Date: 201907
Local time of day: 0001-0600
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Situational Awareness
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural Weight And Balance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Ground Strike - Aircraft
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: At the airport we reviewed the flight plan and weather. There was an alternate and I added 1000 lbs of fuel. The aircraft was preflighted and we briefed. The brief included taxi; terrain; engine failure/t procedures and takeoff profile. The station and ground crew were ready to close/push early. I felt as though they wanted us to push early. We did not push until 5-10 min prior push time. The takeoff data was initially rejected the GW was greater than the TOW. The First Officer entered a takeoff weight of 106.7 vice the correct weight of 160.7. Also the takeoff data was for a flaps 1 takeoff. Both engines were simultaneously started after push. The taxi is relatively short and there were only 1 or 2 aircraft waiting for takeoff. During the taxi; the before takeoff checklist was completed; the incorrect weight was not caught by the crew. We held on the taxiway for a prop aircraft to clear. We took the runway and the aircraft was given to [the First Officer]. There is an upslope [this runway]; however; I did not feel the acceleration was unusually slow. During takeoff roll the aircraft was on centerline but the runway/roll was bumpy. I called out V1; Rotate. The pilot flying initially rotated to 6 degrees at a normal rate and momentarily stopped rotation. Then the rotation continued. The pitch was recorded at 11.4 degrees and the tail strike occurred. With a positive rate the gear was raised. On the climb out I believe the pitch was high greater than 15 degrees and the airspeed was low (and decreasing). At some point during this time the stick shaker activated. I called out airspeed; [First Officer] lowered the pitch and airspeed increased. We continued climb out flying the departure; all altitude and speed constraints were met. During climb out the flight attendants contacted the flight deck and confirmed a tail strike. We continued to fly the aircraft; [after] clearing high terrain I opened the tail strike checklist in the QRH. The aircraft leveled at 19000 ft. [and] was pressurized. We coordinated with ATC for a descent first to 12000; then 10000 ft. and eventually 9000 ft. At 9000 ft. via the checklist we set the outflow valve to manual. We held as shown on the approach charts. We held to burn fuel to the max limit landing weight. We talked and decided not to landed overweight and risk structural damage. We held for over 2 hours. ATC; the company/dispatch; flight attendants and passengers were notified of our situation and intended return to [departure airport]. The aircraft landed (flaps 40 brakes 3) without further incident. The passengers were boarded off the aircraft and handled by station personnel.




Synopsis: B737-800 Captain reported a tail strike occurred on takeoff when the First Officer entered an incorrect takeoff weight that was not caught by either pilot.