#Ace for flight control system full#
#Ace for flight control system series#

The opposite goes if the pilot is pulling back on the control. The concept of TRS is of capital importance to properly understanding how the 777's FBW System works. On any conventional aircraft such as the 737, operating the trim switch will move the pitch angle of the horizontal stabilizer (or horizontal tail-plane) it won't do quite the same on the 777.Įven though the pitch trim system internally works in a different manner with respect to a conventional airplane, it is used in the exact same way, that is, should the pilot find himself pushing the control column forward to keep his desired flight condition, pushing the trim 'up' (what is usually known as a 'nose down' command) will gradually reduce the required force on the control. For now it suffices to say that pushing the trim switches on the 777 will not directly move the stabilizer but will instead set the Trim Reference Airspeed (TRS). On the right (outboard) horn of the yoke you can see the Autopilot (AP) disengage button and the Pitch Trim Switch (or rather, switches, both must be operated simultaneously) which I will discuss in more detail later on. The above image shows the First Officer's (F/O) primary flight controls with yoke in the foreground and rudder pedals in the background below. FBW System Overview and Description Cockpit ControlsĪs mentioned before, cockpit controls consist of yokes, rudder pedals and thrust levers, just as in a conventional 737. The aircraft will warn the pilot should he be dangerously close to the limit of the aircraft's flight envelope and will also impose 'soft limits' to prevent the aircraft from exceeding those limits inadvertently, but the pilot will be able to fly the aircraft out of its envelope if he's determined enough to do so. There's no computer the pilot can't override.

#Ace for flight control system full#

Its rating in the Cooper-Harper scale of handling qualities should be '1' or 'excellent'.įinally and even more importantly, it's Boeing's philosophy that the FBW of the 777 lets the pilot be always in command of the airplane and have full authority over it in all situations. The Boeing 777's FBW has an effect on these qualities as well through the use of Stability Augmentation features and Compensations of different nature.

What is meant by 'well behaved' is a set of superior handling qualities that make the pilot feel like the aircraft is noble and easy to fly. Our 737 pilot could fly the 777 without even knowing it's a FBW aircraft. Langewiesche had in mind when he wrote his beknown 'Stick and Rudder' (see reference 6). In fact, the 777 flies just like the trainer aircraft that Mr. The key idea is that our FBW-ignorant pilot coming from the 737 wouldn't have to learn to fly all over. That's the reason why the cockpit controls for all four Degrees of Freedom (roll, pitch, yaw and thrust) remain unchanged from previous Boeing aircraft, that is: two sets of rudder pedals for governing the rudder (yaw axis), two 'yokes' consisting of control wheel for governing the ailerons, spoilers and flaperons (roll axis) and control column for governing the pitch axis and finally one set of thrust levers to control the engine's thrust output.īoeing also designed its flight deck not only so it 'looks' like one of a conventional aircraft, but also so it 'flies' like one, moreover like an extremely 'well behaved' one. They wanted a 737 pilot (I will often use the 737 as an example of a conventional non-FBW aircraft throughout this article) capable of jumping into the flight deck of the 777 and still feel like 'home'.

Introduction Philosophy of the Boeing 777 FBW Flight Control Systemīoeing intended their 777 to be flown just as a conventional jet aircraft.

Turn Compensation and Bank Limit Protection.

Effect of Thrust Changes (constant Trim Reference Airspeed).

Effect of Trim Reference Airspeed (constant thrust).

Effect of Primary Flight Control Commands.

Philosophy of the Boeing 777 FBW Flight Control System.

This article was written as a read-along companion for my video-analysis below: Table of Contents Introduction

#Ace for flight control system series#

In this article I will analyze the FBW System of the Boeing 777 (Triple Seven) from a pilot's point of view and with the help of a desktop flight simulation through a series of flight tests that will illustrate how the system works, how it makes the job of the pilot easier, and how it protects the aircraft's flight envelope.