zero fuel w & b

[d&tm]

in my PPL training it was drummed in to me the importance of always doing
the w & b calcs with the fuel you were taking and also the zero fuel case.
I posted sometime ago that with the Warriors I flew it was impossible to go
outside the w & b envelope by burning fuel. I have just finished my
transition to the C172 and have extensively investigated different loading
scenarios and found exactly the same thing, at least with this N model I am
flying.
Are there any single engine airplanes out there that really can go outside
the envelope by burning fuel? ( I am only interested in the normal
ategory - not utility). Perhaps the training is just to prepare you for
heavy aircraft?
Terry
PPL downunder

[Peter Duniho]

"d&tm" > wrote in message
...
> [...]
> Are there any single engine airplanes out there that really can go outside
> the envelope by burning fuel?

Sure. Any airplane in which the CG moves as fuel is burned has that
potential, depending on what other aspects of loading exist.

I haven't looked at the 172 case recently. Possibly due to weight
restrictions for baggage or seats you can't load it close enough to the
critical end of the CG range with full fuel for the CG to move outside the
range by using up fuel? I don't know off the top of my head.

What I do know is that I own a single-engine airplane (Lake Renegade) that
can wind up with the CG out of range after fuel has burned. I also know
from my friends who own Bonanzas that at least some models of Bonanza have a
similar issue. I am sure there are a number of smaller single-engine
airplanes that have the same requirement to pay close attention to weight &
balance.

Of course, there's a difference between the potential for problems
generally, and the potential for problems with specific loadings. Generally
speaking, I've found that the issue of CG moving out of range with fuel burn
still only happens in specific loading configurations. For example, in my
airplane the issue is most pronounced when the airplane is heavily loaded to
start with, and when that weight is mostly up front. Even at higher
weights, there are loading configurations that are generally assured to not
wind up outside the CG range as fuel burns.

As long as you've done enough W&B calculations to check the various
configurations and be very familiar with how the CG moves according to
loading and fuel, then to some extent it's not necessary to do a full W&B
calculation for every flight, assuming you've otherwise ensured you're not
overweight and have a loading configuration for which fuel burn isn't an
issue.

But, it's certainly not safe to say that one need not worry about fuel burn
for single-engine airplanes, even if you limit that statement to the smaller
ones (two- and four-seat).

Pete

[john smith]

d&tm wrote:

>in my PPL training it was drummed in to me the importance of always doing
>the w & b calcs with the fuel you were taking and also the zero fuel case.
>I posted sometime ago that with the Warriors I flew it was impossible to go
>outside the w & b envelope by burning fuel. I have just finished my
>transition to the C172 and have extensively investigated different loading
>scenarios and found exactly the same thing, at least with this N model I am
>flying.
>Are there any single engine airplanes out there that really can go outside
>the envelope by burning fuel? ( I am only interested in the normal
>ategory - not utility). Perhaps the training is just to prepare you for
>heavy aircraft?
>Terry
>

Bonanza's come immediately to mind.
I do not know if the current models are built this way, the older models
had the fuel stored in the front of the wing, ahead of the main spar.
Any weight in the aircraft behind the front seats is behind the fuel
weight. As fuel is burned, the weight ahead of the spars decreases while
the weight behind the spar remains the same, hence the cg moves aft. At
some point, the cg moves out of the envelope (the ability of the
horizontal stabilizer to provide sufficient lift).
Piper PA32's will can also develope this situation.
Cessna's seem to have a broader range.
You have to look at each aircrafts envelope.

Van's tandem seat RV-4's had a bad string of fatal accidents until the
word got out and builders became more aware of the potential danger.

[Blueskies]

"d&tm" > wrote in message ...
: in my PPL training it was drummed in to me the importance of always doing
: the w & b calcs with the fuel you were taking and also the zero fuel case.
: I posted sometime ago that with the Warriors I flew it was impossible to go
: outside the w & b envelope by burning fuel. I have just finished my
: transition to the C172 and have extensively investigated different loading
: scenarios and found exactly the same thing, at least with this N model I am
: flying.
: Are there any single engine airplanes out there that really can go outside
: the envelope by burning fuel? ( I am only interested in the normal
: ategory - not utility). Perhaps the training is just to prepare you for
: heavy aircraft?
: Terry
: PPL downunder
:

Cherokee 6 comes to mind right away...

[d&tm]

"Peter Duniho" > wrote in message
...
> "d&tm" > wrote in message
> ...
> > [...]
> > Are there any single engine airplanes out there that really can go
outside
> > the envelope by burning fuel?
>
> Sure. Any airplane in which the CG moves as fuel is burned has that
> potential, depending on what other aspects of loading exist.


Both the Warrior and the C172 c of g moves forward with fuel burn but so
does the allowable limit, at the same or greater rate, which is why it is
not possible to go outside the envelope under any loading conditions.

> I haven't looked at the 172 case recently. Possibly due to weight
> restrictions for baggage or seats you can't load it close enough to the
> critical end of the CG range with full fuel for the CG to move outside the
> range by using up fuel? I don't know off the top of my head.



> What I do know is that I own a single-engine airplane (Lake Renegade) that
> can wind up with the CG out of range after fuel has burned. I also know
> from my friends who own Bonanzas that at least some models of Bonanza have
a
> similar issue. I am sure there are a number of smaller single-engine
> airplanes that have the same requirement to pay close attention to weight
&
> balance.
>
> Of course, there's a difference between the potential for problems
> generally, and the potential for problems with specific loadings.
Generally
> speaking, I've found that the issue of CG moving out of range with fuel
burn
> still only happens in specific loading configurations. For example, in my
> airplane the issue is most pronounced when the airplane is heavily loaded
to
> start with, and when that weight is mostly up front. Even at higher
> weights, there are loading configurations that are generally assured to
not
> wind up outside the CG range as fuel burns.
>
> As long as you've done enough W&B calculations to check the various
> configurations and be very familiar with how the CG moves according to
> loading and fuel, then to some extent it's not necessary to do a full W&B
> calculation for every flight, assuming you've otherwise ensured you're not
> overweight and have a loading configuration for which fuel burn isn't an
> issue.

this is basically why I do the analysis, to break it down to simple rules
that will not require me to have to do the c of g calcs each time.
conclusion with the C172N is that, with the weight restrictions satisfied
1. it is impossible to get c of g too far forward.
2. the only way to have c of g too far back is with more weight in back seat
than front. ( most unlikely situation for me)
3. it is impossible to go outside by burning fuel.
So my simple rule becomes stay within the wt constraints and do a c of g
check only if I want more wt in the back seat than the front. - which is
likely to be never.

> But, it's certainly not safe to say that one need not worry about fuel
burn
> for single-engine airplanes, even if you limit that statement to the
smaller
> ones (two- and four-seat).

I certainly wouldnt assume that without doing the same analysis on the
particular aircraft. It seems to me that the aircraft I have referred to (
warrior and C172N) are probably designed so that fuel burning will not cause
an adverse c of g . I would also be curious to know if other models of C172
or the higher performacne C177, C182 C206, C210 follow the rules I outlined
above.
Excuse my ignorance but I hadn't heard of a Lake Renegade, but I did do a
google and note that it is a beautiful looking amphibious aircraft whch
obviously has some specific design characeristics for its intended
application, namely an engine above and behind the cabin, which makes it a
little different from the aircraft I am likely to fly, but I take your point
that fuel burning may be an issue in some small planes.
terry
PPL downunder

[Jose[_1_]]

> this is basically why I do the analysis, to break it down to simple rules
> that will not require me to have to do the c of g calcs each time.

Try this - start at the bottom of the envelope, and pretend that each
corner represents a zero fuel loading. Then add fuel and see where you
end up. Draw that line on the envelope. The inner envelope is defined
as the the most restrictive envelope from all these lines and the
existing envelope. So long as your loading (with fuel) is within this
inner envelope, you'll be ok to zero fuel. (at least w&b wise. :)

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Newps]

john smith wrote:


>>
>
> Bonanza's come immediately to mind.
> I do not know if the current models are built this way, the older models
> had the fuel stored in the front of the wing, ahead of the main spar.
> Any weight in the aircraft behind the front seats is behind the fuel
> weight.

In my 64 S35 all weight in the plane is behind the fuel. The fuel is at
75 and the front seats are at 85. Rear seats 121 and baggage at 150.

[john smith]

Newps wrote:

> john smith wrote:
>
> Bonanza's come immediately to mind.
>
>> I do not know if the current models are built this way, the older
>> models had the fuel stored in the front of the wing, ahead of the
>> main spar. Any weight in the aircraft behind the front seats is
>> behind the fuel weight.
>
>
> In my 64 S35 all weight in the plane is behind the fuel. The fuel is
> at 75 and the front seats are at 85. Rear seats 121 and baggage at 150.

Any idea where front seats are in the 36 series?

[Newps]

Same place. Although the fuel is the same arm as the front seats in the 36.





john smith wrote:

>
>
> Newps wrote:
>
>> john smith wrote:
>>
>> Bonanza's come immediately to mind.
>>
>>> I do not know if the current models are built this way, the older
>>> models had the fuel stored in the front of the wing, ahead of the
>>> main spar. Any weight in the aircraft behind the front seats is
>>> behind the fuel weight.
>>
>>
>>
>> In my 64 S35 all weight in the plane is behind the fuel. The fuel is
>> at 75 and the front seats are at 85. Rear seats 121 and baggage at 150.
>
>
> Any idea where front seats are in the 36 series?
>

[Kyle Boatright]

"john smith" > wrote in message
...
> d&tm wrote:
>
>>in my PPL training it was drummed in to me the importance of always doing
>>the w & b calcs with the fuel you were taking and also the zero fuel case.
>>I posted sometime ago that with the Warriors I flew it was impossible to
>>go
>>outside the w & b envelope by burning fuel. I have just finished my
>>transition to the C172 and have extensively investigated different
>>loading
>>scenarios and found exactly the same thing, at least with this N model I
>>am
>>flying.
>>Are there any single engine airplanes out there that really can go outside
>>the envelope by burning fuel? ( I am only interested in the normal
>>ategory - not utility). Perhaps the training is just to prepare you for
>>heavy aircraft?
>>Terry
>>
>
> Bonanza's come immediately to mind.
> I do not know if the current models are built this way, the older models
> had the fuel stored in the front of the wing, ahead of the main spar. Any
> weight in the aircraft behind the front seats is behind the fuel weight.
> As fuel is burned, the weight ahead of the spars decreases while the
> weight behind the spar remains the same, hence the cg moves aft. At some
> point, the cg moves out of the envelope (the ability of the horizontal
> stabilizer to provide sufficient lift).
> Piper PA32's will can also develope this situation.
> Cessna's seem to have a broader range.
> You have to look at each aircrafts envelope.
>
> Van's tandem seat RV-4's had a bad string of fatal accidents until the
> word got out and builders became more aware of the potential danger.

It is true that the CG moves aft with fuel burn on all of the 2 place Van's
designs. It is also true that depending on the individual aircraft and the
loading that you could run the CG beyond the aft limit. You certainly can
in my RV-6. That said, please do some fact checking before you conjure up a
"bad string of fatal accidents" for RV-4's due to CG issues. Didn't happen.
There was one accident in the NTSB database between 1980 and today where CG
was listed as a factor...

Not jumping your kimchee or anything, but facts are facts, and making 'em up
(or remembering 'em incorrectly) isn't a good idea when safety is at issue.

KB

[john smith]

> Not jumping your kimchee or anything, but facts are facts, and making 'em up
> (or remembering 'em incorrectly) isn't a good idea when safety is at issue.

Kyle, I have personal knowledge of four, and first hand reports from
others in the RV community. The rash of accidents happened in the late
80's/early 90's. They were the basis for Van revising the aft cg limit
on RV-4's Just because the NTSB doesn't list it doesn't mean they didn't
happen. I also know of other NTSB final reports where the report did not
match the facts. You have to understand that the NTSB does not
investigate all accidents. In most cases, they take the information from
another agency and synthesize the results.

[Michael[_1_]]

d&tm wrote:
> in my PPL training it was drummed in to me the importance of always doing
> the w & b calcs with the fuel you were taking and also the zero fuel case.

Which is amusing, because most flight instructors have never flown an
airplane where this is actually necessary.

> I posted sometime ago that with the Warriors I flew it was impossible to go
> outside the w & b envelope by burning fuel. I have just finished my
> transition to the C172 and have extensively investigated different loading
> scenarios and found exactly the same thing, at least with this N model I am
> flying.

No surprise. I can't think of any trainer where this would be true.

> Are there any single engine airplanes out there that really can go outside
> the envelope by burning fuel? ( I am only interested in the normal
> ategory - not utility). Perhaps the training is just to prepare you for
> heavy aircraft?

Well, not so much heavy as optimized. The trainers you are used to
flying are not really optimized for performance - they are built to be
simple to maintain, rugged enough to take the training regime, and easy
to fly. They have pretty wide cg envelopes, and it's pretty hard to
get into W&B trouble unless you really overload.

Move into something like a V-tail Bonanza, and it's a different game.
The cg range is narrow (due in large part to limited empennage control
- it's a lot wider in the straight tails) and the fuel is way forward
so as you burn it, the cg moves aft - and can easily take you out of
limits. They do it that way for a reason. The V-tail is less draggy.
Keeping the cg close to the aft limit reduces the required downforce
from the tail, and thus the extra lift the wing must generate to
counter it. Generating lift also generates drag, so you get a more
efficient airplane. That's important, because big gains in speed are
made by improving aerodynamic efficiency, not increasing engine power.

Here's something to think about. The Warriors and Skyhawks you fly are
realistically 110 kt airplanes on a good day. They make it happen with
4 seats and 160 hp. Remember that power required goes up with the cube
of airspeed - in other words, making a plane with the same aerodynamics
fly 160 kts would require almost 500 hp. When you see a four seater
doing 160 kts on half that horsepower (as the early Bonanzas did) you
need to ask yourself - what was traded off to get that speed? Where
will I have to work harder, where will I have less margin for error?
In the case of the V-tail Bonanza, the narrow cg (and consequently the
worry about getting out of cg as you burn fuel) is part of the answer.

Hope that makes it all clearer.

Michael

[tom]

I fly a homebuilt Savannah (there are quite a few flying in Oz) and if
the pilot weighs less than about 120 pounds, and the fuel is nearly
exhausted, the CG is just slightly forward of the envelop.
tom

d&tm wrote:
> Are there any single engine airplanes out there that really can go outside
> the envelope by burning fuel?
> Terry
> PPL downunder

[Ron Natalie]

d&tm wrote:

> Are there any single engine airplanes out there that really can go outside
> the envelope by burning fuel? ( I am only interested in the normal
> ategory - not utility). Perhaps the training is just to prepare you for
> heavy aircraft?

I believe Bonanzas can have this problem in certain configurations.

It depends on which where the CG is. If you've got an aft CG
and burning fuel drives it more aft, you've got problems.

In my plane, we typically sit on the forward CG limit with
the tanks full. Since the envelope is sloped on the forward
CG side (the limit moves aft as you go up in gross weight),
even as the CG moves forward with fuel burn, you're also
getting lighter so the CG limit is moving forward faster.

[d&tm]

"Ron Natalie" > wrote in message
...
> d&tm wrote:
>
> > Are there any single engine airplanes out there that really can go
outside
> > the envelope by burning fuel? ( I am only interested in the normal
> > ategory - not utility). Perhaps the training is just to prepare you
for
> > heavy aircraft?
>
> I believe Bonanzas can have this problem in certain configurations.
>
> It depends on which where the CG is. If you've got an aft CG
> and burning fuel drives it more aft, you've got problems.
>
> In my plane, we typically sit on the forward CG limit with
> the tanks full. Since the envelope is sloped on the forward
> CG side (the limit moves aft as you go up in gross weight),
> even as the CG moves forward with fuel burn, you're also
> getting lighter so the CG limit is moving forward faster.

Similar to the Warrior. but you can barely get enough wt in the front to
reach the forward limit. expecially when I am one of them ( 180 lbs). But
it is just possible with a couple of sumu wrestlers and less than full fuel
to exceed the forward limit, in this case burning fuel actually brings you
back in bacause as you say the cg moves forward but the limit moves forward
faster at lower wt.
What is your plane John?
terry
PPL downuder

[d&tm]

"tom" > wrote in message
oups.com...
> I fly a homebuilt Savannah (there are quite a few flying in Oz) and if
> the pilot weighs less than about 120 pounds, and the fuel is nearly
> exhausted, the CG is just slightly forward of the envelop.
> tom

Tom, do you carry some ballast to correct this? I know nobody plans to run
out of fuel but if it happened , say from a fuel leak, I would hate to be
worrying about an off field landing with a forward cg.
terry




> d&tm wrote:
> > Are there any single engine airplanes out there that really can go
outside
> > the envelope by burning fuel?
> > Terry
> > PPL downunder
>

[Steve Schneider]

john smith wrote:
> d&tm wrote:
>
>> Are there any single engine airplanes out there that really can go
>> outside
>> the envelope by burning fuel? ( I am only interested in the normal
>> ategory - not utility). Perhaps the training is just to prepare you
>> for
>
> Piper PA32's will can also develope this situation.
>

I'd previously posted links for some weight and balance info for a few
aircraft I've flown over the years. One of them happens to be a PA32.
This link http://www.4-fs.com/new/flying/N3000AWB.xls is to the W&B
spreadsheet for the Piper Lance (PA32-RT300T) which we've been flying
the last few years. I had included variables for fuel at departure and
'low fuel' for landing for just this reason. You can plug in the
following plausible values for a real flight and end up with the CG in
range (though precariously aft) at the start of the flight and have the
CG aft of the limits with 15 gallons remaining at the end of a flight:

Pilot+no front passenger: 180 lb
Center Passengers: 0
Rear Passengers: 360 lb
Fuel: 94 gal
Front Baggage: 0
Rear Baggage: 90

The CG only moves 0.22 inches to the rear after burning 79 gallons of
fuel, but it does take you 0.20 inches past the aft CG limit during the
flight.

Flying this plane with club seating does allow for some interesting
weight shifting when passengers (wife and kids typically) swap seats in
flight. You definitely do feel the change, and as such I always keep in
mind which passengers sit in which seats. Imagine the above loading
with the rear passengers (2x180lb) in the center row of seats and the
rear seats empty. Once airborne they decide they don't like to fly
'backwards' in the club seating and 'help themselves' to the the empty
rear seats. Suddenly we go from a very comfortable CG to a precariously
aft CG. Not a situation one generally needs to worry about in 2 and 4
seat airplanes.

That is part of why I find these spreadsheets so helpful in quickly
looking at a bunch of 'what if' scenarios before we depart.

Steve

[tom]

I weigh 170, so the only ballast I carry is around my ass. 8^)
tom

d&tm wrote:
> "tom" > wrote in message
> oups.com...
> > I fly a homebuilt Savannah (there are quite a few flying in Oz) and if
> > the pilot weighs less than about 120 pounds, and the fuel is nearly
> > exhausted, the CG is just slightly forward of the envelop.
> > tom
>
> Tom, do you carry some ballast to correct this? I know nobody plans to run
> out of fuel but if it happened , say from a fuel leak, I would hate to be
> worrying about an off field landing with a forward cg.
> terry
>

[Morgans[_2_]]

"Steve Schneider" > wrote

> Flying this plane with club seating does allow for some interesting weight
> shifting when passengers (wife and kids typically) swap seats in flight.
> You definitely do feel the change, and as such I always keep in mind which
> passengers sit in which seats. Imagine the above loading with the rear
> passengers (2x180lb) in the center row of seats and the rear seats empty.
> Once airborne they decide they don't like to fly 'backwards' in the club
> seating and 'help themselves' to the the empty rear seats. Suddenly we go
> from a very comfortable CG to a precariously aft CG. Not a situation one
> generally needs to worry about in 2 and 4 seat airplanes.

With the passengers putting the CG at the most aft limits, do you notice any
increase in speed, with the same power and prop settings? I would think the
aft CG would take the downward lift away from the horizontal, and pick up
some speed, but I don't know. It would seem like the ideal experiment; to
be able to quickly change the CG with no changes in air density, power, or
any other type of changes.
--
Jim in NC

[Jay Beckman]

"tom" > wrote in message
oups.com...
>I weigh 170, so the only ballast I carry is around my ass. 8^)
> tom

"Does this airplane make me look fat...?"

;O)

Jay B

[d&tm]

"Steve Schneider" > wrote in message
...
> john smith wrote:
> > d&tm wrote:
> >
> >> Are there any single engine airplanes out there that really can go
> >> outside
> >> the envelope by burning fuel? ( I am only interested in the normal
> >> ategory - not utility). Perhaps the training is just to prepare you
> >> for
> >
> > Piper PA32's will can also develope this situation.
> >
>
> I'd previously posted links for some weight and balance info for a few
> aircraft I've flown over the years. One of them happens to be a PA32.
> This link http://www.4-fs.com/new/flying/N3000AWB.xls is to the W&B
> spreadsheet for the Piper Lance (PA32-RT300T) which we've been flying
> the last few years. I had included variables for fuel at departure and
> 'low fuel' for landing for just this reason. You can plug in the
> following plausible values for a real flight and end up with the CG in
> range (though precariously aft) at the start of the flight and have the
> CG aft of the limits with 15 gallons remaining at the end of a flight:
>
> Pilot+no front passenger: 180 lb
> Center Passengers: 0
> Rear Passengers: 360 lb
> Fuel: 94 gal
> Front Baggage: 0
> Rear Baggage: 90
>
> The CG only moves 0.22 inches to the rear after burning 79 gallons of
> fuel, but it does take you 0.20 inches past the aft CG limit during the
> flight.
>
> Flying this plane with club seating does allow for some interesting
> weight shifting when passengers (wife and kids typically) swap seats in
> flight. You definitely do feel the change, and as such I always keep in
> mind which passengers sit in which seats. Imagine the above loading
> with the rear passengers (2x180lb) in the center row of seats and the
> rear seats empty. Once airborne they decide they don't like to fly
> 'backwards' in the club seating and 'help themselves' to the the empty
> rear seats. Suddenly we go from a very comfortable CG to a precariously
> aft CG. Not a situation one generally needs to worry about in 2 and 4
> seat airplanes.
>
> That is part of why I find these spreadsheets so helpful in quickly
> looking at a bunch of 'what if' scenarios before we depart.
>

Steve, thanks for that. I have made up similar spreadsheets for the Warrior
and C172 , but perhaps a little fancier in that they are set up to select
different reg numbers from a drop down menu, with the specific aircraft
data ( useful for paupers like me who dont own their own plane), a clear
button to clear all the input data and a message box to warn if any of the
fuel, baggage or total wt restrictions are exceeded. But I like your idea
of showing the low fuel point ( rather than just deleting the fuel as I do)
I think I will steal this idea :<)
As I said in my previous post, it would be very unusual for me to have more
wt in the back than the front, ( which is likely to test the aft cg ) but
I could understand with club seating, the pax might be more inclined to want
to ride in style, instead of up the front.with the driver.

I notice even your 6 seater would struggle to take 4 adults with full fuel.
( the adutls would have to weigh on average less than 180 lbs - counts out
a lot of my friends!
Terry
ppl downunder


>

[Dave S]

d&tm wrote:

> Are there any single engine airplanes out there that really can go outside
> the envelope by burning fuel?

The Bonanza is the big example that comes to mind.

The moment of the Fuel is forward of the main spar and as you burn your
fuel off, the CG moves aft.

If you have the 5th and 6th seats filled or have lots of aft baggage,
you can end up aft of limits, which can bite when you are low/slow on
approach.

Dave

[tom]

Only when I fly naked.
tom

Jay Beckman wrote:
> "tom" > wrote in message
> oups.com...
> >I weigh 170, so the only ballast I carry is around my ass. 8^)
> > tom
>
> "Does this airplane make me look fat...?"
>
> ;O)
>
> Jay B

[Danny Deger]

"john smith" > wrote in message
...
> d&tm wrote:
>
snip
> At some point, the cg moves out of the envelope (the ability of the
> horizontal stabilizer to provide sufficient lift).

Aft c.g. violation makes the aircraft unstable in pitch. Forward c.g.
violation is an ability of the stabilizer to control pitch, i.e. bring the
nose up.

Danny Deger

[Steve Schneider]

As the wife and kids move around, I do need to re-trim -- but I haven't
casually noted a significant speed increase. I'll have to recruit some
'hefty' passengers and perform the experiment (our last experiment was
for my son's 5th grade science class when we capped empty water bottles
at various altitudes and he showed the class how much the bottles
collapsed as we returned to the ground).


Morgans wrote:
> "Steve Schneider" > wrote
>
>
>>Flying this plane with club seating does allow for some interesting weight
>>shifting when passengers (wife and kids typically) swap seats in flight.
>>You definitely do feel the change, and as such I always keep in mind which
>>passengers sit in which seats. Imagine the above loading with the rear
>>passengers (2x180lb) in the center row of seats and the rear seats empty.
>>Once airborne they decide they don't like to fly 'backwards' in the club
>>seating and 'help themselves' to the the empty rear seats. Suddenly we go
>>from a very comfortable CG to a precariously aft CG. Not a situation one
>>generally needs to worry about in 2 and 4 seat airplanes.
>
>
> With the passengers putting the CG at the most aft limits, do you notice any
> increase in speed, with the same power and prop settings? I would think the
> aft CG would take the downward lift away from the horizontal, and pick up
> some speed, but I don't know. It would seem like the ideal experiment; to
> be able to quickly change the CG with no changes in air density, power, or
> any other type of changes.

[Steve Schneider]

d&tm wrote:
>
> Steve, thanks for that. I have made up similar spreadsheets for the Warrior
> and C172 , but perhaps a little fancier in that they are set up to select
> different reg numbers from a drop down menu, with the specific aircraft
> data ( useful for paupers like me who dont own their own plane), a clear
> button to clear all the input data and a message box to warn if any of the
> fuel, baggage or total wt restrictions are exceeded. But I like your idea
> of showing the low fuel point ( rather than just deleting the fuel as I do)
> I think I will steal this idea :<)
> As I said in my previous post, it would be very unusual for me to have more
> wt in the back than the front, ( which is likely to test the aft cg ) but
> I could understand with club seating, the pax might be more inclined to want
> to ride in style, instead of up the front.with the driver.

I'll have to dust off an Excel manual and polish up my spreadsheets with
some of your cool features! :-)

> I notice even your 6 seater would struggle to take 4 adults with full fuel.
> ( the adutls would have to weigh on average less than 180 lbs - counts out
> a lot of my friends!
> Terry
> ppl downunder
>

True, though full tanks would far exceed the typical passenger's bladder
range. Half tanks would still yield over 2 hours of flying time with
reserves (close enough to the upper end of the random passenger's
comfort limit per my experience) and let you carry a 5th person plus a
bit of baggage some 300+nm.

The Lance is by far the most practical aircraft I've ever had the
pleasure to fly. As a coincidental but random trip example, we're
heading off tomorrow to Santa Barbara with a full load of 6 people to
make good on a trip we donated for an event at a local community
college. This will be my wife and I plus 4 people who won the drawing.
Fortunately, the passenger weights are a bit on the low side, so with
partial fuel we can fly the ~300 mile round trip with fuel to spare. It
always seems like our passenger load works out pretty well.

One of the advantages of being a sole owner/operator is that you don't
have to worry about the prior pilot/partner/club member topping off the
tanks when you need to fly with partial fuel. I'd sure hate to drain 40
or 50 gallons before a flight because someone forgot _not_ to top off,
or perhaps the prior scheduled flight didn't occur so the tanks are
still full from the flight before that one.

Steve

[Jose[_1_]]

> I'll have to dust off an Excel manual and polish up my spreadsheets with some of your cool features! :-)

You might also want to take a look at the one I did for our club.

http://www.flying20club.org/planes8237B.html

I did the "new style" spreadsheet a little differently from the others,
take a look at the "how the spreadsheet works" part of the instructions tab.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[d&tm]

"Jose" > wrote in message
et...
> > I'll have to dust off an Excel manual and polish up my spreadsheets with
some of your cool features! :-)
>
> You might also want to take a look at the one I did for our club.
>
> http://www.flying20club.org/planes8237B.html
>
> I did the "new style" spreadsheet a little differently from the others,
> take a look at the "how the spreadsheet works" part of the instructions
tab.
>
> Jose
> --
Jose, I like the way yours does flight envelopes for individual aircraft. I
have separate sheets for warrior and C172 with the ability to select
individual aircraft. my understanding was that different planes of the same
type have different wts but the same envelope.
I will post a link to my own spreadsheets, when I work out how to do that.
can you explain how to do it - or point me to some help?
thanks
terry

[Jose[_1_]]

> Jose, I like the way yours does flight envelopes for individual aircraft.

Thank you. I did give it a bit of thought. :)

> my understanding was that different planes of the same
> type have different wts but the same envelope.

This generally true; it can be trivially true by defining "planes of the
same type" as requiring the same envelope. Marketers will make a plane
of a different type if it's painted a different color, but company
aircraft designers who deal with the FAA want all their planes to be the
same type so they can piggyback on the old type certficates. Also,
"type" and "name" are not to be confused, and "type" also has a specific
FAA meaning, within which I believe it is possible to have a different
envelope, uncommon though it may be for spam cans. But I don't know
whether you mean "type" colloquially or regulationally.

Confused yet, or should I try harder? :)

> I will post a link to my own spreadsheets, when I work out how to do that.
> can you explain how to do it - or point me to some help?

If you go to a web site that has any such link, you can "view source"
and see how they did it. As long as they don't use the mess of scripts
that is becoming popular these days, it will be pretty clear.

Step one: create the spreadsheet, set it up the way you want it to be
seen when it loads (what tab you're on, what cell is active...), and
then upload it to your web server, making note of where you put it.

Step 2: put a link on the page which refers to this file. The format
for such a link is the same as any other link, to wit: an open angle
bracket, the letter 'a', a space, the letters "href", an equal sign, the
target file name (enclosed within double-quotes), including the path if
necesesary, a closing angle bracket, (all the aforementioned "begins"
the anchor tag), the text you want to =be= the link (it will be blue and
underlined by default in the browser), and then to "end" the anchor tag,
an opening angle bracket, a forward slash (usually below the question
mark on a keyboard), the letter 'a', and a closing angle bracket. I'm
being long winded because some newsreaders will grab onto anything that
looks like HTML and try to interpret it instead.

Step III: Upload that page to the web site.

Note that the client computer (the one that clicks on the link) will
need to have an excel-compatible reader to be able to work with the
file, and that some browsers will display the spreadsheet within their
own window, others will simply call Excel to do the work. You can't
control that. Alas, neither can you control whether the user sees your
latest update to the spreadsheet, or their own, old, cached copy (or
even a cached copy along the way). That's why I have the caution to
empty the cache before proceeding. It's the way the web is designed -
no way around it.

Jose

--
He who laughs, lasts.
for Email, make the obvious change in the address.