category helicopter has 17 models

0, m1303	1, m1305	2, m1307	3, m1309
4, m1311	5, m1313	6, m1315	7, m1317
8, m1319	9, m1321	10, m1323	11, m1325
12, m1327	13, m1329	14, m1331	15, m1333
16, m1335