When Popping Off is Necessary

When I joined MAF in 1977, the training department was teaching pilots how to execute a “flap pop-off.” This technique allowed the airplane to “unstick” itself and get flying at a very slow speed when trying to take-off from an extremely muddy airstrip…a trick that became quite useful when I flew in Ecuador.

The Amazon jungle in eastern Ecuador gets between 24 and 28 FEET of rain a year, and the rain-soaked grass and dirt airstrips often hampered the ability to gain much speed on the ground in order to take off. A flap pop-off was occasionally just the right trick that helped lift the plane into the air when mud didn’t want to let go.

Most airplanes have flaps, small airfoils that increase the lift of the wings at slow speeds. Normally flaps are extended appropriately for take-off, before the take-off run is started. With a flap “pop-off,” the flaps are extended abruptly, immediately increasing the lift of the wing,

(a) and in conjunction with ground effect lift, the airplane was popped right into the air. Hence the name of the “flap pop-off.”

(b) with the airplane popping right into the air. Hence the name of the “flap pop-off.”

Mission Aviation Fellowship Airstrip in EcuadorOne afternoon I was flying family physician Dr. Jack Olinger out of a water-saturated, muddy air strip in Ecuador – and taking off here wasn’t going to be easy. If ever the flap pop-off technique was necessary, this situation was it.

Piloting a Cessna 180, with large, lift-enhancing and manually-controlled flaps, I rolled down the airstrip once to determine just how much speed I might be able to gain on the ground. Once I was satisfied that I could employ the flap pop-off technique safely to get us into the air, we began splashing down the airstrip again.

At just the right moment, I jerked the flap lever up and we jumped into the air. The nose of the airplane had to be carefully lowered to gain speed, without touching down again. I think that this maneuver surprised Dr. Olinger, as it was a non-standard maneuver. As we established a solid climb rate and rose over the jungle trees, Dr. Jack said that “this was so much fun,” and “could we land and do it again?” – a request I politely declined.

In most newer planes, electronically-powered flaps render flap pop-offs useless, but in the Cessna 180 and 185 they sure came in handy at the right time and in the right place!

Leave a Reply

Your email address will not be published.