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Four Point Seat Belts Vs Lap Sash in RAA aircraft


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Probably this question has been asked before - however - a four point harness with say 3 inch wide chest straps seems without knowing to be common sense in low impart crash (incident) or roll over compared to a thinner (less wide) lap sash.

 

Has anyone got any medical or specific information on the benefits or problems for or against . Specifically with regard to age of pilots in RAA as we are getting older and bones softer. Reducing the possible injury etc.

I know fitting it in the aircraft has to be correct with angles and attachment points.

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4 points of anchorage and a X body belt system , have got to be better, in most, if not every circumstance.

 

An even distribution of forces beats the unbalanced sash type thats why all race cars have 4 point harness.

 

Remember, when correctly fastened/adjusted the "buckle" should end up at about or slight below your navel. I find it best to have a tight waist and some free movement (kept to a minimum) of my upper body to facilitate reaching for "things" in the cockpit.

 

Your bones are unlikely to be softer, more likely to be less dense and brittle

 

Angles of attachment are important but even more important is the security of those attachment/anchors. Its easy to have a good looking system, not so easy to do it right.

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Four attachment points is obviously better than a lap-sash, but five is better still, because the lower strap prevents "submarining".

I bought a cheap 5-pt harness online, but found it much heavier than expected; I guess it was designed to cope with super-overweight drag racers. There are some good quality, lightweight aircraft harnesses available, but they are pricey.

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In the 95-10 category a 5 point belt is far too heavy.

Will have to use a Lap only, with padding for the head and fingers crossed.

spacesailor

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Your plane is not a race car. With a 45 Kt stall speed your exposure to high "G" loads is pretty limited. If you spiral in from a great height you are outside the envelope where much can be done about it in a real sense. You must have suitable structure to anchor this to. Pretty difficult with side by side. . With aero's I'd see it as needed because you have the seat belts quite tight and it's subject to fairly high "G" forces in a few directions, like a race car. Airlines run the 5 point but the seat and harness are probably worth the price of a U/L.in some cases. and it's landing and taking off at rather high speeds. Nev

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No matter what the speed a 4 point belt is better than lap sash and 5 point better still. Is lap sash or lap only legal? I would hope not.

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I was pax in a R22 cattle mustering. Surprisingly it had a Lap Sash. Not very reassuring. couple mil perspex to hold between thumb and forefinger for added comfort. Forces kept you in the seat though.

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No matter what the speed a 4 point belt is better than lap sash and 5 point better still. Is lap sash or lap only legal? I would hope not.

Yenn,

 

If you take the words of Tech Manual issue 4 as being legally binding then lap sash is not acceptable - see sec 3.1 para 3.1 ©

 

The whole issue of is the tech manual actually legally enforcable against a builder or owner has not been tested but is arguable in many respects - in some respects the legal enforcability of whole slabs of the tech manual are questionable.

 

Apart from is it legally allowed to have a lap sash people need to make the assessment of their personal risk tolerance when they come face to face with any aircraft that did not roll out of a factory as a certified/type accepted airframe.

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Yenn,

If you take the words of Tech Manual issue 4 as being legally binding then lap sash is not acceptable - see sec 3.1 para 3.1 ©

 

The whole issue of is the tech manual actually legally enforcable against a builder or owner has not been tested but is arguable in many respects - in some respects the legal enforcability of whole slabs of the tech manual are questionable.

 

Apart from is it legally allowed to have a lap sash people need to make the assessment of their personal risk tolerance when they come face to face with any aircraft that did not roll out of a factory as a certified/type accepted airframe.

If you build an aircraft you are responsibls for the safety. If there are safety recommmendations or benchmarks or standards and you opted not to comply, no one comes along like they used to and forces you to meet that standard, but if there's an accident and someone is hurt, you've pretty much made it an open and shut case. That's the way it works now.

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If you build an aircraft you are responsibls for the safety. If there are safety recommmendations or benchmarks or standards and you opted not to comply, no one comes along like they used to and forces you to meet that standard, but if there's an accident and someone is hurt, you've pretty much made it an open and shut case. That's the way it works now.

Except how does that sit with the tech manual? You must use three point harness but raaus take no responsibility for airworthiness - you must have build indirections to show acceptable build yet neither raaus nor the inspector can tell you it’s wrong.

 

And all of this is in front of the still untested what can raaus do to a member or non member who contravene a written requirement not required by cao and not enforceable as other than an breach of a membership obligation - what actual sanction is viable against a member who fails to have adequate by raaus standards documentation for something that is not a statutory requirement but an admin requirement.

 

Raaus have not done them any favours by having documentation that is very poorly drafted that would need to to be tested with a member disciplinary system that I itself is very poorly drafted and would likely not stand up in any review for anything less than bringing the raaus into disrepute.

 

I do not question that failing to follow a standard would be a consideration however when the caos under which anything not factory delivered is operated at own risk and raaus have no legal ability to Rufus registration or to direct any design in any real way its of limited applicability. Exactly the same as attempting to apply a manufacturers mandatory change to kit/plans built aircraft of same/similar design - there is no actual authority to do half what some people want raaus to do or what raaus have tried to do Int he past.

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Except how does that sit with the tech manual? You must use three point harness but raaus take no responsibility for airworthiness - you must have build indirections to show acceptable build yet neither raaus nor the inspector can tell you it’s wrong.

 

And all of this is in front of the still untested what can raaus do to a member or non member who contravene a written requirement not required by cao and not enforceable as other than an breach of a membership obligation - what actual sanction is viable against a member who fails to have adequate by raaus standards documentation for something that is not a statutory requirement but an admin requirement.

 

Raaus have not done them any favours by having documentation that is very poorly drafted that would need to to be tested with a member disciplinary system that I itself is very poorly drafted and would likely not stand up in any review for anything less than bringing the raaus into disrepute.

 

I do not question that failing to follow a standard would be a consideration however when the caos under which anything not factory delivered is operated at own risk and raaus have no legal ability to Rufus registration or to direct any design in any real way its of limited applicability. Exactly the same as attempting to apply a manufacturers mandatory change to kit/plans built aircraft of same/similar design - there is no actual authority to do half what some people want raaus to do or what raaus have tried to do In the past.

I could respond to virtually every line of that, but it would be too close to giving legal advice and I'm not a lawyer.

You are looking at most of those issues from a prescriptive regulation point of view, whereas I'm look at the same things based on a benchmark/self administration point of view, and don't have a problem with them. Everyone in the chain of responsibility these days has a duty of care to prevent every forseeable risk.

 

So for example if you are building an aircraft and the benchmark is a three point harness you are responsible for using nothing less than a three point harness and you are responsible for engineering the strength of the harness, the mounting angles and the mounting strength etc.

 

So why would an authority want to assume liability risk by getting involved in the design? You screw up the design, you pay when a plaintiff wins his case.

 

As far as compliance and enforcement is concerned, I've mentioned other Associations many times over the years who have installed systems which have ensured very high standards of safety and incorporate human rights safety nets.

 

The "testing" that you mention will come with public liability lawsuits, so once again only targets the people who were found negligent.

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Early Cessnas etc had lap only seat belts & they were legal. I wouldn't fly in one though with only lap belts. I have hit my head on the cockpit ceiling with lap/sash belts in a C172 in severe turbulence. Not very reassuring. For me 4 point is essential & 5 even better to stop submarining. The cost is not that high. The choice and rigidity of anchor points is super important though.

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It would be rather impossible to fit 4 or 5 point harness to many planes. While they are the best and I'd see the 5 as the deal as you can slide out of the 4 point. Nev

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It would be rather impossible to fit 4 or 5 point harness to many planes. While they are the best and I'd see the 5 as the deal as you can slide out of the 4 point. Nev

I think there's a bit of a mixup here between the applications.

A race car these days usually has the seat back inclined well back which lowers the centre of gravity of the driver, reducing roll by a small %.

Crashes where the car slams into something; the brick wall means the driver can slide down through the waist belt (or "submarine), so the fifth belt is anchored to the floor beween the driver's legs. With some of these belts, if you want to get out in a hurry the lower strap grabs and you have to sit back down to release pressure.

 

In the aircraft application, very few pilots are killed by a head on collision on the ground; the most obvious benefit would be in a nose over where the aircraft is likely to spit the pilot down onto the ground. In addition, most aircraft seats have an elevated cushion and upright squab and submarining is not so common.

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It's not much of an extra for the crutch bit. If I recall correctly the tiger Moth had one and all modern airliners do. Hitting your head on the coming (dash) panel is not uncommon on ground prangs or the roof in turbulence. Suitable padding should be considered. I don't see the usual U/L as requiring of anything special as long as lap sash is considered OK for cars.. Aeros (as I've said) require you be strapped tightly and not come away from the seat in negative"G" situations. IF the landing is "off field" or abnormal, tighten seat belts fully is part of the pre landing actions. Nev

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I could respond to virtually every line of that, but it would be too close to giving legal advice and I'm not a lawyer.

You are looking at most of those issues from a prescriptive regulation point of view, whereas I'm look at the same things based on a benchmark/self administration point of view, and don't have a problem with them. Everyone in the chain of responsibility these days has a duty of care to prevent every forseeable risk.

 

So for example if you are building an aircraft and the benchmark is a three point harness you are responsible for using nothing less than a three point harness and you are responsible for engineering the strength of the harness, the mounting angles and the mounting strength etc.

 

So why would an authority want to assume liability risk by getting involved in the design? You screw up the design, you pay when a plaintiff wins his case.

 

As far as compliance and enforcement is concerned, I've mentioned other Associations many times over the years who have installed systems which have ensured very high standards of safety and incorporate human rights safety nets.

 

The "testing" that you mention will come with public liability lawsuits, so once again only targets the people who were found negligent.

My core challenge to where you are coming from - and I understand and accept where you’re coming from - is that if you as an association are requiring anything like a “benchmark” that only allows registration and operation if that benchmark is met you have defacto created a design standard ... and that is in direct and complete opposition to the CAOs where all homebuilt airframes are not designed to any standard.

 

The conflict between what people may expect or accept as reasonable and what the requirements under the CAOs are is the core of the conflict.

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.

My core challenge to where you are coming from - and I understand and accept where you’re coming from - is that if you as an association are requiring anything like a “benchmark” that only allows registration and operation if that benchmark is met you have defacto created a design standard ... and that is in direct and complete opposition to the CAOs where all homebuilt airframes are not designed to any standard.

 

The conflict between what people may expect or accept as reasonable and what the requirements under the CAOs are is the core of the conflict.

I’ll put something together to explain it.

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The logical end point of this discussion is a requirement for fully engineered five point harnesses and ballistic recovery parachutes. That adds probably another $15,000 to the cost of an aircraft and a weight penalty of 50+ kg. Do we really need to go there?

 

Then we have fire. Shrouded externally drained stainless and teflon lines with steel fittings. An inerting system, fuel cells, break away couplings.

 

Dual batteries, dual everything.

 

ADSB in and out. Strobes, beacons, lifejackets, aviation hard installed EPIRB.

 

‘’Purpose built aircraft engines and professional maintenance. Everything TSO’d. Not so much as fitting a Go Pro without a fully engineered and approved mount.

 

The list is endless. I would suggest that better and more pilot training is a better return on investment.

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A local built a kit aircraft a couple of years ago.

He had to follow the manual exactly, and the tech manager at the time layered his own personal requirements on top of that.

The underlying threat was the aircraft would not be accepted for registration......

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A local built a kit aircraft a couple of years ago.

He had to follow the manual exactly, and the tech manager at the time layered his own personal requirements on top of that.

The underlying threat was the aircraft would not be accepted for registration......

And therein lies the problem with anything that is not a factory built and type accepted/approved airframe.

 

Raaus tech have long behaved in a way that is applying far more power than they have on designer/builders and threatening to withhold or remove registration.

 

When really pushed they have on several occasions over many years admitted lack of power/authority and I have continued to make and modify my airframes as I see fit.

 

And to be clear. I am not trying to be difficult for the sake of being a bastard to the tech manager - I am enjoying the pastime of building and modifying within the bounds of the CAOs and to do as I please given my airframes are not factory built type approved/accepted designs.

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My core challenge to where you are coming from - and I understand and accept where you’re coming from - is that if you as an association are requiring anything like a “benchmark” that only allows registration and operation if that benchmark is met you have defacto created a design standard ... and that is in direct and complete opposition to the CAOs where all homebuilt airframes are not designed to any standard.

The conflict between what people may expect or accept as reasonable and what the requirements under the CAOs are is the core of the conflict.

I've started to prepare a comparison between the two methods of governance, but "the CAOs: was a bit vague to work on; I found this (which I've paraphrased - refer the actual documents for contiguous information)

 

 

RAA Technical Manual issue 4 – August 2016 states:

“Section 3.1 Amateur built and kit built”

  • “CAO 95.10 provides for operation” [of RA amateur built and kit built]

1.6 “Need not be an approved design”

 

 

CAO 95.10 states:

  • “Privately built single place aeroplane where:”
  • It’s registered with RAA
  • MTOW max 300 kg
  • If registered after March 1, 1990
  • Wing loading requirement
  • If you are not the builder must have RAA build certificate

Design

  • By the builder, or
  • To a set of drawings approved by RAA, or
  • Built from an approved kit, or

Was it RAA 3.1 and CAO 95.10 you were specifically referring to?

 

If so, it seems to me that CAO 95.10 is not prescribing a design and nor is RAA 3.1

 

If you could clear that up, I'll keep working on what I started.

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A wing loading on any 95-10 design defeats, 1.6 "need not be an approved design".

If registered after "march 1, 1990" IS WRONG !.

it,s FLYING, registered previous but not flown gets DEREGISTERED

spacesailor

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A wing loading on any 95-10 design defeats, 1.6 "need not be an approved design".

If registered after "march 1, 1990" IS WRONG !.

it,s FLYING, registered previous but not flown gets DEREGISTERED

spacesailor

Space, you need to stay out of this; I have condensed things down to only what Kasper and I were discussing.

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