263,998 service difficulty reports for the Boeing 737 (all variants) across 40 systems (1998–2026).
Reported systems
| System | ATA | Reports | Share |
|---|---|---|---|
| Fuselage | ATA 53 | 113,064 | 42.8% |
| Lights | ATA 33 | 49,810 | 18.9% |
| Equipment & Furnishings | ATA 25 | 19,907 | 7.5% |
| Wings | ATA 57 | 15,205 | 5.8% |
| Stabilizers | ATA 55 | 12,197 | 4.6% |
| Doors | ATA 52 | 8,308 | 3.1% |
| Air Conditioning | ATA 21 | 7,305 | 2.8% |
| Navigation | ATA 34 | 5,432 | 2.1% |
| Engine - Turbine/Turboprop | ATA 72 | 2,955 | 1.1% |
| Flight Controls | ATA 27 | 2,828 | 1.1% |
| Communications | ATA 23 | 2,422 | 0.9% |
| Fuel | ATA 28 | 2,314 | 0.9% |
| Engine Fuel & Control | ATA 73 | 2,179 | 0.8% |
| Ice & Rain Protection | ATA 30 | 2,086 | 0.8% |
| Auto Flight | ATA 22 | 2,076 | 0.8% |
| Auxiliary Power Unit (APU) | ATA 49 | 1,927 | 0.7% |
| Landing Gear | ATA 32 | 1,820 | 0.7% |
| Fire Protection | ATA 26 | 1,749 | 0.7% |
| Electrical Power | ATA 24 | 1,559 | 0.6% |
| Windows | ATA 56 | 1,205 | 0.5% |
| Pneumatic | ATA 36 | 1,132 | 0.4% |
| Nacelles & Pylons | ATA 54 | 922 | 0.3% |
| Hydraulic Power | ATA 29 | 887 | 0.3% |
| Engine Air | ATA 75 | 815 | 0.3% |
| Engine Indicating | ATA 77 | 802 | 0.3% |
| Indicating & Recording | ATA 31 | 647 | 0.2% |
| Starting | ATA 80 | 511 | 0.2% |
| Standard Practices - Structures | ATA 51 | 370 | 0.1% |
| Water & Waste | ATA 38 | 324 | 0.1% |
| Engine Oil | ATA 79 | 290 | 0.1% |
| Ignition | ATA 74 | 268 | 0.1% |
| Engine Exhaust | ATA 78 | 230 | 0.1% |
| Oxygen | ATA 35 | 165 | 0.1% |
| Power Plant | ATA 71 | 124 | 0% |
| Engine Controls | ATA 76 | 108 | 0% |
| Placards & Markings | ATA 11 | 39 | 0% |
| Other | ATA 14 | 9 | 0% |
| Other | ATA 83 | 4 | 0% |
| Propellers | ATA 61 | 2 | 0% |
| Central Maintenance System | ATA 45 | 1 | 0% |
Report counts reflect fleet size and reporting activity, not relative safety or reliability. Source: FAA Service Difficulty Reporting System (public domain).