RAAs and 750kg

[Robert]

Hi All

 

Just wondering whats happening with the RAAs 750kg weight limit

 

Is it going to happen and if so when???

 

Cheers

 

 

[Guest Andys@coffs]

Seems to me that 750 wont happen (if at all) until Pt 103 gets through with the 600kg's that it brings (subject to a manufacturers rated MTOW that equals or exceeds 600) and it would seem, at least to me, that the rate of progress there has slowed somewhat. Perhaps it has electionstallitis, a particularly nasty disease that seems to prevent any forward motion, replacing it with small radius circular motion, by some gov depts departments in the months leading up to and, if a change occurs, months after an election.

 

Andy

 

 

[Guest Teenie2]

Going up in weight limits ,I don't know if its the best idea,probably is .Whats got me worried ,as weight goes up there is a possibility of the complexity and speed increasing in the A/C (who knows,flyby wire,kit planes mag had a article on how to do it.Coupled autopilot.Carbon fiber honeycomb composite,400 hp engines ).Now I'm not being disrespectful but the average RAA pilot and Level 2s might start reaching their limit of abilities,(not just maintenance but piloting skills also) and sometimes its hard to know when you have reached that limit.Safety might start to be compromised .A/c crash, people dead ,public angry, CASA step in. BYE BYE RAA.

 

Who knows? But I hear alarm bells.

 

Have fun

 

 

[TechMan]

Whats got me worried ,as weight goes up there is a possibility of the complexity and speed increasing in the A/C (who knows,flyby wire,kit planes mag had a article on how to do it.Coupled autopilot.Carbon fiber honeycomb composite,400 hp engines ).Now I'm not being disrespectful but the average RAA pilot and Level 2s might start reaching their limit of abilities,(not just maintenance but piloting skills also) and sometimes its hard to know when you have reached that limit.Safety might start to be compromised .A/c crash, people dead ,public angry, CASA step in. BYE BYE RAA.Who knows? But I hear alarm bells.

Have fun

750kgs is a while away yet, and can be measured in the length of a string. A discussion paper on the increase is circulating inside CASA at the moment and should be out on their website for discussion at some point in time, hopefully sooner rather than later.

 

With regard to increasing levels of complexity - they have been around for a little while now. Aircraft with coupled auto pilots / wing levellers, retracts, variable pitch props, exotic composite constructions and close to 300hp engines.

 

I agree that the competencies of the people that are meant to be maintaining these aircraft can be questioned, yet to date the accident statistics do not appear to be related to owner maintenance worries.

 

The bigger issue is training people in how to use the increase in self inflicted complexity to stop them deviating from the first rule - Aviate - that is the hard thing to get across in my opinion. I say self inflicted because we choose to have a variable pitch prop, we choose to have retracts and we choose to pack the cockpit full of the latest hi -tech gear that ensures our heads are more than often inside the cockpit rather than looking outside at what is coming toward you.

 

Chris

 

 

[Yenn]

The article in Kitplanes that I saw some years ago concerning Fly by Wire, came to the conclusion that it was not warranted for homebuilt planes. Maybe there is a later article I missed, but I doubt that many would want it.

 

Wing levellers are a great invention and so long as you know how to use them they are a safety aid.

 

The items that worry me are mixture control and carbie heat which have been around since the start of aviation and seem to cause more than their fair share of accidents.

 

 

[Guest brentc]

I can vouch for the use of autopilot / winglever even in light aircraft. Have been driving around a J430 with IFR Garmin gear and auto-pilot and must say I like it a lot and if I was building again, I'd put it high on my list. It makes the longer trips more enjoyable and comfortable, less tiring and keeps your eyes out the window and not looking at the compass or GPS freuqently.

 

 

[Robert]

Hi All

 

I think up to 750KG would be a good idea. It would make a few marginal two seater aircraft more legal and able to carry up to there designed gross legally.

 

Also a heavier aircraft sits in the air more stable and is not so prone to turbulance etc.

 

I feel limits on speeds and H.P. would be more apropreate

 

Some of the new plastic fantastics are getting fairly fast and I think speed and stability are a good test for a pilots skills.

 

 

[Guest pelorus32]

We also need to be aware of the array of issues with an increased MTOW. I'm a big supporter of an increase to 750kg because it mirrors the maximum potential design weight of most of the European aircraft. It therefore moves MTOW from an arbitrary legislated weight to something based on the design and therefore demonstrated safety. In that scenario if you have a MTOW of say 570kg then it's because that is the design weight of your aircraft. I think at that point pilots will be much more likely to observe MTOW limitations than they are now.

 

However let's look at the Wonderflyer Mk I which has a 1g stall of 40 knots at 544kg. At 750kg the 1g stall will be 1.17 times that or around 47 knots. If we use Vref of 1.3 Vs for our approach then our approach speed increases from 52 knots to over 60 knots. That means th aircraft takes more stopping because it's both heavier and faster and energy is related to mass * velocity sq. Then we can look at C of G issues etc. And whilst the gear will have been drop tested at 750kg if that's the design weight it will nevertheless be more prone to heavy landing damage at 750kg than at 544kg.

 

So again whilst I'm a big supporter this is not a trivial move.

 

Regards

 

Mike

 

 

[facthunter]

750 Kg. auw.

 

I'm all for this , as every time I've looked at design parameters, ( excluding super composites,, ie carbon fibre).

 

To carry two people.

 

Fuel 4.5 hours plus reserves.

 

A bit of overnight gear plus tie-downs etc.

 

Have a decent set of brakes & wheels.

 

Make the aeroplane reasonably strong.

 

big enough wing to stall slow without too many devices.

 

Empty weight comes out at about 360 Kgs.

 

Just add the payload above & it comes out at about 750 Kg.

 

The downside of this scene is not obvious to me. You maintain simplicity, strength, can use steel tube ,wood ,sheet metal, glass fibre, ( all very proven ,long life materials) can run a metal prop decent sized engine,,etc. There is no liability in any of this, in fact you can beef-up a little here & there, without everything going off-scale. You could easily make a case for increased safety, as a result of the increased strength. You still stick to 2 people, as passengers are where you really buy into liability. Nev

 

 

[poteroo]

Possible Developments with 750kg ?

 

(1) A VANS RV-9A fitted with a Jabiru 3300 engine fits below this number, and will happen - because the original VANS development of the -9A included 2 engines and AUW's. The 1600lb,(727kg), weight was for the Lycoming 0-235 118HP engine, and the 1750lb,(796kg), weight was for the Lycoming 0-320 engine. Given the Jab is around 40kg lighter, that match up will work really well. My guesstimate is for an easy-to-fly 135 KTAS aircraft using 22LPH.

 

This aircraft would fit into Experimental only, because there is no way that VANS are going to produce a factory model when they already have the RV12 tested.

 

(2) A whole new service 'life' for training aircraft such as the C150, which fits into the category with an AUW of 1600 lbs, (727kgs). The C152 misses out by being just a few kgs over the 750 bar. Given the 150's demonstrated ability to withstand everything possible from students - as compared to the more fragile structure of many modern RAA aircraft, they would have to be my choice of trainer.

 

And, you can buy a good one for $40,000 ! And, they don't need much change, if any, to make them capable of NVMC, which will happen for RAA sooner or later.

 

happy days,

 

 

[vk3auu]

It is still a bit too early to talk about 750 kg MTOW as we still haven't got 600 kg yet. If we start getting up to those weights, the powers that be might start to think about introducing medicals again too.

 

David

 

 

[eyecast]

Possible Developments with 750kg ?

 

Hi All

 

Is there any movement in the regulation as yet???

 

eyecast

 

 

[Guest Crezzi]

... an increase to 750kg because it mirrors the maximum potential design weight of most of the European aircraft.

Thats because 750kg is the MAUW of the VLA category but I'm not aware of any european countries where you can fly these on the equivalent of our ultralight certificate - AFAIK you need a PPL .

 

Cheers

 

John

 

 

[Guest pelorus32]

Thats because 750kg is the MAUW of the VLA category but I'm not aware of any european countries where you can fly these on the equivalent of our ultralight certificate - AFAIK you need a PPL .Cheers

 

John

Agree John,

 

I guess that the point I was trying to make is that many of these aircraft are designed in accord with CS-VLA though not certified to it. That seems to suggest that 750kg is a natural limit, given that it is the design max for at least some of the aircraft.

 

Regards

 

Mike

 

 

[Guest Crezzi]

I don't know about 750kg being a natural limit - its just another legislative one as far as I can see. Of which they are / have been many in different places over the years.

 

I started flying in the UK when it was only 390kg MAUW - pretty much limited 3-axis to nothing heavier than 503 engine and the CFM Shadow was about the only plane which could vaguely be called high performance. The limit was eventually increased to 450kg which it still is AFAIK. The USA still has FAR103 is 254 lbs. In Aus there have already been increases to 544kg then 600kg (with LSA).

 

My point isn't so much that we are better off here than a lot of other countries (though that is true). In every instance, whatever the weight limit, there were planes that can just squeeze into the category provided they are flown by a skinny crew with 60 mins max of fuel and only a credit card as luggage. And the owners of these planes always (understandably) feel aggrieved that they can't use the full potential & theres pressure to increase the limit !

 

By choosing to register it as an ultralight we are agreeing to abide by the limitations of that category. If one can't or won't do that there is a choice - register it in a different category & get the appropriate licence. Not increasing the ultralight limit doesn't mean the plane can't be flown. So I'm not in favour I'm afraid.

 

Cheers

 

John

 

 

[blueline]

Why have a limit at all?

 

Just a thought, but why are we safer with a 600kg limit or 750kg limit?

 

How does a weight limit make things better or safer?

 

 

[vk3auu]

I'm with Crezzi. If you want to fly heavier, go to the other administration, otherwise we might as well abandon ultralights altogether.

 

David

 

 

[blueline]

Apart from nostalga why are we better off with a weight limit?

 

.......and no, just saying "because thats the way it is" or "95.10 is what the AUF is all about" or "we don't want Cessna's" is NOT an answer!

 

What I am interested in hearing is, is there a sound and justifiable reason why we have a weight limit at all?

 

 

[antzx6r]

I think casa's viewpoint seems to be as simple as less weight - less damage if things go pear shaped. That and we did call ourselves Australian Ultralight Federation in the early years. So you can't blame them for being confused.

 

The point made earlier about safety advantages in higher MTOW is a strong one. I agree with the 750kg MTOW mainly because I fly light because its cheeper. I think a lot are the same. I got to first solo in a 152 aerobat before switching to RAA, and the stability of even that small amount extra weight was very reasuring in the early stages of training. (I imagine a 150 wouldn't be too different)

 

The complexity of twins and IFR flight as well as the carriage of more than two POB are personally what I think warrants a move to a class 2 medical and extra training of PPL(+endorsments). Weight dosn't add compexity, it just changes your critical V speeds. I plan to get my ppl anyway when funds allow, mainly to get that stability in my flying again.

 

It would be nice not to have to...

 

 

[Guest brentc]

Don't make the mistake of thinking that bigger is more stable. It isn't always the case. Same goes with faster aircraft, when they are faster, the bumps become sharper. The trick is finding an aircraft that sits in the middle. The Cirrus for example can be quite a rough aircraft, yet they are heavy.

 

 

[Mick]

My own concern with the idea of upward spiralling weights and increasing complexity is that eventually I fear this will lead to more complication for all of us. Such as an increase in training requirements ( not such a bad thing other than cost ) and a higher medical requirement which may exclude some of us that are currently permitted to operate LSA / Recreational aircraft.

 

I find it hard to believe that the increase in weight and complexity will not eventually lead to us loosing some of the freedoms that have taken so long to be gained.

 

The line between LSA / Rec and GA has to be drawn somewhere. Personally I am happy with where it is now.

 

Cheers

 

Mick

 

 

[eyecast]

It just seems to me that there is a range of a/c's out there that would suit the Recreational Class in a 600 to 750 Kg weight range. Yes I agree that thay are no longer Ultralite and shouldn't be labled as such.

 

Eyecast:yuk::yuk::yuk:

 

 

[Yenn]

antzx6r. Are you aware of any improvement in safety with the medical requirements.

 

The latest Flight Safety magazine mentions a case where an ATPL collapsed and was unconscious on the flight deck. He would have had a medical.

 

A good friend of mine collapsed and died from a heart attack, not long after renewing his medical.

 

I talked to the DAME about this and his response was that it is impossible to tell if someone will die from a heart attack. Really it appears that the requirement to have a medical only makes us aware of our state of health.

 

I would like to know how many accidents in aircraft are caused by medical problems.

 

 

[antzx6r]

Yeah, thats a good point. I suppose CASA needs to be seen to be making flying travel "safer".

 

The only changes i've heard is an artical in Flying about prostate cancer recently. Stating that its no longer a flat cancelled medical if diagnosed.

 

Its probably a good idea if everyone went for a class 2. Just to get a good check up.:ah_oh: Sorry guys...

 

 

[TechMan]

My own concern with the idea of upward spiralling weights and increasing complexity is that eventually I fear this will lead to more complication for all of us.

I am not sure what extra complexity you mean Mick. We already have all the complexity that the lower end of GA have, if not more. Retracts, CSU, Floats, Amphibs, auto pilots, glass cockpits, rescue systems etc etc

 

750kg would allow aircraft like the C150/152, early pipers, RVs to join the ranks if they wished. It would still not allow helicopters, gas turbines and the like to join up.

 

Chris