Citation V/Ultra/Encore (C560)
Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 90; Flight Crew Total 4700; Flight Crew Type 2000
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Procedure
Crew received route clearance prior to taxi. Route clearance given began with the Atlanta Six departure SOONE transition. Departure instructions for Atlanta Six departure off of Runway 9L state 'fly heading 095 and expect RADAR vectors to transition climb and maintain 10;000.' After cleared to line up and wait; Tower then cleared the aircraft for take off on 9L and stated turn heading 110 at the 'Middle Marker.' The complications arose here. This non standard clearance was given after take off clearance given; giving the crew little time to determine exact position on the Middle Marker. The crew assumed the 'middle marker' was for the opposite direction ILS. Again this was not clearly stated by ATC. Also; Tower cleared a heavy Airbus A330 for take off prior to our take off clearance. The crew discussed a maximum performance take off and climb would be executed to avoid wake turbulence. On the take off roll; after receiving the clearance to execute the turn to 110 at the marker; the Captain selected the audible marker beacon tone on. However due to our high climb rate to avoid wake turbulence we were already greater than 4;000 feet when crossing the Middle Marker and no tone or signal was ever received. This is most likely due to the fact that middle marker normal altitude use is 200 feet and not 4;000 feet. The crew was above an overcast layer and could not determine the location of the marker beacon visually. Crew subsequently executed a turn when they were reasonably sure of passing the Marker Beacon. ATC informed the crew they had executed the turn late. To fix this problem- ATC should assign an altitude or a known fix on the departure to execute a turn; not an unknown marker beacon that is in no way shape or form associated with the take off runway. Also; due to our aircraft's steep climb and high altitude; a Middle Marker cannot reasonably be used to determine position at an altitude of 4;000 feet when its normal altitude use is 200 feet.
Citation jet departing ATL Runway 9L on the Atlanta Six SID experienced some confusion when ATC instructed the aircraft to initiate a turn at the Middle Marker after the take off clearance was issued.