Widebody transport aircraft flies 400 ft above assigned altitude to avoid turbulence.

Attributes
ACN	293870
Time
Date	199501
Day	Thu
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : zoa
State Reference	CA
Altitude	msl bound lower : 35000 msl bound upper : 35400
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	DC-10 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	enroute : other oceanic enroute : pacific enroute airway : zoa
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 230 flight time total : 3000
ASRS Report	293870
Person 2
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

At flight level 350 I left the flight deck to use the restroom. After returning I noticed the aircraft level at FL350 plus 400 ft. At flight level 350 there was a cloud deck that resulted in light-moderate turbulence. The captain decided to fly the aircraft 400 ft above the assigned to avoid the cloud deck and thus avoid the turbulence. At no time was a request for either a higher altitude or a block altitude submitted to arinc. The company I work for has conveyed to the pilot group dozens of times the proper procedures to follow when it becomes necessary to deviation from an assigned altitude. None of these procedures were applied. Unfortunately there is 1 percent of the pilot group that does not get the message. Shortly after imputs from the first officer and so the captain descended back to FL350.

Original NASA ASRS Text

Title: WDB ACFT FLIES 400 FT ABOVE ASSIGNED ALT TO AVOID TURB.

Narrative: AT FLT LEVEL 350 I LEFT THE FLT DECK TO USE THE RESTROOM. AFTER RETURNING I NOTICED THE ACFT LEVEL AT FL350 PLUS 400 FT. AT FLT LEVEL 350 THERE WAS A CLOUD DECK THAT RESULTED IN LIGHT-MODERATE TURB. THE CAPT DECIDED TO FLY THE ACFT 400 FT ABOVE THE ASSIGNED TO AVOID THE CLOUD DECK AND THUS AVOID THE TURB. AT NO TIME WAS A REQUEST FOR EITHER A HIGHER ALT OR A BLOCK ALT SUBMITTED TO ARINC. THE COMPANY I WORK FOR HAS CONVEYED TO THE PLT GROUP DOZENS OF TIMES THE PROPER PROCS TO FOLLOW WHEN IT BECOMES NECESSARY TO DEV FROM AN ASSIGNED ALT. NONE OF THESE PROCS WERE APPLIED. UNFORTUNATELY THERE IS 1 PERCENT OF THE PLT GROUP THAT DOES NOT GET THE MESSAGE. SHORTLY AFTER IMPUTS FROM THE FO AND SO THE CAPT DSNDED BACK TO FL350.

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.