It is not usually considered show legal and is used primarily as a training aid.

It was withdrawn from service and transferred to the airport fire department for use as a training aid.

These maneuvers were a valuable training aid to both Mitchell and the submarines.

Home based simulators have been a common training aid for private pilots for many years.

In fact, he said, the temperature was actually a training aid.

The city's science director pretends he is handling a training aid, and is able to do the same.

The "boxing suit" also aims to provide a powerful training aid for coaches and sports scientists.

Previously used at the gunnery range as a live training aid, the gun was last fired in 2005.

Did he use Crysos as some kind of training aid.

It later became a viral phenomenon on the Internet and is still used as a training aid.