LR35 crew was given erratic altitude clearance by ZOA.

Attributes
ACN	419050
Time
Date	199811
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : oak
State Reference	CA
Altitude	msl bound lower : 28000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Learjet 35
Operating Under FAR Part	Part 135
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10100
ASRS Report	419050
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

On nov/xa/98 at XA30 we were told to level off at FL280 by ZOA. 1 min later we received clearance to FL350. I asked center to confirm this, they said 'climb and maintain FL350.' 30 seconds later we were told 'maintain level at FL280.' no further action was taken.

Original NASA ASRS Text

Title: LR35 CREW WAS GIVEN ERRATIC ALT CLRNC BY ZOA.

Narrative: ON NOV/XA/98 AT XA30 WE WERE TOLD TO LEVEL OFF AT FL280 BY ZOA. 1 MIN LATER WE RECEIVED CLRNC TO FL350. I ASKED CTR TO CONFIRM THIS, THEY SAID 'CLB AND MAINTAIN FL350.' 30 SECONDS LATER WE WERE TOLD 'MAINTAIN LEVEL AT FL280.' NO FURTHER ACTION WAS TAKEN.

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.