B737-700
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 200; Flight Crew Type 14000
Communication Breakdown; Confusion
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Ground Event / Encounter Other / Unknown
Flight Crew Returned To Departure Airport
Aircraft; Human Factors
Air return due to pirep telling us we had a 6 foot flame coming out of engine 2 on takeoff.Mid-way down the runway for takeoff; a regional aircraft 'other carrier flagged'; stated 'using the afterburners; huh?' Since we were empty (no Passengers; and not much fuel); we were accelerating quickly; and thus his comments made sense. Upon rotation; the Tower asked the regional aircraft; 'what was that you said'. To which he responded; 'looks like (Company) is using afterburners; a six-foot flame was coming out of the back of the #2 engine'. Upon reaching clean up altitude; we ran all the appropriate checklists; and returned back to ZZZ. The fire trucks were called by ATC; and they performed an inspection upon taxiing clear of the runway. We were cleared to taxi to the gate; and the event was entered in the logbook; and Maintenance and Dispatch; and the Chief Pilots were notified.The regional aircraft could have been more clear in his comments; and we could have aborted the takeoff at low speed.
Air carrier flight crew reported another carrier flight crew commented about flames exiting engine tailpipe during takeoff roll. Flight crew returned to departure airport.