B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 152; Flight Crew Total 3096; Flight Crew Type 3096
Deviation / Discrepancy - Procedural Other / Unknown
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem
Aircraft; Airport
I just think this is worth reporting because in nearly 16 years on the 737 I have never seen the aircraft do this before and had just heard the same story from a different FO (First Officer) about another high altitude airport. Initially we were looking at an intersection departure; bleeds off; but we ended up almost 3000 pounds lighter than planned.  We ended up Flaps 5; bleeds on from the intersection with a reduced power of 98.9 (max 100.7).  Winds were 200 at 16 kts with a gust.  I believe it was less than 20 kts.  We elected to use the reduced setting.  Aircraft accelerated normally with no airspeed deviations. V1 145; VR 146.  FO noted groundspeed 180 kts near the end of rotation.I usually rotate to about 5 deg; hesitate and let the aircraft break ground then continue the rotation.  The aircraft did not break ground until somewhere between 7 and 7.5 degrees.  Once we broke ground; it did not climb. As I felt the end of the runway was getting too close; I continued the rotation to about 10 degrees.  The aircraft recorder recorded 9.8 departure pitch similar to what I thought I did.  That was when the aircraft started climbing.The FO and I discussed this at some length and felt we did everything correctly.  He also said he noted nothing abnormal with the departure; power setting (it actually settled on 99.1- 02 above reduced) or any part of the takeoff roll except that he noted I kept pulling back farther and farther on the yoke and the aircraft was not climbing. Although we are aware of no mistakes we made on this takeoff; it is worth noting that had the aircraft not started climbing within a very short time after it did; I probably would have been firewalling the throttles and risking a tail strike with increased pitch.
During takeoff roll at a high-altitude airport; B-737 crew experienced an abnormally slow start of the aircraft climb after rotation. Crew felt that it took more nose up pitch than normal for the aircraft to break ground.