Date: 201706
Local time of day: 1801-2400
Location: ZZZZ.Airport, FO
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
ATC / advisory: Tower ZZZZ
Aircraft component: Speedbrake/Spoiler
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Other / Unknown; Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Ground Event / Encounter Ground Strike - Aircraft
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Executed Go Around / Missed Approach; General Maintenance Action
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: Normal approach and landing to a very smooth touchdown. After touchdown the spoilers extended normally as I held the nose up to facilitate aerodynamic braking. The spoilers then retracted and I felt the airplane become airborne again. The pilot monitoring re-extended the spoilers. I called for a [go around] and advanced the throttles to a vertical position. The spoilers did not stow with throttle advancement and the airplane was slow to accelerate and climb. We realized the spoilers did not retract and the pilot monitoring retracted the spoilers as I continued to advance the throttles. The airplane responded and immediately started climbing. We cleaned up the aircraft and complied with the missed approach instructions. I called back to our Flight Attendants and asked if they heard or felt anything unusual and they described a rumble; which I attributed to the spoilers being extended with the throttle advancement during the [go around]. The First Officer called the tower and we were re-cleared for the approach and landing. A normal approach and landing ensued. After parking we saw the tail strike indicator was compressed and a drain mast was scraped. I made the appropriate aircraft log book entries and pulled the cockpit voice recorder circuit breaker. After our initial touchdown and spoiler deployment; the spoilers stowed on their own and the increase in lift caused the plane to become airborne again. After I elected to reject the landing and advanced the throttles the failure of the spoilers to auto stow caused me to have to increase the pitch attitude until we were able to re-stow the spoilers manually. On a normal landing; be ready for the spoilers to deploy then auto stow on their own. When executing a rejected [landing] be ready for the spoilers to fail to stow with throttle advancement. Be ready to manually stow the spoilers; if they fail to auto stow as they are designed to do; during a [go around].


Second narrative: On flap 40 landing the automatic spoiler extension took place on touchdown. Almost immediately the spoiler lever retracted. I manually extended them again as the PM but the PF had already applied back pressure to control the nose and we entered a nose high position. The PF elected a [go around]. We went airborne again and landed uneventfully. After parking we discovered the tail skid was damaged (did not damage the bulkhead) and a drain mast was scraped.


Synopsis: B737 flight crew reported experiencing automatic spoiler extension on touchdown followed quickly by automatic retraction.  A go-around was quickly called for and upon postflight flight crew noted a tail strike had occurred.