Offset Runway Distance Calculation Using MMR and Radioaltimeter

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for determining the distance between an aircraft and the azimuth beacon during offset approaches require additional equipment like DME or GPS, which can be costly and introduce electronic disturbances.

Innovation Solution

The method utilizes existing aircraft equipment, such as a radioaltimeter for height measurement and a multimode receiver (MMR) to calculate the distance from the azimuth beacon using the aircraft's height and angles provided by the elevation beacon, employing the formula ρ=(hTan⁡(φ)-D⁢⁢2Cos⁡(θ))²+h², where θ and φ are the angles decoded by the MMR, and D2 is the distance between the beacons.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional equipment like DME or GPS is used to determine distance during offset approaches, then distance measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvedistance measurement precisionVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the existing MMR equipment perform multiple functions by using it not only for receiving MLS signals but also for calculating distance information through trigonometric computations combining angle data with radioaltimeter height measurements, thereby eliminating the need for separate DME or GPS equipment

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses the aircraft's own existing equipment (MMR and radioaltimeter) to generate the distance information it needs, rather than relying on external dedicated distance measurement devices, thus achieving self-sufficiency and reducing equipment requirements

Inventive Principle:

Principle #25Self-service

2Measurement precision

If additional equipment like DME or GPS is installed, then distance information accuracy is improved, but electronic disturbances increase

Engineering Contradiction:

Improvedistance information accuracyVSAvoidelectronic disturbances

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the distance calculation function from separate dedicated equipment (DME/GPS) and integrates it into the existing MMR system, thereby removing the source of additional electronic disturbances while maintaining the required measurement accuracy

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system merges the distance measurement function with the existing angle measurement capability of the MMR equipment, combining multiple functions into a single system to avoid the electronic interference that would result from having separate distance measurement devices

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If existing equipment (MMR and radioaltimeter) is used to calculate distance, then device complexity is reduced, but measurement precision may be affected

Engineering Contradiction:

Improvedevice complexityVSAvoiddistance information accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces direct mechanical/dedicated distance measurement systems with a computational approach that uses trigonometric relationships (combining angle measurements from MMR with height measurements from radioaltimeter) to calculate distance, thereby reducing hardware complexity while maintaining accuracy through mathematical computation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reconstructs distance information using existing aircraft equipment, avoiding the need for additional devices and potential electronic disturbances, thereby reducing costs and improving operational efficiency during offset landings.

Implementation Method 1

a radioaltimeter which makes it possible to provide the information about the height of the aircraft with respect to the closest ground point

Methodology Applied

Scientific EffectRadio wave reflection: Reflection

Implementation Method 2

The elevation station is situated on the side of the runway, about 300 meters from the runway start threshold. Each station transmits a narrow beating beam

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentUS8682510B2Method for enabling landing on an offset runway

Publication Date: 2014.03.25 THALES SA

AI summary

A method for determining the distance of an aircraft from an offset runway during a landing by offset approach, the offset runway being situated at a distance D from a main runway equipped with at least one elevation beacon, comprises at least the following steps: determining the height h at which the aircraft is situated, height determined with respect to a point T1 of the offset runway, height measured by a radioaltimeter with which the aircraft is equipped, determining the angle of elevation φ of the MLS mode by using the information of the elevation beacon provided by an elevation beacon with which said main runway is equipped, determining the value of the distance ρ of the aircraft from the azimuth beacon (10) by using the following formulaρ=(hTan⁡(φ)-D⁢⁢2Cos⁡(θ))2+h2,and, using said distance ρ to obtain a point of location of the aircraft in an offset runway reference frame.