A similar contra-rotating propeller unit was later used on production Seafire 46 and 47s.

One possibility is to enclose the contra-rotating propellers in a shroud.

The contra-rotating propellers also created instability that required an increase in fin area, all of which cost Browning more than $300,000.

The drums were connected via a differential gear to twin contra-rotating propellers.

Contra-rotating propellers have benefits in providing thrust for boats for the same reasons.

Contra-rotating propellers have one propeller close behind another on the same axis, but rotating in the opposite direction.

These drove eight paired contra-rotating propellers on four forward-facing nacelles.

The contra-rotating propellers and compressor are driven by the 5-stage axial turbine.

The strength of contra-rotating propeller limited launch height .

For the 803 the engineers decided to avoid this problem by simply not using a common crankshaft, and driving a set of independent contra-rotating propellers.

Two Ha-40 coupled together with a common gearbox, driving a twin three-blade contra-rotating propeller.

Variations of propeller layout include contra-rotating propellers and ducted fans.

In 1940, Piaggio still had to solve three major issues: contra-rotating propellers, power transmission, and engine cooling.

Contra-rotating propellers have been found to be between 6% and 16% more efficient than normal propellers.

Eventually most of these problems were fixed in Seafire 47 when the 6 bladed contra-rotating propeller was adapted.

This engine would have driven eight-blade contra-rotating propellers.

Not long afterward the idea of contra-rotating propellers was introduced (at Woolwich), to avoid the need for the vane.

This is achieved by four pairs of contra-rotating propellers, similar to those on the Tupolev Tu-114.

Nonetheless, coaxial contra-rotating propellers and rotors are moderately common in military aircraft.

The Short Sturgeon used 2 Merlin 140s with contra-rotating propellers.

It is powered by four Progress D-27 propfan engines driving contra-rotating propellers.

The B-54 had a piston engine and the B-88 a gas turbine driving a large contra-rotating propeller.

A further improvement led to P.8011, which replaced the supercharger with two smaller turbochargers, driving contra-rotating propellers.

Finally is the propulsion section which houses the electric motor, four rectangular control fins and two contra-rotating propellers.

While the 101 continued to drive a five-blade propeller, the 121 and 130 series were designed to drive contra-rotating propellers.