Flight — Control Manual Fokker F27

The most famous section of the manual is the “Propeller Asymmetry” chapter. With two Rolls-Royce Dart engines, each turning a large four-blade propeller, an engine failure at low speed produces yaw far beyond rudder authority if not caught immediately. The manual prescribes a sequence memorized by generations of Friendship pilots: “Power – Identify – Feather – Rudder – Trim – Climb.” But uniquely, it adds: “If rudder pedal force exceeds 150 lbs, you have waited too long. Reduce power on the good engine before you lose control.” That counterintuitive advice – reduce power to regain control – saved lives in the 1960s and remains a classic case study in upset recovery training. The F27 flight control manual evolved through hard experience. The 1972 revision followed a series of tailplane icing accidents. Fokker discovered that a thin layer of rough ice on the horizontal stabilizer could cause elevator buffet and increased stick forces. The manual added a new procedure: “In known icing, do not retract flaps beyond 15° until clear of ice. Flap retraction changes tail angle of attack. Ice contamination may lead to loss of pitch authority.”

In the end, the manual’s most important lesson appears not in the emergency section but in the preface, in plain block letters: “THIS AIRCRAFT HAS NO FLY-BY-WIRE. YOU ARE THE WIRE. FLY ACCORDINGLY.” End of essay Flight Control Manual Fokker F27

Instructors often said: “The manual is your co-pilot. But you must become the manual.” Checkrides included a “blindfold test” – covering control surface position indicators – where the candidate had to state control surface angles from control column position alone. A typical question: “Flaps 25°, speed 120 KIAS, power 25 lbs torque, engine out left. Where is the rudder trim?” The answer was not in a table but in a feel described in Section 4.3. The most famous section of the manual is

Introduction: The Manual as a Living Document In the pantheon of postwar turboprop airliners, the Fokker F27 Friendship occupies a singular space. It is neither the fastest, nor the most glamorous, nor the most technologically radical. Yet from its first flight in 1955 to the end of production in 1987, over 580 units were built, serving on every continent. The secret to its longevity lay not only in Dutch engineering but in the clarity, rigor, and philosophy embedded in one unassuming publication: the Flight Control Manual Fokker F27 . This essay argues that the F27’s flight control manual was not merely a technical reference but a pedagogical tool that shaped generations of pilots, codified the aircraft’s unique handling characteristics, and mirrored the transition from stick-and-rudder intuition to systems-based airmanship. Part I: The Genesis of the F27 Flight Control System To understand the manual, one must first understand the machine. The Fokker F27 was designed to a mid-1950s specification for a rugged, high-wing, twin-turboprop regional airliner. Its flight controls are entirely manual – no power steering, no irreversible hydraulic servos. Ailerons, elevators, and rudder are actuated by cables, push-pull rods, and bellcranks, with trim tabs and spring-loaded servo tabs providing aerodynamic assistance. The control forces are therefore “natural,” directly proportional to airspeed and control surface deflection. Reduce power on the good engine before you lose control