Chapter 15-Transition to Jet Powered Airplanes
Table of Contents
Jet Engine Basics
Operating the Jet Engine
Jet Engine Ignition
Thrust to Thrust Lever Relationship
Variation of Thrust with RPM
Slow Acceleration of the Jet Engine
Jet Engine Efficiency
Absence of Propeller Effect
Absence of Propeller Slipstream
Absence of Propeller Drag
Recovery from Overspeed Conditions
Mach Buffet Boundaries
Low Speed Flight
Pilot Sensations in Jet Flying
Jet Airplane Takeoff and Climb
Rotation and Lift-Off
Jet Airplane Approach and Landing
The Stabilized Approach
Touchdown and Rollout
The entire runway length should be available for takeoff, especially if the pre-calculated takeoff performance shows the airplane to be limited by runway length or obstacles. After taxing into position at the end of the runway, the airplane should be aligned in the center of the runway allowing equal distance on either side. The brakes should be held while the thrust levers are brought to a power setting beyond the bleed valve range (normally the vertical position) and the engines allowed to stabilized. The engine instruments should be checked for proper operation before the brakes are released or the power increased further. This procedure assures symmetrical thrust during the takeoff roll and aids in preventing overshooting the desired takeoff thrust setting. The brakes should then be released and, during the start of the takeoff roll, the thrust levers smoothly advanced to the pre-computed takeoff power setting. All final takeoff thrust adjustments should be made prior to reaching 60 knots. The final engine power adjustments are normally made by the pilot not flying. Once the thrust levers are set for takeoff power, they should not be readjusted after 60 knots. Retarding a thrust lever would only be necessary in case an engine exceeds any limitation such as ITT, fan, or turbine r.p.m.Ch 15.qxd 5/7/04 10:22 AM Page 15-18
If sufficient runway length is available, a ôrollingö takeoff may be made without stopping at the end of the runway. Using this procedure, as the airplane rolls onto the runway, the thrust levers should be smoothly advanced to the vertical position and the engines allowed to stabilize, and then proceed as in the static takeoff outlined above. Rolling takeoffs can also be made from the end of the runway by advancing the thrust levers from idle as the brakes are released.
During the takeoff roll, the pilot flying should concentrate on directional control of the airplane. This is made somewhat easier because there is no torque- produced yawing in a jet as there is in a propeller driven airplane. The airplane must be maintained exactly on centerline with the wings level. This will automatically aid the pilot when contending with an engine failure. If a crosswind exists, the wings should be kept level by displacing the control wheel into the crosswind. During the takeoff roll, the primary responsibility of the pilot not flying is to closely monitor the aircraft systems and to call out the proper V speeds as directed in the captainÆs briefing.
Slight forward pressure should be held on the control column to keep the nosewheel rolling firmly on the runway. If nosewheel steering is being utilized, the pilot flying should monitor the nosewheel steering to about 80 knots (or VMCG for the particular airplane) while the pilot not flying applies the forward pressure. After reaching VMCG, the pilot flying should bring his/her left hand up to the control wheel. The pilotÆs other hand should be on the thrust levers until at least V1 speed is attained. Although the pilot not flying maintains a check on the engine instruments throughout the takeoff roll, the pilot flying (pilot in command) makes the decision to continue or reject a takeoff for any reason. A decision to reject a takeoff will require immediate retarding of thrust levers.
The pilot not flying should call out V1. After passing V1 speed on the takeoff roll, it is no longer mandatory for the pilot flying to keep a hand on the thrust levers. The point for abort has passed, and both hands may be placed on the control wheel. As the airspeed approaches VR, the control column should be moved to a neutral position. As the pre-computed VR speed is attained, the pilot not flying should make the appropriate callout and the pilot flying should smoothly rotate the airplane to the appropriate takeoff pitch attitude.