Narrative:

I was assigned as PIC performing the duties of pm from the right seat of a ce-650. We departed runway 24 teb in the early evening. Our clearance included the RUUDY4 departure which specifies an altitude of 1;500 feet at wentz and 2;000 feet at tasca. The departure procedure was loaded into the FMS prior to departure and checked for accuracy per standard crew procedure. The altitude alerter was set to 1;500 feet during the required crew departure briefing prior to engine start. After takeoff; the PF called for gear up; flaps up; and auto pilot engage per normal procedures. These calls occurred during a heavy workload period for the pm. I called 500 feet for 1;500 feet; received the required PF acknowledgement; and reached across the center console and engaged; I thought; the auto pilot per the PF request. The aircraft was climbing at approximately 3;000 feet per minute. After completing a frequency change; I performed an instrument scan and saw that the aircraft was climbing through approximately 1;700 feet indicated and that it did not appear that the LNAV course had been captured; the flight director command bars had disappeared and neither the altitude capture armed message nor altitude capture message was displayed on the ADI. The PF was in the process of engaging the yoke mounted autopilot disconnect switch; reducing thrust to begin a descent; and turning the aircraft to intercept the departure course. This action had already begun when I announced 'altitude.' ATC requested an altitude report to which a called the altitude and that we were descending to 1;500 feet. The PF hand flew the aircraft to required course and altitude. Once stabilized; we jointly reattempted an autopilot and LNAV engagement which was successful. At no time during this period did we receive an RA or TA alert. After a brief discussion with ATC over the altitude restrictions of the RUUDY4 we were given a frequency change. We continued to exercise the afs during the duration of the flight to destination with no notable exceptions. Therefore; a maintenance discrepancy was not entered into the log as we were not able to duplicate the situation on departure. In retrospect; it appears that the fact that this was our first kteb RUUDY4 departure in this aircraft at night; combined with the ergonomic issue of the ap/afs control panel being located on the far left side of center console; that either the afs/ap did not function properly; or I inadvertently pressed the wrong button on the control panel due to the lack of adequate lighting and/or high work load.

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Original NASA ASRS Text

Title: A CE-650 departed on the TEB RUUDY4 Departure; but the autopilot did not engage. At 1;700 FT the flying pilot descended the aircraft to 1;500 FT. Pilot experience and workload were issues.

Narrative: I was assigned as PIC performing the duties of PM from the right seat of a CE-650. We departed Runway 24 TEB in the early evening. Our clearance included the RUUDY4 Departure which specifies an altitude of 1;500 feet at WENTZ and 2;000 feet at TASCA. The departure procedure was loaded into the FMS prior to departure and checked for accuracy per standard crew procedure. The Altitude Alerter was set to 1;500 feet during the required crew departure briefing prior to engine start. After takeoff; the PF called for gear up; flaps up; and auto pilot engage per normal procedures. These calls occurred during a heavy workload period for the PM. I called 500 feet for 1;500 feet; received the required PF acknowledgement; and reached across the center console and engaged; I thought; the auto pilot per the PF request. The aircraft was climbing at approximately 3;000 feet per minute. After completing a frequency change; I performed an instrument scan and saw that the aircraft was climbing through approximately 1;700 feet indicated and that it did not appear that the LNAV course had been captured; the flight director command bars had disappeared and neither the altitude capture armed message nor altitude capture message was displayed on the ADI. The PF was in the process of engaging the yoke mounted autopilot disconnect switch; reducing thrust to begin a descent; and turning the aircraft to intercept the departure course. This action had already begun when I announced 'altitude.' ATC requested an altitude report to which a called the altitude and that we were descending to 1;500 feet. The PF hand flew the aircraft to required course and altitude. Once stabilized; we jointly reattempted an autopilot and LNAV engagement which was successful. At no time during this period did we receive an RA or TA alert. After a brief discussion with ATC over the altitude restrictions of the RUUDY4 we were given a frequency change. We continued to exercise the AFS during the duration of the flight to destination with no notable exceptions. Therefore; a maintenance discrepancy was not entered into the log as we were not able to duplicate the situation on departure. In retrospect; it appears that the fact that this was our first KTEB RUUDY4 departure in this aircraft at night; combined with the ergonomic issue of the AP/AFS control panel being located on the far left side of center console; that either the AFS/AP did not function properly; or I inadvertently pressed the wrong button on the control panel due to the lack of adequate lighting and/or high work load.

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.