Weight restricted MTOW

[Oscar]

The stall may be limited by elevator authority but such a plane is not pleasant to land. It is pretty safe however. Nothing I say here should make people fly slower approaches than they are comfortable with. A margin of speed is needed for safety. If you are consistently floating a long way or tending to land on the nosewheel, do some revision with an instructor and see if you can get a bit slower especially later in the approach . Speed control should be consistent. You can't really be looking at the A/S much under 100', but if power and attitude don't change nothing bad will happen. If you are unsure do it dual. Nev

Nev: the Seeker is a bit 'squirmy' to land, for sure. But if you pull it back to the end of the elevator travel, it settles into a high-drag mush that is fairly reminiscent of a well-developed side-slip, without the sideslip components. You just hold everything on the back stop and play the throttle to achieve the aiming point.. and actually push the sick sightly forward to soften the flare.

 

 

[turboplanner]

If you aren't stopping until just after the end of the runway Turbs you might have to push those brakes a bit harder, or close the throttle a bit more:whistling:

Smartarxx, start of first piano keys, to end of first piano keys. We had a red hot instructor who would pull one on us when we least expected it. C152 pilots were expected to land and pull up on the keys. Cherokees with tyres squealing were just over the edge.

 

 

[Oscar]

WOW: Superman.

 

The official figure for a Piper Warrior Ground Roll is 595 feet: 181 meters. Of course, that is only what was achieved by a professional test pilot flying for certification purposes.

 

Measuring from Google Earth, the Piano keys at Moorabbin are around 30 metres long.

 

I am impressed that you can negate the rules of physics. Any of those Worriers still airworthy?

 

 

[facthunter]

Reputed to have brake wear problems. Nev

 

 

[Oscar]

And excessive costs for main gear tyre replacement.

 

 

[turboplanner]

WOW: Superman.The official figure for a Piper Warrior Ground Roll is 595 feet: 181 meters. Of course, that is only what was achieved by a professional test pilot flying for certification purposes.

Measuring from Google Earth, the Piano keys at Moorabbin are around 30 metres long.

 

I am impressed that you can negate the rules of physics. Any of those Worriers still airworthy?

The keys are about 120 feet, you'll get down to about half that ground roll on dry bitumen with full brakes, so 250' - keys 120' = 130' beyond the keys = just past the end on a 3500' runway

 

 

[Guest Andys@coffs]

So when we are on our mains having just landed, or just about to head up the AOA is determined by the undercarriage geometry rather than the airfoil. If the pitot was placed as you suggest to make the figures, better, from an LSA OEMs perspective then wouldn't we see an immediate change in IAS as weight comes off the wheels? I can't say I've looked for it myself but doubt that I see drops of heaps of knots......

 

Of course that presumes that the pitot to ground reference when on wheels is such that the they are parallel......

 

Anyway, just asking cause I don't know....not suggestion anything......

 

 

[coljones]

Sorry col, my grasp of the english language isnt complete despite my pilot licence professing me to be an expert in it. Perhaps thats why I ended up an engineer....What I am trying to imply is that the difference in stall speed between a jabiru and an rv7 means that the approach speed is faster making them generally a little bit harder to handle. You have to be that little bit more precise to do a successful landing.

Sorry Nobody. Today I went flying an LSA55. The slower it went the quicker it fell out of the air on final, bugger!!!

 

 

[Head in the clouds]

So when we are on our mains having just landed, or just about to head up the AOA is determined by the undercarriage geometry rather than the airfoil. If the pitot was placed as you suggest to make the figures, better, from an LSA OEMs perspective then wouldn't we see an immediate change in IAS as weight comes off the wheels? I can't say I've looked for it myself but doubt that I see drops of heaps of knots......Of course that presumes that the pitot to ground reference when on wheels is such that the they are parallel......

 

Anyway, just asking cause I don't know....not suggestion anything......

I'm assuming this was in response to my post yesterday?

 

You're saying "doubt that I see drops of heaps of knots......", well, no, you wouldn't, even if you were looking at the point of 'rotation'.

 

Firstly, we're no talking 'heaps of knots', in the Sling example we're only talking 3.9kts low reading at the full stall. Hopefully, when you 'rotate' to climb attitude you'd be setting your plane and wing up at best L/D which would be at maximum 9 degrees AoA (alpha), that's only two degrees past where the off-axis pitot error begins, and given that pitot error is aomething like exponential with the extent of off-axis-ness, then at 9 degrees there'd be very little error in the ASI indication anyway. It might be just one knot at climb alpha.

 

Secondly, throughout the take-off you're accelerating. If you weren't accelerating but instead you were running along the runway at constant speed just below flying speed and you rotated but didn't lift off, you might observe a small drop in the indicated airspeed, perhaps of about 1 or 1.5kts if you rotated to 9 degrees alpha. However, in reality you are accelerating during the take-off and so, if you looked at the ASI during rotation, you might see a hesitation in the advancement of the airspeed instead of a small drop.

 

Regardless of the above, our ASI instruments are not what would be described as sensitive* instruments so a drop of 1 knot, or a slight hesitation might not even be noticeable.

 

*An example of a sensitive instrument is an altimeter that has two pointers (the type with an adjustable subscale) where the scale of the longer pointer is divided into 10ft increments, one full rotation is a thousand feet. A non-sensitive altimeter is the type with only one pointer and the scale is usually divided into 100ft increments with one full rotation of the pointer indicating 10,000ft, or sometimes 5,000ft or 20,000ft.

 

EDIT - Also - if your pitot and the ground are in fact parallel when sitting on your wheels, and assuming the fuselage is set level when on your wheels, then your pitot is actually angled down by 3 degrees or so due to the rigging angle whereby the wing is usually set with about 3 degrees angle of incidence to the longitudinal axis. In which case you probably wouldn't see a change at rotation.

 

 

[facthunter]

Since we accept there are significant errors of indicated speed(s)possible with some installations It would be wise to not place total emphasis on what the instrument actually reads. How the plane flys is most important. If it has the speed the book says and still flys like it's near to stall play it safe and do some stall or near stall speed manoeuvering at height and adjust your speeds. Planes we fly vary a lot. If you are flying a Corporate jet etc you expect these things to read very accurately. You are expecting that for the type of machine.

 

Things like......Your static line can be venting to cabin and the pitot can have the dreaded wasp mud plug in it. Don't blindly trust any one indication with an aeroplane. Back it up with something else. Nev

 

 

[kasper]

Since we accept there are significant errors of indicated speed(s)possible with some installations It would be wise to not place total emphasis on what the instrument actually reads. How the plane flys is most important. If it has the speed the book says and still flys like it's near to stall play it safe and do some stall or near stall speed manoeuvering at height and adjust your speeds. Planes we fly vary a lot. If you are flying a Corporate jet etc you expect these things to read very accurately. You are expecting that for the type of machine.Things like......Your static line can be venting to cabin and the pitot can have the dreaded wasp mud plug in it. Don't blindly trust any one indication with an aeroplane. Back it up with something else. Nev

And that would be visual attitude to the extended horizon ... VFR is Visual Flight Rules ... how about some Visual Flight with reference to the world you presumably as a recreational pilot went up to look at and fly around in? If you are ever so constrained by Instruments then I suspect IMC and Instrument flying should be your pleasure ... and the cheapest option for doing that is a flight simulator or computer program.

Strangely you might find MOST weightshift pilots (and most old school AUF pilots) flying mostly by reference to attitude, power and control position ... indeed any WS pilot looking in the pod to the aispeed on final approach deserves a whack in the back of the helmet from the instructor in the back .. "fly the bloody wing not look at whats an out of date and inaccurate reading of what your speed was a few seconds ago" ... sort of still rings true

 

 

[DonRamsay]

I'm aware that the manufacturer has done "in-house" testing and are confident that the Sling should pass proper (i.e. independent") certification for VLA. That isn't the same as actually having VLA certification and a type certificate for 700kg. The only category for which the manufacturer are allowed to self-certify factory built aircraft is LSA which are limited to 600kg.

Thanks John, clearly I was not aware that VLA required "type certification" by independent authority. EASA do suggest that VLA is intended to be an easier form of certification than full on GA and VLA limitations are very similar to LSA with the exception of the 750 kg MTOW instead of 600kg. Day VFR, 2 pax, 1 x piston engine, etc. Type Cert would also put limitations on who can maintain and that could get ugly.

 

The VLA standard IS accepted in Australia but GA factory built Sling are still limited to 600kg because they are only certified as LSA not VLA.

I was not aware VLA was available in Aus but then, until RPC can fly at >600kg, there was no interest for me.

 

The manufacturer can't just "declare" that an aircraft is now a VLA without an appropriate type certificate which the Sling doesn't have AFAIK.

I've sent an enquiry to the factory to find out for certain.

 

On that basis, an increase in the weight limit for RAAus aircraft won't allow you to legally fly your aircraft at more than 600kg.

You really know how to ruin somebody's day John. But I know and accept that you were just being helpful and it is always better to know than be living under an albeit pleasant delusion - so thanks again.

Don

 

 

[jetjr]

"On that basis, an increase in the weight limit for RAAus aircraft won't allow you to legally fly your aircraft at more than 600kg."

 

Depends how the weight increase is structured, LSA could move to E reg and through MARAP raise it using factory data to back it.

 

It does seem VLA isnt going to help, and it still keeps 45kts stall so wont help anyone much.

 

Just go for 700kg and 50kts min stall dirty. Make it happen Don :)

 

 

[facthunter]

If your aircraft can be legally flown at higher weights based on design structural factors, when the system it's operating in allows a weight increase, it should be free to run the the structural limit, if all else would allow it.

 

The exception with BRS and floats make no sense at all. I wonder what would happen if one failed due the allowed overload? Airframe life is reduced when operated at higher weights. Not easy to quantify but the reduced life of aerobatic aircraft is an example. Dynamic loads being just as important. Nev

 

 

[DonRamsay]

Depends how the weight increase is structured, LSA could move to E reg and through MARAP raise it using factory data to back it. . . . Just go for 700kg and 50kts min stall dirty. Make it happen Don :)

The 600kg for LSA is pretty well a worldwide standard (except for the UK?) - could be difficult getting CASA to move ahead of the world on that one.

And as we are targeting equality with the RPL at 1,500 kg you can always go to a gas guzzling 2 seat C180 with a 100 hourly costing many thousands of dollars. Sweet.

 

 

[facthunter]

What the rest of the world does with U/L's has little relationship with what we COULD achieve/do here. It doesn't have to conform with much at all. If we wanted freedom we could have it. Nev

 

 

[turboplanner]

What the rest of the world does with U/L's has little relationship with what we COULD achieve/do here. It doesn't have to conform with much at all. If we wanted freedom we could have it. Nev

Exactly, and the first step is to prove you are capable of self administration, and so far that's proved to be the insurmountable hurdle; it doesn't take that much to get the momentum going.

 

 

[jetjr]

And the song starts again....

 

Theres some variation with the 600 kg limit as some countries have different stall requirements and or HP limits too

 

 

[facthunter]

There's no need to be ICAO compliant. IF you were in the EU it would be different. Exemptions became a so called problem. Why when there is no migration/connection with other systems in this country? We are autonomous by our geography. Why wait till the rest of the world is ready to be the same? Nev

 

 

[turboplanner]

There's no need to be ICAO compliant. IF you were in the EU it would be different. Exemptions became a so called problem. Why when there is no migration/connection with other systems in this country? We are autonomous by our geography. Why wait till the rest of the world is ready to be the same? Nev

There is a need for some areas to be ICAO compliant, since some aircraft effectively fly Internationally.

 

There are also manufacturing and parts availability advantages in complying with an international standard (immediately lost if local conditions preclude the specification item)

 

However, the rest is exactly as you say.

 

What is required is a study to identify what fits where.

 

For several years people on this forum have spruiked the easier FAA regulations as a much better option than Australia's rapid move into ICAO standards, but in recent times when I've checked the FAA website for comparisons, I've found they also are well down the road to ICAO compliance.

 

We shouldn't lose sight of the fact that there are recreational aviation groups in all ICAO countries, many with the same problems we face, so the best path, and the most difficult may be to start heading in the direction of getting some ICAO regulations changed to suit recreational flying - start from the top down, instead of bashing against the glass ceiling.

 

 

[kasper]

There's no need to be ICAO compliant. IF you were in the EU it would be different. Exemptions became a so called problem. Why when there is no migration/connection with other systems in this country? We are autonomous by our geography. Why wait till the rest of the world is ready to be the same? Nev

Unless you are looking at plans built or one off self design the desire to go with a design standard that is international is that Australia just aint big enough a market to sustain design/manufacture on other than a 2-3 person 'factory' not faced with the initial certification costs ... you might sell 25-50 airframes into the australian market before the customer starts demanding MORE than can be provided from your basic design and you go again ... 25-50 airframes can't cover design/test/certify so you have to make the production run bigger ... you NEED international markets to cover the initial certification AND if that certification is accepted in another country BRILLIANT. That is why nearly all of Europe has a 450/472.5kg two seater classed as ultralight/microlight and you see sales between all of these countries because the certification costs in 1 country covers others.

Similar with Jabiru - they certified to Australian first with the SLA55 ... not allowed/accepted in UK due to stall speed - same in Canada ... so they came up with a fuse stretch and wing stretch to lower the stall ... two new markets but at additional design and cert costs. They learned their lesson ATSM certification LSA has more acceptance around the world so one set of tests covers more airframes.

 

Simple really - its economics of profitable operation

 

 

[facthunter]

You could do a lot worse than follow the way EAA did it in the USA. EAA Biplane Basic concepts and a few generic designs. Still use the Euro stuff if you can afford it. Fly a Jabiru if you wish Pick the eyes out of all of it Single seat and two seat versions Steel tube wood and fabric sheet metal mixes. Firewall forward packages/kits. Plenty of possibilities and use general proven methods of construction, and testing. Nev

 

 

[DonRamsay]

What the rest of the world does with U/L's has little relationship with what we COULD achieve/do here. It doesn't have to conform with much at all. If we wanted freedom we could have it. Nev

"Freedom" is the key word here, Nev.

RAAus no longer sees flying as a privilege. We see it as our right in a free country. Obviously, we recognise that almost all rights in a free country may need to be constrained for the safety and benefit of all. But, for any constraint of a freedom there has to be a well argued safety case. The example often given theses days is shouting "BOMB" in a crowded theatre. Doing that would most likely see people killed in the stampede.

 

So, RAAus does not seek more privileges but removal of unreasonable restrictions on our flying freedoms.

 

 

[DonRamsay]

Exactly, and the first step is to prove you are capable of self administration, and so far that's proved to be the insurmountable hurdle; it doesn't take that much to get the momentum going.

Really, the first step is for CASA to put forward a sound and balanced safety case that justifies any restriction that they place on our flying freedoms. In allowing RAAus pilots exemptions from certain regulations, CASA is expressing its faith in the capability of RAAus to administer effectively. I doubt that they care too much whether it is done efficiently because they are not footing the bill for the administration. They supervise our rules as contained in the Ops & Tech manuals and audit our effectiveness and, where they perceive it necessary, require correction of any non-conformances. As we all know, RAAus went through a very dark patch a couple of years ago but is doing much better now. Not perfect but, in my view, sustainable and improving.

 

 

[JabiruJoe]

So, RAAus does not seek more privileges but removal of unreasonable restrictions on our flying freedoms.

Hope you are right there Don. So far, my experience is not showing that. HOWEVER, I have made contact with the CEO and he has asked for some paperwork and is looking into it (the original thread post, #1). Hope you are right there Don.