H-NADU
1927-AUG-22 · Underriver, Kent, United Kingdom

KLM — Flight H-NADU

A KLM Fokker F.VIII crashed near Sevenoaks after a structural failure of the tail assembly caused the aircraft to become uncontrollable. Approximately ten minutes after departing Croydon Airport, a tensioning wire in the tail section snapped, leading to the complete separation of the rudder and tailfin. The aircraft descended into a wooded area on the St Julian's estate at Underriver, striking the crowns of trees. The flight mechanic was killed when he was crushed by one of the engines during the impact, while the pilot and seven passengers sustained injuries.

Aircraft
Fokker F.VIII
Registration
H-NADU
Phase
Cause
Souls on Board
11
Fatalities
1
Origin → Dest
Croydon Airport, United Kingdom → Waalhaven Airport, Netherlands
Report

Investigation Summary

The accident involved one of the early Fokker F.VIII twin-engine airliners, which had been in service for less than two months. While cruising toward Rotterdam, the aircraft suffered a catastrophic failure of the vertical stabilization surfaces. The investigation determined that a critical tensioning wire at the rear of the fuselage broke, which immediately compromised the structural integrity of the tail. The aerodynamic forces then tore the rudder and tailfin away from the fuselage. These components were later recovered more than one kilometer away from the main crash site. Without a rudder or vertical fin, the pilot was unable to maintain directional control, leading to the inevitable crash into the grounds of the St Julian's estate.

Final Conclusions

The crash was caused by the structural failure of a tail tensioning wire, which resulted in the loss of the rudder and tailfin in flight. The loss of these control surfaces rendered the aircraft uncontrollable.

Photographic Evidence (1)

Omschrijving: Luchtvaartramp. Politie houdt toezicht bij wrakstukken van een tweemotorig vliegtuig, een Fokker H-NADU type VIII uitgerust met Jupiter motoren, stort neer. Het stuurroer breekt af door storm en piloot Evert van Dijk zet het toestel met acht passagiers op grond in Seven Oaks nabij Croydon, Engeland. Daarna raakt hij met rechterzijde een boom waardoor mecanicien [werktuigbouwkundige] J.L.A.M. Brunklaus zijn leven verliest. Het toestel kwam vanuit Londen. Engeland, 1927.
© Unknown author Unknown author · Wikimedia Commons

Video Analysis

No video analysis linked for this case file yet.

Systems & Failure Modes

i

Tail Assembly

The vertical stabilizer (tailfin) and rudder provide directional stability and control; the failure of a tensioning wire led to the aerodynamic separation of these components.

i

Fokker F.VIII Structure

A twin-engine airliner design of the late 1920s utilizing a combination of wood, fabric, and wire tensioning for structural integrity.

Interesting Facts

  • 01The aircraft was manufactured in 1926 (construction number 4993) and had entered service with KLM on 24 June 1927.
  • 02The tailfin and rudder were found over 1 kilometer away from the main wreckage.
  • 03The aircraft was carrying 13 kilograms of mail and 144 kilograms of freight at the time of the accident.
  • 04The total damage to the aircraft was valued at 68,985.07 Dutch Guilders.

Location

Underriver, Kent, United Kingdom · 51.2560, 0.2250

ACCIDENT SITE · Coordinates taken from the entered by an editor.

Case File History

  1. New evidenceUpdated sources.
  2. New evidenceUpdated findings and sources.

Related Cases

Case ID · sevenoaks-klm-1927Last updated · Filed

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