The Zenith CH-701 + CH-750 and ICP Savannah VG, XL and S Comparison :-)

[flymate]

I have a question on the Savannah VG 'real' cruise speed. I see all kind of numbers for this particular model. So, with the 100hp ULS and a Kiev prop ( ajusted for 5500-5600 full throttle rpm ) ...what would I expect for cruise speed at 5000 rpm ?

 

at an usual altitude 3-4000'

 

thanks

 

 

[Neil_S]

Hi Folks,

 

In my Savannah S with 100hp Rotax ULS and 3 blade DUC prop I cruise at 5000rpm and get 85kts indicated. I use 90kts TAS for flight planning, which seems to be fairly accurate so far....

 

Cheers,

 

Neil

 

 

[flymate]

Thanks Neil

 

from these specs here http://savannahac.co.za/specs/ the S is 5mph faster that the VG . You wrote ''indicated''...is this the real speed .did you check with GPS ? Thanks

 

 

[Kyle Communications]

My VG XL at 5000 rpm with a 72 inch (70) Bolly Optima prop cruises at 84 knots..... at 5200 it is 87 knots at 5600 max rpm is 93 knots

 

 

[Ultralights]

My VG XL at 5000 rpm with a 72 inch (70) Bolly Optima prop cruises at 84 knots..... at 5200 it is 87 knots at 5600 max rpm is 93 knots

pretty much identical numbers to what i get, cruise at 5100 rpm is 87 indicated.

 

 

[facthunter]

I have to support David in the cruise speed thing. A small plane designed for slow speed work is not generally too worried about high cruise speed. Wing thickness and shape square fuselage no fairings etc. You can get away with these things at about 75 knots. To go faster seems to require a new approach to more and more drag detail. Of course you can power through it but it's a situation of diminishing returns for power expended. The airframe , not the engines power will decide the most efficient cruise speed, climb speed and glide speed. Incidently what down load is normal for cruise from the tailplane which is designed for down load primarily with it's reversed lift set up. Nev

 

 

[Neil_S]

Thanks Neilfrom these specs here http://savannahac.co.za/specs/ the S is 5mph faster that the VG . You wrote ''indicated''...is this the real speed .did you check with GPS ? Thanks

Hi,

 

Not sure what you mean by "real speed" - I meant indicated as on the Airspeed Indicator. As noted I reckon on a True airspeed of about 90 knots, but that will vary with altitude etc. My GPS shows my groundspeed, but I haven't done the fly 3 perpendicular legs, noting groundspeed, then do the maths to work out my TAS from the GPS as per http://www.eaa62.org/technotes/speed.pdf

 

Cheers,

 

Neil

 

 

[Ultralights]

what ever happened to TAS = IAS + (IAS/60 x Ht (in thousands of feet))

 

 

[flymate]

Neils, by real, I meant GPS verified/corrected using what ever methoh : no wind , triangle, head/down wind. I rarely had planes that had airspeed indicators that had the correct speed. Sometimes, it's the instrument itself, sometimes the pitot, sometimes the static, or a mix of the 3.

 

Anyway, with the answers I got here , I will plan for 80kts ..well 92 mph as the plane ASI is in mph . And this is more for a purpose of having the plane owner planing the trip that for me. He is new at flying and planning this trip ( 2000NM across Canada in April ) keep us busy and ''flying on paper'. And it's just 'planning'..it's gonna be what's it's gonna be the day I take off. Never flown a Savannah before, so it will be fun to see how it goes. Thanks all

 

 

[Kyle Communications]

Jacques the Sav is one of the easiest aircraft you will ever fly ...I think you will want one by the time the 2000 nm trip is over. Especially the STOL side of them and yet they still have a respectable cruise speed

 

 

[flymate]

Yes Mark, I'm sure I will love the ride. But it's not exactly the kind of plane for my needs. My runway is long and don't really need a STOL plane. Moreover, I would need to sell my SW first...not easy.. But I'am looking forward to try the Sav.

 

 

[Ultralights]

yes, but a STOL aircraft gives you more options. and a few more hours in the logbook.