133365
Tests showed that the aircraft was unstable , with numerous changes being made to the tail surfaces to try and rectify the problems before the prototype was badly damaged in a forced landing caused by an engine failure on 17 February 1938 .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None