#Airfoil surfboard series#

The wing skins would be thin, but the plan was to machine-rivet the sections that would form the leading edges. To start with, engineers used the new cantilever wing design that was being introduced on the ’67 Centurion, built with scaled-down component thicknesses for the lower target gross weight of 2,350 lb. Cessna was so confident that it ordered 2,000 four-cylinder, 150 hp O-320s before the 172J flight testing was finished, and they took an option on 2,000 more: there was much joy in Williamsport. However, for some reason Continental was abandoning its lower-power engines. And, by management decree, it had to use a 150 hp engine for cruise efficiency.Īll previous flat-engine Cessnas had been powered by Continental, and the 172 had used the 145 hp six-cylinder O-300 model since its 1956 introduction. The new 172 would have a large, spacious cabin, better pilot visibility, more speed, easy entrance and exit through 47½” wide doors, better flying qualities, tubular steel landing gear and a modern, streamlined appearance. It was referred to internally as the “J-bird,” and security was tight. Planning for a 1968 introduction, work was started on the 172J in 1965. But one way to get the best value for money spent was to spread the expense across several models, and the venerable 172 seemed to be a good place to start. It would take a long time to recoup the investment. Gross weight had, of necessity, grown 100 pounds, and cruise speed increases were a modest two to three mph, although ongoing refinements over the next 15 years would eventually net an additional 20-30 mph.Įven though Cessna had spent millions in development, the 1967 models were priced virtually the same as the year before.

The cantilever laminar flow wing debuted on the 1967 210H/T210H. was added to the horizontal tail (a fully articulated tail had been considered, but was abandoned after testing). That was when it was evident that more elevator power was needed, and six sq. Next, the wing was moved 4½ inches aft for better visibility, but that created a nose-heavy condition and stability problems, the solution of which was a higher-dihedral wing.ĭozens of other compromises had to be made before it was test flown in mid-1965. Cessna was able to breach the problem (at great expense) by machining a tapered spar. The next obstacle was that because a cantilever wing is inherently heavier than a strut-braced wing, it normally requires a heavier main spar. First off, the proposed location of the main spar didn’t match the door posts on the existing 210, so a heavy supporting structure had to be added-but that lessened headroom, which required another compromise. Design work began on the new wing in 1964. The high-performance 210 Centurion was the logical candidate. At the same time, it appeared that higher cruising speeds could be achieved by eliminating the wing struts then in use on all Cessna singles. Data showed extraordinarily low drag coefficients if precise wing smoothness could be achieved.

#Airfoil surfboard series#

In reaction to customer demand and a desire for higher performance, Cessna engineers had become intrigued with the NACA series of laminar flow airfoils. That having been (hopefully) explained may help you understand some of the problems created by the inevitable compromises that surround the introduction of a totally new airplane like the Cardinal. There are manufacturing considerations, of course: the longer tooling can be used, the less the unit cost, but the principal reason is that basic engineering, testing and use history has proved a structure to be of a predictable strength and performance. The average customer may not comprehend the reason aircraft designers and manufacturers recycle their basic designs. Why new designs are as rare as a tailwind