B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 211
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
During our preflight inspection; a thin; vertical crack was discovered in the left main wheel well forward bulkhead. Maintenance was notified. They noted that the crack was about 10 inches long and was difficult to see; due to fluids and dirt; as well as hydraulic and electrical fixtures in the area. My First Officer; who discovered the crack; stated that he has seen [multiple] such occurrences previously; all of which had required repairs prior to operating the aircraft. I had personally never heard of a problem in this area. Maintenance subsequently decided to take the aircraft out of service for repairs. My concern is that looking for cracks in this area in not highlighted as part of our normal walk around. If they are important enough to warrant immediate repair; looking for them should be emphasized to the Aircrews by verbiage in the AOM or Safety Alert.
[Report narrative contained no additional information.]
The flight crew of a Boeing 737 reported that they found a crack in the MLG wheel well bulkhead.