A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed. The fundamentals of aircraft controls are explained in flight dynamics. This article centers on the operating mechanisms of the flight controls. The basic system in use on aircraft first appeared in a readily recognizable form as early as April 1908, on Louis Blériot's Blériot VIII pioneer-era monoplane design.[1]
(*1) Side Stick Control Column id the replacment of Conlrol Column/Wheel Conrol Conlumn. A light weight control stick Which is fixed by Pilot Arm in Cockpit
Fly-By-Wire (FBW) Control Law. (Chapter) of Automatic Flight Control by E.H.J Pallet & Shwan Coyle.
Achitecture of FBW
In advance FWB Control System There are two basic terminologies are used such Architecture & Control Laws.This system is also called active control system.
Architecture
The general Layout of the components such as computers and their function are called architecture.These computer are working with redundancy to enhance the stability and the less failure system In A320 there are seven operational computer working with ARINC 429 Data Bus in communication among them and listed as under
The manner in which the operational computers are expected to control the control surfaces are called Control Laws Keeping in mind the concept of redundancy & the safety factors these controls law are listed as under with there respective computers
Normal Control Law ---ELACs Alternate Control Law ---SECs Direct Control Law --Stick to Elevator/Direct Control Mechanical Backup --Mechanical Link to the Pitch Trim
Special C-Star(C*) Control Law:
C* is the special type of Pitch Control Law which has much acceptance in commercial airlines. This is a flight path command control law even at low speed including pitch command rate.In general the pilot is able to select a particular flight path with particular angle such as level flight.Once this particular flight path with angle is achieved then if Pilot releases the control stick this law ensures that that particular angle is retained By introduction of pitch ate command this helps us to overcome Lags& over pitch activity at low speed and in flare mode at 50 ft above the ground.
Q1) What are the fundamental requirements of Automatic landing?
In order to achieve safe landing the aircraft has to be So controlled that: 1) its wheels should touch the ground comfortabliy 2) its should be within the paved surface of the runway 3) its should be with in the longitudinal limits 4) its sinking speed should not be greater than 1/2 ft/sec 5) its touch-down speed should be greater 30% of stalling speed 6) Wings should be levelled prior to the actual landing 7) its should be yawed to bring is longitudinal axis parallel to the center line of runway 8) its de crabbing or Kick-off man-oeuvre should be removed
Q2) What is the minimum accident of acceptance in UK-CA?
According to United Kingdom Certification Authorities A system should not cause fatal accident more often than one million landings.
Q3) What is weather minima and its parameters?
In low visibility condition the weather limits for londing its called weather minima & its parameters are Runway Visual Range(RVR) & Decision Hight(DH).
Q4) What is "Sland Visual Range (SVR)"? The factor in which the pilot must take an account or makes sure everything to avoid any misinterpretation of visual cues
Q5) What are ICAO categories of Landing.Give name & Ranges?
There are three categories of landing defined by ICAO and given as under: Category 1 (RVR should & DH should be minimum 800m & 200 ft Respectively). Category 2 (RVR should & DH should be minimum 400m & 100 ft Respectively). Category 3A (RVR should & DH should be minimum 200m & 50-100ft Respectively with external NavAids). Category 3B (When the taxiing operations is visible at 50ft DH with external NavAids). Category 3A (When the taxiing operations is visible on runway at 50ft DH without external NavAids).
Flight Control System
ReplyDeleteA conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed.
The fundamentals of aircraft controls are explained in flight dynamics. This article centers on the operating mechanisms of the flight controls. The basic system in use on aircraft first appeared in a readily recognizable form as early as April 1908, on Louis Blériot's Blériot VIII pioneer-era monoplane design.[1]
To Read further Click :
http://en.wikipedia.org/wiki/Aircraft_flight_control_system
..
ReplyDeleteChapter 11 : Fly-By-Wire (FBW) Control System
ReplyDelete--Fly by wire is the concept that provide effective computer link between the
pilot control and control surface.
--This concept was implented first in concorde(elevon control)
& Boeing 767 for its wing control spoilers.
-- Airbus A320 was the only plance which FBW was designed for.
-- The inceased effectiveness by Side-Stick(*1) Conroll column
Advantages of FBW Control System:
1) Weight Saving
2) Reduced Maintenance Time
3) Gust Load Alleviation
4) Atomatic Manoeuvre Envelop Protection
5) Improved Handling
6) Fuel saving
(*1) Side Stick Control Column id the replacment of Conlrol Column/Wheel Conrol Conlumn.
A light weight control stick Which is fixed by Pilot Arm in Cockpit
Continued
Remaining
ReplyDeleteFly-By-Wire (FBW) Control Law.
(Chapter) of Automatic Flight Control by E.H.J Pallet & Shwan Coyle.
Achitecture of FBW
In advance FWB Control System There are two basic terminologies are used
such Architecture & Control Laws.This system is also called active control system.
Architecture
The general Layout of the components such as computers and their function are
called architecture.These computer are working with redundancy to enhance the stability
and the less failure system
In A320 there are seven operational computer working with ARINC 429
Data Bus in communication among them and listed as under
1) ELACs Elevator/Aileron Computer (2)
2) SECs Spoiler/Elevator Computer (3)
3) FACs Flight Augmentation Computer(2)
Control Laws
ReplyDeleteThe manner in which the operational computers are expected to control the control surfaces are called Control Laws
Keeping in mind the concept of redundancy & the safety factors these controls law are listed as under with there respective computers
Normal Control Law ---ELACs
Alternate Control Law ---SECs
Direct Control Law --Stick to Elevator/Direct Control
Mechanical Backup --Mechanical Link to the Pitch Trim
Special C-Star(C*) Control Law:
C* is the special type of Pitch Control Law which has much acceptance in commercial airlines.
This is a flight path command control law even at low speed including pitch command rate.In general the pilot is
able to select a particular flight path with particular angle such as level flight.Once this particular flight path with angle is
achieved then if Pilot releases the control stick this law ensures that that particular angle is retained
By introduction of pitch ate command this helps us to overcome Lags& over pitch activity at low speed and in flare mode at 50 ft above the
ground.
Answers Ref-1
ReplyDeleteChapter 10
Q1) What are the fundamental requirements of Automatic landing?
In order to achieve safe landing the aircraft has to be So controlled that:
1) its wheels should touch the ground comfortabliy
2) its should be within the paved surface of the runway
3) its should be with in the longitudinal limits
4) its sinking speed should not be greater than 1/2 ft/sec
5) its touch-down speed should be greater 30% of stalling speed
6) Wings should be levelled prior to the actual landing
7) its should be yawed to bring is longitudinal axis parallel to the center line of runway
8) its de crabbing or Kick-off man-oeuvre should be removed
Q2) What is the minimum accident of acceptance in UK-CA?
According to United Kingdom Certification Authorities A system should not cause fatal accident more often than one million landings.
Q3) What is weather minima and its parameters?
In low visibility condition the weather limits for londing its called weather minima & its parameters are
Runway Visual Range(RVR) & Decision Hight(DH).
Q4) What is "Sland Visual Range (SVR)"?
The factor in which the pilot must take an account or makes sure everything to avoid any misinterpretation of visual cues
Q5) What are ICAO categories of Landing.Give name & Ranges?
There are three categories of landing defined by ICAO and given as under:
Category 1 (RVR should & DH should be minimum 800m & 200 ft Respectively).
Category 2 (RVR should & DH should be minimum 400m & 100 ft Respectively).
Category 3A (RVR should & DH should be minimum 200m & 50-100ft Respectively with external NavAids).
Category 3B (When the taxiing operations is visible at 50ft DH with external NavAids).
Category 3A (When the taxiing operations is visible on runway at 50ft DH without external NavAids).