In late 1948, Cessna began sales of the 170, with a metal fuselage and tail and fabric-covered constant-chord wings.

The Bird Dog was extensively redesigned from the basic 170 and included a revised tandem-seat fuselage and a wing with large modified Fowler flaps that deployed up to 60°.

In 1952, the Cessna 170B was introduced, featuring a new wing tapered outboard of the flaps, incorporating dihedral similar to the military version.

The B model was equipped with very effective modified Fowler (slotted, rearward-traveling) wing flaps which deflect up to 40°,[1] adapted from the C-305/Bird Dog, a wing design that lives on in the Cessna light singles of today (constant NACA 2412 section with a chord of 64 inches (1,600 mm) from centerline to 100 inches (2,500 mm) (the outboard end of the flaps), then tapering to 44-inch (1,100 mm) NACA 2412 section chord at 208 inches from centerline, with three-degree washout across the tapered section).

Better results were obtained by departing from the Arado jet pump method and using an engine-driven generator to power electric motors driving axial fans to move the internal air.

[5] This concept was adopted on the Model 319 but substituted an engine-driven hydraulic pump to drive hydraulic-powered axial fans.

[5] The 309 and 319 were meant to be research aircraft only, and no plans were developed to incorporate boundary layer control technology in then-current Cessna models.