Overview
ISO 1466:1973 - Lever-operated manual switches for aircraft - Performance requirements defines performance, construction and test requirements for single-hole fixing, lever-operated manual switches used in aircraft electrical systems. The standard covers two classes of switches: Class 1 (sealed - high altitude/temperature use) and Class 2 (sealed only at lever entry - lower altitude/temperature use), and applies to nominal 28 V d.c. and 115/200 V three‑phase, 400 Hz a.c. systems. It specifies dimensions, operation, electrical ratings, environmental performance, type and production tests, marking and declarations.
Key Topics and technical requirements
- Design & dimensions
- Single-hole mounting per ISO/R 493; lever movement in a plane at right angles to the panel.
- Terminations by screws (M4 x 0.7 or No.6 UNC) able to accept two crimped tag‑type terminations.
- Classes & environmental limits
- Class 1: suitable up to 21 400 m altitude and −40 to +70 °C (resists −65 °C storage).
- Class 2: suitable up to 6 100 m (occasional use to 18 300 m) and −20 to +55 °C (resists −40 °C storage).
- Operation & mechanical
- Positive lever action; angular travel nominally 18–23° from centre with ±2° tolerance.
- Operating force declared by manufacturer; nominal force between 4.5 N and 45 N (max not > 100% above min).
- Lever must resist 90 N steady force without damage; locking and release forces defined.
- Electrical ratings
- Suitable for 28 V d.c. and 115/200 V, 400 Hz a.c.; must operate down to 4 V.
- Nominal current ratings include 15 A resistive, 10 A inductive, lamp-load ratings (7.5 A at 28 V; 2.5 A at 200 V).
- Inductive load characteristics specified (e.g., 28 V d.c. - 10 A, 40 mH).
- Tests & performance
- Type and production tests: mechanical strength, operating forces, endurance (50 000+ cycles electrical, 100 000 mechanical cycles for endurance subtests), insulation and high-voltage tests (1 500 V r.m.s.), voltage drop limits (≤100 mV normally; ≤150 mV in some checks), insulation resistance (≥100 MΩ after HV test).
- Temperature rise limits for accessible parts and conductors; sealing and resistance to environmental factors including vibration and climatic conditions.
Applications - who uses this standard
- Aircraft component manufacturers and electrical switch designers (design verification and acceptance).
- Avionics engineers and systems integrators selecting panel switches for cockpit and equipment panels.
- Certification authorities and approvals bodies for type testing and compliance evidence.
- Maintenance, repair and overhaul (MRO) organisations specifying replacement parts that meet aircraft performance requirements.
Related standards
- ISO/R 493 - Dimensions for single‑hole mounting, lever‑operated switches for aircraft.
- ISO 1540 - Aircraft electrical power systems - Characteristics.
- ISO documents on aircraft environmental and operational conditions (referenced for climatic and vibration tests).
Keywords: ISO 1466:1973, lever-operated manual switches, aircraft switches, performance requirements, electrical ratings, environmental tests, type tests, aviation components.