I just recently purchased a kr2 that was started in 1984. It is complete
up to weight and balance and seems to have very good workmanship. The
engine is a modified revmaster. With the following information I am
trying to calculate if I infact have an increased Gross Weight
considering the increased wing span and increased HP?
Engine 2100D- 75hp. vs factory 2100 -65hp
wing span 23-8 vs factory 20-8
Length 15-4 vs factory 14-6 (includes
spinner)
Total wing area ?___ vs factory 78s/f
Empty weight 659lbs vs factory 480
Gross weight ?___ vs factory 900 lbs
Usefull load ?___ vs factory 420lbs
_MFG NOTES;_
Wingloading 11.5 lbs/sq.ft
Power Loading 13.9 lbs/hp
Gross Weight _/* 900 lbs*/_
_Weight and balance_
factory; +4/-4 inches from aft of main spar at wing root
8 to 16 in aft of L/E
Actual;
Datum @ firewall
Spar @ 24in to 26.25 in
Fwd c/g 21.4in Aft c/g 29.4
Empty Weight 659 lbs
Empty weight cg 18.9in
Full fuel header tank weight 731 lbs
Full Fuel c/g w/out pilot 18.99"
Pilot #1 w/out fuel 23.54in , W/12gal. fuel 23.75
Pilot #2 w/out fuel 24.21in, W/12gal. fuel 23.38
Main Wheels C/L 82-1/2"
Fixed gear tail drager with 7" pneumatic tire.
_Wing;_
124"length x 50" i/b x30" o/b
124 x 30= 3720 +{(124x20~2)=1240}=3720+1240=4960x2 wings
=9920~144"= 68.9 S/F.
Why does this not calculate above mfg 78s/f ??? What don't I
see? Try another way,
Alternate figure; figure added lenght to each wing tip;;
18"x30"= 540"x 2 wing tips= 1080~144= 7.5 S/F, add to factory 78=
85.5 s/f
85.5 x 11.5 factory wing loading=/_ *983 LBS*_ = 83 lbs i/ncrease
in gross weight !!???
Maybee I need to add Horz stab surface to first calculations or maybee
lower fuselage area between wings?
stab and elevator;
35 1/2"x 26 I/B x 22 1/2 O/B calculates to 7.5 S/F
7.5s/f + calculated wing area of 68.9 s/f = 76.4s/f ( still
less than factory 78)
_Engine._
75h/p x 13.9 lbs/hp =_*/1042 lbs/* _gross weight capabilities???
WHAT IS MY CORRECT GROSS WEIGHT SO I CAN FLY WITH PILOT #1 @ 170 lbs
AND PILOT #2 @ 212 Lbs =382 LBS +730 lbs =/ /*_/1112 lbs/ _*w/out baggage ?
Thank You in advance
Keith and Brent Wiese
