Flight Management System

Introduction

The project which you are about to read is a study which I have conducted in relation to Flight Management systems on aircraft. I will take you through various different factors including where and when it was first introduced, its development over the years including how newer technologies have assisted it, its operation and what benefits and drawbacks it has. There are several major factors which influence the Flight management system an example of these ould be;

1. Flight management computer (FMC)

2. The users role

3. Navigation systems

Each topic will be discussed and I will explain them individually to help give the reader a better understanding of the subject in question. I hope you will find the information which I have gathered interesting to read and that it helps to expand your knowledge as an individual.

FMS's History

The first Flight management system that was introduced was the Collins Air Navigation System or (ANS-70). It was installed in the DC-10's of National Airlines in the year of 1973. This was the first time a FMS system had ever been used in a commercial airline. Soon after National airlines introduced there new navigation system, Delta introduced there navigation system which was produced by the ARMA corporation. Both systems were literally identical, using the same format to of storing information. The only difference being that the designers of the two systems came up with solutions to the other systems problems and implemented it in their own

In 1973 a committee was formed to standardize aeronautical databases. It was in 1975 when they finally produced there first standard which was known as ARINC specification 424. This has remained the standard used until this present day, although it has been revised over seventeen times! Some of these revisals include

* January 17 1983 - added runway transitions

* August 1993 - Added radius to Fix (RF) Leg types

During the 80's several other advancements were made to the FMS systems. The performance data computer (PDC) added some new features. It now had a speed and thrust setting which enabled the pilot to choose different levels which best suited his situation, like optimizing fuel efficiency. Then in 1984 the first fully coupled lateral and vertical navigation flight management computer was certified. In 87 Required Time of arrival (RTA) and Aircraft Communications Addressing and Reporting Systems (ACARS) were added to the FMS systems.

It was in 1992 when GPS and updating and RNP/Actual Navigation Performance (ANP) alerting were added. They GPS allows the pilot to know exactly where he is at any give time and which direction he's traveling in. It achieves this by using a receiver to measure the distance between itself and GPS satellites (Normally about three), then uses trigonometry to pin point your position. This is an essential key when it comes to navigation. The 90's was the period when FMS systems became more readily available. This was because GPS capable receivers and smaller, cheaper, FMS's have been introduced. This in turn allows more people to have this capability installed in there equipment.

Operation

Gathering info for Navigational databases

There are several different factors which influence the FMS systems; one of theses factors is the upkeep of the databases themselves that poses all the info. Each individual country establishes their own aeronautical information service (AIS). This AIS is responsible for making available information about flying in that territory. There are certain standards which have to bet which insure that data is accurate, although mistakes can still occur. The people who gather this information for the countries are a group of established suppliers. Some examples of these are;

* Jeppesen

* LIDO

* EAG

They compile all there data first on paper and then transfer it onto an electrical format. This is then packaged into a standardized format called the ARINC 424. This information is then shipped to FMS manufacturers in the set up which their system runs on. Certain specifications are put in place by the manufacturer to insure certain standards are met and needs met. Like for example content and geographical coverage area. Problems can occur during this process. This could be the manufactures not taking procedure design criteria into consideration when producing a product. The model below illustrates this

As shown in the diagram on the previous page issues like this could cause serious issues. In the case where an issue like this does occur a pilot will normally inform his engineers on landing so they can re program the system. Of all the manufacturers (Honeywell, Thales) for these systems they all cover separate aircraft with overlaps here and there. They also have quality standards to follow among themselves like filtering data or perform quality checks. The standard which they go buy is the RTCA DO 200A. Once all the data has been collected and stored in the FMS'S FMC then it is up to the crew to interpret the information and use the data. This Data inputting and updating is usually carried out on a 28 day cycle.

The user is essentially the last link in the chain when it comes to collection and using the database. It is their duty to carry several different procedures to insure that the database is kept up to date with current records. They must ensure that manufacturer's updates are current and accurate as well as have a good understanding of all the avionic material and how FMS actually uses the data. Users can demand special systems for their own use. These require special codes to be set up; this is normally left in the operators hands. If they do decide to modify or create a procedure they can do so by contacting the database supplier

The role of the User

For the FMS system to work properly the User themselves becomes a vital component in the set up. The pictures below show the kind of layout which a user is likely to