Finally Group G is getting closer

[BrendAn]

4 minutes ago, BrendAn said:

lots of 150s out there. at my club anyway.

maybe 152s, i don't look very close

[facthunter]

THEY would have to be a bit heavier. Their cockpits are not very WIDE. (both). Nev

[BrendAn]

9 minutes ago, facthunter said:

THEY would have to be a bit heavier. Their cockpits are not very WIDE. (both). Nev

thats what i like with the xair. heaps of room once you get in there.

[Thruster88]

28 minutes ago, BrendAn said:

another thing but same topic. are they going to raise the stall speed min to allow a lot of the heavier craft to even qualify for raaus.

There is no stall speed limit for group G. This would allow my RV6a, 53kts stall to be eligible. Mine is definitely staying VH reg. If I can't pass a class 2 medical or the new class 5 then it will be sold. I feel it would be worth more with VH reg.

[BrendAn]

5 minutes ago, Thruster88 said:

There is no stall speed limit for group G. This would allow my RV6a, 53kts stall to be eligible. Mine is definitely staying VH reg. If I can't pass a class 2 medical or the new class 5 then it will be sold. I feel it would be worth more with VH reg.

thanks. that makes sense, i just assumed, wrongly that group g would have the same stall limit.

[Kyle Communications]

Group G was originally 45 kts but RAA negpotiated with CASA and a lot of other in their survey thingy so CASA ended up relaxing the stall speed

 

[LoonyBob]

11 hours ago, skippydiesel said:

"RA aircraft must be as small/light/slow/useless as governments can possible mandate"

 

TO weight is mandated  - don't think size is.

From what I have read, speed would seem to be a US mandate. Don't recall a speed limit on AU registered RA aircraft (?) and these days some leave their GA cousins in their slipstream. 

95:10 has a stall speed limited by wingloading, which automatically limits the cruise etc (physics); 101:55 had 40?kts clean stall, the ASTM (LSA) had 40kts clean in the USA, 45kts clean in Aus.

 

Since the root bending moment the wingspar has to cope with is a function of the span, and the spar strength is a function of the square of the depth, and the spar stiffness (flutter resistance) is a function of the cube of the depth, pushing the span up very quickly pushes the weight up. Also, as the airfoil 2-dimensional L/D is very sensitive to the thickness-chord ratio, deepening the spar means increasing the chord in proportion; the inverse cube law again pushes the weight up fast. A bigger wing needs a bigger HS for positive longitudinal stability, and bigger / further out ailerons mean a bigger VS, both of which require a stronger rear fuselage, all of which put more energy into the undercarriage, hey poop it won't climb, get a bigger engine...

 

How many RAAus aircraft have much more than 10m wingspan or 12 square metres of wing?

 

Re the speeds, if you're prepared to have marginal hot & high performance at MTOW (PA-28-140? VP2? asthmatic J-160 with big wheels & no spats? T83 with the original 277?), then cruise will be about 1.6~1.75 x the clean stall speed. If you manage a better power to weight, especially with a cleaner airframe, you can see Vno = 2Vs1, and with an RAAus wingloading, climb will be spritely. More is possible, but that low wing loading means convection will tend to break your teeth as Vno gets up, and the limit load factor will exceed 4G at not much over 100kts.

 

M. DelaMontez's polygonal wing (which also incorporates 3 airfoil changes and rather tricky washout) manages to trick the problem, to the stage that the D18 has a Va twice  Vs1, but Vno = 2.25Vs1 (i.e. 90kts). The Thruster T300 uses one of the very few airfoils known to have a LOWER Clmax at higher Re, thus allowing Newton H. to push the Vno (Vb) up to match the Va, at 72kts, which is also Vc for that aircraft.

 

I have given the matter considerable thought, as I personally want an RAAus owner-maintained single seater with a Vno of 250kts... and I imagine I will continue to do so!

[LoonyBob]

I'll throw this out: Did RAAus finally get the go-ahead for CTA endorsements, because Badgery's Creek is going to close (CTA) off the whole Sydney basin to lowlife scum like us?

[BurnieM]

You mean Western Sydney International ?

Almost certainly this was a factor.

Edited January 30 by BurnieM

[turboplanner]

15 hours ago, BrendAn said:

thanks. that makes sense, i just assumed, wrongly that group g would have the same stall limit.

If you look back on this site to around 2010 you’ll find Sydney schools with RA Aircraft having the required specification, and students having the required qualification travelling through CTA as they today.  It’s no hardship learning the procedures as you learn to fly.

[BrendAn]

13 minutes ago, turboplanner said:

If you look back on this site to around 2010 you’ll find Sydney schools with RA Aircraft having the required specification, and students having the required qualification travelling through CTA as they today.  It’s no hardship learning the procedures as you learn to fly.

15 minutes ago, turboplanner said:

If you look back on this site to around 2010 you’ll find Sydney schools with RA Aircraft having the required specification, and students having the required qualification travelling through CTA as they today.  It’s no hardship learning the procedures as you learn to fly.

 

I have no idea why you are talking about training. I was talking about raaus stall speed requirements.

[turboplanner]

12 minutes ago, BrendAn said:

I have no idea why you are talking about training. I was talking about raaus stall speed requirements.

Sorry posted in the wrong place

[turboplanner]

2 hours ago, BurnieM said:

You mean Western Sydney International ?

Almost certainly this was a factor.

If you look back on this site to around 2010 you’ll find Sydney schools with RA Aircraft having the required specification, and students having the required qualification travelling through CTA as they today.  It’s no hardship learning the procedures as you learn to fly.

Edited January 31 by turboplanner

[Blueadventures]

8 minutes ago, turboplanner said:

If you look back on this site to around 2010 you’ll find Sydney schools with RA Aircraft having the required specification, and students having the required qualification travelling through CTA as they today.  It’s no hardship learning the procedures as you learn to fly.

Once they get their certificate will they be able to continue the fly there; most can't continue the access CTA post completing their training.

[turboplanner]

6 minutes ago, Blueadventures said:

Once they get their certificate will they be able to continue the fly there; most can't continue the access CTA post completing their training.

I haven't looked at the fine details for a school in CTA.

When they complete first solo and qualify to fly in the Training Area, what happens?

When they complete Pilot Certificate and fly in the Training Area, what happens?

When they complete and pass all Nav and are qualified to fly cross country, what happens?

(all the above in a School RA Aircraft with CTA Specification.)

Are there some gaps there?

 

[BurnieM]

I believe currently when you get your RPC you can no longer takeoff/land at Bankstown. Can somebody confirm.

BT lane of access and training area are fine but where do you take off from ?

 

When WSI goes live we lose Bankstown lane of access, Bankstown training area and part of Camden training area and these areas all become controlled. You would require a massive westerly detour if you want to stay uncontrolled. I believe this is a significant part of RAA getting CTA access.

The size of this political problem is why I think owner maintained group A will have access.

 

Question I have is what equipment requirements will there be ?

ADS-B ?

A harder attitude to 2 yearly calibrations ?

?

Edited January 31 by BurnieM

[turboplanner]

37 minutes ago, BurnieM said:

I believe currently when you get your RPC you can no longer takeoff/land at Bankstown. Can somebody confirm.

BT lane of access and training area are fine but where do you take off from ?

 

When WSI goes live we lose Bankstown lane of access, Bankstown training area and part of Camden training area and these areas all become controlled. You would require a massive westerly detour if you want to stay uncontrolled. I believe this is a significant part of RAA getting CTA access.

The size of this political problem is why I think owner maintained group A will have access.

 

Question I have is what equipment requirements will there be ?

ADS-B ?

A harder attitude to 2 yearly calibrations ?

?

The answers will probably be in th regulations that allow schools to operate now. Question is where are they and what do they say?

[RFguy]

18 hours ago, LoonyBob said:

 

 

Since the root bending moment the wingspar has to cope with is a function of the span, and the spar strength is a function of the square of the depth, and the spar stiffness (flutter resistance) is a function of the cube of the depth, pushing the span up very quickly pushes the wei.......o Vc for that aircraft. I have given the matter considerable thought, as I personally want an RAAus owner-maintained single seater with a Vno of 250kts... and I imagine I will continue to do so!

 

Love it .

How about some reflexing flaps to increase Vso  and thus Va ? or does it hurt L/D too much ?

Edited January 31 by RFguy

[LoonyBob]

2 hours ago, RFguy said:

 

Love it .

How about some reflexing flaps to increase Vso  and thus Va ? or does it hurt L/D too much ?

NACA 23012 is very close to NACA 2412 with built-in reflexed flap, and it has a slightly higher Clmax; unfortunately, that form of variable geometry doesn't achieve what you want!

 

Reflexing flaps tend to help overall aircraft L/D in cruise, because as the speed goes up and the nose comes down, most aeroplanes start getting separation off the underside of the fuselage.

 

Assuming only mild convection (Europe, North America), Vno is set by Vb. The lower the aspect ratio, the less the (vertical) gust sensitivity, which is mainly why US aeroplanes are fond of an AR of 6.0 (Hersheybar Cherokee, Cubs, some Maules, etc). Unfortunately, this increases the induced drag...

If one flies in a Strayan summer, convection can be strong enough to stall the wing, so Va becomes Vno. One needs some serious variable geometry to get an advantage... F111 style works!

[LoonyBob]

10 hours ago, BurnieM said:

You mean Western Sydney International ?

Almost certainly this was a factor.

Sydney West Welcamp? have a look at the airspace around Brisbane West Welcamp...

[RFguy]

for those interested, the expansive report on the NACA 23012 is available from 1934...

https://ntrs.nasa.gov/api/citations/19930091603/downloads/19930091603.pdf

 

as for tomcats, there are no RAAus swing wing  / variable geometry aircraft, that I know.  Cirrus have that dual airfoil wing. 
I guess we do variable geometry all the time  in boats,

I'm going to look up the airfoil used for the B2 and head to bed shortly after.

 

Edited January 31 by RFguy

[LoonyBob]

Check out Gottingen 382(?)... there's a low Re report out there somewhere!

[RFguy]

so the '382 ......

 

wow the CL/Cd versus alpha   is really mild mannered , quite a soft dome. IE a good range of high L/D v AoA - compared to a '2412

.. The 382 airfoil shape reminds me of an aircraft canopy and fuselage side on.

I quite like the jabiru 230 wing. (4412  or 4414 I think) . chord is only 1m of course (lower Re) ... is high aspect. low induced drag, thus likes to float, drag does not  go through the roof when it gets slow, thus not so good for short landing  in my opinion where you want an airfoil that ramps up the induced drag when it gets slow (IMO) .comments ? 

Edited January 31 by RFguy

[facthunter]

You just need spoilers.  Nev

[LoonyBob]

15 hours ago, RFguy said:

so the '382 ......

 

wow the CL/Cd versus alpha   is really mild mannered , quite a soft dome. IE a good range of high L/D v AoA - compared to a '2412

.. The 382 airfoil shape reminds me of an aircraft canopy and fuselage side on.

I quite like the jabiru 230 wing. (4412  or 4414 I think) . chord is only 1m of course (lower Re) ... is high aspect. low induced drag, thus likes to float, drag does not  go through the roof when it gets slow, thus not so good for short landing  in my opinion where you want an airfoil that ramps up the induced drag when it gets slow (IMO) .comments ? 

The trick of 382 is the Clmax is higher at very low Re than at higher Res, which is the opposite of most airfoils. It does make Thrusters (with more wing "ribs" than the early ones!) quite well mannered trainers...

 

4412 a la Rod is actually less draggy than it "should" be... perhaps a tiny detail in his development of the profile, perhaps a remarkably good flap-wing interaction.

 

I'm with Nev on spoilers/lift dumpers; they're magic when spot-landing a glider... mind you, I've become quite enthusiastic about severe sideslips, which give as much glideslope modification, but with divebrakes you can slow down after the flare; and lift dumpers allow use of the wheelbrakes immediately on touchdown.