Altitude deviation altitude undershot in climb.

Attributes
ACN	203379
Time
Date	199202
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zdc
State Reference	DC
Altitude	msl bound lower : 33900 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 25000 flight time type : 5600
ASRS Report	203379
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Climbing through FL340 I called 34 for 35. Aircraft on autoplt, pms mode. First officer flying. I looked at map for next airway radial and also talked to ATC. I called level 330, then corrected call to level FL350. ATC acknowledged. I got busy with PA for a few mins, then looked at my altimeter again. Was I looking at FL339 or FL349? I asked the first officer if we were level at FL350 at the same time looking at his altimeter. We were at FL340. We climbed to FL350, ATC never questioned our altitude. We must have been at FL340 for at least 5 min. There is no doubt that FL350 was in the armed mode on altitude select. In trying to figure this one out, the only thing I can think of is that 1 pilot must monitor the automated flight system 100 percent of the time and that the PNF must double check all final altitude or parameters!

Original NASA ASRS Text

Title: ALTDEV ALT UNDERSHOT IN CLB.

Narrative: CLBING THROUGH FL340 I CALLED 34 FOR 35. ACFT ON AUTOPLT, PMS MODE. FO FLYING. I LOOKED AT MAP FOR NEXT AIRWAY RADIAL AND ALSO TALKED TO ATC. I CALLED LEVEL 330, THEN CORRECTED CALL TO LEVEL FL350. ATC ACKNOWLEDGED. I GOT BUSY WITH PA FOR A FEW MINS, THEN LOOKED AT MY ALTIMETER AGAIN. WAS I LOOKING AT FL339 OR FL349? I ASKED THE FO IF WE WERE LEVEL AT FL350 AT THE SAME TIME LOOKING AT HIS ALTIMETER. WE WERE AT FL340. WE CLBED TO FL350, ATC NEVER QUESTIONED OUR ALT. WE MUST HAVE BEEN AT FL340 FOR AT LEAST 5 MIN. THERE IS NO DOUBT THAT FL350 WAS IN THE ARMED MODE ON ALT SELECT. IN TRYING TO FIGURE THIS ONE OUT, THE ONLY THING I CAN THINK OF IS THAT 1 PLT MUST MONITOR THE AUTOMATED FLT SYS 100 PERCENT OF THE TIME AND THAT THE PNF MUST DOUBLE CHK ALL FINAL ALT OR PARAMETERS!

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.