Reverser Actually Deployed in Flight

[pelmet]

Not a good situation.....


C-GTJL, a Learjet 35A operated by Sunwest Aviation Inc., was on a flight from Kelowna (CYLW),
BC to Calgary (CYYC), AB. While in cruise, the flight crew observed that the right hand thrust
reverser (TR) "UNLOCK" light had illuminated. They did not initially notice any yaw and it did not
feel like the TR had deployed. While the flight crew were reviewing the abnormal checklist, they
were cleared to descend to 15 000 feet at their discretion. As part of the descent checklist, the TR
test button was selected and they noticed the aircraft momentarily yawed to the right. After a brief
moment, the aircraft yawed even harder to the right, to approximately 20-30 degrees. The flight
crew responded by selecting idle thrust on the right engine, declared a PAN PAN, and actioned the
abnormal checklist for "Inadvertent Thrust Reverser Deployment In Flight". They completed the
abnormal checklist and the TR unlock light remained illuminated, so the right engine (Garrett,
TFE731-2-2B) was shutdown in accordance with the checklist. A single-engine approach and
landing was completed into CYYC without further issue.
Company maintenance has ordered a replacement pneumatic latch control valve and solenoid.

[Daniel Cooper]

So does the Learjet TR Unlock abnormal checklist tell you not to press the TR test button?

[HO Driver]

As part of the descent checklist, the TR
test button was selected and they noticed the aircraft momentarily yawed to the right.

[North Shore]

Not so sure that I'd be in a hurry to press the 'Test' button for any system that was displaying an abnormality...but then, I might be Monday morning quarterbacking..

[digits_]

Not so sure that I'd be in a hurry to press the 'Test' button for any system that was displaying an abnormality...but then, I might be Monday morning quarterbacking..

On a Tuesday?