F-16 Fighting Falcons and F-15 Eagles - fighter jets that can streak through the sky at twice the speed of sound - were among the first planes ordered deployed to the Persian Gulf region.

The F-16, a single-engine fighter with one pilot and a crew of one or two, is a small and speedy plane with a sharp nose and a single tail fin. It can cruise at 1,500 mph - twice the speed of sound, or Mach 2 - and maneuver quickly enough to put nine times the force of gravity on plane and pilot. The $34 million planes can fight other aircraft or launch missiles against targets on the ground.

The F-15, a twin-engine fighter with twin tail fins, has one pilot and a crew of one or two. Larger than the F-16, the F-15 can cruise at more than 1,800 mph - Mach 2.5. F-15s are made to control the sky, and shoot down enemy aircraft. Some models can bomb targets, as well. The $34 million planes are used to patrol the no-fly zones in Iraq.

With two aircraft carriers in the region and two others possibly on the way, the Navy could bring to the fight F-14 Tomcats and F/A-18 Hornets, which launch from the carriers.

The Tomcats, first used in 1970, are two-engine, two-man fighter jets that can dogfight and attack ground targets. The $38 million planes can carry up to 13,000 pounds of weapons and exceed Mach 2.

Hornets are two-engine fighters that can be flown with a one- or two-person crew. The $29 million planes can fly faster than Mach 1.7 and can carry cruise missiles, rockets and bombs to attack ground targets.

Also going to the Middle East are B-52 Stratofortress bombers, the Air Force's workhorse bomber for more than four decades. Each $74 million B-52 can carry up to 70,000 pounds of bombs and missiles and can fly 8,000 miles without refueling.

Two of the aircraft carriers that might be called into duty - the USS Carl Vinson and the USS Theodore Roosevelt - are the latest, Nimitz-class vessels, the largest warships in the world. Powered by nuclear reactors, they carry a crew of nearly 6,000 and can carry up to 85 aircraft. Each one costs about $4.5 billion.

One bomber that might be used is the B-1B, a long-range bomber first built to carry Cold War nuclear weapons. Its first combat use was in 1998 in support of operations against Iraq during Operation Desert Fox. The $200 million planes can carry up to 80 conventional bombs, 30 cluster bombs or 24 guided ''smart'' bombs.

The United States also could use B-2 Spirit stealth bombers and F-117A Nighthawk stealth fighters, although those units have not said they are being sent to battle.

Their radar-evading characteristics would serve limited purpose in Afghanistan, which, unlike Yugoslavia and Iraq, does not have the sort of high-tech air defenses they were built to overcome.

Three kinds of tanker planes keep fighters and bombers in the air.

The largest is the KC-10A Extender, an $88 million jet that can carry up to 356,000 pounds of fuel as well as up to 75 people and 170,000 pounds of cargo.

The more common refueling plane is the KC-135 Stratotanker, a four-engine jet that can carry up to 200,000 pounds of fuel and 83,000 pounds of cargo, with 37 passengers. First introduced in 1956, the Stratotankers cost about $40 million each.

The Air Force also uses the HC-130P/N, a propeller-driven tanker, to refuel combat and search and rescue helicopters. The $16.5 million planes can fly more than 4,000 miles at a time.

The military has several different kinds of missiles and guided bombs.

The most advanced is the SLAM-ER missile - Standoff Land Attack Missile - Expanded Response. The jet-powered cruise missiles can be launched from airplanes and fly more than 150 miles, using television or infrared cameras to help operators guide them to their targets. SLAM-ERs cost about $500,000 each.

A missile more familiar to Osama bin Laden - the prime suspect in the attacks - is the Tomahawk, a jet-powered cruise missile fired from Navy ships and submarines.

In 1998, the United States fired Tomahawks at suspected bin Laden terrorist training camps in Afghanistan after the U.S. embassy bombings in Kenya and Tanzania. Each Tomahawk - the name is a trademark of the federal government - costs about $600,000.

The cruisers and destroyers that accompany aircraft carriers are armed with Tomahawk missiles.

On the Net:

Air Force facts: http://www.af.mil/news/indexpages/fs-index.shtml

Navy facts: http://www.chinfo.navy.mil/navpalib/factfile/ffiletop.html