LR60 captain reported and uncontrolled 800 ft climb from FL290 because of updraft.

Attributes
ACN	1016979
Time
Date	201206
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Learjet 60
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Air Traffic Control Military 27 Air Traffic Control Non Radar 20 Air Traffic Control Radar 20 Flight Crew Last 90 Days 95 Flight Crew Total 13000 Flight Crew Type 2500
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Inflight Event / Encounter Weather / Turbulence Inflight Event / Encounter Loss Of Aircraft Control
Miss Distance	Vertical 800

Narrative:

[We were] flying through an area of weather at FL290. Without warning aircraft was caught in an updraft. Immediate call to center to advise of the uncontrollable ascent; aircraft vertical ascent of about 700 to 800 ft. Once the aircraft was under control [we] returned to assigned altitude. Center immediately asked if all passengers were okay. They were and we continued to destination without further incident.

Original NASA ASRS Text

Title: LR60 Captain reported and uncontrolled 800 FT climb from FL290 because of updraft.

Narrative: [We were] flying through an area of weather at FL290. Without warning aircraft was caught in an updraft. Immediate call to Center to advise of the uncontrollable ascent; aircraft vertical ascent of about 700 to 800 FT. Once the aircraft was under control [we] returned to assigned altitude. Center immediately asked if all passengers were okay. They were and we continued to destination without further incident.

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.