Date: 202008
Local time of day: 1201-1800
Location: ZZZ.TRACON, US
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Workload
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Almost every -800 takeoff requires more than a normal amount of back pressure to rotate. I believe that our weight and balance methods are somewhat flawed. Due to concern of a tail strike (-800) I tend to apply normal rotation back pressure and if no normal results occur then slowly apply more; and do not rotate more than 10 degrees until at least 50 ft AGL (Above Ground Level). Quite often I find myself after gear retraction trimming at least one more unit of nose up; and it is not unusual to have to add even more. This was our first leg in this aircraft. Runway X is not short; but neither a very long runway. On this leg we were 20;000 lbs below ATOG (Allowable Takeoff Gross Weight) with a reduced temp takeoff. Dispatch planned a flap 15 and honestly I can't remember if Weight and Balance had us at flap 10 or 15. Anyway it was not the usual flap 5; so I had anticipated the aircraft easily 'levitating' rather than the usual flap 5 lift off attitude.Normal back pressure produced no effect so I slowly added more until we became airborne. This aircraft had a small nose wheel shimmy and wheel noise was somewhat louder than normal (small distraction). With a positive rate I called for 'landing gear up' and at 1;000 ft began calling for flap retractions just as ATC (Air Traffic Control) switched us. Departure gave a heading and altitude turning us into the sun...eyes outside; but a normal scan inside as needed. During the first minute of flight I commented that the nose wheel snubbers seem to be very worn; as the nose wheels rotated much longer than usual. I also commented that this bird was a lot louder than most; and this would be a long flight to ZZZ1. As I scanned inside I saw that the landing gear was extended; made a verbal comment as such and immediately the First Officer retracted the gear. I called out (but too late) that we were near the max retraction speed as clean acceleration had begun. Lots of events were happening simultaneously; but I believe we were approximately five knots below the limit. At cruise altitude we went over what had occurred and believe the cause to be mainly the trim issue distraction. That caused a slow rotation in the last 1;500 ft or so of the runway. This First Officer hovered his hands near the yoke during takeoff and landing (as trained in the Air Force) so was mentally ready to take over so (I think) became overly focused on having to assist in rotation. That caused the 'landing gear up' call to 'not be heard'. My failure to insure that gear retraction was taking place (never in my four decades of flying has this happened). A noisy nose wheel inducing an additive. ATC (Air Traffic Control) most always calling us as we passed through 1;000 ft AGL; another additive. When I was commenting on the additional noise and searching for the cause saw the gear still extended I should have immediately reduced some power; pitched up while verbally stating what I was doing to ensure that we were well below gear the retraction limit speed. Instead by saying 'oh the gear is still extended' this caused the First Officer to act rather than react. We both feel assured that retraction was near the limit speed but still below. Upon landing no message was indicated on the FMS (Flight management System) as it does for flap limit or over speeds; but I'm not sure if a message is generated for gear issues?Yes; our weight and balance is tested and approved; but if it is correct then almost every -800 takeoff would not require additional nose up trim after airborne. I have seen a very small improvement as we use bag scanners; but still not up to what I believe is correct. As a Crew; what was commented on when describing the event covered the rest. I would like to know if the FMS messages for gear limit speed Exceedances.




Synopsis: B737 Flight Crew reported they forgot to retract landing gear after takeoff.