Nav Aids 11
what is the function of ACAS?
To reduce the incidence of mid-air collisions and near misses.
What is the basic principal of operation of ACAS 11 co-ordinated collision avoidance manoeuvres?
Two or more S MODE transponder eqipped A/Cs issue voice and visual indications to modify flight trajectory.
What is the minimum level of equipment that an intruder aircraft must be fitted with before ACAS will detect it?
A transponder, even if the pressure encoder is not working
what is the minimum level of equipment that an intruder aircraft must be fitted with before ACAS 11 will issue an RA
A transponder in MODE A or C with the pressure encoder working.
What is the ACAS display symbol for proximate traffic?
A sold Cyan or White Diamond
What is the minimum rate of climb or decent for the data tag of a target aircraft to include a vertical trend arrow?
What is a traffic advisory?
A preliminary alert (Caution) to warn the crew that intruder traffic is in the near vicinity (Caution Area)
what is the minimum equipment requirement for ACAS to issue co-ordinated collision avoidence manoeuvres?
TCAS II and a MODE S transponder in each of the aircraft in conflict.
When will ACAS issue a traffic Advisory?
When an intruder A/C enters the caution area, which is about 40secs from the collision area.
When will ACAS issue a resolution advisory?
When an intruder A/C enters the warning area, which is about 25secs from the Collision Area.
What is CPA?and re the time to CPA and volume of protected airspace of the caution and warning areaas constant?
Collision Point of Impact No, they vary depending on A/C , alt, spee etc.
What flight crew action is required if ACAS issues a Traffic Advisory (TA), and a Resolution Advisory (RA) respectively?
Carry out a visual search for the intruder A/C
Promptly disconnect the A/P and smoothly follow the pitch change directions.
What is an ACAS escape maneouvre?
An indication of a range of vertical speeds that must be flown to avoid threat. Can be corrective (change V/S immediatley) or preventative (maintain within a V/S range)
How many escape manoeuvres can ACAS 11 simulatneously co-ordinate?
up to 3
Nav Aids 11
Airborne Collision Avoidence