old man emu Posted February 28, 2023 Share Posted February 28, 2023 A 5-point harness is, indeed, the best restraint system, but the next best is the over-shoulder/waist system. Then there is the lap/sash system with inertia locking, and finally the lap only system. The use of these is a compromise between restraint and freedom of movement. Available attachment points create another factor in the choice. The result is a compromise, in which the lap/sash wins out. The purpose of a restraint system in an aeroplane used for A to B transport is to prevent the upper body rotating forward when the impact forces act parallel, or within about 10 degrees of the longitudinal axis of the aircraft, and similarly for the lateral axis. If the forces act at a much greater from the longitudinal axis, rotation around the vertical axis occurs. If a lap/sash restraint is used, and the force comes at an angle to the side of the body opposite to the shoulder that the sash runs over, then the body can rotate under and out of the sash. If the impact forces act from below the longitudinal axis, that would induce rotation around the lateral axis. Usually those forces come from the front. In that case the body can slide under and out of the lap belt. Link to comment Share on other sites More sharing options...
farri Posted March 1, 2023 Share Posted March 1, 2023 Ok Guy! Keep in mind yesterday I said " I was told, one person on board, was thrown through the windscreen and was lying on the ground several mts from the AC". Today, I contacted the guy who told me that, again! had a good long talk with him and he assures me, that is correct! From what I`ve been told, it looks like a stall, spin, into the ground, from a low-level turn, following some engine problems. That`s all I`m prepared to say at this point. Franco. 2 1 1 Link to comment Share on other sites More sharing options...
old man emu Posted March 1, 2023 Share Posted March 1, 2023 3 hours ago, farri said: it looks like a stall, spin, into the ground, from a low-level turn, I like that opinion. The damage supports it. As does the ejection through the windscreen. 1 Link to comment Share on other sites More sharing options...
kgwilson Posted March 1, 2023 Share Posted March 1, 2023 It looks as though the plexiglass windscreen has popped out, probably when the person hit it which is a good thing in that would have slowed the ejection speed a bit & the person may very well have landed on it. Based on the description of the injuries "One patient has minor lacerations to the head and foot. The second patient, a male, has a suspected ankle fracture" the person got off very lightly. 3 Link to comment Share on other sites More sharing options...
spacesailor Posted March 1, 2023 Share Posted March 1, 2023 Thanks Franco , Excellent & precise . spacesailor Link to comment Share on other sites More sharing options...
Barto Posted March 2, 2023 Share Posted March 2, 2023 On 27/02/2023 at 10:44 AM, old man emu said: Notice the bark and stuff on the road on the other side of the truck? Also the port wing has detached and the nose looks moved to port. My opinion is that the plane impacted somewhere left of the picture and began to rotate as it crossed the left side of teh road, still rotating, then the front impacted the roadside bank of the drain. You would need photos from back along that path to confirm Point of Impact and direction of rotation. Doesn't look like it hit a substantial tree. I was the one that seen it. your onto it. came down level, clipped a tree with the left wing, spun to the right underneath powerlines and bounced across the road and on final impact one of them was thrown through the windscreen. the seatbelt wad torn from the fuselage and a hole remains where it was bolted in. I Learnt to fly in this exact plane so I know it quite well 2 1 3 1 Link to comment Share on other sites More sharing options...
Barto Posted March 2, 2023 Share Posted March 2, 2023 they came through the trees with the LHS wing hitting the tree with the red arrow. they then impacted the ground in the blue circle. the LHS main gear was left at the fence and they then bounced from there to the southern side of the road as seen in other photos. I'm the guy in the red and seen it all. first question I asked was "what happened" the student said engine failure, got it running then partial engine failure and went below the power lines on purpose. My partner seen the passenger get ejected through the front windscreen and when I ran to the plane the guy was laying in the long grass on the southern side of the plane( he was in the passenger seat on the northern side) I know both pilots and the plane as I trained in it 2 1 Link to comment Share on other sites More sharing options...
RFguy Posted March 2, 2023 Share Posted March 2, 2023 jesus.... Barto, was it a 'LSA55 ? hopefully there will be an investigation and AD on the seatbelt restraints. -glen 1 Link to comment Share on other sites More sharing options...
BrendAn Posted March 2, 2023 Share Posted March 2, 2023 On 01/03/2023 at 7:40 AM, old man emu said: A 5-point harness is, indeed, the best restraint system, but the next best is the over-shoulder/waist system. Then there is the lap/sash system with inertia locking, and finally the lap only system. The use of these is a compromise between restraint and freedom of movement. Available attachment points create another factor in the choice. The result is a compromise, in which the lap/sash wins out. The purpose of a restraint system in an aeroplane used for A to B transport is to prevent the upper body rotating forward when the impact forces act parallel, or within about 10 degrees of the longitudinal axis of the aircraft, and similarly for the lateral axis. If the forces act at a much greater from the longitudinal axis, rotation around the vertical axis occurs. If a lap/sash restraint is used, and the force comes at an angle to the side of the body opposite to the shoulder that the sash runs over, then the body can rotate under and out of the sash. If the impact forces act from below the longitudinal axis, that would induce rotation around the lateral axis. Usually those forces come from the front. In that case the body can slide under and out of the lap belt. thanks, i wondered what seatbelt were for. 1 Link to comment Share on other sites More sharing options...
Jabiru7252 Posted March 2, 2023 Share Posted March 2, 2023 1 hour ago, RFguy said: jesus.... Barto, was it a 'LSA55 ? hopefully there will be an investigation and AD on the seatbelt restraints. -glen It appears to have fuel caps on the wings, LSA55 did not have wing tanks. Correct me if I'm wrong. (which is extremely rare)... Link to comment Share on other sites More sharing options...
BrendAn Posted March 2, 2023 Share Posted March 2, 2023 it has a full size rudder its not a 55. Link to comment Share on other sites More sharing options...
RFguy Posted March 2, 2023 Share Posted March 2, 2023 (edited) Oh yeah . I see .I didnt see those other pictures. my bad I see someone has stuck it into a db https://aviation-safety.net/wikibase/308770 Jabiru are going to have to do something about seat belt anchors failing, that's another I have heard about from a factory aircraft. *unacceptable* Edited March 2, 2023 by RFguy Link to comment Share on other sites More sharing options...
old man emu Posted March 2, 2023 Share Posted March 2, 2023 12 hours ago, Barto said: I was the one that seen it. Thank you so much for that post. Now we all know what happened. No more conjecture on the movement of the aircraft. As for the seatbelts, these are the forgotten safety devices in all moving vehicles. Just the other day I was looking at my driver's seat belt in my car. The car is 18 years old. Now this question of seatbelt integrity has come up as a result of this incident, so I Googled "service life of seatbelts" and the first link that was returned was this: And here is a quote from that AWB: The difficulty is, that while seat belt webbing may appear to be free of detrimental fraying, fading from exposure to ultraviolet light, and chemical contamination, the only way of ensuring that seat belt webbing is safe to use, is to test the webbing to destruction. This, of course, renders the belt assembly unusable. To overcome this problem, some rotorcraft manufacturers have implemented a 10-year service life on seat belts and shoulder harnesses. Recommendation 1. Remove from service and destroy all seat belts and shoulder harness webbing when it reaches 10 years time in service. 2. Implement inspection procedures to ensure that safety belts and shoulder harness assemblies, particularly those in the pilot and co-pilot positions, are maintained during the recommended ten-year service life to a standard that requires prematurely faded, chafed, or otherwise damaged or chemically contaminated seat belt webbing to be replaced with serviceable assemblies Link to comment Share on other sites More sharing options...
onetrack Posted March 3, 2023 Share Posted March 3, 2023 I replace my seatbelts in my vehicles regularly, as soon as they start looking tired, frayed, won't retract, or display damage in any part of the seatbelt tongue or latch. They're not expensive to repair, I paid $110 for a replacement drivers seatbelt about 18 mths ago. I removed the entire seatbelt assembly from the vehicle myself, and replaced it myself. Any seatbelt repairs or webbing replacement must be done by a certified repairer, because the repair must be certified and recorded. Locally, two of the companies who do aviation seatbelt repairs, also do vehicle seat belt repairs as well. https://aircraftinteriors.com.au/ https://www.transport.wa.gov.au/mediaFiles/licensing/LBU_VS_IB_110.pdf It sounds like the Jab seatbelt retention points need a metal spreader plate around their locations to ensure the load is spread across a wider area. The Jab cabin is obviously a very robust structure, but the seatbelt mount tearing out, is a real concern. In most cases, anyone ejected through a window or windscreen in a crash is often killed. A broken neck is the highest potential cause of death. That Jab passenger needs to go buy a lottery ticket. Link to comment Share on other sites More sharing options...
facthunter Posted March 3, 2023 Share Posted March 3, 2023 I would be very surprised if Jabiru was deficient in this respect. The location may be well to the rear and the fuselage was damaged. From memory the load is 10 G. Nev. 1 Link to comment Share on other sites More sharing options...
kgwilson Posted March 3, 2023 Share Posted March 3, 2023 4 hours ago, onetrack said: It sounds like the Jab seatbelt retention points need a metal spreader plate around their locations to ensure the load is spread across a wider area. The Jab cabin is obviously a very robust structure, but the seatbelt mount tearing out, is a real concern. Where is the report stating the seatbelt retention points failed? Link to comment Share on other sites More sharing options...
RFguy Posted March 3, 2023 Share Posted March 3, 2023 https://www.recreationalflying.com/topic/38878-jab-down-chinchilla-airport-260223/?do=findComment&comment=542249&_rid=11148 " the seatbelt wad torn from the fuselage and a hole remains where it was bolted in. " 1 1 Link to comment Share on other sites More sharing options...
spacesailor Posted March 3, 2023 Share Posted March 3, 2023 (edited) Was that seat-belt bolt only through the ' skin ' & not through a glassed indoubler or lontitudle stiffener of some substance. I have heard of the undercarriage bolts pulling through . spacesailor Edited March 3, 2023 by spacesailor Missed word 1 Link to comment Share on other sites More sharing options...
Thruster88 Posted March 3, 2023 Share Posted March 3, 2023 24 registration so factory built. We would assume it was done correctly. 1 1 Link to comment Share on other sites More sharing options...
kgwilson Posted March 3, 2023 Share Posted March 3, 2023 (edited) There are a number of reasons why the seatbelt anchor was torn out including previous stresses from earlier issues with the aircraft. Back in 2016 I was one of the first on the scene when a J230 went in under power in a cow paddock just short of Runway 08 at South Grafton. There was extensive damage and the entire front of the aircraft was torn off and partially went under the fuselage. The pilot and passenger were left in their seats looking out at a bunch of startled cattle. Injuries were a cut on the head of one and a sore knee from the other. Jabirus are tough and the passenger compartment is amazingly strong. Photo of this one below In a lot of other aircraft GA & RA the occupants would not be here to tell the tale. Edited March 3, 2023 by kgwilson 2 Link to comment Share on other sites More sharing options...
dmech Posted March 3, 2023 Share Posted March 3, 2023 On 27/02/2023 at 8:53 AM, RFguy said: Good result if pax are in stable condition . Cannot see fuel vents so likely is inboard tank variety. Jabs rarely have fuel delivery issues (good design) and shouldnt have vapour issue with pump on, so something else. Wasnt particularly hot at AP at 0930 local (24C) http://www.bom.gov.au/products/IDQ60801/IDQ60801.99402.shtml J 160 ,wet wings. Engine looks like a g4 maybe Link to comment Share on other sites More sharing options...
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