked. On all flights, commercial and light aircraft, pilot error is the leading cause of accident, possibly more than 50% of the time. |
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Almost 90% of accidents are light aircraft, but of commercial airline accidents, the second leading cause was landing gear malfunction. |
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Landing is described as the most dangerous phase of flying and the [link] backs this up, with 36% of accidents happening at this stage. |
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I imagine light aircraft are limited to speeds which make parachute deployment more feasible. |
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The airdrop systems apparently have issue with landing on target, but then, you don't need a runway or a pilot. |
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Insufficient advocacy of inadvisable use of dangerous and
inappropriate pyrotechnics. |
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However, to address some of the points raised ... |
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// On all flights, commercial and light aircraft, pilot error is the leading
cause of accident, possibly more than 50% of the time. // |
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How many of those "accidents" result in serious injury or death ? |
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// of commercial
airline accidents, the second leading cause was landing gear
malfunction. // |
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So, the answer would be an auxiliary landing gear system, or
sacrificial skids ? On an aircraft with underslung engines, the skids
could be integral with the engine nacelles. |
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// Landing is described as the most dangerous phase of flying and
the [link] backs this up, with 36% of accidents happening at this stage.
// |
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Landing is the most dangerous phase of flight, when the aircraft is
required to stop flying in a controlled way. |
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// I imagine light aircraft are limited to speeds which make
parachute deployment more feasible. // |
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Don't "imagine" - check your facts. You've done laudably well so far,
keep it up. And yes, few light aircraft routinely travel at more than 200
KIAS. |
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// The airdrop systems apparently have issue with landing on
target, but then, you don't need a runway or a pilot. // |
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Wind drift is always going to be a problem. |
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How much does the ballistic parachute system weigh ? Well, a T-10,
weighs 15 kg and is good for 150 kg of payload. A Dash 8 has a
MTOW of about 15000 kg. So you'd need the equivalent of 100 T-10s (
not really, bcause there are huge economies of scale). That's 1500 kg. |
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Let's say that through cunning design and using components
fabricated from Unobtanium, you can get the 'chute mass down to
500 kg. That's about 6 or 7 average passengers ... call it 6. The Dash 8
seats about 40, so you have to lose 1/6.5 = 15% of your capability. |
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That means a 15% increase in price per seat. |
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The regulators could mandate fitment, ensuring a level playing field
for operators, but a Government-imposed 15% price hike is not going
to play well with voters. |
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The Hajile project was initiated too early. It should have
been nuclear. |
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Maybe you could get the project a do-over? |
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Whereas there seem to be negligible fatalities on commercial airlines, the fatality numbers for light aircraft are downright horrific, numbering over 400 people in a year's time (I think). |
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The T-11 parachute has a normal weight of 53 pounds (24 kg).The link for the low velocity airdrop system says that it requires 12 modified G-11C parachutes.That would possibly make the system 700 pounds (288 kg) |
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Airplanes in the Dash-8 series have a maximum takeoff weight of 36,300 lb (16,470 kg) - 64,500 lb (29,260 kg) and a typical payload weight of 7,511 lb (3,407 kg) - 19,114 lb (8,670 kg). |
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We're looking at 4 fewer passengers on a fully loaded plane, or less fuel, payload, etc. Not sure if packages or people are more lucrative to carry. Given that the largest of the Dash 8s would seem to be the only model pushing weight restrictions, the cost of those 4 passengers would have to be distributed across the remaining 74 seats, or 4/74. Most modern RFPs ask for the 42k airdrop system, so it seems this 60k version may only be a prototype. |
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The most popular airplane in the world, the Cessna 172 has Gross weight: 2,450 lb (1,111 kg). |
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In that case I recommend 1/4 the parachutes or, better yet, the BMD-1 airdrop technique, wherein "a single large main chute opens" and "triggers the deployment of four long rods which hang beneath the pallet. As soon as the rods touch the ground a retrorocket fires, slowing the BMD to a descending speed between 6 m/s and 7 m/s and giving it a relatively soft landing." |
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A BMD-1 is approximately 5x the gross weight of a Cessna 172, so its airdrop system might be used for quite a few light aircraft auxiliary systems. |
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// We're looking at 4 fewer passengers // |
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No, your 288 kg is just for the canopy packs. |
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You need an attachment/deployment system, mounting and load
distribution structures within the airframe, a release triggering
system … if you manage that in a 100kg weight budget you>ll be
doing well. |
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We stand by the "6 or 7 passengers" estimate of weight penalty. |
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if the plane does parachute down, I suspect that hitting the
ground, in a seated position, at regular parachute descent
speeds would still be enough to ruin some spines. |
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