Too good to be true?

[wanabigaplane]

[ATTACH]11932.vB[/ATTACH]

 

I attended the recent Moruya fly in and saw this plane for sale. In excellent condition. Jab 3300, Low hours, does 105 knots. $48K. It sounded too good to be true.

 

I did my due diligence and it checked out fine. My only concern was that it lived by the sea with subsequent concerns about corrosion – but it had not been there that long.

 

Hmm. A bit more digging. That Zenith website says it stalls at 47 knots. Well that’s pretty close to 45 knots. Would RAAus let it be registered? I decided to visit Steve Bell at the RAAus offices to make sure. The conversation went pretty much like this:

 

If it does not stall below 45 knots, it cannot be registered under RAAus.

 

But aren’t some already on the register?

 

Yes, but I don’t know how they got there – before my time.

 

Could they have done something like lowering both ailerons, or some modification?

 

I would be surprised if that would be enough to do it. If you bought the aircraft and the mod was not enough, you would be stuck with an aircraft you couldn’t register.

 

45 knots, 47 knots – there is not much difference. Is the ruling that black and white?

 

Yes it is - The ruling is by CASA, not me. Recently they reviewed two aircraft already on the RAAus register, and they had to be de-registered.

 

It is hard to tell that precisely what speed it stalls at. If I say it was 45 knots, that’s good enough isn’t it?

 

No. I will ask you to demonstrate it.

 

So, as you can see, I did not buy the aircraft.

 

 

 

[Mick]

How is the aircraft currently registered? ie, RAAus or VH.

 

 

[wanabigaplane]

VH. When I enquired it the 100 hourly had to be done before test flying. Jack.

 

 

[Timm427]

There is a speed wing option (I Think) for that model with a higher stall speed - Might want to check its not that wing.

 

Changing the flap to a slotted flap (lot of engineering) can change the Coefficient of lift from around 1.6 to 1.8. although its not all about overall lift and the Ailerons and empennage controls also need to have enough authority to land it.

 

One simple option may be to use VGs to reduce stall by 2 knots - someone in the world has probably used them on a 601 and could give you an answer.

 

 

[Timm427]

Found this web site - just remember these people are selling the VGs :) StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft

 

 

[Spin]

Interesting that CASA have had a closer look at some aircraft already on the register, we all know there are some "funnies" out there and it is probably a worthwhile thing to remember when looking to buy - imagine the rigmarole of trying to get an aircraft maintained under the RA Aus scheme back onto the VH register - $$$$$$!

 

I recall seeing a VH reg homebuilt with a MAUW of around 800kg being advertised as being capable of being re-registered RA Aus, not sure about the stall speed but probably also a bit high, imagine having that conversation with Steve Bell - caveat emptor as they say in the classics.:black_eye:

 

 

[Guest disperse]

Surley VG's would bring it under 45kt's.

 

 

[farri]

[ATTACH=CONFIG]18701[/ATTACH]45 knots, 47 knots – there is not much difference. Is the ruling that black and white?

 

Yes it is

 

It is hard to tell that precisely what speed it stalls at. If I say it was 45 knots, that’s good enough isn’t it?

 

No. I will ask you to demonstrate it.

 

So, as you can see, I did not buy the aircraft.

SSSSSOOOOOOOOO much BS.

 

Ok so we`ve determined the ASI is deadly accurate??????? and up we go,at what point do we determine the exact moment and IAS of the stall ?

 

Cheers,

 

Frank..

 

 

[Gibbo]

How about limiting the MTOW.

 

May currently be 600kg but could you live with 544kg.

 

 

[wanabigaplane]

Anyhow..

 

The plane is advertised in the latest RAAus mag.

 

I only made this post so that any other forumites who might be interested in it would be forewarned about a possible difficulty of registering it under RAAus.

 

Thanks Cameron, but there is no need to make any further investigations - I am fully satisfied that the plane is in excellent condition, that the owner is fully above board, and that all work has been done by your local lame. It is really good value for the money, and I don't question the price at all.

 

Thanks for the info on VGs - they lowered the stall speed of that one particular plane by 3 knots. A little too close for comfort for me.

 

As Steve said, if I bought the plane, and I could not prove it stalled at under 45 knots CAS, I would be stuck with an aircraft I could not register. I really cannot afford the time to be trying this and going for tests, then trying that and going for tests, and be chasing down variable after variable.

 

Jack.

 

 

[farri]

Hi Frank,The methodology is clearly spelt out in the CAOs; 101.55 from memory. These are CASA's rules not ours. The ASI is calibrated with a correction chart in the cockpit which should clearly show the calibration due to positional error ((CAS) Corrected airspeed) and then the true stall speed can be clearly demonstrated to the CAS. This is the same method used for GA aircraft.

David

Good Onya David.......I`ve done enough stalls to know the score and I say that when we`re talking about a difference of 2 kts IAS , we`re talking BS, I don`t care who`s rule it is.

 

Cheers,

 

Frank.

 

 

[Spin]

So where do you draw the line Frank, give 2 kts the tick, but draw the line at 5kts over? Someone, somewhere is always going to fall just on the wrong side of the divide and want to be included. If there is any BS in the system it is allowing a 2 seater with a 160hp Lycoming and CS prop to be registered under a rule which caters for a 544kg max.

 

 

[farri]

G`Day Spin, technically you and David are correct,no problem with that,what I`m on about is this.

 

Does the ASI register in increments of one knot and if not how do we determine it is exactly 47 kts. and not 46 or 48 and could the pilot hold an absolute accurate figure,in any case?.

 

I still ask, at what point in the the stall do we determine the IAS to be the exact correct figure?,hold it in the stall and you`ll get 45.

 

Shouldn`t it be more about wheather the aircraft is safe to fly and the pilot is capable of flying it safely?

 

Cheers,

 

Frank.

 

 

[facthunter]

The "Rules"

 

This discussion is OK but won't alter anything. Stephen has to go by a set figure. That is not RAAus's fault.

 

David has his point that the "real" stall airspeed HAS to be used otherwise we are kidding ourselves.

 

Ga aircraft have a stall speed in the POH, for a given aircraft. The method of obtaining it is a standard formula which is ( I think),

 

Power off, max AUW, Most forward C of G position obtainable and you would not be allowed to do "odd" things like pulling the plane up into an excessive nose high position and recording the lowest speed attained as the nose drops when the plane is in a less than 1 G situation. (In other words you have to be "fair dinkum" about it).. Nev

 

 

[farri]

[ATTACH=CONFIG]18701[/ATTACH]It is hard to tell that precisely what speed it stalls at. If I say it was 45 knots, that’s good enough isn’t it?

 

No. I will ask you to demonstrate it.

Hi Nev and thanks for you`re input, I`m mostly about causing discussion.

 

The quote I`ve used is supposed to have been a discussion with Mr Steve Bell........the reason I bothered.

 

Cheers,

 

Frank.

 

 

[facthunter]

More Discussion.

 

sure Frank. I agree with your sentiments, but I don't believe that Mr Bell could ever answer any differently to the question put to him. With CASA breathing down his neck, and plenty of RAAus detractors out there waiting for an opportunity to attack this organisation, he has to be bomb proof and how would the situation that "I just accepted what the owner said", (even though it contravenes known facts in the industry), stand at LAW, as a responsible way of administering his post? Nev.

 

 

[farri]

Nev,I agree completely,I wouldn`t want to be administering the Regs.

 

Frank.