The Navy is considering buying 69 F/A-18E/F Super Hornet fighters to bridge a ?strike-fighter gap? that commanders fear could imperil aviation readiness at a time when older jets are wearing out before new aircraft are ready to take their place, top service officials said Wednesday.

Chief of Naval Operations Adm. Gary Roughead, who appeared before a Senate panel with Navy Secretary Donald Winter and Marine Corps Commandant Gen. James Conway, mentioned the ?fighter gap? in written testimony submitted to the Senate Appropriations Committee defense subcommittee, which convened to review the Department of the Navy?s fiscal 2009 budget request.

After the hearing, Roughead said Navy planners worried that many of today?s Super Hornets would be at the end of their service lives by about 2015, but their scheduled replacement, the F-35 Lightning II, might not be ready to fill the vacancies in carrier air wings. They also worried that the exiting fighters would wear out quicker than planned. Roughead said he doesn?t know if the Navy would buy the existing E- or F-variants of the venerable fighter or if planners would be interested in a so-called ?4.75 generation Hornet? with improved avionics that manufacturer Boeing has mentioned as an option for some defense clients.

?We?re still a ways away from all that,? Winter said.

The Navy is to be just one of many customers for the Lockheed Martin-built F-35, which also will be manufactured in two other versions for the Air Force and Marine Corps, as well as export versions for several countries, including the United Kingdom, Australia and Canada. But it isn?t the first future client to consider buying a batch of new Super Hornets as a stop-gap measure in case the F-35 doesn?t enter the fleet on schedule: In 2006, Australia?s defense ministry said it wanted to buy 24 F/A-18Es or Fs to be sure it had a reliable air defense capability until its first F-35s arrived.