ETSO-C119c#21
Deviate from EUROCAE ED-143 2.2.3.12 to use a variable suppression time T, which is given by T = MAX (35, Tmax * 10^(ATN / 20)), where Tmax is 75 microseconds for top antenna transmissions, Tmax is 95 microseconds for bottom antenna transmissions, and ATN is the power transmitted (in dB) relative to the maximum power out.
ETSO-C119c#22
Deviate from EUROCAE ED-143 2.2.4.5.4.1.2, by amplifying the whisper-shout (step 2) interrogations by 1dB, and by raising the MTL of whisper-shout interrogations by 1 db, for those transmissions which are attenuated by more than 3 dB.
ETSO-C119c#23
When the landing gear is not extended, deviate from EUROCAE ED-143 2.2.4.6.2.2.2 by using the antenna through which the squitter was received for the first two acquisition interrogations. If these two acquisition interrogations to the target fail to elicit valid replies, the next two acquisition interrogations to that target shall be transmitted using the other antenna.
ETSO-C119c#24
If two successive tracking interrogations fail to elicit valid replies from a target, deviate from EUROCAE ED-143 2.2.4.6.2.2.3, by using the same antenna for the next tracking interrogation, and then using the other antenna (to the previously used antenna) for each successive tracking interrogation.
ETSO-C119c#25
Deviate from EUROCAE ED-143 2.2.4.6.2.2.3 to allow an additional interrogation before 5 seconds to re-interrogate if an additional interrogation is needed to improve the bearing estimate for the intruder aircraft.
ETSO-C119c#26
Deviate from EUROCAE ED-143 2.2.6.3.1.1 to allow an audio tone, as a strappable configuration item, before the voice message is presented.
ETSO-C119c#27
Deviate from EUROCAE ED-143 2.2.6.3.4 to alert additional traffic alerts during a traffic alert by the aural annunciation "TRAFFIC” instead of the aural annunciation "TRAFFICTRAFFIC" which is only used when there is no other traffic alert.
ETSO-C119c#28
Deviate from EUROCAE ED-143 2.2.4.8.1, 2.2.4.6.2.1.2, 2.2.4.6.2.2.1, 2.2.3.10.2.1, 2.2.4.6.2.2.2 and 2.2.4.6.2.2.3 by allowing a configuration option to provide information for aircraft that are determined to be on the ground to the CAS logic; to make available to the collision avoidance logic Mode C intruder reports that are identified as having been formed by replies from aircraft that are on the ground; to interrogate for purposes of tracking Mode S targets that are established and determined to be on the ground and own aircraft is less than or equal to 2000 ft. AGL at a rate not to exceed once every five surveillance update intervals; and to acquire and establish tracks on Mode S targets determined to be on the ground, if own aircraft is at or below 2000 ft. AGL.
ETSO-C119c#29
Deviate from EUROCAE ED-143 2.2.7.3.5 to have the monitor of the TCAS only be capable to receive 2 advisory inhibit discretes from the aircraft instead of 4.
Comments are invited and should be sent by mail or electronic mail (preferred means), no later than the indicated deadline.
