She takes them to the high-school shop class, where they meet Cooter Davenport, who gives them a fast engine.

During this period, the surviving aircraft were re-equipped with AM-35As, which gave them a shorter range, but a more reliable engine.

This type was also later given a more powerful engine, but not a new designation.

The low temperature of the air permits light alloy construction to be employed which gives a very lightweight engine - essential for reaching orbit.

Despite being given a more powerful engine, it was not a success.

In September 1938 it was given a larger engine with the tax rating of 17.9 hp though it retained the name Fifteen.

Some minor problems were found during testing and the aircraft was given a more powerful engine.

In August 1934 in anticipation of the reduction in annual tax charge it was given a larger 2-litre engine.

The B5N2 was given a much more powerful engine, and various modifications were made to streamline it.

Simple design with few moving parts, giving a compact engine with low maintenance costs and reduced frictional losses.