This chapter examines the problems associated with an engine failure and how engine out flight testing is accomplished. The discussion will begin with performance issues, how engine loss affects the takeoff and initial climb segments. Next, the equations of motion are introduced, modified for an engine failure. They are used to show how minimum control speeds are determined by design. Finally, flight test techniques are introduced for the evaluation of engine out flying characteristics of multiengined aircraft.
From the designer to the pilot, everyone associated with the flying qualities of high performance military aircraft, particularly the fighter or attack variety, is or should be aware of the importance of the high angle of attack flight regime. It is here that the aircraft will spend a significant amount of its time when performing the mission for which it was designed. It is here that the aircraft must display its most outstanding performance. It is also here that the aircraft, when pushed beyond its limits of controllability, can seemingly defy all laws of physics and principles of flight with which its surprised and often bewildered pilot is acquainted. The frequency of inadvertent loss of control at high angle of attack is such that many combat aircraft pilots are becoming firmly convinced that all pilots may be divided into two categories: those who have departed controlled flight, and those who will. Most thoroughly convinced are those pilots who fall into the former category. The unfortunate fact concerning departure from controlled flight at high angle of attack is that many aircraft and pilots are lost each year due to failure to recover from the out-of-control flight condition. The circumstances surrounding the losses are varied. Departures from controlled flight may occur unintentionally during high-g maneuvers or intentionally during a nose-high deceleration to zero airspeed in an attempt to gain an advantage over an opponent in combat maneuvering; the aircraft may spin and the gyration be identified too late for recovery or a steep spiral may be mistakenly identified as a spin, causing recovery controls to be misapplied. Whatever the circumstances, departures from controlled flight result all too often in catastrophe. For this reason, test pilots in particular must be familiar with every facet of the high angle-of-attack flight regime.
This chapter studies the algebra and calculus of vectors and matrices, as specifically applied to the USAF Test Pilot School curriculum. The course is a prerequisite for courses in Equations of Notion, Dynamics, Linear Control Systems, Flight Control Systems, and Inertial Navigation Systems. The course deals only with applied mathematics; therefore, the theoretical scope of the subject is limited.
Textbook introducing the fundamentals of aircraft performance using industry standards and examples: bridging the gap between academia and industry Provides an extensive and detailed treatment of all segments of mission profile and overall aircraft performance Considers operating costs, safety, environmental and related systems issues Includes worked examples relating to current aircraft (Learjet 45, Tucano Turboprop Trainer, Advanced Jet Trainer and Airbus A320 types of aircraft) Suitable as a textbook for aircraft performance courses
Your study of flying qualities to date has been concerned with the stability of the airplane flying in equilibrium on symmetrical flight paths. More specifically, you have been concerned with the problem of providing control over the airplane's angle of attack and thereby its lift coefficient, and with ensuring static stability of this angle of attack. This course considers the characteristics of the airplane when its flight path no longer lies in the plane of symmetry. This means that the relative wind will make some angle to the aircraft centerline which we define as Beta. The motions which result from Beta being applied to the airplane are motion along the y-axis and motion about the x and z axes.
This chapter examines the theory and flight tests required to determine cruise data presented in aircraft flight manuals. Aircraft cruise performance is dependent upon the combination of airplane aerodynamics and engine characteristics. Basic aerodynamic and engine theory applied to cruise testing are covered. Aerodynamic forces acting on the aircraft, i.e., lift and drag, and engine thrust and fuel flow are presented as functions of easily measured parameters. Engine and aerodynamic functions are then combined to complete the analysis. The end result provides a method by which engine and airplane cruise performance characteristics may be determined with minimum flight testing. The data obtained from the flight tests are used to determine cruise performance charts and tables presented in the flight manual, and to determine cruise specification compliance and military utility. The basic assumption of cruise theory is that during cruise the aircraft maintains level, unaccelerated flight. When the aircraft is in level, unaccelerated flight, the sum of the forces acting upon it equals zero. Assuming the thrust acts along the direction of flight (or differences in direction of thrust due to engine installation angle and aircraft angle of attack are negligible), the lift force, L, is equal to the aircraft weight, W, and the net thrust, Fn, is equal to the aircraft drag, D.
This chapter reviews the mathematical tools and techniques required to solve differential equations. Study of these operations is a prerequisite for courses in aircraft flying qualities and linear control systems taught at the USAF Test Pilot School. Only analysis and solution techniques which have direct application for work at the School will be covered.
