A400M Dass System Test. Flares Trajectory Calculation

Francisca Coll Herrero, HO Methods and Tools Department / Development Flight Test, Airbus Defense and Space,
Getafe-Madrid, Spain

Abstract

The A400M defensive aids Sub-System (DASS) include a radar warning receiver, missile launch and approach warning, and chaff and flare decoy dispensers.

The analysis of the safe separation of flares from A400M within its flight envelope is required as part of the A400M DASS certification process.

In order to validate the model used by the Aerodynamics Department to calculate the theoretical flare trajectories, several safe separation flight tests had to be performed.

The aim of this document is to present a methodology used to calculate a real case of flares trajectories on A400M, and in particular the results of the flares trajectories ejected from the left Rear sponsor (SP13& SP14) and left Rear wing fairing (WR11&WR12).

The trajectories are calculated by applying Photogrammetry techniques to the films extracted from onboard High Speed Video (HSV) cameras.

Four synchronized cameras are needed to cover all theoretical paths, two cameras for the initial part and two for the final part of the path. These are:

• C3S, installed under the left wing, close to the tip.
• HS3, installed on a balcony in the place of the last left side window.
• J1S, installed under the left HTP.
•  HS4, installed on the left wing- centre fuselage.

As C3S and J1S cameras are not installed in a fixed part of the aircraft, it is therefore necessary to calculate the position of these cameras during the test; this is done using special stickers, placing them on a fixed part of the aircraft and within the cameras’ visible field.

The trajectory is calculated by sections, J1S and C3S for the initial part and HS4 and HS3 for the rest of the path.

The trajectories are calculated using a program named FOLLOWME developed by the Methods and Tools Department of Airbus Defense and Space.

The tool has been developed using Matlab working environment and it is based on image recognition and photogrammetry calculations.