Sir - Congratulations on the publication of the Turbine Engine Directory (Flight International, 2-8 August, P27).
I was disappointed that no indication of weight was included.
The importance of the weight parameter can be seen when various US Department of Defense contracts for improved high-performance turbine-engine technology, etc, are examined, with targets of 30-50% weight reduction relative to current engines. The difficulty of obtaining a meaningful weight from manufacturers is appreciated, but, without it, comparison is impossible.
Secondly, a simple table of current Russian engine companies, compared to previous organisations, would have been much appreciated.
On a lighter note, it would appear that Allison, at 9.8m diameter for the AE3007, has gone into the ducted-propeller business.
D F NEWLAND
Watford, Hertfordshire, UK
Source: Flight International
