Date: 201409
Location: SUN.Airport, ID
Flight conditions: IMC
Light: Daylight
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Landing
Airspace: Class D SUN
ATC / advisory: Tower SUN
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Flying
Anomaly: Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert
Contributing factors: Chart Or Publication; Airport; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: It started off with a routine flight from to SUN (Sun Valley Idaho). We were aware that the weather was down and from what I can remember we would be the 3rd [company] flight to try and get in that day. There were multiple passengers while boarding that questioned whether or not we would be able to get in. I responded that the weather was improving and we would do everything we could within the realm of safety. Knowing there would be some external and internal pressures associated with the route we made sure we briefed early and went over all the possible scenarios including the fms failure; balked landing procedure; and the missed approach procedure. As we approached our destination I got the latest atis and we had good enough weather to shoot the approach. As my captain briefed the GPS X rwy31 approach he mistakenly briefed 12500ft for the missed and neither him or I caught where it says 'when authorized by ATC; climb in hold to 12;500ft' The proper brief should of been to an altitude of 8;700ft then if we are authorized by ATC up to 12;500ft in the hold. As we approached our minimums I called missed approach as I had no runway in sight. After our call outs I told tower we were going missed and he told us to contact center. As I called center I stated we were executing the published missed out of Sun Valley and climbing to 12500ft. I did not get a response until the 3rd or 4th attempt to reach them. After we established radio contact he said; 'Look at your approach plate and tell me what altitude it says on the missed.' That's when I instantly looked and noticed it said 12;500 WITH ATC AUTHORIZATION! I apologized for it and explained we overlooked the 12;500ft. He kindly explained and said they protect the airspace to 8;700ft. I acknowledged and he said it was fine because there was no other traffic in the area and approved us to climb to 13;000ft while we entered the hold. I think there were a number of contributing factors that led to the altitude deviation. First off; we were planning on having a thorough briefing on the ground before even getting airborne to Sun Valley. We did this however; we were delayed getting to [our intermediate stop] because of our late arriving aircraft. This meant that we would have little time in Salt Lake to brief before heading to Sun Valley. I also believe that our emphasis on all the company procedural information going into there led to us overlooking a simple thing. I think safety is always on our mind and I do believe that there are stringent procedures that we must essentially memorize prior to even commencing an approach into an unforgiving place such as Sun Valley. I feel we focused more on the worst case scenario procedures and omitted something because of it.I have two suggestions that I think will help other air crews avoid a similar situation. Being the unforgiving airport Sun Valley is; having adequate time to brief is crucial. I feel having a crew that is arriving late and that has to do a quick turn to a place like this needs adequate time to prepare especially when weather is down.My last and most important suggestion to help avoid this in the future is to have one of the altitudes on the missed approach procedure deleted. In my personal opinion I think the 8;700ft should be reconsidered. I feel that if ATC can protect the airspace to 12;500ft it will allow the crews to have one less thing on the missed procedure and will provide much greater protection from surrounding terrain. The missed approach procedure brings you over terrain as high as 7;299ft; meaning you're only clearing it by 1401ft.


Second narrative: I briefed the RNAV GPS RWY 31 approach into SUN including the missed approach altitude of 12500. I also briefed the balked landing; missed approach; and FMS failure procedure.I mistook that altitude as part of the missed approach procedure and so did the PNF both times we referenced it.The root cause is the inclusion of an irrelevant altitude in the missed approach procedure. Contributing is when descending to DMDA into SUN there are 4 different possible outcomes when reaching DMDA and each procedure is unique. i.e.:  1. Normal landing2. Missed approach.3. Balked landing4. Balked landing with FMS failure.That is a lot of stuff to cram into short term memory.[I believe the] phrase 'When authorized by ATC; climb-in-hold to 12500 FT should be removed from the missed approach procedure because it is not part of the missed approach procedure.


Synopsis: A commercial fixed wing flight into SUN conducted a GPS X Runway 31 approach to decision height with no contact and went around; climbing to 12;500 FT per the MAP. When in contact with ATC they were advised the actual MAP altitude was only 8;700 FT with a requirement to obtain ATC authorization to continue the climb to 12;500. The reporters cited an excess of options at decision height and the decision to place the 12;500 altitude in the MAP description as contributing factors.