HISTORY OF FLIGHT On December 14, 2005, at 0230 central standard time, a Boeing 727-2S2F, N213FE, Flight 1472, registered to and operated by Federal Express Corporation, collided with a tug during pushback at Memphis International Airport, Memphis, Tennessee. The scheduled domestic/international cargo flight was operating under the provisions of Title 14 CFR Part 121, with an instrument flight plan filed. Visual meteorological conditions prevailed at the time of the accident. The airplane was substantially damaged. The airline transport rated pilot-in-command (PIC), airline transport rated first officer, and airline transport rated flight engineer reported no injuries. The tug driver received serious injuries. The flight was originating from the Memphis International Airport, Memphis, Tennessee, on December 14, 2005 at 0230. The flight crew stated that as the number 3-engine was being started the Captain mentioned that during the initial movement the tug was out of position for a normal push back. As the airplane was being pushed back the flight crew heard, and felt a few rough jolts from the nose wheel area. When the airplane stopped moving, there was no communication from the pushback crew over the intercom. The wing-walker gave the flight crew the emergency stop signal, and the Captain set the parking brake. In an interview by an FAA inspector, the tug driver stated that the tow bar, and the tug were inspected before it was used. The tug driver felt that the both pieces of equipment were acceptable for the pushback. The tug driver stated that during the pushback they did not notice anything unusual. The tug driver stated while towing the airplane forward and looking back to align the airplane with the taxiway, she heard the wing walker yell as the airplane rolled forward, and collide with the tug. The wing-walkers stated that it was raining as the push back procedure was initiated and they noted a smell of glycol. The tug appeared to loose traction as the airplane moved passed the main landing gear chocks. The tug driver regained control of the tug, and continued the push back. The tug driver stopped the airplane and motioned the wing-walkers to reposition so that the airplane could be towed forward. As the tug operator began to tow the airplane forward the wing-walkers noticed that the airplane continued to roll forward when the tug stopped. The airplane collided with the tug, and stopped with the tug on the right underside of the airplane. The wing-walker gave the flight crew the emergency stop signal, however the airplane had already stopped. PERSONAL INFORMATION Review of personnel records revealed that the Federal Express Corporation hired the tug operator on November 1, 1991. Training records revealed that the tug operator completed the Federal Express T-300 tug-training course on February 21, 2005, and completed the Federal Express 727-100/200 pushback-training course on June 6, 2005. Further review of training records revealed that the tug driver also completed the 727 push back & tow safety course on June 6, 2005. The tug operator had no other collisions or mishaps within the last calendar year. AIRCRAFT INFORMATION The airplane is a Boeing 727-2S2F, serial No. 22935, registration No. N213FE. The airplane is registered to and operated by Federal Express Corporation Memphis, Tennessee. The airplane is equipped with three Pratt & Whitney JT8D-17 SER, 16,000 pounds of thrust engines. Maintenance records indicate the last continuous airworthiness inspection was conducted on December 2, 2005. The airplane has flown 18 hours since the last inspection and has accumulated 23,717 total airframe hours. METEOROLOGICAL INFORMATION The Memphis International Airport, 0253 surface weather observation was clouds scattered at 5,500 feet, visibility 10 miles with light rain, temperature 57 degrees Fahrenheit, dew point temperature 32 degrees Fahrenheit, wind 330 degrees at 12 knots, and altimeter 30.03. MEDICAL INFORMATION Toxicology testing of specimens from the tug driver was not preformed. WRECKAGE AND IMPACT INFORMATION Post-accident examination of the airplane revealed, that the right side of the airplane had a 5-foot tear on the underside of the belly. Further examination of the belly revealed two ribs, and five stringers were damaged. Examination of the tow bar revealed the shear pins of the plane hitch head were sheered off. The aircraft hitch was still attached to the landing gear, and the tow bar was buckled at the pushback hitch end main structure. TESTS AND RESEARCH Metallurgical examination of the shank of the pin revealed that the pin was separated in two locations. Both fractures consisted of a flat surface displaying a small crescent shape with the remaining surface displaying a grainy texture. The fracture face adjacent to the nut also displayed a small lip directly opposite to the crescent shape. The features are typical of what is termed "double shear". Review of records revealed the Flight Line Company manufactured the 1980 model tow bar, model number FLTB272. Examination of the tow bar revealed it was equipped with a 727-shear pin, part number AN5-36A. Review of records showed that the tow bar was last inspected on September 21, 2005, and the shear pin was replaced on November 30, 2005.