Narrative:

We were assigned the 130 degree heading; climb to 2;000 ft MSL on the KENLN5 departure off runway 13R at bji. On initial climb the takeoff was normal until I called for 'VNAV; flaps 5; speed clean maneuver' at 1;000 ft AGL. FMS/flight director commanded a descent and a speed reduction then retarded the thrust levers through the autothrottles. I notified the captain; who commanded; 'auto throttles off; flight director off; continue the climb raw data.' I complied and maintained the flight path to climb to 2;000 ft on a 130 degree heading. We retracted flaps to zero on profile and accelerated to clean maneuver airspeed; approximately 207 KIAS.subsequently directed by seattle departure to; 'turn left heading 070; climb to 6;000 ft.' I initiated the turn and climb raw data. Captain was trouble-shooting the FMS. We encountered a couple of audible warnings in trying to re-engage the automation. I became distracted in the turn; dropped my heading scan and turned through 070 degrees. Seattle departure prompted us and called to assign a new heading of 040 degrees. I turned to 040 degrees; and refocused my scan on climb and heading. Subsequently I did not deviate from assigned clearances; headings; altitudes or airspeeds.the failure to roll out on 070 degree heading as assigned was my fault; because I allowed myself to become distracted in a high workload environment by automation audible warnings/cautions. I think we did a good job of reverting to raw data flying and ensuring a safe initial climb flight path despite bad flight director commands. I think I should have focused more and complied with the vector the first time.in later discussing the incident with the captain; we determined the FMS/cdnus were properly programmed and cross checked for vertical and lateral navigation. No errant altitude entries were made that would explain why the flight directors commanded a descent and speed reduction. I think we were prepared to revert to basic piloting skills; and did a good job of flying while continuing the climb.KENLN5 departure has a history of unreliability for navigation purposes. There was a flight crew letter which stated the airport authority did not want crews to use the departure. I think there is an anomaly in this departure which the FMS does not deal with well. Recommend that our flight crews not program the KENLN5 until further notice.

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Original NASA ASRS Text

Title: A B-767-200 flight crew; cleared to climb to 2;000 FT MSL on a 130 degree heading after takeoff from BFI; encountered confusing and possibly erroneous pitch and thrust commands from the FMS when transitioning to VNAV and starting to clean up while climbing through 1;000 FT MSL. They transitioned to raw data and manual control of the thrust levers. They believed all pre-event programming of the FMS to have been correctly entered.

Narrative: We were assigned the 130 degree heading; climb to 2;000 FT MSL on the KENLN5 departure off Runway 13R at BJI. On initial climb the takeoff was normal until I called for 'VNAV; Flaps 5; Speed Clean Maneuver' at 1;000 FT AGL. FMS/Flight Director commanded a descent and a speed reduction then retarded the thrust levers through the autothrottles. I notified the Captain; who commanded; 'Auto throttles off; flight director off; continue the climb raw data.' I complied and maintained the flight path to climb to 2;000 FT on a 130 degree heading. We retracted flaps to zero on profile and accelerated to clean maneuver airspeed; approximately 207 KIAS.Subsequently directed by Seattle Departure to; 'Turn left heading 070; climb to 6;000 FT.' I initiated the turn and climb raw data. Captain was trouble-shooting the FMS. We encountered a couple of audible warnings in trying to re-engage the automation. I became distracted in the turn; dropped my heading scan and turned through 070 degrees. Seattle Departure prompted us and called to assign a new heading of 040 degrees. I turned to 040 degrees; and refocused my scan on climb and heading. Subsequently I did not deviate from assigned clearances; headings; altitudes or airspeeds.The failure to roll out on 070 degree heading as assigned was my fault; because I allowed myself to become distracted in a high workload environment by automation audible warnings/cautions. I think we did a good job of reverting to raw data flying and ensuring a safe initial climb flight path despite bad Flight Director commands. I think I should have focused more and complied with the vector the first time.In later discussing the incident with the Captain; we determined the FMS/CDNUs were properly programmed and cross checked for vertical and lateral navigation. No errant altitude entries were made that would explain why the Flight Directors commanded a descent and speed reduction. I think we were prepared to revert to basic piloting skills; and did a good job of flying while continuing the climb.KENLN5 departure has a history of unreliability for navigation purposes. There was a Flight Crew Letter which stated the Airport Authority did not want crews to use the departure. I think there is an anomaly in this departure which the FMS does not deal with well. Recommend that our flight crews not program the KENLN5 until further notice.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.