Simple weight/balance question

Hi!

I am part owner of an Arrow 180 hp.

We haven't had a weight and balance done in a while, and I was wondering one
thing.
It seems on the old numbers that me and my wife cannot ride in the front
seat together when fully fueled....

I weigh in at around 100 kg (approx 220 lbs) and wife is around 70 kg
(around 150 lbs)

Is this normal for this plane, or am I doing something wierd with the
figures? I would think that two adults should be ok in this plane with full
tanks? Its an arrow for goodness.....hehe....no?

Any input appreciated.
I will be doing my nigh rating next week, and would be nice to know if my
instructor and I will be legal flying around in the dark with full tanks....

Frode Berg
Norway

Your calculations are probably correct. I cannot sit in the front of my
Cherokee 140 with a passanger unless I put some weight in the back.


"Frode Berg" wrote in message
...
Hi!

I am part owner of an Arrow 180 hp.

We haven't had a weight and balance done in a while, and I was wondering
one
thing.
It seems on the old numbers that me and my wife cannot ride in the front
seat together when fully fueled....

I weigh in at around 100 kg (approx 220 lbs) and wife is around 70 kg
(around 150 lbs)

Is this normal for this plane, or am I doing something wierd with the
figures? I would think that two adults should be ok in this plane with
full
tanks? Its an arrow for goodness.....hehe....no?

Any input appreciated.
I will be doing my nigh rating next week, and would be nice to know if my
instructor and I will be legal flying around in the dark with full
tanks....

Frode Berg
Norway

It seems on the old numbers that me and my wife cannot ride in the front
seat together when fully fueled....

Well, there is "should not" and there is "cannot." Obviously, it is
possible to fly an Arrow with two adults in the front seat with full fuel.
It's done every day, all over the world, safely.

That said, you may be a bit out of CG range -- which is obviously computed
rather conservatively.

Just put a sand bag in the luggage compartment, and you'll discover that
flaring to land is MUCH nicer.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Steve Foley wrote:
Your calculations are probably correct. I cannot sit in the front of my
Cherokee 140 with a passanger unless I put some weight in the back.


"Frode Berg" wrote in message
...

Hi!

I am part owner of an Arrow 180 hp.

We haven't had a weight and balance done in a while, and I was wondering

one

thing.
It seems on the old numbers that me and my wife cannot ride in the front
seat together when fully fueled....

I weigh in at around 100 kg (approx 220 lbs) and wife is around 70 kg
(around 150 lbs)

Is this normal for this plane, or am I doing something wierd with the
figures? I would think that two adults should be ok in this plane with

full

tanks? Its an arrow for goodness.....hehe....no?

Any input appreciated.
I will be doing my nigh rating next week, and would be nice to know if my
instructor and I will be legal flying around in the dark with full

tanks....

Frode Berg
Norway





Far better to be nose heavy than tail heavy.

"Jay Honeck" writes:

Just put a sand bag in the luggage compartment,

Sand?! I thought that was something only renters did. Don't
owners have plenty of junk in the luggage compartment(s)
already? With the "oh, ****!" gear and extra engine and turbo
oil I usually carry, I've got no need for dead weight

Hmmm...has there been a "what stuff do you have tucked away
in the recesses of your plane" thread? (I'm not sure where
to start with a search.)

--kyler

Sand?! I thought that was something only renters did. Don't
owners have plenty of junk in the luggage compartment(s)
already?

For sure! Although, I just cleaned it out (to carry my Mom-in-law's and
Aunt's luggage) the other day, so I'm probably WAY nose-heavy now!

(Back to the original poster: If you think an Arrow is nose heavy with two
in the front seats, try flying a Cherokee with a 6-cylinder engine! We're
always nose heavy, unless we've got two in the back seat, or a case of oil
in the way-back...)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Frode Berg" wrote in message ...
Hi!

I am part owner of an Arrow 180 hp.

We haven't had a weight and balance done in a while, and I was wondering one
thing.
It seems on the old numbers that me and my wife cannot ride in the front
seat together when fully fueled....

I weigh in at around 100 kg (approx 220 lbs) and wife is around 70 kg
(around 150 lbs)

Is this normal for this plane, or am I doing something wierd with the
figures? I would think that two adults should be ok in this plane with full
tanks? Its an arrow for goodness.....hehe....no?

Any input appreciated.
I will be doing my nigh rating next week, and would be nice to know if my
instructor and I will be legal flying around in the dark with full tanks....

Frode Berg
Norway



I have a PA28R-200, Arrow II. With 370 lbs in the front seat, I am
well within the CG limits. From what I can tell (a friend has a
PA28R-180) the CG envelope for the PA28R-180 is not that much
different than mine, and I can't imagine that you have that much gear
in the panel that the CG would move so as to be out of the envelope.


Maurice Givens

"Jay Honeck" wrote in message news:lWn_b.380048$xy6.2073697@attbi_s02...
Sand?! I thought that was something only renters did. Don't
owners have plenty of junk in the luggage compartment(s)
already?

For sure! Although, I just cleaned it out (to carry my Mom-in-law's and
Aunt's luggage) the other day, so I'm probably WAY nose-heavy now!

(Back to the original poster: If you think an Arrow is nose heavy with two
in the front seats, try flying a Cherokee with a 6-cylinder engine! We're
always nose heavy, unless we've got two in the back seat, or a case of oil
in the way-back...)

One other thought...

Most pilots are smart enough to do a pre-flight W&B calculation prior
to launching, which is great. There are two additional numbers you
want to calculate: 1) what's happening to my CG as burn my planned
fuel?, and 2) What's my CG with zero fuel? The latter becomes
important if you get caught in bad weather, or have to make an
unplanned diversion. In the case of my Bonanza, the CG moves aft at a
good rate as I burn fuel. The last thing we want to do is land an
outside-the-envelope airplane when the going gets tough.

My flight planning software package taught me this trick, as it always
spits out the zero fuel CG number when it computes weight and balance.

Rob

That sounds about right. Our Cherokee 180 is right at the edge of the forward
envelope with 400 lbs (marginally fatso pilot + copilot) at full fuel. I can tell
flying it there, because the elevator trim barely runs out on a slow short final to
landing (80 mph IAS or so). That's part of the reason a bit of power in the flare on
these Cherokees helps keep the nose from "plopping" on landing.

I've run the math with a matlab script that implies it's virtually
*impossible* to aft-load the thing. Put a 120 lb pilot, enough fuel for a spin around
the patch, the maximum of 100 lbs in the baggage compartment, and enough fat-asses in
the back seat to gross... still not outside the aft limit.

Of course, your plane may vary so do your own W&B. Ever notice how all the
Cessnas on the field have their nose in the air after a snow but the Pipers never do.

Another note is moving the CG further aft gives a non-trivial speed increase
for a Cherokee. I've seen almost 10 mph with three 200 lb people in a Cherokee 150
from front/front/rear - front/rear/baggage. Tough to climb over that back seat,
BTW....

-Cory


Frode Berg wrote:
: Hi!

: I am part owner of an Arrow 180 hp.

: We haven't had a weight and balance done in a while, and I was wondering one
: thing.
: It seems on the old numbers that me and my wife cannot ride in the front
: seat together when fully fueled....

: I weigh in at around 100 kg (approx 220 lbs) and wife is around 70 kg
: (around 150 lbs)

: Is this normal for this plane, or am I doing something wierd with the
: figures? I would think that two adults should be ok in this plane with full
: tanks? Its an arrow for goodness.....hehe....no?

: Any input appreciated.
: I will be doing my nigh rating next week, and would be nice to know if my
: instructor and I will be legal flying around in the dark with full tanks....

: Frode Berg
: Norway



--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

wrote:

: That sounds about right. Our Cherokee 180 is right at the edge of the forward
: envelope with 400 lbs (marginally fatso pilot + copilot) at full fuel. I can tell
: flying it there, because the elevator trim barely runs out on a slow short final to
: landing (80 mph IAS or so). That's part of the reason a bit of power in the flare on
: these Cherokees helps keep the nose from "plopping" on landing.

Also note that there is a Piper service bulletin that extends the forward
CG envelope a moderate amount, so that the situation of 2 * 200 lb front
seat passengers + fuel + no rear seat pax or baggage is within the CG
envelope. It is purely a paper change, you get a new CG envelope sheet.
It came with my Cherokee 180, and I believe that it applies to straight-wing
Arrows too (ie, PA-28-180 and PA-28-200).

Me? I keep a tool box in the baggage compartment.
--
Aaron Coolidge (N9376J)