One way is to make a functional hatch where the rider scale has one.

In my 33% Extra 230, I made such a hatch on the foredeck where the 1:1 has a service access. Being a scale effort, I used piano hinge material and screws like the prototype.

Only have the one old black and white photo, so what you cannot see is that under the hatch is a pivoting bracket which holds three barrel-type 2.5 mm. barrel type power receptacles to charge the three on-board batteries, and in the bottom of the compartment are two [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXD745&P=7]of these [/link]for filling/emptying the fuel and smoke oil tanks. The power connectors are the same as are used for the charge connectors on most transmitters.