Cessna Test Pilot Days:
Production Flight Testing, 1952
Test pilot – the idea thrills some and makes others sweat, wondering why someone would want to pilot an aircraft on its first flight. Cessna has been making pre-delivery flight testing a habit for more than half a century. Mort Brown was Cessna’s Chief Pilot of Production flight test for almost thirty-five years where he personally flew 14,000 first-flight aircraft. But Mort also had a staff of other pre-delivery flight testing pilots. Their task was to evaluate both ground and flight characteristics for every Cessna aircraft, direct any fixes that needed to be completed by the production team and then accept the aircraft before it was delivered to a dealer. Let’s look back at what made some of their daily ups and downs.
A normal day began early. Each pilot was assigned several specific aircraft, usually a mix of first-flight and various model aircraft to retest. So the team of Mort Brown, Bill McNeil, Doyle Worley and Ted Hart needed to plan their day according to the aircraft that needed to be tested: 190s, 170s, an L-19, all in a day’s work. If the inventory of aircraft listed included an initial flight test, a first-time flight for that aircraft, the pilot was required to wear a parachute. It was only required on an initial flights, though. Ted Hart (photo) is seen wearing a slim profile parachute as he completed the initial flight checklist on this 170B model Cessna. This particular aircraft is no longer in service.
The tools of the test pilot in those days were quite simple. Beyond their superior pilot skills and experience they used a clipboard and a series of specific checks to accept the airplane. That clipboard was important and was strapped to each test pilot’s knee so that it was always handy should they need to note peculiarities or “squawks” as they were called then. That clipboard followed the aircraft from pilot to line mechanic to pilot, documenting the inspection and corrections that were required to each of the aircraft.
The first step in preparing for an initial flight, like any flight, was the preliminary ground check. The test pilot always performed his inspection personally and naturally was much more thorough than a general pilot’s inspection. As he walked around the aircraft he would individually inspect the ailerons, trim tabs and other outside elements of the airplane, looking for damage, incomplete assembly or loose connections. The test pilot would check to see that all controls would move their prescribed distances and check the overall fit and trim of the exterior. He constantly made notes as appropriate to ensure the aircraft was later adjusted to meet delivery to standards.
Stepping into the aircraft, the test pilots scrutinized the compartment for nonconformities, looking over the entire compartment. They would review a checklist similar to one that any pilot would use and then go the next step, as if they were personally purchasing the aircraft. They would check the fit of the doors to see how easy they closed, check the dome and navigation lights, fuel tank selector, trim tabs and check the mags. The pilots would feel how easily control knobs moved and determine the personality of the aircraft. In essence, the test pilots insured each aircraft would meet the expectation of every new Cessna pilot.
Being satisfied with the interior and exterior checks, the pilot prepared for take-off by gaining clearance from the tower for the first flight. Different aircraft typically required different amounts of flying test time. There were minimums; a 170 called for an hour of flight time, an L-19 an hour and fifteen minutes and a 190 two hours. While they were in flight the pilot would pursue a number of checks which included stall speeds with and without flaps, rpm at cruising speed and attitude of the airplane in normal flight.
The test time of an hour may seem short for a new aircraft like a 170 but it was a proven test time. During the hour flight a test pilot traveled about 120 ground miles, giving significantly more inspection time than an automobile received at its factory. If a pilot wasn’t completely convinced of an aircraft’s dynamics they could fly a longer test. Each pilot was given the latitude to fly the airplane a reasonable length of time until he felt satisfied that the aircraft’s flight characteristics met the standards set by the Civil Aeronautics Administration (CAA). At the end of the hop, or flight, each aircraft was either signed off by the test pilot as being ready for delivery, called “bought” by the test pilot, or turned back to production for adjustments that had been noted on the clipboard “squawk sheet.” The typical aircraft required two hops and occasionally a third.
The formal documentation that completed the flight testing was called The Production Flight Test Report. It documented the full series of tests and checks made both on the ground and in the air for a particular aircraft. It presented the details of the inspection checks including flight instruments, the electrical system, control systems and engine tests. It notated the length of the flight test, too. The test pilot personally signed the report when the aircraft passed inspection and placed the report in the aircraft log book. The aircraft was then prepared for distribution into the dealer network. The test pilots of the early fifties worked long tough days averaging 500 flight miles a day. Mort Brown, the chief test pilot for Cessna, himself logged over 20,700 flight hours testing aircraft. It’s a remarkable achievement and demonstrates the determination and focus that test pilots then and now provide behind the scenes.
John Cilio is a freelance writer, aviation historian and member of the Connecticut Lost Squadron Veterans Group. He lives in Sherman, CT. You can contact John at: questions@vintageflyer.com