79088
The aircraft 's development was impeded by the unreliability of its Maybach HS engines , and when it was eventually accepted for military service , it was only in a training role .
 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