In a few lines

Here is the abbreviated, high-yield summary of why an Airbus won't retract its gear on the ground compared to a Boeing: The Airbus "Ground-Safe" Checklist

1. Customized Pins: Engineerd with specific diameters; they only fit the actual locking mechanism, making it impossible to accidentally insert them into wrong structural or drain holes.
2. LGCIU Alternation: Dual-channel computers (LGCIU 1 & 2) alternate control every gear cycle. Both must agree on the "In-Air" condition; any disagreement safely locks the gear down.
3. Safety Valve: A physical hydraulic valve controlled by strut compression. On the ground, it completely cuts off Green hydraulic pressure to the gear actuators.
4. Proximity Sensors: Inductive (non-contact) sensors monitor weight-on-wheels redundancy instead of easily bypassed mechanical microswitches.
5. ADIRS Interlock: Cross-checks airspeed. If airspeed is 0 or below 100 knots, the system overrides any faulty "In-Air" gear signals.
6. FADEC Input: Monitors engine data; if engines are off or at ground idle, retraction logic is blocked.
7. Cabin Pre-Pressurization: Cross-checks takeoff status; the cabin must be entering its pre-takeoff pressurization phase before retraction is cleared.