The second prototype of the F-4 Phantom II was equipped with water injection and flown by CDR Lawrence E. Flint in a series of twelve ballistic zoom climbs from 50,000ft at maximum power between October and December 1959
To meet the Navy’s need for a high‑altitude interceptor capable of protecting carriers with long‑range air‑to‑air missiles, McDonnell Aircraft Company developed the F4H, later known as the F‑4 Phantom II. It first flew in 1958, and Navy and Marine Corps squadrons began receiving it in 1960. Thanks to its strong performance and adaptability, the aircraft was eventually adopted not only by the US Air Force, but also by the air forces of ten other countries, making it one of the most extensively used aircraft in aviation history.
The F‑4 made its first flight on May 27, 1958, and entered operational service in 1961. The Phantom II soon proved to be an exceptional aircraft, setting twelve world records for speed, altitude, and time to climb within only 28 months.
The twelfth production aircraft (BuNo 145311) was officially assigned to Aircraft and Engine Performance testing, which in reality focused on attempts to set world speed records. Encouraged by the impressive results of the second phase of the Navy Preliminary Evaluation (NPE) in July 1959, the Navy was eager to see the F4H‑1’s remarkable capabilities formally recognized.
Tragically, the first bid for a world altitude record—Project Top Flight—ended in disaster. During its 295th flight, the first prototype lost an engine access door while performing a high‑altitude zoom climb at over Mach 2. The resulting fire destroyed the aircraft, and company test pilot Gerald “Zeke” Huelsbeck was subjected to fatal g‑forces that trapped him in the cockpit.
Peter E. Davies, in his book Gray Ghosts, U.S. Navy and Marine Corps F‑4 Phantoms, describes how the second prototype (BuNo 142260) was fitted with water injection and flown by CDR Lawrence E. Flint in twelve ballistic zoom climbs from 50,000 feet at full power between October and December 1959. The aircraft had its radar and other nonessential equipment, including the rear seat, removed, and the engine’s rpm, fuel flow, and afterburner nozzle settings were adjusted to maximize thrust. Just before entering Edwards AFB airspace and initiating a 3.5‑g, fifty‑degree zoom climb for measurement, CDR Flint reached speeds of up to Mach 2.41.
As each vertical climb neared its peak, fuel flow was reduced to prevent overheating, and the afterburners flamed out above 65,000 feet due to lack of oxygen. In the clear, unpolluted upper atmosphere, the darkness was so deep that when Flint’s shadow fell across the instrument panel, he could no longer see the gauges. At the top of each zoom, the engines were shut down, speed dropped to roughly 45 mph, and the aircraft then descended to 45,000 feet, where the engines were restarted and the jet recovered to normal flight.
After landing, much of the aircraft’s orange paint had been scorched away by the heat generated during Flint’s low-altitude, high-speed run, and the outer windscreen panels had warped from the temperature.
On one climb, CDR Flint could not shut down the right engine near the top of the ascent until it had exceeded 120 percent rpm and the turbine outlet temperature had gone beyond the gauge’s limit. Fortunately, the engine stayed intact, though inspection later showed that up to half an inch had melted off the outer tips of each turbine blade.
The project’s maximum altitude was 98,557 feet, achieved on December 6, 1959, although this record was surpassed by a USAF F‑104C later that same year. For any potential adversary, these impressive flights dramatically showcased the new aircraft’s value as a high‑altitude interceptor.
Larry Flint, a former commander of VF‑11 “Red Rippers” during the Korean War, had been a test pilot since 1944. He later became Chief Test Conductor for the Apollo space program and managed the F‑14 Tomcat Aircrew Training Program for both the U.S. Navy and the Iranian Air Force.
Gray Ghosts, U.S. Navy and Marine Corps F-4 Phantoms is published by Schiffer Publishing and is available to order here.
Photo by U.S. Navy
