In 2005 Tomy began releasing a pack based on the Thomas and Friends episode of the same name for the Motor Road & Rail export ranges and later the Japanese Thomas Plarail series. The Thomas included has a shocked face, high-speed gearbox, and includes a representation of the jet engine seen in the show with a flashing red light in the tail "jet" output.
Around August 2005 the initial Thomas the Jet Engine packs were released as part of the European Motor Road & Rail range and the American Motorized Road & Rail range with the three-piece train and a DVD containing the episode of the show it is based on. In the United States it was released as 4742 Thomas & the Jet Engine. This pack had different packaging in the United States and Europe, as can be seen on the Thomas Motorized wikia.
Thomas has a shocked face and painted whites in his eyes but uses the standard undecorated chassis and boiler.
The jet engine and boxes are on a single long flatbed in the T.V. show episode but they have been split apart for this release. The red jet engine turbine lights up as the jet rolls along.
The jet engine takes two AAA batteries and has a switch on the rear wheels to activate the light as it rolls. In 2006 the standard box portion of the flatbed was released in the United States in the Sodor Passenger Car Set, although it is far from a passenger car.
In early 2008 the Thomas the Jet Engine pack was released in late blue Motor Road & Rail packaging as a special edition alongside the Percy and the Chocolate Crunch pack. In later 2008 the pack was rereleased again in Tomy TrackMaster packaging as Thomas & the Jet Engine.
Thomas and the Jet Engine was released in Japan as part of the Plarail Thomas series as Thomas the Tank Engine and the Jet Engine in May 2006. The Thomas uses the nice more detailed body shell and chassis as well as the high-speed gearbox and shocked face.
The eyes on the Jet Engine Thomas face are fairly downcast, similar to the later Doki Doki Mountain set Thomas. I thought that this Thomas would have had more forward-facing eyes, and maybe mine are cast particularly low, but I don't think there was another surprised Thomas in production in July 2006 when this one was made...
Inside, the gearbox tooling originally used for the Talk 'n' Action Thomas and other Thomas-gearbox engines has been adapted to house a higher-speed geartrain that causes Thomas to run faster. These gearboxes stick out further back than the regular Thomas gearbox and have one of the shafts visible in a divot in the top of the gearbox, and you can see where the gearbox originally had a cutout to let the additional wires out of the gearbox in its original use.
It isn't really all that much faster, but the Jet Engine Thomas does outpace its regular counterparts.
In 2010 the box car portion of the jet engine flatbed was given away at Toys R Us for buying a certain amount of Thomas Plarail. These box cars are made of a darker, oranger plastic than the original cars.