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Air Chief Marshal Sir Alasdair McKay Sinclair Steedman , GCB , CBE , DFC ( 29 January 1922 – 2 January 1992 ) was a senior commander in the Royal Air Force .
 Alasdair, Steedman, Royal Air Force
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Alasdair, Steedman, Royal Air Force