Sportsman STOL

Seaplanes North is the Exclusive Alaska stocking dealer for the famous Sportsman STOL kit

About the Sportsman STOL

The Sportsman STOL modifications itself was originated by Marvin Davis, a Lockheed Skunkworks engineer who developed it while studying NASA technical notes pertaining to airfoil stall and spin characteristics from NASA’s Langley Research Center. After finalizing his findings through wind tunnel tests, Marvin obtained the rights from Lockheed. Sadly, Mr. Davis passed away before realizing the full potential of this discovery. Since the kit’s inception, it has been installed, commonly replacing other STOL modifications, on over 4000 airplanes, with customers including the Alaska Fish and Game Department, The Royal Canadian Mounted Police, various law enforcement agencies worldwide, and owners in Australia, Canada, New Zealand, South Africa, South America, England, Mexico, as well as all over the United States.

The Sportsman STOL wing cuff is a state of the art modification designed to increase light plane utility and safety by increasing the wings efficiency and resistance to stalls and spins. The kit consists of a glove that fits over the wings leading edge, extending approximately two inches forward from the original wing, and further drooping the leading edge. The Sportsman STOL is not just a lip on the bottom, but is a re-engineered airfoil. The aim of the Sportsman STOL modification is to improve aerodynamics. The Sportsman STOL achieves this by streamlining the impingement point for smoother airflow and less drag. The second benefit is that the airflow remains smooth to a greater angle of attack (increased Laminar Flow) and the stall curve is considerably extended. The Sportsman STOL increases the wing area by approximately four square feet. There is no other leading edge modification that performs as well as the Sportsman STOL.

What will it do for me?

-Nearly double the lift co-efficient
-Increase flap efficiency
-Increased rate of climb
-Eliminate the classic stall
-Increase glide ratio from 7:1 to 13:1 (170B)
-Increase fuel economy
-Raise service ceiling
-Reduce landing & take off speeds up to 37%
-NO reduction in cruise performance
-Reduce stagnation point drag
-Make flying fun again

Added Performance Benefits:

-ADDED Wing Area
-Stall speed REDUCTION over stock wing and other STOL mod’s
-Softer stall characteristics
-NO drag penalty


Sportsman STOL approved model list:


SA4302WE SA4303WE SA2256WE
150A 182 170B
150B 182A 172, 172A-L
150C 182B 172M, N, P, Q
150D 182C R172K
150E 182D 175, 175A
150F 182E 180, 180A-H
150G 182F 180J, K
150H 182G 185, 185A-E
150J 182G A185E, A185F
150K 182J 205, 205A
150L 182K 206, P206
150M 182L P206A-E
A150M 182M U206
152 182N U206A-G
A152 182P TP206A-E
182Q new! TU206A-G
182R new! 206H
182S new! T206H
182T new! 207, T207 new!
R182 new! 207A, T207A new!
T182 new!
T182T new!
TR182 new!

Sportsman STOL Performance Figures:


Cessna 170B Cessna 170B
Standard (mph) Modified (mph)
Top Speed 136 140
Cruise @ 7500ft 121 130
Landing Speed (40* flaps) 58 40
Stalling Speed (0* flaps) 60 43
Sugg. Gliding Speed 89 69
Take-Off Speed (20* flaps) 67 41
Vx Climb Speed 67 48
Vy Climb Speed 89 69
Take-Off Ground Roll (20* flaps) 617 ft 420 ft
-Clear 50′ Obstacle 1625 ft 520 ft
Landing Roll Out 458 ft 380 ft
-Clear 50′ (40* flaps) 1145 ft 760 ft