document: A U.S. Air Force F-111 fighter-bomber crashed today in Saudi Arabia , killing both crew members , U.S. military officials reported . It was the fourth American aircraft to crash in three days among those deployed to this kingdom for Operation Desert Shield . Eight Marines are missing in the crash of two helicopters in the northern Arabian Sea on Monday . An Air Force F-4 reconnaissance jet also went down that day , killing both crew members . Lt. Cmdr. J.D. van Sickle , a military spokesman , said the F-111 crashed in the `` southern Arabian peninsula '' while on a training mission and that the incident was under investigation . The names of the flyers were withheld pending notification of next of kin . The aircraft was attached the 48th Tactical Fighter Wing based at RAF Lakenheath Air Base in Britain . The wing was sent to Turkey as U.S. forces massed in the region in response to Iraq 's Aug. 2 takeover of Kuwait . Today 's crash brought to at least nine the number of Americans killed in the Persian Gulf region since Operation Desert Shield began . The eight Marines aboard the two UH-1 Huey helicopters that vanished Monday are still officially listed as missing . In addition to those killed in Saudi Arabia , 13 other Air Force personnel were killed in a crash of a C-5 jet cargo plane in Germany . That aircraft was ferrying supplies and equipment to the Saudi peninsula . Officials said the F-111 crashed at dawn . The aircraft was an F-model , the latest version of the 23-year-old swing-wing jet that first saw action in Vietnam . The F-model has more powerful engines , and state-of-the-art equipment to operate against enemy targets at night . The plane can carry up to 12 tons of bombs and missiles and has a crew of two , a pilot and a weapons systems officer .
extractive_keyphrases: crash saudi arabia crew members operation desert shield
abstractive_keyphrases: u.s. air force f-111 fighter-bomber f-model