A be-400 right thrust reverser arm and master warning flashed momentarily during descent accompanied...

Narrative:

While in a center issued descent and in a small (ten degree) turn to the left to join another vector for an ILS approach; the plane suddenly and violently banked 45 degrees toward the right and pitched down slightly. We were passing through approximately 4000' and the power was at idle to slow from 220 to a newly assigned airspeed of 180 with the autopilot coupled on the left during the captain's leg. The rapid drop toward the right was accompanied with a noise similar but louder to speed brakes being extended at high speeds. I had time to see a master warning flasher illuminate and a 'right TR arm' illuminate; both briefly. I never saw the master warning that was associated with the flasher. The whole event lasted approximately 2 seconds and conditions returned to normal. We monitored systems; continued the approach; kept both power levers just forward of flight idle until landing flare and landed without incident.

Original NASA ASRS Text

Title: A BE-400 R Thrust Reverser ARM and Master Warning flashed momentarily during descent accompanied by a violent 45 degree right roll and loud rumbling noise. The whole event lasted approximately 2 seconds and conditions returned to normal. The approach was continued to a normal landing.

Narrative: While in a Center issued descent and in a small (ten degree) turn to the left to join another vector for an ILS approach; the plane suddenly and violently banked 45 degrees toward the right and pitched down slightly. We were passing through approximately 4000' and the power was at idle to slow from 220 to a newly assigned airspeed of 180 with the autopilot coupled on the left during the Captain's leg. The rapid drop toward the right was accompanied with a noise similar but louder to speed brakes being extended at high speeds. I had time to see a Master Warning flasher illuminate and a 'R TR ARM' illuminate; both briefly. I never saw the Master Warning that was associated with the flasher. The whole event lasted approximately 2 seconds and conditions returned to normal. We monitored systems; continued the approach; kept both power levers just forward of flight idle until landing flare and landed without incident.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1206796
Time
Date	201409
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Make Model Name	Beechjet 400
Operating Under FAR Part	Part 91
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Reverser Lockout
Person 1
Function	Pilot Not Flying First Officer
Person 2
Function	Captain Pilot Flying
Events
Anomaly	Aircraft Equipment Problem Critical

A be-400 right thrust reverser arm and master warning flashed momentarily during descent accompanied by a violent 45 degree right roll and loud rumbling noise. The whole event lasted approximately 2 seconds and conditions returned to normal. The approach was continued to a normal landing.