Bjorn’s Corner: Aircraft Structures Part 4. Airframe Structure Fatigue.

Key Takeaways

• British Airways 787‑8 nose‑gear collapsed due to mis‑inserted safety pin
• Lufthansa 787‑9 retracted nose gear on brand‑new aircraft at Frankfurt
• Landing‑gear lever cycling can unintentionally trigger gear retraction
• Absence of locking‑pin on main gear increases reliance on sensor integrity

Pulse Analysis

Landing‑gear systems are among the most heavily engineered components on modern airliners, combining hydraulic actuation, sensor feedback, and mechanical locks to ensure safe take‑off and landing. The main gear typically incorporates a weight‑on‑wheels (WOW) sensor that tells the flight‑control computers whether the aircraft is on the ground, but many designs omit a physical locking pin, relying on the sensor’s electronic integrity. By contrast, nose‑gear assemblies often include a manual safety pin to prevent inadvertent movement when the aircraft is stationary, a redundancy that proved crucial in the British Airways incident.

The two recent events underscore how routine maintenance actions can inadvertently trigger a gear‑retraction sequence. In June 2021, a British Airways mechanic inserted the safety pin into the wrong aperture, causing the nose gear to collapse while the 787‑8 sat idle at Heathrow. Five years later, a Lufthansa 787‑9 experienced an unexpected nose‑gear retraction at Frankfurt, despite being a brand‑new aircraft. Both cases illustrate that a simple procedural slip or a design omission—such as the lack of a locking pin on the main gear—can translate into significant operational disruptions, repair costs, and safety concerns.

Industry stakeholders are now weighing procedural reforms and potential design upgrades. Airlines are tightening checklists for ground‑crew actions, emphasizing correct pin placement and sensor verification before lever cycling. Meanwhile, manufacturers are evaluating whether adding a mechanical lock to the main gear could provide an extra safety layer without compromising weight or performance. Regulators may also issue guidance to harmonize best practices across fleets, ensuring that human‑factor considerations are baked into both training and aircraft architecture. The goal is to safeguard aircraft integrity while minimizing downtime and expense, reinforcing confidence in the reliability of modern airframes.