Cobra Arrow 912 repower

[Stevesb]

Hi just wondering if anyone out there has droped a 912 into there Cobra. 

If so would be interested in stall speeds ECT as mine is getting closer to finished.

[facthunter]

Related to any Weight & Balance changes, Mainly.  Nev

[Stevesb]

Hi Nev,

Weight much better 912 setup 40 kg lighter than Subaru.

Balance has moved more to the Centre of range which is all good.

 

Cheers Steve

[BrendAn]

tom wickers the designer is still around.

you will find him in the bushflyers group on facebook.

 

[Stevesb]

Thanks

[BurnieM]

https://aeropedia.com.au/content/tomair-cobra-arrow/

 

Interesting.

First Cobra Arrow in NZ.

 

[FlyBoy1960]

Those numbers in the specifications are, well, dreaming.  200 kts max speed, no way.  Most owners couldn't get above 120 knots in a dive. 

 

The weight was also over 340 kgs empty.

 

Let's just make it all up.

[FlyBoy1960]

So if somebody quotes “280 kg empty,” it is probably technically possible by using advanced manufacturing techniques that are not consistent to the models manufacturing. 280 kg is not representative of any real owner aircraft flying around Australia today.

 

A very realistic “honest” empty weight for a normal Cobra Arrow with a Rotax 912 and practical avionics is around:

315–340 kg empty

rather than the often-advertised 280 kg.

Edited May 20 by FlyBoy1960

[BrendAn]

4 minutes ago, FlyBoy1960 said:

So if somebody quotes “280 kg empty,” it is probably technically possible by using advanced manufacturing techniques that are not consistent to the models only fracturing. 280 kg is not representative of any real owner aircraft flying around Australia today.

 

A very realistic “honest” empty weight for a normal Cobra Arrow with a Rotax 912 and practical avionics is around:

315–340 kg empty

rather than the often-advertised 280 kg.

Most of those aeropedia facts are bullshit.  Certainly got your attention though.

[Stevesb]

Hi great guess on the weight can't quite remember the numbers from when we had her on the scales . but i think 

that you are very close.

As for speed with the new finer nose and at least 20 more HP I'm hoping to see cruse round 100kts

flat our 110 - 115. 

Pulse 40 kg lighter.

At the end of the day bought her because i loved the way she looked not because of speed. 

[facthunter]

I would be very surprised IF you don't get 100 Kts TAS. Cruise. Nev

[Stevesb]

Hoping to be pleasantly surprised when she get into the air

[BrendAn]

1 minute ago, Stevesb said:

Hoping to be pleasantly surprised when she get into the air

What is your mtow in nz

[Rapture]

Tom Wickers recently posted on Facebook seeking opinions on whether there might be a market for the Cobra XLT if he put it back into production. Tom indicated a 132ktas cruise with the Rotax 912ULS installed.

[FlyBoy1960]

I think the market is supersaturated with low wing, side-by-side aircraft.

 

The instant gratification of buying something used, (that is also certified and proven) has a big appeal against building something over many years for most people.

 

20 years ago, maybe but people have changed and they no longer accept a job that may take 10 years or more a rather spend the dollars now and go flying tomorrow. The EAA recently published information about the number of kits currently being built and it was less than 1/5 of what they were building 20 years ago

[sfGnome]

That may be true, but I know that I wouldn’t swap what the last few years of building has given me for the instant gratification of flying something off the shelf (though I’m happy to accept that I’m possibly not ‘normal’ 😁).

[BrendAn]

46 minutes ago, sfGnome said:

That may be true, but I know that I wouldn’t swap what the last few years of building has given me for the instant gratification of flying something off the shelf (though I’m happy to accept that I’m possibly not ‘normal’ 😁).

So how many young people have access to a garage  or workshop 

These days. Lifestyles have changed 

Edited May 21 by BrendAn

[skippydiesel]

23 hours ago, FlyBoy1960 said:

 280 kg is not representative of any real owner aircraft flying around Australia today.

 

 

Not sure you are correct on this statement:

 

ATEC aircraft (who I used to represent) had the Zephyr (mixed construction materials) and now the Fatera (carbon fibre) both powered by Rotax 912 (80-100 hp) engines.

Examples of both aircraft are flying in Australia and have the potential to be well under 300 kg empty weight.

With purchaser/builder additional accessories (not required for legal flight) they usually end up at about 300 kg +/-

 

As far as performance goes:

 

Zephyr; (now discontinue) Stall 30 Knots - High Speed Cruise 120+ Knots

Faeta (T tail); Stall 127 Knots - High Speed Cruise 135 Knots

 

Note: ATEC have always been conservative with their performance claims - unlike most aircraft manufactures.

 

😈

[T510]

8 minutes ago, skippydiesel said:

 

 

As far as performance goes:

 

Zephyr; (now discontinue) Stall 30 Knots - High Speed Cruise 120+ Knots

Faeta (T tail); Stall 127 Knots - High Speed Cruise 135 Knots

 

Note: ATEC have always been conservative with their performance claims - unlike most aircraft manufactures.

 

😈

Hope that stall speed is a typo or that's a very narrow flight envelope 😉

[BrendAn]

8 minutes ago, T510 said:

Hope that stall speed is a typo or that's a very narrow flight envelope 😉

Has 8 knots to play with 

[facthunter]

Clearly it's a TYPO. Correct cruise speed should depend on wt. and headwind.. Think on that. Nev

[BrendAn]

19 minutes ago, facthunter said:

Clearly it's a TYPO. Correct cruise speed should depend on wt. and headwind.. Think on that. Nev

And we were joking 

[facthunter]

I realise that, but is everything a JOKE here? That's MORE for the Other Place.  Nev

[BrendAn]

3 minutes ago, facthunter said:

I realise that, but is everything a JOKE here? That's MORE for the Other Place.  Nev

Nev, you make funny comments and jokes on every thread and then tell us we can't 

[facthunter]

Not usually, when it's about safety. Safety is MY thing remember. . I know it's Boring but Maybe someone will benefit from it, or Perhaps HAS.  I'm glad you realise I'm Funny ha ha sometimes. Thanks. Nev 

Edited May 21 by facthunter
expand