3-number code for labelling helicopters??

[Kulwin Park]

Why is it that most manufacturers use a 3-letter/number code for labelling their range of products??

E.g. Bell 412, 407, 427, 429, 204, 214, etc....
Eurocopter 350, 355, 120, 130, 135, 145, 155, 365, etc...
MD 500, 520, 600, 900, 902, etc...
Schwiezer 269, 300, 333, etc...
Augusta 109, 119, 139, 169, etc...
Cessna, 152, 172, 182, 210, 401, 414, 510, 550 etc...
Boeing 707, 717, 727, 737, 747, 757, 777, etc...
Airbus 310, 320, 330, 380, etc...
Dornier 128, 228, 328 etc...
Socata 700, 750, 850, etc...
Air Tractor 301, 401, 501, 701, 801 etc...
Gulfstream 150, 200, 300, 500, 550 etc...

and many others! They must be about to run out of 3 number codes soon

Just an ironic and wondering thought?

Cheers, KP

[Noiseboy]

For EC it denotes civil (1) or military (7) max weight rounded up and then single engine (0) or multi (5)

so EC120 is civil, between 1000 - 2000kg AUW and single engine.

EC145 civil 3-4k kg and multi engine

the EC225 is 1-civil, up to 12 ton And multi engine, so becomes 225 etc.

[Wizzard]

the EC225 is 1-civil

?????

Am I missing something here?

[Noiseboy]

it would be EC1125, but they add the 1's to keep to 3 digits...

[212man]

EC Mil is 6 not 7.

[212man]

Correct!

[Bravo73]

re 6 or 7: it's actually a bit simpler than that. Just add 5 to the first digit for a military version. So EC135 becomes the EC635, the EC225 becomes the EC725 etc etc.