Northrop Corp. lost 780 secret Stealth documents.

As reported by The Times last month, an investigation requested by the House Energy and Commerce subcommittee on oversight and investigations determined that Northrop’s Pico Rivera plant has been unable to locate a large number of documents, but the company already has tightened its security system. A General Accounting Office investigation, requested by the subcommittee, found that out of more than 2.7 million classified documents at the Pico Rivera plant, 1,822 have been reported missing since 1983. Of those, 780 were unaccounted for. The report said many of the missing documents may have been destroyed without proper record-keeping. The report, however, generally commended the contractor for improving procedures.