On 21 May 1921 they ordered three aircraft for $48,000 each.
It ordered 187 aircraft with the last received by early Q2 2012.
Another concern for United is that it has fallen behind in ordering new aircraft.
It ordered seven aircraft with deliveries to completed in 2012.
The Navy approved the design and ordered 27 aircraft, later reducing this to 15.
Imperial Airways ordered eight aircraft which had all been delivered by 1933.
In 1976 the Federal Council ordered 72 aircraft, all of which were delivered by 1979.
In the last four years, Executive Jet has ordered 587 new aircraft worth $9.75 billion.
In the end of 2003, Emirates ordered 71 aircraft at a cost of $19 billion.
To help to meet the expanding need for training, the Navy ordered 150 aircraft in November 1940.