F-16 Fighting Falcons (World Fighter Aircraft Collection)

Two California air national guard F-16 Fighting Falcons during the opening ceremony for the 2009 Riverside airshow.

Unusually for an American airshow, they're both fitted with extra fuel tanks and short-range and long-range practice missiles, however unlike at foreign airshows, flares aren't permitted during these demonstrations.

The F-16 is the workhorse of the USAF, less capable than its twin-engined brother the F-15 Eagle, but cheaper to build and operate, and therefore able to be fielded in greater numbers.

First flying in 1974, the F-16 has been a phenomenal success, going beyond its original brief as a daytime fighter to become a true multirole aircraft equally as capable doing ground attack and air-to-air combat.   It now operates with about 25 air forces around the world, and comes in a variety of configurations, including two-seater models.   It has taken part in many military operations and shot down a wide variety of other aircraft in combat.

Polikarpov I-16 fighter plane (Unusual Aircraft Collection)

The Polikarpov I-16 was a very innovative fighter which first flew at the end of 1933.   It was the first cantilevered monoplane fighter with retractable undercarriage, which greatly increased the top speed, making it the world's fastest fighter of the time.   Although some people thought it was based on the American P-26 "Peashooter", it was in fact an original design.

About 500 I-16s fought with the Republicans during the Spanish civil war, completely dominating the air until the Messerschmitt Bf 109 appeared.   When Germany invaded Russia in 1941, about two-thirds of the Russian fighter force still consisted of the I-16, even though the Russians had already realized that it was at the end of its development potential.   The I-16 was still capable of operating against the early-model Bf 109E "Emil" at low altitudes, but by 1943 it had been replaced by more modern aircraft.

P-38 Lightning and Mitsubishi Zero (World Fighter Aircraft Collection)

The Chino-based P-38 Lightning "23 Skidoo" chases the Commemorative Air Force's Mitsubishi Zero during the 2006 Arizona Skyfest held near the town of Prescott.

The Zero was Japan's main fighter throughout World War Two, and American forces made extensive use of the Lightning during thePacific War because of its long range, especially when using drop tanks like the ones visible in this photograph underneath "23 Skidoo".   An aircraft with two engines also has considerable advantages when flying over vast stretches of ocean, though flying a P-38 on only one engine is no easy matter.

Ultimately the Lightning shot down more Japanese aircraft than any other USAAF fighter, though navy and Marine Corps F6F Hellcatsdid shoot down more.

P-47 Thunderbolt (World Fighter Aircraft Collection)

The P-47 Thunderbolt was the largest and heaviest single-engined fighter of World War Two, and one of only two American fighters to use a turbo super-charger, the other being the twin-engined P-38 Lightning.

In spite of its size and weight, the Thunderbolt was a very effective fighter, able to tackle even the best German fighters of the time, like the Focke-Wulf FW 190.   Unusually for American land-based fighters of the time, the P-47 wasn't powered by an inline piston engine like the Spitfire, P-40 Warhawk or P-51 Mustang, but a radial piston engine just like the FW 190, a power source also favored by American naval fighters.   Indeed the Thunderbolt used the same R-2800 Double Wasp engine as the F6F Hellcat and F4U Corsair, though it managed to fly slightly faster than the F4U.

Red Bull Bo-105 Helicopter (Unusual Aircraft Collection)

As anyone who has seen the movie Blue Thunder can tell you, helicopters just aren't supposed to do loops!   This German-designed Bo-105 not only breaks that rule, it does all sorts of other aerobatic feats too, especially when flown on the airshow circuit as part of the Red Bull display team.

Although it's not a well-known helicopter in America, the Bo-105 has been very successful since it was certified in 1970.   Since then it has been exported to 20 different countries, where it's used for many civilian purposes as well as police and military operations.