Sir - In the article "Highly rated" (Flight International, 11-17 September, P46) the acronym CCQ is written as cross-crew qualification. I have heard, however, the term crew cross-qualification. I believe that the latter is correct, since it depicts what it is, the cross qualification of crews between two or more types of aircraft.

The way in which you have written it means the qualification of crewmembers who are cross at each other.

This, of course, is also an important safety issue, but is independent of aircraft type.

HALUK TAYSI

Weyhe-Lahausen, Germany

[The point is well-made in grammatical terms. The industry, however, appears to have adopted the less logical of two alternatives, or - as the industry would incorrectly call them - two alternates. Editor]

-Sir - One US carrier, TWA, has long practised mixed-fleet flying (MFF), or dual qualifications, as we called it.

A small cadre of line pilots voluntarily remained dual on eligible aircraft combinations (for instance, Boeing 707/727 or Boeing 747/Lockheed Martin L-1011) for extended periods of time - in my case for six years and five-plus years, respectively.

If one wished to endure intervening decontamination checks, it was also possible to be "triple" (747/L-1011/Boeing 767 extended-range twinjet operations). Only one or two pilots did this.

MFF on the 767/757 or the Airbus A340/330 should be a piece of cake. MFF does, however, require extra study on the part of the flight-crews.

PHIL RIMMLER

Scottsdale, Arizona, USA

Source: Flight International