What is the procedure for a deployment of thrust reverser in flight?

Cut power to the reversed engine, and attempt to stow the reverser.

I think that is pretty much obvious.

But the very first step would be for the crew to be AWARE that the reverser has deployed.

They is not one thrust reversers are deployed when the wheels are on the ground.

You flyboys crack me up!

The Lauda Air accident was uncommanded and may have been due to electrical problems with hydraulic valves, see

https://aviation.stackexchange.com/questions/34962...

The TAM was also uncommanded and caused by problems elsewhere with a switch, and no indications of a deployed reverser for the pilots

https://en.m.wikipedia.org/wiki/TAM_Transportes_A%...

Thrust reversers aren’t usually deployed in flight, especially with high bypass jets. Aircraft that used to do so included the IL62 just before landing on the outer of each pair of jets - google for pics.

To deploy an undeployed thrust reverse defector while in flight:

Open emergency exit over wing area.

Take a fire ax from the cabin emergency supplies.

Step out onto the wing and proceed to engine nacelle. If a 737 with high bypass fanjets, you can slide down onto the rear part of engine. Caution, it is very hot there. If a Boeing other 700 series or an Airbus, you will have to shimmy down the stalk holding the engine, then reach around to the back portion.

Fire ax can be used to pry open the diverter buckets. Watch out for the jet blast!

Or read the aircraft's operating procedure manual to see if it can be done in air by pulling back the thrust levers all the way.

There is no procedure to deploy in flight. Our C-141's system was tied into the Weight on Wheels switches.

Don’t deploy thrust reverser s in flight. ;)

But probably the easiest thing is to retard all of the thrust levers at once. That way you don’t have to identify which specific engine is causing the problem and you immediately cure thrust asymmetry. Then identify the engine and shut it down while slowly adding power to the remaining engines and correct rudder input.