Tuesday, November 22, 2011

The Bantam X-Plane

For the next few weeks, the Tuesday mid-week updates will feature old-style PR photos that were released to newspapers. In the years before the digital revolution, newspapers primarily received their black and white photos via wireservices. Wirephotos long pre-dated fax machines, but used the same concept, line-by-line scans transmitted over telephone lines (a fascinating 1937 article in Popular Mechanics on how wirephotos work can be found here). Newspapers typically then filed away 8x10 prints for possible future use. With the arrival of the digital age, some of these have been filtering out into the collector's world, and the MojaveWest archive has been able acquire some.

One of the "forgotten" X-planes from the late 1940s was the Northrop X-4 Bantam, of which two airframes were built. Our photo shows the second aircraft, 46-677, on its maiden flight at Edwards. The photo still has the "ditto" caption taped to the back (for the younger generations who read this, "dittos" were a pre-photo copy means of reproduction...and the smell of ditto fluid is one of those staples from when I attended elementary school). The caption read:

"First Flight of the Northrop X-4, star performer in one of the Air Force's secret projects at Edwards Air Force Base, shows the small Flying Wing-type research airplane streaking over the California desert on a test flight. Northrop pilot Charles Tucker has flown the X-4 repeatedly during the past several months in a test program intended to explore flight characteristics of the high sub-sonic zone. The fourth in a series of 'X' ships ordered by the Air Force, the X-4 will continue research pioneered by the Bell X-1, the first airplane to fly faster than the speed of sound. One of the smallest airplanes ever built for the Air Force, the X-4 measures approximately 25 feet from wing tip to wing tip. The X-4 is patterned after the big Northrop Flying Wing bombers. A single pod houses the pilot and elaborate instrumentation. The unusual tail consists only of a vertical stabilizer and rudder. There is no horizontal stabilizer or elevator assembly. 'Elevons', developed by Northrop for use on the Flying Wings, serve as both elevators and ailerons."

The first X-4, 46-676, took its maiden flight on December 15, 1948, but had a really troubled flight test program, being plagued by seemingly unending technical problems. The second aircraft, 46-677 took to the air in mid-1949 (the photo and caption are undated). When Northrop had completed the initial handling qualities testing and turned the aircraft over to the Air Force in February 1950, the first aircraft was permanently grounded, and was cannibalized for parts to support the second one.

The goal of the program was to evaluate the characteristics of a flying wing's reaction to transonic speeds, and above all else, the X-4 program proved that a flying wing with analog flight controls did not have ideal handling qualities. The Bantam experienced continual pitch oscillations (porpoising) as it approached the speed of sound, and there was nothing the pilot could do to dampen it. In fact, engineers would not be able to overcome these issues until the advent of digital fly-by-wire control, which would allow a computer to fly the plane, leading to the current rash of flying wing designs, including the B-2 Spirit and the X-47B N-UCAS.

Both X-4s survived their era, however. 677 resides at the Air Force museum in Dayton Ohio, and 676 is currently being restored at the Air Force Flight Test museum at Edwards AFB.

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