Fort Monmouth radar and T-33 sightings

September 1951. The Air Force's UFO project was called Project Grudge. Fort Monmouth, near the New Jersey coast, was an Army Signal Corps radar centre.

Monday, 10 September 1951. Late morning. A student radar operator, PFC Clark, was showing an AN/MPG-1 radar to visiting officers. He picked up a low-flying target about 12,000 yards southeast of the station, heading north. It moved faster than the automatic tracking could follow and stayed in range for about 3 minutes. Edward J. Ruppelt recorded his words: "It's going too fast for the set. That means it's going faster than a jet!"

About 25 minutes later, a T-33 jet was flying from Dover AFB, Delaware, to Mitchel AFB, New York, at 20,000 feet and 450 mph. Lt. Wilbert S. Rogers, an experienced WWII fighter pilot, was at the controls. Major Edward Ballard Jr. sat behind him. Near Point Pleasant, they saw a dull silver, flat disc-like object well below them, descending toward Sandy Hook. The pilots called it "perfectly round and flat with the center of the object being somewhat raised."

Rogers saw no "exhaust or propulsion units." Both men put it at 30 to 50 feet across. Rogers turned to intercept. The jet flew a full 360-degree descending turn, dropping to about 17,000 feet, just to keep the object in sight. It "curved in more tightly on the turn than the T-33."

By Ruppelt's account it stopped descending and hovered. Then it sped off. Rogers throttled up to 550 mph. The object still outpaced them, heading out to sea near Point Pleasant. The whole sighting lasted about two minutes.

At about 3:15 p.m., an SCR-584 radar tracked a slow target at about 93,000 feet. Ground observers saw "a silver speck in the sky." The next day, radar caught targets that climbed, levelled off, climbed again and dived.

An "Operational Immediate" teletype went to Wright-Patterson Air Force Base. Yet Maj. Gen. Charles P. Cabell, the Air Force Director of Intelligence, learned of the case from a press leak, about 18 days late. He sent Project Grudge officers to Fort Monmouth. At a Pentagon meeting, he was blunt: "I've been lied to, and lied to, and lied to. I want it to stop. I want the answer to the saucers and I want a good answer." Ruppelt ran the reorganised project from November 1951. In March 1952 it became Project Blue Book.

Lt. Henry Metscher delivered the official answer. The radar target, Ruppelt wrote, "turned out to be a 400-mile-an-hour conventional airplane," and the operator had fouled up the automatic tracking. Two balloons had gone up from Evans Signal Laboratory at 11:12 a.m. The T-33 sighting "fell apart when Metscher showed how they'd seen a balloon." Grudge Special Report No. 1 called it "probably a balloon." Blue Book later dropped the "probably."

Later researchers pushed back. Brad Sparks noted that two balloons went up but the crew saw one object. Rising at about 1,300 feet per minute, the balloons would have been near 27,000 feet by 11:35, above the jet. And a rising balloon cannot descend and circle. James E. McDonald calculated that a balloon would have looked only "about 0.6 arcminute" across, below what the eye can resolve. Kevin Randle notes that Rogers denied being fooled by a balloon.

Ruppelt told the story in his 1956 book, The Report on Unidentified Flying Objects. An Army history piece credits the case with reviving the Air Force investigation that became Blue Book. The 1951 press had its own headline: "450 MPH Jet Tails 900 MPH 'Thing' Over N.J."