terry
May 3rd 08, 01:22 AM
On Apr 18, 1:27*am, Dudley Henriques > wrote:
> tman wrote:
> > Flown C172's for quite a while, and never had anybody in the back.
> > Now I'm planning on quite a trip, with 2 pax and luggage.
>
> > When I fill the fuel to the *tabs*, calc everyone's weight honestly and
> > consider baggage -- I'm 75 lbs over the 2450 gross on departure. *Maybe
> > 100 over gross if I assume a "lie about weight" factor or some
> > inaccuracy with filling the tanks. *Now I'm scratching my head about
> > just how risky this is. *I know (others) have pushed over gross in these
> > planes way more under worse conditions, and have almost always gotten
> > away with it. *I'm inclined to just do it, and be cognizant that it will
> > perform differently, i.e. don't expect the same picture on climbout that
> > you would when solo.
>
> > Risky? *Or just roundoff error on the weight? *Here are some other factors:
>
> > This is the 160HP C172, standard.
> > Departure runway is 5000'.
> > No steep terrain to climb out of.
> > Plenty of alternates along with the way with > 3000 runways.
> > Not particularly hot, humid, or high. *50 degrees at 1000 MSL for
> > departure or any point of landing.
>
> > I'm figuring I'm 3% over gross, causing most of my V speeds to increase
> > 1.5%, so say -- instead of flying short final at 65 knots, I'd fly at 66
> > knots... OK wait I can't hold airspeed to +/- 1 knot on most days anyways.
>
> > I'm thinking through many of the factors, and it is only a "little" over
> > gross, only on the first hour or so of the trip. *What else should I be
> > aware of? *Am I dangerous?
>
> > T
>
> I never advise a pilot to load any airplane over gross.
> I will tell you that the big killer in these situations is the cg
> location, especially the aft cg.
> Tell you what; instead of my "advising you" on what to do specifically
> with this flight, let me suggest to you that you run a weight and
> balance for this aircraft at full tanks, THEN run the same pax and
> baggage loading figuring 1/4 tanks, just to see what this does to the cg.
>
> --
> Dudley Henriques- Hide quoted text -
I was taught to do c of g calcs with the fuel I was carrying and MT.
For a while I did this religously , and then after making up my own
weight and balance calculator and playing around for ages with
different combinations of fuel , pax and baggage, I found that for the
172N and Warriors I was flying , you could not put the c of g
outside the envelope by burning fuel. ( that is if the c of g is
inside the evelope with fuel , it will stay inside as you burn
fuel ). In both aircraft the c of g comes forward as you burn fuel
but the allowable c of g also comes forward as you lower the weight.
It may ( probably is ) different in other types. But you can
learn alot by playing around with your aircraft weight and balance
calcs. I broke mine down to a few simple rules
1. The no brainer, stay under MTOW for the density altitude ,
airfield available
2. If possible put more wt in front seats ( unusual not to anyway)
If I dont have any baggage and I know I have met the above , I know I
dont need to look any further.
If I am carrying any baggage or want to have more wt in the back seats
than front, I do the calcs
( ie hardly ever)
OK I have one other very obscure rule, ( If I have a 400 pound sumu
wrestler in the front with me, I might check the forward c of g.
Terry
PPL Downunder
> tman wrote:
> > Flown C172's for quite a while, and never had anybody in the back.
> > Now I'm planning on quite a trip, with 2 pax and luggage.
>
> > When I fill the fuel to the *tabs*, calc everyone's weight honestly and
> > consider baggage -- I'm 75 lbs over the 2450 gross on departure. *Maybe
> > 100 over gross if I assume a "lie about weight" factor or some
> > inaccuracy with filling the tanks. *Now I'm scratching my head about
> > just how risky this is. *I know (others) have pushed over gross in these
> > planes way more under worse conditions, and have almost always gotten
> > away with it. *I'm inclined to just do it, and be cognizant that it will
> > perform differently, i.e. don't expect the same picture on climbout that
> > you would when solo.
>
> > Risky? *Or just roundoff error on the weight? *Here are some other factors:
>
> > This is the 160HP C172, standard.
> > Departure runway is 5000'.
> > No steep terrain to climb out of.
> > Plenty of alternates along with the way with > 3000 runways.
> > Not particularly hot, humid, or high. *50 degrees at 1000 MSL for
> > departure or any point of landing.
>
> > I'm figuring I'm 3% over gross, causing most of my V speeds to increase
> > 1.5%, so say -- instead of flying short final at 65 knots, I'd fly at 66
> > knots... OK wait I can't hold airspeed to +/- 1 knot on most days anyways.
>
> > I'm thinking through many of the factors, and it is only a "little" over
> > gross, only on the first hour or so of the trip. *What else should I be
> > aware of? *Am I dangerous?
>
> > T
>
> I never advise a pilot to load any airplane over gross.
> I will tell you that the big killer in these situations is the cg
> location, especially the aft cg.
> Tell you what; instead of my "advising you" on what to do specifically
> with this flight, let me suggest to you that you run a weight and
> balance for this aircraft at full tanks, THEN run the same pax and
> baggage loading figuring 1/4 tanks, just to see what this does to the cg.
>
> --
> Dudley Henriques- Hide quoted text -
I was taught to do c of g calcs with the fuel I was carrying and MT.
For a while I did this religously , and then after making up my own
weight and balance calculator and playing around for ages with
different combinations of fuel , pax and baggage, I found that for the
172N and Warriors I was flying , you could not put the c of g
outside the envelope by burning fuel. ( that is if the c of g is
inside the evelope with fuel , it will stay inside as you burn
fuel ). In both aircraft the c of g comes forward as you burn fuel
but the allowable c of g also comes forward as you lower the weight.
It may ( probably is ) different in other types. But you can
learn alot by playing around with your aircraft weight and balance
calcs. I broke mine down to a few simple rules
1. The no brainer, stay under MTOW for the density altitude ,
airfield available
2. If possible put more wt in front seats ( unusual not to anyway)
If I dont have any baggage and I know I have met the above , I know I
dont need to look any further.
If I am carrying any baggage or want to have more wt in the back seats
than front, I do the calcs
( ie hardly ever)
OK I have one other very obscure rule, ( If I have a 400 pound sumu
wrestler in the front with me, I might check the forward c of g.
Terry
PPL Downunder