DCA09FA004

United Airlines flight 1449, an Airbus A320, experienced a tailstrike on landing. Substantial damage occurred to the underbelly and aft bulkhead area. There were no injuries among the crew or passengers. According to the pilots, the approach was stabilized, on speed and on glide path, until the aircraft descended below 100 feet above the ground (AGL). Then, the airspeed began to slow below the approach speed of 141 knots, and the aircraft pitch attitude increased. At about 100 feet above the field elevation, the first officer pulled the thrust levers to idle. Shortly thereafter, the airspeed decreased to about 10 knots below approach speed. The first officer stated that he felt a “sense of ground rush” during the flare at about 70 feet and he increased back pressure on the side-stick to arrest the sink rate. The airplane touched down with a nose up pitch attitude of 12.3 degrees with the main landing gear compressed. The tail strike pitch limit at touchdown with the main landing gear compressed is 11.9 degrees nose up.

HISTORY OF FLIGHT On October 20, 2008, at approximately 1242 Mountain Standard Time, a United Airlines Airbus A320 operating as a regularly scheduled passenger flight number 1449 from Denver, Colorado, to Phoenix, Arizona, experienced a tailstrike on landing on runway 8 at Phoenix Sky Harbor International Airport (PHX). The airplane, which was being operated under 14 CFR Part 121, experienced substantial damage to the underbelly and aft bulkhead area. There were no injuries among the crew of 7 or the 156 passengers. The accident crew departed Denver International Airport (DEN), Denver, Colorado, about 1147 mst, bound for PHX, on the first flight of a three day trip. The first officer was the flying pilot. According to interviews, during the flight the accident crew discussed the recent change in United Airlines standard operating procedure to the use of flaps 3 for landing. During the descent, the first officer conducted an approach briefing for landing on runway 8. The brief was for a visual approach to runway 8 using flaps 3 for landing. Weather conditions at the airport were VMC with wind reported to be from the southeast at approximately 4-6 knots. About the time the air traffic controller issued a turn for the base leg, the first officer stated that he turned off the auto pilot and auto thrust. As the aircraft descended below 100 feet above the ground (AGL), the airspeed began to slow below the calculated V approach speed (VAPP) of 141 knots, and the aircraft pitch attitude was increasing. According to the pilots, the approach was stabilized, on speed and on glide path, until about 100 feet above field elevation. At about 100 feet above the field elevation, the first officer pulled the thrust levers to idle. shortly thereafter, the airspeed decreased to about 10 knots below VAPP. The first officer stated that he felt a “sense of ground rush” during the flare at about 70 feet and he increased back pressure on the side-stick to arrest the sink rate. After landing, the cabin crew notified the flight deck crew that they believed they had hit the tail on landing. During his post flight inspection, the first officer confirmed that this had occurred. INJURIES TO PERSONS None DAMAGE TO AIRCRAFT The aircraft suffered skin damage for a distance of 6 frames beginning at the aft pressure bulkhead (frame 70) and moving forward. In addition, damage was found to the pressure bulkhead web and structural stiffeners. PERSONNEL INFORMATION The accident flight crew consisted of a captain, first officer, and four cabin crewmembers. The captain and first officer had flown together previously. However, the accident flight was the first flight of a three day trip and the first flight they had flown together in more than one month. Both crewmembers were current and qualified under United Airlines and FAA requirements. AIRCRAFT INFORMATION No preaccident mechanical anomalies were evident. The following information was obtained from the United Airlines weightmanifest: Basic Operating Weight 97,852 lbs. Passenger Weight 29,285 lbs. Baggage & Cargo 4,360 lbs. Zero Fuel Weight 131,497 lbs. Fuel 14,300 lbs. Ramp Weight 145,797 lbs. Taxi Fuel Burn 400 lbs. Takeoff Weight 145,397 lbs. Maximum Takeoff Weight Allowed 151,100 lbs. Landing Weight Est 136,400 lbs. Maximum Landing Weight Allowed 142,200 lbs. The landing center of gravity (CG) and weight were within limits for landing on runway 8 at PHX. TESTS AND RESEARCH According to flight data obtained from the airplane digital flight data recorder (DFDR), the airplane touched down with a nose up pitch attitude of 12.3 degrees with the main landing gear compressed. According to Airbus, the tail strike pitch limit at touchdown with the main landing gear compressed is 11.9 degrees nose up.