riddle me this - Page 3

D-Luv · 04-18-2008, 01:38 AM

Quote:

Originally Posted by RBower

Ok here we go:

1) We can only legally take off with the trim between 6 and 8 units.
2) With the trim at barely 6 up, our cg is at the aft limit takeoff.
3) An aft cg is the most efficient loading for the airplane, reducing tail down force during the whole flight.4) Airplane burns less fuel than cg at full forward limit.

I cant help you any further than this.

You need to be more specific here, in swept wing airplanes (like ours) there is a point where moving the CG aft decreases efficiency (generally further after than 32% MAC). None of us have any knowlege of where 6,7,or 8 units up lies in realation to MAC.

WetPink · 04-18-2008, 12:28 PM

Quote:

Originally Posted by D-Luv

You need to be more specific here, in swept wing airplanes (like ours) there is a point where moving the CG aft decreases efficiency (generally further after than 32% MAC). None of us have any knowlege of where 6,7,or 8 units up lies in realation to MAC.

You may be able to figure it out here,

http://www.airweb.faa.gov/Regulatory...E/T00011AT.pdf

C.G Limits
(landing gear extended)
592.4 to 623.3 inches (15.6% to 43% MAC) with 42,549 lbs (19,300 kg).
592.4 to 623.3 inches (15.6% to 43% MAC) with 42,328 lbs (19,200 kg).
588.3 to 623.3 inches (12% to 43% MAC) with 34,171 lbs (15,500 kg).
588.3 to 623.3 inches (12% to 43% MAC) with 28,660 lbs (13,000 kg).
619.9 inches (40% MAC) with 26,455 lbs (12,000 kg).
Straight linear variation between the points given.
Moment due to landing gear retraction - 10,155 in-lbs (-117 kgf-m)
(the aircraft C.G. is moved forward with the retraction).

or here,

http://www.legacydriver.com/Legacy%2...Procedures.pdf
trim.JPG

8 up is for small people.