B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 226; Flight Crew Type 1100
Other / Unknown; Distraction
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Air Traffic Control Issued New Clearance; Aircraft Equipment Problem Dissipated; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport
Aircraft; Human Factors
Departure and climb out was normal. A maximum power takeoff was performed to get above gusty winds. Cruising at FL380; the A FA called to let us know they smelled a faint burning rubber odor around Row 7-8 on the captain's side. We reviewed the Smoke; Fumes; Odors Checklist and agreed that we would hold off on running the complete checklist until the FAs had a chance to investigate or we smelled any odor. We analyzed divert options and identified ZZZ1 as a potential divert if any smoke; fumes; or fire were discovered. We notified ARTCC; notified Dispatch of our plan; and requested Maintenance. We got an update from the FAs who told us that the smell was dissipating and they had searched bins; computers; etc.; and found no sign of smoke or fire. Based on this assessment; we elected to return to ZZZ. We briefed and accomplished the Divert Checklist; reviewed the arrivals and approach; and determined our plan and possible contingencies after landing. We updated Passengers and Flight Attendants on the plan. During this update; the FAs said they could no longer smell any odor. When time permitted during descent; we reviewed the Smoke; Fumes; Odors Checklist again and accomplished the first page of items; then reprioritized in preparation for the approach and landing. The Captain accomplished a visual approach; taxied clear of the runway; and had fire/rescue perform an inspection of the aircraft. Their inspection was clear and we continued to parking uneventfully.We should have prioritized a complete review of the applicable QRH checklists before becoming distracted by the divert and contingencies.
B737 First Officer was informed by the Lead Flight Attendant that a faint; burnt rubber smell had been detected in the forward cabin while at FL380. Although the smell becomes undetectable; the crew elected to return to the departure airport.