First, if you had questions about the clearance on the ground, you should have called Clearance Delivery again to obtain clarification. Departing with a looming question like that can be extremely dangerous, especially under the assumption that the departure airport is located in an area of mountainous terrain. In VFR conditions, you could just elect to execute a VFR climb over the airport, but you make no mention of the weather.
Next, when departing from a non-towered airport, you always have the ability to use the ODP even if ATC has not explicitly cleared you to do so. In this case that would be highly advisable. A normal departure dictates that you depart and climb to 400' AGL above the runway departure end elevation prior to beginning a turn on course.
"ODPs are recommended for obstruction clearance and may be flowing without ATC clearance unless an alternate departure procedure (SID or radar vector) has been specifically assigned by ATC" (AIM 5-2-8)
"Unless otherwise specified, required obstacle clearance...is based on the pilot crossing the departure end of the runway at least 35 feet above the departure end of runway elevation, climbing to 400 feet above the departure end of runway elevation before making the initial turn, and maintaining a minimum climb gradient of 200 feet per nautical mile, unless required to level off by a crossing restriction, until the minimum IFR altitude. ... If an initial turn higher than 400 feet above the departure end of runway elevation is specified in the DP, the turn should be commenced at the higher altitude
" (AIM 5-2-8)
An obstacle departure will be implemented sometimes for airspace reasons, but usually because there is something penetrating airspace in the immediate vicinity of the runway ends. That area is called the obstacle identification surface (OIS). The latter is
actually the case at HKS due to trees, antennas, etc. that you can read about in the textual departure procedure.
Additionally, you probably need to go back and re-listen to what your clearance actually was. If a runway was specified, it was probably done so in the context of issuing the ODP: "Cleared to ILM Airport via the Runway 34 (obstacle) departure procedure, direct MIE, then as filed." It seems unlikely to me that the controller would have said "...via Runway 34, direct MIE." If the latter were actually the case, I would immediately ask for a different clearance. You can put in a FOIA request for the recordings of the clearance delivery position on the day/night of your flight, or just call the facility directly and ask for a copy.
The ODP for Runway 34 at that airport says to fly runway heading and climb to 900' before turning on course.
HAWKINS FIELD (HKS)
AMDT 1 10266 (FAA) TAKEOFF MINIMUMS:
Rwy 11, 300-1¼ or std. w/ min. climb of 230' per NM to 600. Alternatively, with standard takeoff minimums and a normal 200' per NM climb gradient, takeoff must occur no later than 1800 prior to DER. DEPARTURE PROCEDURE:
Rwy 11, climb heading
115° to 900 before proceeding on course. Rwy 16, climb heading 159° to 1400 before turning right. Rwy 29, climb heading 295° to 1400 before turning left. Rwy 34, climb heading 339° to 900 before proceeding on course. NOTE:
Rwy 11, trees beginning 1141' from DER, 33' right of centerline, up to 100' AGL/374' MSL. Trees beginning 460' from DER, 155' left of centerline, up to 100' AGL/406' MSL. Tower 5514' from DER, 1566' left of centerline, 164' AGL/483' MSL. Rwy 16, trees beginning 1023' from DER, 373' right of centerline, up to 100' AGL/438' MSL. Trees beginning 588' from DER, 27' left of centerline, up to 100' AGL/449' MSL. Rwy 29, hangar, 481' from DER, 357' right of centerline, 13' AGL/332' MSL. Light, 880' from DER, 255' left of centerline, 10' AGL/339' MSL. Antenna on hangar, 1065' from DER, 595' right of centerline, 40' AGL/362' MSL. Trees beginning 698' from DER, 186' left of centerline, up to 100' AGL/426' MSL. Rwy 34' terrain 50' from DER, 316' right of centerline, 345' MSL. Trees, 2700' from DER, 884' left of centerline, up to 100' AGL/410' MSL.
So the question is, should we climb to 1000' and then select direct to MEI and fly that course or turn to intercept the course draw from KHKS to MIE . I believe that since the clearence is from KHKS direct MEI we should intercept that course line.
I would not do that. Fly the departure procedure, then go direct MEI from your present position when reaching 900' MSL per the DP. There's no sense in going back to the original course line. This is really up to you and your captain/FO, however.
If you were cleared "via direct MIE, then as filed", then no, you're expected to start a turn direct to MIE after takeoff (around 400' AGL, I believe) - not fly a departure procedure thence direct MIE.
This would likely put you in hot water with the FAA. You cannot accept a clearance that puts you in violation of the regulations. Even if that's what the clearance delivery controller "expects" you to do, you still can't legally do it. References:91.103 Preflight action91.13 Careless or reckless operation91.123 Compliance with ATC clearances and instructions
(last sentence of (a)).
"[An ATC clearance] is not authorization for a pilot to deviate from any rule, regulation, or minimum altitude nor to conduct unsafe operation of the aircraft" (AIM 4-4-1)
. Regarding the regulatory nature of the AIM, as I'm sure this may come up, it is not intrinsically regulatory, but is cited in FAA Chief Counsel legal interpretations, which are regulatory. References: Dormier letter & Kilcullen letter.
Finally, I would also advise you file a NASA ASRS report. The information collected in those reports can be used to develop solutions to confusion that arises among pilots and ATC regarding topics just like this. There is no downside to filing the report; your personal information is removed, and the FAA cannot use anything you say in that report against you.