Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 9.4; Flight Crew Total 1050.9; Flight Crew Type 426
Communication Breakdown; Confusion
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic; Flight Crew Became Reoriented
Human Factors; Procedure
I was preparing to depart Runway 35 at CON on an IFR flight plan. Weather in Concord was CAVU; but I expected possible IMC during the let-down; so I stuck with the IFR. My accepted clearance was from CON; direct CON VOR; V93 [southwest bound]; then as filed. When I called for my release from CON; the Controller asked if I was able to remain clear of terrain and obstacles northbound. This is phraseology I am familiar with when departing uncontrolled fields in mountainous areas; so I thought it was a little odd to ask in this case; but I thought that perhaps ATC procedures had changed. The published Obstacle Departure Procedure (ODP) at CON calls for a climb northbound to 1;300 FT before turning on course; in this case it would be to the VOR. Since the ODP would keep me clear of terrain and obstacles; I acknowledged with an affirmative. In fact; since the ODP provides for terrain and obstacle clearance in all directions after reaching 1;300 FT; I thought the question was superfluous; but I did not question the Controller; (which I should have). I was released and again told that I was to maintain my own terrain and obstacle clearance northbound; and there was Mooney traffic inbound from the northwest. I read that back and indicated I would keep my eyes peeled for the Mooney. I thought his comments were emphasizing the terrain and obstacle clearance; and that 'northbound' referred to a general direction I would be headed on the first part of the ODP; having departed on the northbound runway; and did not perceive that as direction to fly heading 360. I also thought the Mooney must not be IFR; because in the past I have been held on the ground at CON for any inbound IFR traffic to clear. So I thought the Mooney reference was simply pointing out VFR traffic in the area; just as traffic is pointed out to IFR flights operating in VMC all the time. After takeoff; I executed the ODP; including the turn to the VOR. Upon initial call-up; I was asked to confirm I was northbound. I indicated that I was not; and began a turn back to the north. The Controller then instructed me to instead fly heading 210 for traffic. There was no indication from the Controller of a conflict. After a few moments; I queried the Controller for clarification; explaining that when I was asked about remaining clear of terrain and obstacles northbound; I did not interpret that as direction to remain on a northbound heading. The Controller explained that in order to release me and NOT use the published departure procedure; they had to confirm that I could remain clear of terrain and obstacles in the direction of travel; and that by asking that question and my accepting terrain and obstacle responsibility northbound; they assume I would have continued northbound and that they would call my turn. After I thanked him for the clarification; the Controller indicated no problem; so I assume there was no loss of separation. There was no further discussion on the matter. Clearly; I misinterpreted the intended departure clearance; and fortunately there was no real harm done; this time. I interpreted 'Can you remain clear of terrain and obstacles northbound' as 'Can you remain clear of terrain and obstacles while northbound on the ODP; having departed the northbound runway'; whereas what was being asked was; 'Can you remain clear of terrain and obstacles if you were to continue to fly northbound and NOT use the ODP'? I thought the emphasis was on the terrain and obstacles; and I did not understand that they were asking me to abandon the ODP. In retrospect; I did accept a clearance to remain clear of terrain and obstacles northbound; so it is reasonable that ATC would assume I would do exactly that. What will I do in the future? 1. If ATC provides direction that I find unexpected for the situation; question it; especially since it was mentioned more than once. In this case; if I had questioned the use of the terrain and obstacle clearance phraseology; we probablywould have sorted it out before takeoff.2. Listen carefully to the words coming out of my mouth; I did accept a departure clearance to remain clear of terrain and obstacles northbound.3. If; when acknowledging the ability to remain clear of terrain and obstacles I had said something like; 'yes; the ODP takes care of that; so no problem'; the Controller would have been tipped-off that I did not understand his intent. So; don't be too verbose but don't be afraid to add enough detail to convey your understanding.4. If the Controller says or asks something that sounds superfluous; do not assume that I know why it was asked; and ask why. What might ATC have done differently?1. If my release had contained the phraseology 'fly heading…' or 'for traffic; fly heading' or 'fly northbound for now and we'll call your turn'; that might have been a bit clearer. Whenever I depart controlled fields and there is a desire from ATC to deviate from the published departure procedure; they say; for example; fly heading 360; Runway 35; cleared for takeoff. 2. When they asked about remaining clear of terrain and obstacles northbound; if they had explicitly indicated that was in lieu of the ODP; that would have also made it clear; but I think from their perspective; they essentially had done that. 3. If my actual clearance; had been amended to 'Radar vectors to CON VOR; fly heading 360 for now;' that too would have done it. I have one last thought. During my request for clarification; the controller's description of the ODP was either customized to this situation; or it is different from mine. In his clarification; the controller said the procedure calls for a turn to the VOR; but the procedure reads 'climb to 1;300 before turning on course'; without specifying the VOR. I wonder if this difference in interpretation of the ODP may have also biased my thinking and the Controllers thinking in different ways such that we thought we were on the same page; but in fact were not.
PA28 pilot reports misunderstanding his IFR clearance departing CON. An ATC question about maintaining terrain clearance northbound is interpreted as just that; a question and not a clearance to maintain runway heading after takeoff.