Gulfstream G200 (IAI 1126 Galaxy)
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Time Pressure
Inflight Event / Encounter CFTT / CFIT
Flight Crew Took Evasive Action
Human Factors
Early morning flight from 36U. Terrain all around airport. I've been to 36U once before I believe; maybe twice. We're loaded to 8K+ in gas with 1 passenger. FBO not open when we arrived; so late start to preflight and [we had to] deal with flight planning/issues. We don't rush through our preflight; however. During departure planning I consult the ODP which requires a climb over the airport to 11;300 FT MSL prior to on course headings. After start-up and in the taxi out while Taxi Checks are being completed; my partner calls SLC Center for the clearance and we are issued the COOLI3 departure off of Runway 4. I asked him if second segment considerations were met during the taxi but did not look at page 3 of the G200 PERF section of the FMS that shows Climb Gradient % for second Segment. The departure requires a 10.9% gradient to 8;700 FT MSL to clear a ridge of hills that I estimate at around 7;500 FT MSL 4.5 NM from the departure end of Runway 4. I performed a static power takeoff off of Runway 4 and out of 400 FT AGL; my focus immediately shifted to the ridge line ahead and what appeared to be our need to climb more rapidly. Our slats were extended and speed was 220 so I pitched up purposely and smoothly to trade speed for altitude. I briefed my partner that 'We're going to see and avoid. I'm sure why (at this point) those hills are there but if I'm not satisfied that we're going to clear in just a moment; we'll turn left to do the ODP procedure.' He seemed confused by the position of the terrain as well. It was soon very clear that we would safely clear the ridge visually BUT; GPWS detected a rapid closure rate of terrain and did what it does; gave us a TERRAIN warning. I estimate we cleared the terrain by 900-1;000 FT but the GPWS did not like the closure rate as detected by the RA is my guess. In cruise I asked my flying partner to simulate another takeoff on the PERF page with the fuel load on departure and looked at the COOLI3. My eyes bugged out of my head as I asked him... 'What about that 10.9% requirement for second segment?!' I'm not sure he fully understands what was even needed for second segment to accept the COOLI3. If the climb gradient was correct that we simulated in the FMS; we had a 4% second segment and needed 10.9%. When I asked him about second segment requirements on the COOLI3; he responded that 'we are good' with confidence. I believed him. Trust but verify. I'll need to see it for myself from now on. There has been a large emphasis on LNAV deviations lately and I believe that it may be a great idea to require both pilots to verify the second segment climb requirements prior to takeoff in lieu of an Airport Analysis Program that takes the guess work out of last minute gotchas like the COOLI3 provides once the aircraft is in motion. I feel very strongly that with the on demand; anywhere; anytime schedule that [our employer] flies; crews should be able to consult the PERF section of the release to see a simple second Segment number required for departure.
G-200 Captain reported on takeoff from 36U he had not properly briefed the second segment climb requirements and got a GPWS TERRAIN alert.