21.   First they commandeered commercial aviation to serve as an instrument of terror.

22.   For example, he argues that commercial aviation is a highly reliable system, even though flying would itself appear to be extremely risky.

23.   He began his career in commercial aviation as an airmail pilot with Robertson Aviation, flying between St. Louis and Chicago.

24.   He said air travel is gradually increasing as tighter security measures reassure people about the safety of commercial aviation.

25.   In the increasingly volatile world of commercial aviation, Boston is one of the few markets that is up for grabs.

26.   In the highly technical, highly competitive world of commercial aviation, consumers can easily track how often their airline arrives on time and how frequently it loses baggage.

27.   Industry leaders say failure to deliver the necessary financial resources may destroy the commercial aviation system.

28.   It now gets a greater proportion of its revenue from products for commercial aviation than from Defense Department and space-launch contracts.

29.   It also makes aviation controls, management systems for commercial aviation systems, digital displays, digital fire controls and related products.

30.   Long after commercial aviation returned to the skies following the attacks, general aviation remained grounded, bankrupting many smaller businesses.