RE: BME 110
Well. . really it was only 28.25, till I added two elevator servos for 3D flying and an Emcotec Powerbox.
Given that other examples of the BME110/Composite-arf 40% Extra are coming in around 34-36 lbs (Kind of amazing how those guys with HEAVY 150's come in at 33, isn't it?) the only answer is tha airframe is lighter than "normal"
Composite-Arf laid me up a lightened airframe, that came in a full 5 lbs lighter than normal, at 16.5-17 lbs with LG and hardware. The BME/exhaust, radio gear and batteries add another 10 lbs, and the paint/graphics add 1.5 lbs.
Remember these numbers. . . A BME110 with Canister style exhaust and ignition, is about 6.3 lbs total weight, about 4.75 with stock exhaust and ignition. A DA150 with Mufflers and ignition is about 9.5 lbs, and the props have a 3-5 ounce weight difference between the two engines. Realistically, the DA150 combintaion will ALWAYS weigh at least 3.5 lbs more than a BME110, even if the BME has canisters, and will be 5 lbs heavier if you use stock exhaust on the BME.
I just proved this by swapping a 3W 150 over onto my heavier plane, and removing the BME. . they used the same canisters. All else being equal, since I did not add/remove ballast weight, but just shifted radio gear and batteries around, the plane should now be 4 lbs heavier. Amazingly enough, it IS 4 lbs heavier, at 40 lbs even. A DA150 weighs 12 ounces more than the 3W150, too.
When they tell you that one of these planes wil come it at 35 lbs with a 150, do you REALLY believe it? Not unless you do some serious removal of extra materials and resin from the airframe to get it down to 16-17 lbs before you add hardware.
My "Heavy" plane, bare, was 21.5 lbs fresh out of the crate. . the Light one was 16.5. There's your weight difference.