A United Airlines flight 2498 experienced a tail strike while landing at George Bush Houston Intercontinental Airport (IAH), Houston, Texas. The flight was a regularly scheduled domestic passenger flight from Phoenix Sky Harbor Airport (PHX), Phoenix, Arizona to IAH. The flight crew statements and flight data showed a stable approach to the landing flare. The first officer was pilot flying and stated he began the flare slightly late. Both crewmembers stated the touchdown was firm with a slight ?nose-high? bounce. The flight crew was not aware the airplane?s tail had impacted the runway until the ground crew at the gate notified them. Flight data showed that the airplane touched down on the runway with a 6.5-degree nose-up attitude and vertical acceleration of 1.87g. The speed brakes deployed two seconds after the initial touchdown. At the same time, the aircraft became airborne again and the nose began to lower. Two seconds later, as the speed brakes retracted, the airplane?s pitch began to increase, and the airplane touched down a second time with pitch of 7.2 degrees and a vertical acceleration of about 2.87g. The airplane became airborne for a 3rd time for about a second before it touched down for the final time. The nose was lowered to the ground, and speed brakes were extended again. Post-accident assessment of the aircraft revealed substantial damage to the auxiliary power unit (APU) firewall bulkhead that occurred as a result of the aircraft?s aft fuselage?s contact with the runway.A United Airlines flight 2498 experienced a tail strike while landing at George Bush Houston Intercontinental Airport (IAH), Houston, Texas. The flight was a regularly scheduled domestic passenger flight from Phoenix Sky Harbor Airport (PHX), Phoenix, Arizona to IAH. The flight crew statements and flight data showed a stable approach to the landing flare. The first officer was pilot flying and stated he began the flare slightly late. Both crewmembers stated the touchdown was firm with a slight ?nose-high? bounce. The flight crew was not aware the airplane?s tail had impacted the runway until the ground crew at the gate notified them. Flight data showed that the airplane touched down on the runway with a 6.5-degree nose-up attitude and vertical acceleration of 1.87g. The speed brakes deployed two seconds after the initial touchdown. At the same time, the aircraft became airborne again and the nose began to lower. Two seconds later, as the speed brakes retracted, the airplane?s pitch began to increase, and the airplane touched down a second time with pitch of 7.2 degrees and a vertical acceleration of about 2.87g. The airplane became airborne for a 3rd time for about a second before it touched down for the final time. The nose was lowered to the ground, and speed brakes were extended again. Post-accident assessment of the aircraft revealed substantial damage to the auxiliary power unit (APU) firewall bulkhead that occurred as a result of the aircraft?s aft fuselage?s contact with the runway.