Air carrier flight crew deviation from altitude after level off.

Attributes
ACN	317144
Time
Date	199509
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pvd
State Reference	RI
Altitude	msl bound lower : 10000 msl bound upper : 10400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute airway : zbw
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 210 flight time total : 11000 flight time type : 3500
ASRS Report	317144
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 180 flight time total : 11000 flight time type : 1500
ASRS Report	316640
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Miss Distance	horizontal : 30000 vertical : 1500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Captain was flying aircraft. A failure occurred to maintain assigned altitude of 10000 ft MSL. I had made appropriate callouts on approach to altitude. It appears that the vertical speed command wheel on autoplt did not fall into detent or was nudged out to allow a slow rate climb. While attending to other essential duties, I verbally noted altitude at 10200 ft and climbing. Corrective measures were started, however, 10400 ft was top of climb. A TCASII TA shortly followed by ATC inquiry occurred. Supplemental information from acn 316640: I normally use heading select mode but heading select on this aircraft caused aircraft to fly 'wing down.' as aircraft was leveling at 10000 ft ATC requested a turn to 170 degrees and advised of traffic at 1-2 O'clock. The vertical speed wheel was rotated to the detent and the crew looked for the traffic. Aircraft continued to climb until the on board altitude alert activated. PF should verify that the detent is engaged and that the aircraft actually levels off before shifting attention outside of cockpit. Use of turn knob and thoughts about 10000 ft announcement could also have been a factor.

Original NASA ASRS Text

Title: ACR FLC DEV FROM ALT AFTER LEVEL OFF.

Narrative: CAPT WAS FLYING ACFT. A FAILURE OCCURRED TO MAINTAIN ASSIGNED ALT OF 10000 FT MSL. I HAD MADE APPROPRIATE CALLOUTS ON APCH TO ALT. IT APPEARS THAT THE VERT SPD COMMAND WHEEL ON AUTOPLT DID NOT FALL INTO DETENT OR WAS NUDGED OUT TO ALLOW A SLOW RATE CLB. WHILE ATTENDING TO OTHER ESSENTIAL DUTIES, I VERBALLY NOTED ALT AT 10200 FT AND CLBING. CORRECTIVE MEASURES WERE STARTED, HOWEVER, 10400 FT WAS TOP OF CLB. A TCASII TA SHORTLY FOLLOWED BY ATC INQUIRY OCCURRED. SUPPLEMENTAL INFO FROM ACN 316640: I NORMALLY USE HDG SELECT MODE BUT HDG SELECT ON THIS ACFT CAUSED ACFT TO FLY 'WING DOWN.' AS ACFT WAS LEVELING AT 10000 FT ATC REQUESTED A TURN TO 170 DEGS AND ADVISED OF TFC AT 1-2 O'CLOCK. THE VERT SPD WHEEL WAS ROTATED TO THE DETENT AND THE CREW LOOKED FOR THE TFC. ACFT CONTINUED TO CLB UNTIL THE ON BOARD ALT ALERT ACTIVATED. PF SHOULD VERIFY THAT THE DETENT IS ENGAGED AND THAT THE ACFT ACTUALLY LEVELS OFF BEFORE SHIFTING ATTN OUTSIDE OF COCKPIT. USE OF TURN KNOB AND THOUGHTS ABOUT 10000 FT ANNOUNCEMENT COULD ALSO HAVE BEEN A FACTOR.

Data retrieved from NASA's ASRS site as of July 2007 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.