AMC3 ACNS.E.LAD.320 Flight dynamics and locating the aircraft

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO SOLUTIONS BASED ON AN ELT(DT) AND TO SOLUTIONS BASED ON HRT

(a)     The system should meet the conditions of AMC1 ACNS.E.LAD.320.

(b)     If the system transmits activation signals before or without deploying equipment, the performance that is defined as successful regarding:

—          automatic activation (refer to CS ACNS.E.LAD.240);

—          transmission of the activation signals (refer to CS ACNS.E.LAD.110 and CS ACNS.E.LAD.120);

—          detection of the activation signals by the communication infrastructure; and

—          position accuracy of the point of end of flight (refer to CS ACNS.E.LAD.410),

should be demonstrated on typical accident flight trajectories with parameter values within the ranges of Table 1 of CS ACNS.E.LAD.320. In addition, the position accuracy of the point of end of flight for survivable accidents (refer to CS ACNS.E.LAD.420) should be demonstrated on typical flight trajectories of survivable accidents. The demonstrations should be made in the most unfavourable conditions of time and location, or a sensitivity analysis should be conducted to demonstrate that the variation in time or location does not significantly affect the result. The threshold values for automatic activation should be contained within a range where successful transmission is demonstrated.

Verification may rely on computer-based simulations and ground tests. In the case of a subsonic aeroplane, a verification method may be to:

(1)     demonstrate that the system was successfully automatically activated and transmitted the activation signals, and that the communication infrastructure detected the activation signals (including assessment of the link budget) based on the flight data sets on accidents and incidents that are referred to in EUROCAE ED-237, Appendix 1;

(2)     demonstrate that the example flight trajectory of Subpart 3, Section E, Appendix A meets the position accuracy requirement of CS ACNS.E.LAD.410 (‘Position accuracy for non‑survivable accidents’); and

(3)     demonstrate that the position accuracy requirement of CS ACNS.E.LAD.420 (‘Position accuracy for survivable accidents’) is met, assuming that during the last 20 seconds before reaching the point of end of flight:

(i)      valid position data is available from the position source of the system; and

(ii)     the aircraft makes a stabilised turn at a ground speed of 180 knots and a bank angle of 45°.

(c)      The antennas that are used by the system, including position source antennas, should be installed so that position determination and transmission of the activation signals are successful at all aircraft attitude angles and aircraft speeds that correspond to normal operation.

(d)     The antennas that are used by the system, including position source antennas, should be installed so that position determination and transmission of the activation signals are likely to be successful at aircraft pitch attitudes, aircraft roll attitudes, aircraft speeds, and rates of change of these parameters that might be experienced between the time of activation of the system and reaching the point of end of flight.

[Issue: CS-ACNS/3]