PM reinforcement in May 1942 is a problem most players deal with.
C-47 are very usedul for troop transport, but will leave behing radars, bulldozers, tanks and heavy guns. Rather logical.
On a side note, C-47 are not very useful to transport supplies. Better send a FT TF or a lonely transports (as has been said, it won't be attacked by Rabaul-based bombers). C-47 don't bring much and op losses may be heavy.
Bulldozers (engineers vehicles) can be carried by FT TF (try to imagine a bulldozer being loaded on a DD and then unloaded in a primitive port, or even a beach.... of, now forget that. It could be done in the game) so you can combine C647 and FT TF to bring a full ENG unit to PM.
About FT TF to PM, use a slow ship (speed 19-20) in your TF from Ciarns, or send fast ones (DD and cruisers) from Townsville. If all you ships have speed of 30 or so on, they will leave Cairns and arrive in daylight off PM and get blasted by the Betties and Nells of Rabaul. FT TF arrive at night in dangerous places, but I think PM is supposed to be a rear area in games terms in May 1942. At least not dangerous enough to take care of IJN bombers.
As for base expansion, PM airfield is big enough at the start of the game. I rather build fortications, that are more needed as the prime invasion target of the IJN is PM. If you don't build fortification but expand the airfield, you will just give the IJN a bigger airfield.
To have a quick base expansion, you need supplies (4 times the minimum level) and support units. In the base screen, in the low left corner, you have the number of support points needed and available (under the same things for aviation support). You should have more than the number needed. HQ units are there to provide this kind of support.
You can overdo the base thing as well-especially the Japanese player. Some players start building up everything they can. However, you do not want to build up a base that you cannot protect. Eventually, the Allies will be on the offensive and you do not want to leave the bases that the can easily grab and exploit.
It is a rare treat for the Japanese player to be able to use 300 planes at one base. Plane and base unit limitations prevent this. Why should you build that base up to level 8 or 9 when the Allies can then take it from you and shortly begin flying 450 planes out of that captured base?
Remember, at the point when the Japanese player is on the defensive, he will be playing for time. Make the Allies work for everything.
Crsutton, I disagree here. It's useless to overbuild the frontline bases, especially Port Moresby, but you have to build at maximum sizes the rear bases, esp the ports. A full-built Wewak base is worth 1350 points and is a long way from Brisbane to be taken by the Allied player.
As for the base support, the IJN may have two super-bases at any time. If a base has more than 250 aviation supports, it may support an infinite number of planes. And the IJN has two big base forces, combined with three 40-pts one, you will have two super-bases. I use one for training and the other for operations. In this case, having an AF Size 9 in Lunga and Dobadura is useful.