Boeing 747 nose-dives over North Sea after ice-induced electrical failure
A Boeing 747 departing Heathrow for Hong Kong suffered an electrical fault that caused the aircraft to nose-down, but it landed safely at Amsterdam Schiphol.
During a flight from London Heathrow to Hong Kong International Airport, a Boeing 747-433 experienced water and ice entering its environmental system, which froze the pitot-tube heating elements. The loss of electrical buses caused numerous system warnings and a loss of accurate airspeed data, prompting the crew to issue a PAN alert and begin a diversion. As the aircraft entered icing conditions, the autopilot kept the nose pointed down to increase indicated speed, reaching a 7.6° nose-down pitch and a descent rate of 6,240 ft/min.
Once the plane exited the ice, correct airspeed was restored and the autopilot pitched up, ending an 18-kt overspeed. The jet subsequently landed without injury at Amsterdam Airport Schiphol. The Air Accidents Investigation Branch released its findings and issued four safety recommendations, including adding a fiberglass reinforcing overcoat to prevent similar water ingress.
Why it matters
The incident highlights vulnerabilities in aircraft heating systems that can lead to dangerous flight-control failures.
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