It corrects a high drag area of the airplane to more closely match the design of the 1970 and later Cardinals, improving airflow, rate of climb and cruise speed.

We also like the mods for twins that increase single-engine rate of climb.

Performance (rate of climb, or RoG) resulting from various airplane configurations is plotted in the graph on the opposite page, broken down into two sub demonstrations: The [V.sub.YSE] demonstration itself, where only airspeed is varied, plus one demonstrating the impact various combinations of extended landing gear, flaps and windmilling propeller flown at the same speed.

This demonstration shows how varying degrees of parasitic drag compromises rate of climb. In fact, for several combinations of landing gear and flap deployment, as well as for the wind-milling propeller, a positive rate of climb cannot be achieved; a disappointing rate of descent occurs.

Single-engine service ceiling (50 FPM

rate of climb) is 3200 feet.

The pilot said the airplane was descending very steeply even with full power and with the airspeed at best

rate of climb speed.

We came to a few conclusions: that the big benefit to gap seals is not widely recognized -- improved handling in roll and rate of roll; the mod shops make speed claims in MPH because it sounds better than knots; there will be some speed increase, but don't count on more than one or two percent -- with potentially some increase in

rate of climb and flap gap seals do not adversely affect stall speeds.

When flying aircraft equipped with wings built around laminar-flow airfoils, a higher airspeed/lower angle of attack is necessary to achieve the same

rate of climb. This quickly can be a problem if one is familiar with the 172's behavior and jumps into a 177.

Where horsepower increases shine are in

rate of climb and takeoff distance.

The pilot-in-command reported that, after takeoff and obtaining a positive

rate of climb, he selected the gear-up handle.

The basic formula is that the

rate of climb in feet per minute equals the climb rate in feet per mile multiplied by the result of dividing the groundspeed by 60.