The F-4C Phantom II
Posted on December 10, 2009
The McDonnell F-4 Phantom II was the West’s premier Cold War fighter during the 1960s and most of the 1970s. This big Mach 2 fighter was flown by all three U.S. services, providing all-weather interception, air superiority, bomber escort, tactical bombing, deep interdiction, reconnaissance, and SAM suppression services. Vietnam was its first war; its final combat deployment came enforcing the Iraq no-fly zone in 1996. During its long production life, 5,195 were built—the most of any U.S. supersonic fighter. The F-4 was used by many other Western countries in combat, especially by the Israelis. The Phantom II was enormously fast, able to exceed Mach 2 in level flight. It also had a spectacular rate of climb. In its first two years, it set many speed, altitude, and climb records. One record was a flight from Los Angeles to New York in only two hours and forty-nine minutes. In Vietnam, the F-4 was used most heavily as a tactical bomber. It could carry an amazing 16,000 pounds of bombs. Unfortunately, bombing usually meant flying through small arms fire, flak, SAMs, and other ground fire. Of the 585 Phantom IIs lost in the war, most were lost to ground fire.
As an escort and air superiority fighter, the F-4 was only moderately successful in Vietnam. It’s main opponent there was the MiG-21. The Phantom II was twice as big as the MiG-21 and had two and a half times the power , but the small MiG-21 was almost as fast and considerably more nimble. F-4 crews claimed 164.5 MiG kills in Vietnam, and its final tally over its life was 280 air kills. However, its kill-to-loss ratio in Vietnam was far from spectacular—only about 2:1. Late in the war, the Navy created its Top Gun program to improve air combat training. Randy Cunningham, one of America’s only two front-seat F-4 aces, was a graduate of Top Gun. Later models also got an internal gun and better missiles, making them inherently better dogfighters.
On Display at Pacific Aviation Museum
This Phantom II is an F-4C, which was the first version of the Phantom II flown by the Air Force. It was built in August 1965 with serial number 64-792. A year later, it moved to Cam Ranh Bay with the 12th Tactical Fighter Wing’s 559th Tactical Fighter Squadron (the Billy Goats.) The 792’s aircraft commander late in the war, Captain Frederick W. Siebert, named her Smoothie. Although hit by ground fire four times, Smoothie survived the war. Unfortunately, four months before the wing was deactivated, Capt. Siebert died while flying another of the squadron’s F-4Cs in a close support mission, Captain Siebert ran into heavy ground fire, and his aircraft exploded in a fireball.
Why Does It Look Weird?
The first reaction of most people who first see a Phantom II is, “Why is it so weird?” The wing tips and horizontal stabilizers look broken, and the bird has a bulbous nose. Initially, the F-4 design had none of this. However, prototypes soon found instability both near the speed of sound and at Mach 2—the two ends of the Phantom II’s supersonic speed range. In both cases, the aircraft would pitch up and put the pilot in danger of losing control. To solve the pitch-up near Mach 1, the wing’s cord (front-to-back length) had to be lengthened. In addition, the wing needed a 3 degree dihedral (upward slant) for horizontal stability. Rather than redesigning the entire wing, which would have repercussions for the design of the landing gear and would have been expensive because changing the titanium inner-wing design would be very complex, McDonnell only changed the outer folding part of the wing. This required a 12 degree dihedral on the outer wing. In addition, the cord of the outer segment was increased by 10% giving the wing a saw tooth. Near Mach 2, a different problem occurred: The wing’s wind flow partially covered the slab horizontal stabilizer. Rather than move the stabilizer, McDonnell again chose a simpler solution—to give the tail a 23 degree anhedral (downward slope) to get it in clean air.
Up and Straight Ahead
To fly as fast as possible, the Phantom II itself became a streamline missile. Radar was its eyes, and while visibility straight was good, there was absolutely no rearward visibility, even with cockpit rear-view mirrors. “Checking 6” is not a concern for a bomber interceptor. In other roles, however, poor visibility to the back was a critical flaw.
To intercept distant bombers, the F-4 needed a very sophisticated interception and weapons radar system. This was the Hughes AN/APQ-50. The complexity of this system required a second crew member to control the radar and weapons. The Navy called the front-seater a naval aviator and the back-seater a naval flight officer (NFO), who was the radar intercept operator or RIO. The Air Force called the front-seater a pilot and the back-seater a weapons system operator (WSO), pronounced “wizzo.” Having a second pair of eyes proved invaluable in dog fighting. The crew worked as a team, and when they made a kill, both received credit for the kill. In Vietnam, the Air Force had three F-4 Aces, two of which were back-seaters. In the Navy, a single front-seat/back-seat pair made Ace.
To go fast, the F-4 needed massively powerful engines. This came in the form of the J79-GE turbojet engine. The versions of this engine used in early Phantoms had 10,900 pounds of thrust at military power and 17,000 pounds of thrust in afterburner. The Navy prefers two-engine aircraft for survivability, so the Phantom II had all the thrust it needed to reach high altitude and dash to its target at blinding speeds. However, these engines did have a major problem. At military power, they left a trail of smoke that could be seen 30 miles away. This, along with the F-4’s large size, meant that in dogfights, the Phantom II was nearly always seen first. This is a recipe for disaster in the air superiority role, especially against small MiGs.
For its interceptor role, the F-4 needed long-distance radar missiles. This came in the form of the AIM-7 Sparrow. The Sparrow was a semi-active radar homing (SARH) missile with a range of up to 25 miles. In semi-active radar homing, the fighter has to keep illuminating the target with its radar. The missile reads radar reflections and uses these reflections to find the target. For closer-in fighting, the F-4 needed a heat seeker. This came in the form of the AIM-9 Sidewinder. These missiles could hit targets up to 2.6 miles away, at least in theory. Sadly, neither missile did well in Vietnam. Phantoms fired 612 Sparrows during the war. These missiles only downed 56 MiGs—a kill rate of only 9%. The Sidewinders did only a little better, with 187 launches and only 29 kills—a kill rate of 16%. In fact, 56% of the Sidewinders failed to guide at all. The Air Force temporarily used its own heat seeker, the Falcon. This was no better than the Sidewinder. The miserable performance of the Sparrow was due at least in part to the way it was used. The AIM-7 weapons system assumed that the Phantom II would be fighting straight and level at the attacker and could illuminate the target with radar during the missile’s entire flight. In dog fighting, this rarely happened. F-4 pilots usually had to shoot in bore-sight mode, which was much less accurate. Even the way missiles were selected assumed an unhurried launch process. The missiles were selected by a switch low on the instrument panel. To select AIM-7s, AIM-9s, or to cycle through the AIM-9s to find the one with the best tone, the pilot often had to take his eyes off his quarry. The Navy saw no need for a gun in interceptors, so the F-4 became a gunless fighter. Even in early models, a gun pod could be added, but Phantom IIs did not have the predictive gun sights needed to use these pods effectively. Even the F-105 fighter bomber had an internal 20 mm cannon, and these lumbering attack aircraft managed to kill 23 MiGs with gun fire. Not until the F-4E late in the war did the Air Force get an internal gun and good sights. Fortunately, Phantoms had few limits in the close air support, attack, and interdiction missions. The big Phantom II could carry over eight tons of bombs, rockets, missiles, and guns , and it could carry almost any bomb in the inventory. Fortunately, its main role in Vietnam was as a bomb truck. Post by Ray Panko