The first phase late on the 26th consisted Cause_to_be_included of air strikes by torpedo bombers from the British aircraft carrier , which disabled Destroying `` Bismarck '' s steering gear , jamming her rudders in a turning position and preventing Preventing_or_letting her escape .

Investigators with the Civil Aeronautics Authority , a predecessor organization of both the FAA and the NTSB , determined Deciding that both vertical fins and both rudders were missing from the twin-tailed aircraft .

The Department ordered Request that the rudders of all Super Electras be modified Change so as to eliminate Removing the possibility that flutter Motion would cause Causation an in-flight break-up Destroying .