Narrative:

Local control 2 (LC2); cleared aircraft X for takeoff and issued a 270 heading; LC2 then cleared aircraft Y on a FIXIT3 RNAV departure. Aircraft Y is supposed to fly a heading of 251 and with a 270 heading issued to aircraft X establishes a 15 degree divergence. After replaying the scenario in falcon; aircraft Y was showing a heading of 269 offshore which cannot be explained by the service center who initiated a risk analysis event (rae). If aircraft Y was indeed on a 269 heading that would mean that the aircraft was not flying the SID as issued and would be a pilot deviation. The winds at the time were 250@7 which indicated the wind to be right down the runway.the two aircraft appear to be flying away from each other and it looks like the aircraft Y is tracking a 251 course and it says a 269 heading probably because the aircraft is crabbing for wind adjustment possibly for winds aloft and the aircraft nose is possibly facing to a heading of 269. If this indeed is the case you cannot expect the tower controller to know what the aircraft; pilots and winds are doing west of the airport at 2;000 feet; especially when the winds are showing a direct headwind on the ground which is what we used in determine what can happen offshore. In the 7110.65 5-8-3(a) outlines the successive departures but only RNAV departures. There is no reference as a RNAV vs non RNAV aircraft. Since there is no guidance and using the lax SOP 7110.1F; 7-1-9(a) which outlines issuing a 270 heading to a prop off the 24 complex; we used the 15 degree rule which was successfully applied.in its email to the front line manager (flm) regarding the rae; the service center itself stated that it was not sure about the rules and will be asking whoever they need to ask to get a clarification.there should be some rule that states the separation the FAA wants in relation to RNAV vs non RNAV procedure aircraft.the service center should also do all its research and get clarifications before issuing rae's that they themselves are unsure of.

Related reports:

Google
 

Original NASA ASRS Text

Title: LAX Controllers reported of a loss of separation that they did not know about until well after the fact. Someone from the service center advised the Front Line Manager (FLM) about the loss of separation; and in doing so were not sure about the rules and needed more clarification. The controllers want the procedure fixed so this does not happen again. Controllers thought they were using the 15 degree course separation rule.

Narrative: Local Control 2 (LC2); cleared Aircraft X for takeoff and issued a 270 heading; LC2 then cleared Aircraft Y on a FIXIT3 RNAV departure. Aircraft Y is supposed to fly a heading of 251 and with a 270 heading issued to Aircraft X establishes a 15 degree divergence. After replaying the scenario in FALCON; Aircraft Y was showing a HDG of 269 offshore which cannot be explained by the service center who initiated a Risk Analysis Event (RAE). If Aircraft Y was indeed on a 269 HDG that would mean that the Aircraft was not flying the SID as issued and would be a pilot deviation. The winds at the time were 250@7 which indicated the wind to be right down the runway.The two aircraft appear to be flying away from each other and it looks like the Aircraft Y is tracking a 251 course and it says a 269 heading probably because the aircraft is crabbing for wind adjustment possibly for winds aloft and the aircraft nose is possibly facing to a heading of 269. If this indeed is the case you cannot expect the tower controller to know what the aircraft; pilots and winds are doing west of the airport at 2;000 feet; especially when the winds are showing a direct headwind on the ground which is what we used in determine what can happen offshore. In the 7110.65 5-8-3(a) outlines the successive departures but only RNAV departures. There is no reference as a RNAV vs non RNAV aircraft. Since there is no guidance and using the LAX SOP 7110.1F; 7-1-9(a) which outlines issuing a 270 HDG to a prop off the 24 complex; we used the 15 degree rule which was successfully applied.In its email to the Front Line Manager (FLM) regarding the RAE; the service center itself stated that it was not sure about the rules and will be asking whoever they need to ask to get a clarification.There should be some rule that states the separation the FAA wants in relation to RNAV vs non RNAV procedure aircraft.The service center should also do all its research and get clarifications before issuing RAE's that they themselves are unsure of.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.