Grob 109 performance

[bpg]

I was wandering if you could send me a technical spcification of the
motorglider 109B. I am negotiating one at the moment ,but don't know many
details about it. if you know, at least glide ration, would help me a lot.

Thanks
marcel
Pleaase reply to:
str...@strauhs.com.br

[ven...@hotmail.com]

Why dont you get information on the Ximango which is built in Brazil.
www.ximango.com

Chris
ven...@hotmail.com

[Larry Goddard]

And exactly how is the performance characteristics on the Ximango going to help
him in his quest for information on Grob 109?

LG

[Nils Rostedt]

Here's some numbers from the pilot's operating handbook of our club 109B.

engine 90 hp at 3000 rpm
mtow 850 kg
vne 240 km/h
stall speed 73km/h
empty weight typical 620 kg
typical cruise speed 175 km/h
takeoff over 50ft obstacle, msl isa 316m
landing over 50 ft obstacle, msl isa 390m
max climb rate 3.4m/s
glide ratio 28 at 115 km/h
minimum sink 1.1m/s at 108 km/h

rgds, Nils

"bpg" <avia...@research.flyer.co.uk> wrote in message
news:t9qs46o...@corp.supernews.co.uk...

[.]

I might be able to help you there as I owned a G109B for a few years. The
figures given by Grob for the glide performance do not necessarily give the
full picture as regards teh capabilities of this very capable aircraft.

Engineer's performance numbers are great in their place, but I feel that
glide performance is often best judged by the average glider pilot by
comparing the performance of the subject glider with that of a "known"
glider.

I have done this with the G 109-B by flying beside a Bergfalke 4. At 55
knots, the G-109B was very nearly keeping up with the Bergfalke - the
difference in apparent performance being very small, and (if we think
positively with owner's optimism) possibly being attributable to air mass
movement.

By comparison, at 55 kjnots against a Blanik, the Blanik dropped away below
quite markedly. With the speed bought back to 50 Knots the Blanik was
staying much closer to the G 109B in the glide.

However, out and out glide performance is only one aspect of a glider's
performance. With an MOTW of 850 Kg, and a minimum sink of 1.1 m/s, the G
109B will thermal, but the large majority of sailplanes out there will have
a far better rate of climb in the same thermal.

That said, in Australian summer conditions (ie big lazy thermals) the G 109
(and a lot of the other "travelling motorgliders" for that matter) are able
to thermal quite well. Cross countries (soaring that is) are quite feasible
in good conditions, but don't expect to win the day at the Comps.

In summary, I highly recommend the G 109B. It is a great aircraft - it is a
hell of a lot of fun. We'd all like to own a Stemme or a Ximango, or one of
the other new motorgliders, but as usual money often rules the choice.

Hope you enjoy your new Grob.

Roy

"bpg" <avia...@research.flyer.co.uk> wrote in message
news:t9qs46o...@corp.supernews.co.uk...

[Colin Wray]

"Nils Rostedt" <sai...@dlc.fiNOSPAM> wrote:

>Here's some numbers from the pilot's operating handbook of our club 109B.
>
>engine 90 hp at 3000 rpm
>mtow 850 kg
>vne 240 km/h
>stall speed 73km/h
>empty weight typical 620 kg
>typical cruise speed 175 km/h

That'd be at full power, more like 88kts at 2500 rpm. - Colin

[Colin Wray]

"." <rjg...@excite.co.uk> wrote:

>I might be able to help you there as I owned a G109B for a few years. The
>figures given by Grob for the glide performance do not necessarily give the
>full picture as regards teh capabilities of this very capable aircraft.
>
>Engineer's performance numbers are great in their place, but I feel that
>glide performance is often best judged by the average glider pilot by
>comparing the performance of the subject glider with that of a "known"
>glider.
>
>I have done this with the G 109-B by flying beside a Bergfalke 4. At 55
>knots, the G-109B was very nearly keeping up with the Bergfalke - the
>difference in apparent performance being very small, and (if we think
>positively with owner's optimism) possibly being attributable to air mass
>movement.
>
>By comparison, at 55 kjnots against a Blanik, the Blanik dropped away below
>quite markedly. With the speed bought back to 50 Knots the Blanik was
>staying much closer to the G 109B in the glide.
>
>However, out and out glide performance is only one aspect of a glider's
>performance. With an MOTW of 850 Kg, and a minimum sink of 1.1 m/s, the G
>109B will thermal, but the large majority of sailplanes out there will have
>a far better rate of climb in the same thermal.

The glide performance at 70 or 80 kts is not so good, I guess the
polar drops away quite rapidly. Having said that, 50% of my time over
16 years in our G109B has been engine off, so it definitely soars ok -
even in UK. One tip if you are buying - look very carefully at the
cylinder heads, they are prone to leakage at the head-to-cylinder
joint and once it starts you have to have the heads reground (or worse
still replaced). If you do buy it, be very carefull with the head
temperature cycles, rapid changes cause the trouble.
Check the works number, a/c before 6340 missed out on a significant
upgrade. Check the prop last overhaul date - it is on a five year
cycle and is expensive.

>That said, in Australian summer conditions (ie big lazy thermals) the G 109
>(and a lot of the other "travelling motorgliders" for that matter) are able
>to thermal quite well. Cross countries (soaring that is) are quite feasible
>in good conditions, but don't expect to win the day at the Comps.
>
>In summary, I highly recommend the G 109B. It is a great aircraft - it is a
>hell of a lot of fun. We'd all like to own a Stemme or a Ximango, or one of
>the other new motorgliders, but as usual money often rules the choice.
>
>Hope you enjoy your new Grob.

I have thoroughly enjoyed mine.
- Colin