Here is the continuing evolution of my P51 copied from the dimensions of my Tower Hobbies 40" P51. I first flew it as an elevon only plane which was interesting but rather cumbersome with slow responsiveness and an inability to loop.
Then I tried cutting the horizontal tail off and flying it which was a disaster.
Then I added the horizontal stabilizer back with elevator and after a few days of crashes and adjustments it flies. Also extended the nose by a couple of inches to counter the weight added to the tail for the elevator mods.
I now need to cut the ailerons down in size as they are way too responsive - on my radio the elevator is 100% but the ailerons are about 30% and still too touchy.
Am using an 1800kv motor, 8*5 prop, 1100 mAh battery. AUW is just under 700 grams (24 ounces). Get about 5 minute flights on this little lipo - not bad for such a heavy plane. I overbuilt it and it is pretty tough.
Foam is 9mm EPP laminated with copy shop laminate and reinforced in the nose with a couple of bamboo strips taken from a place mat and held on with hotglue and strapping tape.
The wing is held on by little hair bungees coupling bamboo strips to chop sticks poking through the fuselage reinforced by pieces of acrylic ruler.
The motor mount backing plate is held on with bungees too.
Also use a prop saver (also using hair bungees) as was tired of bending aluminum prop adapters.
Got to change date on my keychain hatcam someday.
Update Jun 8,2013: I now fly this plane on 1800 mah 3s lipo. It is auw of about 800 grams. I built a new horizontal stabilizer with a balsa elevator I found in a crashed plane. It flies great. About 8 mins on the lipo.