Why did Spain reject the first Coandă biplanes?

Short answer

Because the B.R.7 failed to meet the specification: early trials showed its wings gave too little lift due to the shallower camber typical of monoplanes. A higher-camber wing and a four-blade propeller were tried without enough improvement, and the Spanish contract was cancelled.

Published: November 5, 2026 · Updated: November 5, 2026 · Edited by Above Ten Thousand · Editorial policy

Why did Spain reject the first Coandă biplanes?

Bristol TB8

A biplane with low-camber wings

Romanian designer Henri Coandă joined Bristol in January 1912. Early trials of the B.R.7 showed that its wings produced too little lift because they used the shallower camber associated with monoplanes. The wings were replaced with others of greater camber, which improved performance, but not enough to meet the specification.

The Spanish order

The first of the five B.R.7s ordered by Spain was shown at the Olympia Aero Show in February 1913 and made its first flight in March at Larkhill. The Spanish had requested the use of the 70 hp (50 kW) Renault engine already used in their Maurice Farmans. Experiments with a four-blade propeller also failed to produce a sufficient improvement, and the Spanish contract was cancelled.

The fate of the aircraft

The second aircraft was lost in a fire, and the remaining four of the Spanish order flew only rarely. In total, eight examples were built, including one of German manufacture.