For such an installatiion I prefer the Hitec HS 85 and normally reserve the 81's for throttle. I have a number of airplane that I have used the 85's on dual airlerons.

Remember the servos are going to get far less load than a single servo set up especially all that load producing extrainious linkage and bellcranks.

The loads on that small 25 sized Heath Parasol will be very small indeed. People tend to get into the habit in recent years of using far more servo power than needed and not every airplane is a firebreathing aerobat.

Here are photos of two of my twin engine ships using .25's and HS-85's on the airlerons and both have been performing well for a number of years now. One of them actually is a Seniorita flown with the .25's or without and aerotowed:

John


Hmm the servers are being cranky tonight I will have to add the pics in the morning.