206 fore or aft?

[B4RT]

Hey any of you oldtimers know which will give me a faster cruise,
forward or aft cg?

TIA,

Bart

[SelwayKid]

"B4RT" > wrote in message >...
> Hey any of you oldtimers know which will give me a faster cruise,
> forward or aft cg?
>
> TIA,
>
> Bart
Aft c.g. When its trimmed the tail will be trimmed to give some
UPwards lift that unweights the tail a little.

[SelwayKid]

(SelwayKid) wrote in message >...
> "B4RT" > wrote in message >...
> > Hey any of you oldtimers know which will give me a faster cruise,
> > forward or aft cg?
> >
> > TIA,
> >
> > Bart
> Aft c.g. When its trimmed the tail will be trimmed to give some
> UPwards lift that unweights the tail a little.
Bart
Whoops on my part...I was thinking of the Cessna 206 but I feel the
same holds true in the B206 (got about 1200 hrs in the B206)

[B4RT]

The reason I asked was because last year I put floats on our ship and they
slowed it down by about 7 knots on avg. Theres this magic point at about
50 gals of remaining fuel at which I suddenly gain almost 10 kts of
airspeed.
I figure it can't be related to the lighter load because the airspeed
increase
is not linear with respect to decreased fuel load, so CG is a likely
candidate.

If its true that its CG, then I'd like to exaggerate this effect because I
really
want my airspeed back.

BTW: I dont think your "same holds true" thing for the Cessna 206 is
applicable. The reason they tweak an airplane that way is to aid in
dynamic stability, and I don't think the same aerodynamic reasons
apply to sling-wings.

Bart


"SelwayKid" > wrote in message
om...
> (SelwayKid) wrote in message
> >...
>> "B4RT" > wrote in message
>> >...
>> > Hey any of you oldtimers know which will give me a faster cruise,
>> > forward or aft cg?
>> >
>> > TIA,
>> >
>> > Bart
>> Aft c.g. When its trimmed the tail will be trimmed to give some
>> UPwards lift that unweights the tail a little.
> Bart
> Whoops on my part...I was thinking of the Cessna 206 but I feel the
> same holds true in the B206 (got about 1200 hrs in the B206)

[SelwayKid]

"B4RT" > wrote in message >...
> The reason I asked was because last year I put floats on our ship and they
> slowed it down by about 7 knots on avg. Theres this magic point at about
> 50 gals of remaining fuel at which I suddenly gain almost 10 kts of
> airspeed.
> I figure it can't be related to the lighter load because the airspeed
> increase
> is not linear with respect to decreased fuel load, so CG is a likely
> candidate.
>
> If its true that its CG, then I'd like to exaggerate this effect because I
> really
> want my airspeed back.
>
> BTW: I dont think your "same holds true" thing for the Cessna 206 is
> applicable. The reason they tweak an airplane that way is to aid in
> dynamic stability, and I don't think the same aerodynamic reasons
> apply to sling-wings.
>
> Bart

Bart
Are they pop outs? I would imagine so. Don't often see helos flying
around with inflated ones anymore. When I was flying 47's on floats it
was really noticable and on the H500 series too. But, I never noticed
any appreciable difference in speeds with less fuel. Have you changed
cabin loading to any extent? I'm also curious about this one.
As for the Cessna 206, or most fixed wings, having the aft cg requires
some trim that effectively changes the speed and economy. Lots of the
XC racers used that to gain a few kts and in fact that was where I
learned it many many years ago.
Best Regards
Rocky
>
>
> "SelwayKid" > wrote in message
> om...
> > (SelwayKid) wrote in message
> > >...
> >> "B4RT" > wrote in message
> >> >...
> >> > Hey any of you oldtimers know which will give me a faster cruise,
> >> > forward or aft cg?
> >> >
> >> > TIA,
> >> >
> >> > Bart
> >> Aft c.g. When its trimmed the tail will be trimmed to give some
> >> UPwards lift that unweights the tail a little.
> > Bart
> > Whoops on my part...I was thinking of the Cessna 206 but I feel the
> > same holds true in the B206 (got about 1200 hrs in the B206)

[B4RT]

"SelwayKid" > wrote in message
om...

> Bart
> Are they pop outs? I would imagine so. Don't often see helos flying
> around with inflated ones anymore. When I was flying 47's on floats it
> was really noticable and on the H500 series too. But, I never noticed
> any appreciable difference in speeds with less fuel. Have you changed
> cabin loading to any extent? I'm also curious about this one.
> As for the Cessna 206, or most fixed wings, having the aft cg requires
> some trim that effectively changes the speed and economy. Lots of the
> XC racers used that to gain a few kts and in fact that was where I
> learned it many many years ago.
> Best Regards
> Rocky

Yeah, they're pop-outs. When we installed them, I had the "vibration
reduction system" removed from the chopper as well . I never used it and it
weighed about 35lbs. Its removal helped offset the weight gain of the
floats. My normal full fuel Lon CG is now 112 in a range of 106 to 114.3,
which gives me a noticably aft CG . With 50 Gals it becomes 111 ( a little
more forward). They also added some ballast in the tailboom when they
installed the floats, but upon reviewing this here I'm not sure why they
needed to.

On the stuck wing side of things. I bought a Lancair Columbia 400 this June
to use as my personal rocket (235kts) , and it has a really forward CG by
default. With two guys in front and a full bag of fuel you need to have
50lbs of stuff in the aft baggage compartment to keep the CG in limits.
Since I almost never have more than 1 pax, I just leave a 50lb sandbag back
there all the time. When I've got no pax, I do notice a couple knot speed
increase buy I'm not sure if its more attributable to the lighter load , or
the increased aft cg.

Nice hearing from you again Rocky,

Bart