Multi­Engine Airplane Guide PA­44­180 Piper Seminole Copyright © 2009 Embry‐Riddle Aeronautical University All Rights Reserved. Written by Robert Thomas Cover picture courtesy of Steven Pellegrino. ERAU Multi­Engine Airplane Guide TABLE OF CONTENTS Introduction to Multi‐Engine Aircraft ............................................................................................................. 1 V‐Speeds ....................................................................................................................................................................... 2 Performance and Limitations .............................................................................................................................. 4 Engine Ceilings ...................................................................................................................................................... 4 Single‐Engine Climb Performance ................................................................................................................ 5 Multi‐Engine Aerodynamics ................................................................................................................................ 6 Induced Flow .......................................................................................................................................................... 6 Turning Tendencies ............................................................................................................................................ 6 Engine Failures .......................................................................................................................................................... 9 What Happens When an Engine Fails ......................................................................................................... 9 Critical Engine .................................................................................................................................................... 10 P‐Factor ............................................................................................................................................................ 10 Accelerated Slipstream .............................................................................................................................. 11 Torque .............................................................................................................................................................. 13 VMC ................................................................................................................................................................................ 16 VMC For Certification – FAR 23.149 ........................................................................................................... 17 Recognizing and Recovering From VMC ................................................................................................... 18 VMC vs. Stall Speed ................................................................................................................................................. 18 Factors Affecting VMC ............................................................................................................................................ 19 Power ..................................................................................................................................................................... 19 Density Altitude ................................................................................................................................................. 20 C.G. Location ........................................................................................................................................................ 21 Gear Position ....................................................................................................................................................... 22 Propeller Windmilling vs. Feathered Propeller ................................................................................... 23 Flaps Down .......................................................................................................................................................... 24 Weight .................................................................................................................................................................... 25 Bank Angle ........................................................................................................................................................... 27 Amount of Horizontal Component of Lift .......................................................................................... 27 Angle of Attack on the Rudder – Rudder Effectiveness ............................................................... 27 Direction of Relative Wind – Slipping vs. Coordinated ................................................................ 28 Amount of Fuselage Lift Produced ....................................................................................................... 28 Bank Angle Examples ...................................................................................................................................... 29 i ERAU Multi­Engine Airplane Guide 0° of Bank ......................................................................................................................................................... 29 2°‐3° Bank Toward Operating Engine ................................................................................................. 30 8° Bank Towards Operating Engine ..................................................................................................... 31 5° Bank Towards Inoperative Engine .................................................................................................. 32 Summary of Bank Angle Relating to VMC Speed and Drag ........................................................... 32 Critical Engine Failure ..................................................................................................................................... 33 In Ground Effect.................................................................................................................................................. 33 Chart Of Factors Affecting VMC .......................................................................................................................... 35 Seminole Systems ................................................................................................................................................... 36 Dimensions ........................................................................................................................................................... 36 Key Numbers ....................................................................................................................................................... 37 Airframe ................................................................................................................................................................. 37 Engine ..................................................................................................................................................................... 38 Cowl Flaps ............................................................................................................................................................. 42 Propeller ................................................................................................................................................................ 43 Landing Gear ........................................................................................................................................................ 48 What Happens When the Gear is Raised or Lowered ................................................................... 56 Brakes ..................................................................................................................................................................... 60 Flight Controls And Trim ................................................................................................................................ 61 Flaps......................................................................................................................................................................... 64 Fuel ........................................................................................................................................................................... 65 Electrical ................................................................................................................................................................ 72 Vacuum System ................................................................................................................................................... 76 Pitot Static ............................................................................................................................................................. 78 Environmental .................................................................................................................................................... 79 Annunciator Panel and Warning Lights ................................................................................................... 84 Stall Warning ......................................................................................................................................................