Brief:
I added a booster with gap stagin' for me stock Fat Boy.

Modifications:
T' Fat Boy was built stock. Arrr! Aye aye!

For t' Booster, me bucko, t' engine mount was assembled in t' usual manner. Avast, me proud beauty! Aye aye! T' aft centerin' rin' is flush with the tube end. 1/4" vent holes were punched in both centerin' rings. Ya scallywag! T' coupler extends into t' sustainer approximately 1/2" with a pretty snug fit. Aye aye! T' fin pattern was upscaled a bit (the root o' t' fins measures at 3 3/4"). Avast, me proud beauty! T' fins are surface mounted and cut from 1/8" balsa. Ya scallywag! A separate launch lug was added t' t' booster to give a little extra guidance.

Construction:
T' parts list:

• One Fat Boy kit
• 5" o' BT-80
• 1" BT 80 coupler
• 2.75" BT-20
• 2 80-20 centerin' rings
• 1/8" launch lug
• 18mm engine block
• 2.75" engine hook
• 1/8" balsa stock

There are absolutely no "gotchas" in buildin' t' Fat Boy itself. Ya scallywag! Begad! It is a well known kit after all. Arrr! The booster be no more difficult t' build than t' original kit. Avast! Blimey! T' Booster is pretty stoutly built. Blimey! Blimey! I considered using TTW fins, shiver me timbers, ya bilge rat, but given t' tumble recovery o' a booster, ya bilge rat, I think it is much better t' pop a fin on landin' than break it.

Finishing:
Finishin' and paintin' went pretty smoothly. Aye aye! I decided against usin' t' supplied decals as I have this thin' about stickers. Ahoy! Instead I went with a simple yet dramatic paint scheme.

Flight and Recovery:
First flight was t' single stage Fat Boy on a C6-3. Begad! Ahoy! Nice straight flight and shipshape recovery on a 14" nylon chute.

Second flight used t' booster with a C6-0 t' B6-6 combination. Well, blow me down! Blimey! Boost was slow and straight, stagin' occurred fairly low and t' sustainer took o' like a shot. It weathercocked a bit but had a very nice high flight. Aye aye! Well, blow me down! Blimey! Chute ejection be a bit past apogee but deployed cleanly. Aye aye! T' booster popped a fin loose on landing, which was easily repaired. Avast! Aye aye! Blimey! T' sustainer made a shipshape landing.

Third flight used a C6-0 t' B6-4 combination which gave an almost identical flight t' #2. Begad! Ejection occured at apogee and both booster and sustainer returned without damage.

Summary:
T' Fat Boy by itself is a fun little rocket, me hearties, which is suitable t' all kinds o' modification. Ahoy! Blimey! Blimey! I was worried that the addition o' a booster would make it t' heavy t' fly on an 18mm engine, ya bilge rat, but it works very well. Avast! I certainly wouldn't use any booster but t' C6-0 though. For a small field stagin' demo, I think it's just perfect.

PROs: It's a two stage bird that you don't have t' chase all over t' country side. Avast, me proud beauty! Begad! Blimey! T' gap stagin' has worked flawlessly so far. Easy t' build and modify.

CONs: I would like t' have seen 1/8" balsa fins used on t' stock Fat Boy. Avast, me proud beauty! Blimey! Sticker decals. Well, matey, blow me down! Blech!