hen I was a kid, I was fascinated with the Cessna airplanes overflying our house in the summertime. I then gradually became an airplane fanatic, devouring books, visiting museums, going to airshows, building kites, then gliders, then radio controlled airplanes, and finally obtaining my private pilot’s license.
I came to aviation alone, as no one else in my family had any link to aviation. I wished an adult had taken me for an airplane ride when I was a kid, but it just didn’t happen. So naturally, when I got my private pilot’s license, I invited lots of people for sightseeing rides. It is a great pleasure to share my passion for aviation with other people.
So, on an early spring day, I was on a sightseeing circuit above downtown Montreal. When the time came to come back to the St-Hubert airport on the south shore, I had to cross the St. Laurence river above the Victoria bridge and switch to the tower’s frequency as I crossed the body of water. As I was crossing, I came upon a huge cloud of Ephemeroptera (flying insects), and shortly thereafter my airspeed indicator dropped gradually to 30 knots indicated. This was in a Cessna 172N, with an engine obviously developing a healthy dose of power. I knew I had to be flying faster than that, otherwise the airplane would have stalled by now. Just to make sure, I initiated a dive. I then heard the engine revving higher than usual, so I reasoned that my airspeed indicator must have become inop, and I resumed level flight, ignoring the airspeed indicator.
I communicated my problem to ATC and asked the controller at which speed he saw me on his radar. He responded that he saw me at 70 knots ground speed (which is not the same as airspeed). So I asked for the longest runway, and proceeded to a visual approach towards the runway, in what visually looked like a faster than usual approach. I then flew over the numbers, set the engine to idle, and let the airplane slowly bleed speed and gently settle in a ever so slightly nose up configuration when it was ready.
I landed safely, and my passengers did not ever notice there was a problem with the flight. I parked the plane, tied it down, and reported the blocked pitot to the school I had rented the airplane from.
In retrospect I could have read my groundspeed myself on the airplane’s GPS, but the idea did not cross my mind during the event. The airspeed indicator is a veryy important instrument. When you think about it, in the takeoff, approach and landing procedures, there are several airspeeds to follow. Without an airspeed indicator, who says you are going slowly enough to deploy the flaps? At least I was lucky to have lost the airspeed indicator during the day; I was still able to see the terrain moving underneath me which gave me a sense of the speed I was going at. So I just performed a normal approach, carrying just a little more speed than usual for safety, flying the airplane at the usual engine RPMs I usually flew it at during the various phases of flight; 2300 RPM in level flight, and 1700 RPM on downwind, putting 20 degrees of flap after turning base, and 30 degrees of flaps on short final.