Date: 201210
Local time of day: 0601-1200
Location: JNU.Airport, AK
Light: Daylight
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower JNU
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Distraction; Situational Awareness; Communication Breakdown
Second reporter function: Local
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown; Ground Incursion Runway
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Issued Advisory / Alert
Contributing factors: Airport; Environment - Non Weather Related; Procedure
Primary problem: Ambiguous

Narrative: On departure from JNU off Runway 26; we were notified by JNU Tower to contact them with a 'possible pilot deviation.' After landing I phoned JNU Tower and was informed that we had taken off on a closed portion of the runway and to hold to speak to the Supervisor. Supervisor stated we had taken off from the closed end of Runway 26 and it was being reported. I explained that apparently we had mistaken the closed portion as being beyond the barricades and flags and the fact that there were construction vehicles operating beyond the barricades. The Supervisor said that a previous air carrier flight conducted the same operation and had reported the same reason for using the closed portion. The Supervisor indicated they might need to reassess their methods for more clearly identifying the closure. The Supervisor further stated the closure was in a FDC NOTAM. I told her it would have been appreciated had the Tower Controller acted to warn us not to takeoff from the closed portion. The Supervisor obviously observed us back taxi and takeoff and contacted us in the initial climbout. Primary cause was my personal failure to read; understand and apply the FDC NOTAM in the flight paperwork. I believe as I scanned the first part of the NOTAM I misinterpreted the relocated threshold as displaced threshold and moved on. Contributing causes were: Most construction closures I have experienced have utilized a large X on the runway surface and or signs with barricades blocking entrance into the closed portion. The barricades and flags sucked us in. Inconsistencies in the landing clearance we received on arrival vs. the takeoff clearance verbiage; IE.; 'Cleared to land Runway 8 shortened' vs. 'Cleared to takeoff Runway 26;' no mention of shortened. I had expectations of back taxiing to the end to utilize the total available surface for takeoff. Day 3 of 4 day trip with close to 8 hour block on Day 1; over 8 hours on day two; early van times everyday and 3 hour time zone swaps. First Officer and I discussed what we perceived to be the closed end; we agreed and continued back taxi for takeoff. I should have queried the Tower to confirm. Long and short of it is I blew it. In the future I will take as much time to ensure the regulatory requirements of the flight as I spend on ensuring the safe operation of the flight.


Second narrative: An [air carrier] was holding short of Runway 26 at Foxtrot. I cleared the aircraft for take off by saying '[Flight #]; Runway 26 at Foxtrot; back taxi approved. Runway 26 shortened; cleared for take off'. The aircraft taxied past the relocated threshold; and on takeoff; blew down some construction barriers. The aircraft had the ATIS information which stated that Runway 26 is shortened by 600 FT due to the relocated threshold. There is also a painted white line at the approach end of Runway 26 which indicates the end of the runway; which the pilot should not taxi past. I kept an eye on this aircraft as it was taxiing. The angle from the Tower however makes it very hard to see whether the aircraft had passed the threshold line or not. It was reported by airport safety that the pilot did cross the threshold line. The NOTAMs may also be a little confusing to the pilots; but we were instructed to read them on the ATIS just the way that they were printed. I would recommend that airport safety and/or FSS revise the NOTAMs to make them easier for the pilots to understand.


Synopsis: An Air Carrier flight crew used the east 600 FT closed section of JNU Runway 8/26 as part of the takeoff runway because the runway closure makings; lights and barricades did not clearly define the usable beginning of Runway 26.