1 Chapter 6 The Airline Planning Process Learning Objectives: Student will learn these FACTS 1. Three airline planning decisions: (1) Fleet, (2) Route, and (3) Schedule 2. Aircraft Technical Performance 3. Fleet Selection Trade‐off 4. Hub‐and‐Spoke versus Point‐to‐Point Airline Networks 5. Route Profitability Analysis 6. Schedule Development processes (4) Student will learn these SKILLS 1. Interpret Aircraft Payload‐Range Capability Chart 2. Perform a Route Profitability Analsysi 2 Chapter 6 The Airline Planning Process 1. Draw a Hierarchy Map of Chapter 6 Airline Planning Process Fleet Planning (6.1) Route Planning (6.2) Schedule Development (6.3) Integrated Airline Planning (6.4) 3 2. Name and describe the three categories of airline planning decisions: Category Description 1. 2. 3. 4 FLEET PLANNING 1. An airlines fleet is described by: a. ______________________________________________________________ b. ______________________________________________________________ 2. The most important characteristic of technical performance of an airplane is: _______________________________________________________________________ _______________________________________________________________________ 3. Decisions made by an airline to acquire new aircraft or retire aircraft in it’s fleet have direct impact on: a. _________________________________________________________ b. _________________________________________________________ c. _________________________________________________________ 4. In 2008 dollars the price of the following aircraft are: Aircraft Type Price Twin Engine, Narrow body, 150 seats, short/medium haul Long‐range, wide body, +400 seats Long‐range, wide‐body, +600 seats 5. The typical life‐span of a commercial airplane is: _________________________________________________________________ 6. Why does the life‐span of a commercial airplane create difficulties for fleet planning. Explain. 5 ___________________________________________________________________________________ ____________________________________________________________________________________ 7. The major technical performance characteristics of an airplane are: Technical Performance Characteristic Description 1. 2. 8. Figure 6‐1 (page 156) plots the size versus range capabilities of different commercial aircraft. a. Which part of the state‐space exhibits the most competition? ___________________________________________________________________________ b. What has happened to the range of the largest aircraft over time? ___________________________________________________________________________ 6 10. What is “fleet commonality” and why is it important to the airlines? ______________________________________________________________________________ ______________________________________________________________________________ 11. Figure 6‐2 (page 157) is the Payload‐Range curve for the B767‐300ER. The curve has 3 linear segments. What is traded‐off in each segment? Explain. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 7 NOTES ON RANGE Range is the maximum distance that an aircraft flies without refueling. Range is a tradeoff between distance and payload. Range is estimated using Breguet Range equations as follows: 1. Additional distance flown (dR) is derived from the Velocity (V) over the incremental period of time (dt). dR = V * dt 2. As aircraft flies it burns fuel and loses significant weight. The change in weight (dW) over time (dt) is a product of the Specific Fuel Consumption (SFC) and the Thrust (T) required to maintain constant velocity at Cruise Flightlevel dW/dt = SFC * T Notes on SFC: SFC = lbs/hr/lbf = pounds per hour per pound of force produced. Varies with altitude and speed. SFC for Pratt & Whitney engine 4806 on Boeing 777 at 0.8M at 11,000m = 0.6 lb/hr/lbf. 3. Specific Air Range (SAR) is a measure of the efficiency of an aircraft = ratio of distance flown per unit of fuel consumed dR/dW = V/SFC*T 4. Breguet Range Equation: R = (V/SFC) (Lift/Drag)ln(Initial Weight at start of Cruise/Final Weight at end of Cruise How to derive Breguet: Start with SAR equation, replace Thrust with estimate based on Lift and Weights, integrate dR over weight range. NOTE: Range is a function of Weight 8 Notes on Payload‐Range Diagrams MTOW = Maximum Take Off Weight Three corner points represent combinations of range and payload. • Point 1: aircraft carries its maximum load (i.e. departs with maxi mum takeoff gross weight). Corresponding range is limited. • Point 2: compromise between payload and range. Aircraft departs with full fuel load, but limits passenger and cargo weight to provide extended range. • Point 3: maximum range. Aircraft departs with full fuel load and no passengers or cargo. Typically a ferry/delivery mission. Limitations of Payload‐Range Diagrams applicable for only: • zero wind conditions • 0.84 Mach • Standard day conditions (e.g. standard atmosphere) • Fuel reserves for additional 1.25 hours 9 12. There two ways airlines acquire aircraft. Identify and describe the advantage/disadvantages of each one. ______________________________________________________________________________ ______________________________________________________________________________ 13. When the airline purchases an aircraft, full payment to the manufacturer is required at time of aircraft delivery. Name 4 sources of capital. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 14. In addition to the purchase price, initial costs for a new aircraft include: ______________________________________________________________________________