CREATE TABLE table_204_353 (id NUMBER, "no." NUMBER, "date/time" CLOB, "aircraft" CLOB, "foe" CLOB, "result" CLOB, "location" CLOB, "notes" CLOB)

are there any other aircraft listed besides the nieuport 17 ?
SELECT "aircraft" FROM table_204_353 WHERE "aircraft" <> 'nieuport 17'
SELECT "aircraft" FROM "table_204_353" WHERE "aircraft" <> 'nieuport 17'