🔹 – Often a zone or structural reference code in an Aircraft Maintenance Manual (AMM) or Structural Repair Manual (SRM). In some ATR documentation, SR2 can indicate a fuselage section or a particular longeron/frame station.
Here’s an informative post tailored for aviation maintenance technicians, engineers, or EASA Part-66 students: sr2 ece r66 bus skin
🔹 – Not to be confused with UN ECE regulations for vehicles. In aircraft wiring/electrical bonding, ECE may stand for “Equipment Chassis Earth” or “Electrical Common Earth” in certain manufacturer wiring diagrams (especially older European designs). 🔹 – Often a zone or structural reference