Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer; Flight Crew Instrument
Flight Crew Last 90 Days 150; Flight Crew Total 13000; Flight Crew Type 300
Communication Breakdown
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors; Procedure
Ground gave the following clearance prior to take off: 'Cleared direct to SADDE; maintain runway heading to the LAX 315 radial then turn to a heading of 250 degrees; vectors to V-299. Climb and maintain 3;000 FT; expect 5;000 FT ten minutes after; squawk XXXX; Departure XXX.X' I repeated the clearance back and was not corrected (except for a confirmation of the squawk code). I flew directly to SADDE and when passing the LAX 315 radial; I turned to 250 degrees. In retrospect I realize that the Controller didn't really mean to use the word 'direct' SADDE but 'cleared' to SADDE via runway heading; crossing the LAX 315 radial turn to 250 for vectors to V-299.I failed to realize at the time 'runway heading' and 'direct' were contradictory and should have questioned the clearance further. It was only after contacting Departure Control that I realized the obvious. To the best of my knowledge; no conflict was created as no mention was made by Tower or Departure. Soon after I contacted Departure I was given a vector. I will be more diligent in the future when copying; reading back and making sense of clearances.
Pilot of a small aircraft experienced a track deviation on takeoff from SMO. After contacting Departure Control; Reporter realized that there was a contradictory element in the takeoff clearance which he had missed.