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Four Point Seat Belts Vs Lap Sash in RAA aircraft


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Has anyone retro fitted a 4 point to a Jabiru???

(that all I have seen have 3 point lap/sash- which I am not keen on compared to a four point. Tricky for composite finding an a suitable anchor point since it is going to have some high loads. From my POV the 3 point does not provide enough restraint from possible movement - hence I think for a 3 point in a small cockpit, a helmet is 'a good idea' . I wrote ' mandatory' instead of "good idea" first but that's not quite what I meant- IE I like how we can still decide the risk .

 

The Brumby has a four point.

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The airlines are a good example of deciding what to do about the conflict between safety and practicability. Airliners do not provide their passengers with parachutes, for example, even though there has been at least one incident where they would have saved many lives. They don't provide 4 or 5 point harnesses either. Or mandate that you wear a helmet. ( You need a helmet to legally ride a bike around here. This has had the effect of making bike riding a rare thing to do )

 

In all these things, the extra weight is a safety negative which is there all the time, lowering structural margins and increasing stall speed and reducing fuel capacity.

But a polystyrene helmet would have saved this guy I knew from a minor injury. He up-ended his Jabiru and cut his head on something sharp. Except that he would not have had time to put it on, and as Nev pointed out, padding would have been a better option.

 

If you fly in good weather in daylight then you can always aim the ( 40 knots ) fuselage between the trees and after the wings are ripped off, the impact will be nothing like some of the amazing things that race car drivers ( helmets, roll-cages, suits and 5 point harnesses ) survive, from about 100 knots.

Another guy I knew came down in mulga-tree scrub, in the dark, in a glider with a 4 point harness. He said that just when the altimeter read ground level, the wings got ripped off but he was unhurt himself. I think the glider was a write-off.

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But a polystyrene helmet would have saved this guy I knew from a minor injury. He up-ended his Jabiru and cut his head on something sharp. Except that he would not have had time to put it on, and as Nev pointed out, padding would have been a better option.

Hi Bruce. Well yeah - A road cycling helmet would afford your brain alot of protection for 300 grams ! and there are full/half full face mountain bike helmets that are around 800 grams !. Again, they are not trying to protect you from a 200kmh crash, they are suitable for the sort of crash speeds LSAs might commonly encounter .

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Need to figure out how to integrate the headset or ear cups . Bone conduction can also work well in conjunction with earplugs.

You can buy proper aviation helmets with headsets built in, but cheapskates like me adapt less expensive stuff. My wife's old bike helmet has a hard shell, so it wasn't difficult to cut out recesses and bolt the outer parts of my Dave Clarkes to it. More recently I also bolted a small ANR battery box to the back of it.

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While the 3500 $ helmets are an overkill for these speeds etc, . and the road bike helmet seems a good utility, you must not make modifications to the helmet .... like cut bits out- well you can - at your peril. You can certainly cable tie (gently, wide ties) stuff to the slots and holes....

 

I am thinking bone conduction with ear plugs, or just air driven air buds (they're good and they seal well) , together with a cable tied on boom mic, or a dual throat mic.

 

Needs a different topic..... this one is drifting.

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Too uncomfortable and not really needed. It will also reduce sensory awareness. Peripheral vision ,sounds etc and it's a weight on your neck and there's often not a lot of spare headroom in the sort of stuff you will most likely be flying. ..OK in a cropduster where I'd also have flame proof suit and gloves .Nev

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Too uncomfortable and not really needed. It will also reduce sensory awareness. Peripheral vision ,sounds etc and it's a weight on your neck and there's often not a lot of spare headroom in the sort of stuff you will most likely be flying. ..OK in a cropduster where I'd also have flame proof suit and gloves .Nev

Modern road cycling helmets would satisfy all those concerns, I think. (low profile, 200 to 300 grams, no effect of peripheral vision) . As a road cyclist, and mountain-biker, I know.....

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Not much air over you in most cockpits. Some are hot especially when on the ground. I just don't really believe the situation requires it. It will interfere with headphones, sunnies and your tennis shield for when you are landing into the sun. Those 3 items ARE needed if you go distances. You may also need some form of sun protection to cover an arm and the side of your face. The sun is fiercer above the dust and smog. Nev

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...you must not make modifications to the helmet .... like cut bits out- well you can - at your peril...

Why not? Even with ear cut-outs, it's mobs better protection than none.

 

Too uncomfortable and not really needed. It will also reduce sensory awareness. Peripheral vision ,sounds etc and it's a weight on your neck..

That hasn't been my experience, Nev.

 

Not much air over you in most cockpits. Some are hot especially when on the ground. I just don't really believe the situation requires it...

Valid points; my head is closer to the roof than most, so I'm accustomed to putting up with limited headroom.

Bicycle helmets are designed for good ventilation. Any possibility of whacking my head on a hard surface is enough reason to wear a lightweight helmet.

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If you have an open cockpit or can fly with the canopy open a helmet might work without cooking your head. With my 4 point harness tightly fastened I'm not going to hit my head on anything unless it is a major impact that crushes the entire fuselage in which case it won't matter.

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If you have an open cockpit or can fly with the canopy open a helmet might work without cooking your head. With my 4 point harness tightly fastened I'm not going to hit my head on anything unless it is a major impact that crushes the entire fuselage in which case it won't matter.

I have an old Alpha that has been converted to GA comms, a Lightspeed Zulu, a Bose A20 and an in ear headset. I love the in ear headset, the Lightspeed and Bose are awesome, but I end up wearing my helmet because even when wearing a cap my ears get burned with the in ear set, and with the Bose or Lightspeed, by the time I've got my cap headset and sunnies adjusted just right, I move and have to adjust them again. So I throw them over the back and plonk my lid on. It's nearly as quiet as the ANR headsets, and I just drop the visor in the sun.

The crashes that worry me are the ones I read about that have landed in water or been on fire when the pilot has had minor head injuries and is unconscious and would have survived if they were awake to extricate themselves. It's not much of a stretch to smash your head on the panel in a lot of aircraft. In a lot of low wing aircraft, the panel may even meet you halfway.

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If you have an open cockpit or can fly with the canopy open a helmet might work without cooking your head. With my 4 point harness tightly fastened I'm not going to hit my head on anything unless it is a major impact that crushes the entire fuselage in which case it won't matter.

KG I agree- with a four point you are well restrained from hitting your head in an undamaged airframe . I am quite happy with the four point harness in the Brumby I am flying. Although I think I might still smack my head on the door pillar .

And, shortly, I will start wearing a bike helmet for all flying. (not RPT !) I need to integrate the headset.

 

My concern was with a 3 point, or just a lap belt as you know.

Modern road cycling helmets are super materials. you don't get hot in them. They do cost about an 2 inches of headroom though.

I've seen a few head injuries in older folk from fairly minor bicycle bingles without helmets. Older brains do not like it. When I climb step ladders > 3meters I wear my rock climbing helmet. Again- my heightened caution because I have seen many head injuries in colleagues and friends .

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KG I agree- with a four point you are well restrained from hitting your head in an undamaged airframe . I am quite happy with the four point harness in the Brumby I am flying. Although I think I might still smack my head on the door pillar .

And, shortly, I will start wearing a bike helmet for all flying. (not RPT !) I need to integrate the headset.

 

My concern was with a 3 point, or just a lap belt as you know.

Modern road cycling helmets are super materials. you don't get hot in them. They do cost about an 2 inches of headroom though.

I've seen a few head injuries in older folk from fairly minor bicycle bingles without helmets. Older brains do not like it. When I climb step ladders > 3meters I wear my rock climbing helmet. Again- my heightened caution because I have seen many head injuries in colleagues and friends .

It's important not to fall into the cargo cult trap of seeing something and THINKING it's better, or wearing something and thinking you're safe.

There's a helmet modification shown above which would give you a frontal lobotomy. I've been present where medics spent two hours extracting the side of a driver's head off a roll cage mounted camera. There's no point fitting a four point harness if it's just going to snap a quarter of a square metre out of an FRP fuselage.

There's nothing wrong with reinventing the wheel as long as your inputs don't come from other products designed for other forces and circumstances.

The better way to go about it is to research the accidents, see how the pax were injured, what the forces were, and what could make a difference and MOST importantly, would the aircrraft be practical with that equipment in it. Right now though you should be totally focused on your BAK so you can go solo safely. Nothing beats avoiding the accident in the first place.

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I like this guys channel very much, he built a helmet to suit his needs...

Not too different from my own helmet, but I’m with Turbs; that solid box mounted on the helmet is not clever.

I’ve tried several different GoPro locations and the helmet is the worst. As well as the safety aspects, the footage makes you seasick because of constant scanning for traffic.

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Believe me, just because I wear a helmet on my bicycle doesn't make me take bigger risks. Hitting the ground always hurts. But with a helmet you can reduce the chance of a life changing event (brain injury)- even a subtle brain injury .

 

I'm rather against people putting go-pro cameras on their helmets. dumb idea, voids the ability of the helmet to do its job.

 

Hence, like I said, no helmet modifications or warts permitted. About as far as I would go is some cable ties stopping say a head band falling down. Need to find a good solution to integrate the radio stuff.

I think a push-in pneumatic tube earpieces are very suitable. They seal in the ear canal nicely. A mic boom is then required. Some innovation with a 3D printer wouldn't take much. Throat mics are effective in high noise environments but sound pretty awful.

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Hence, like I said, no helmet modifications or warts permitted. About as far as I would go is some cable ties stopping say a head band falling down.

Even that creates a potential cracking point; the helmet would disqualify you in racing.

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Turbs- yeah..... a loose ish wide cable tie through one of the air vents and out would be OK, I think.

Walrus- yeah so my question was, is it practical to fit a 4 point to a 3 point setup like the Jabiru 3 point setup.

You'd assume (!) they put a bit of thought and meat into the anchor for the over the shoulder attachment. Or not.

not so easy my thinks. The four pointers I have seen would be better described as a FOUR BELT, three attachments-

 

IE the SINGLE anchor behind your head that goes through a Y and over each shoulder.

In the Brumby that single rear anchor point is a long way behind you, so there would be some motion permitted laterally which in a SIDE impact might not do much to restrict side motion (like hitting your head on the fairly solid door pillar) .

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Before you prescribe things for a use, workout just what problem you are attempting to address. Not general ones.. "You would be safer IF.you had one on."(.speak).. specific instances when the FIX you propose would have been very appropriate. in our type of planes. Helmets ARE appropriate for parachuting speedboat racing waterskiing Racing go Karts Snow skiing, Ice Hockey etc. Fire or going through a wire fence are more risky than dropping on your head when the plane tips over and you release the seat belt. That's the only instance I can recall in a lifetime of flying where a helmet would have definitely helped the bloke in a tiger Moth that it happened to. Nev

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