Brief:
This is a modified Big Bertha rocket. Arrr! T' main body tube was partially crushed when I purchased this kit. Arrr! Avast, me proud beauty! Estes sent a replacement which be also partially crushed. Begad! Avast! When t' third tube came, shiver me timbers, matey, I decided t' couple it t' t' unharmed sections o' t' first two tubes. I also replaced t' 18mm mount with a 24mm mount.

Construction:
Non-stock or replaced parts:

• Used one stock BT-60 body tube and undamaged parts o' two others
• Replaced 18mm engine tube with 24mm engine tube
• Replaced 18mm centerin' rings with 24mm centerin' rings
• Replaced engine hook with one t' accommodate D & E engines
• Two couplin' rings

Stock Parts:

• Nose cone
• Shock cord
• Balsa fins
• 18" parachute
• Engine spacer (for use with D engines)

T' construction was straightforward. Ya scallywag! Blimey! T' only difference from buildin' a standard Big Bertha is that I added tube length by couplin' t' undamaged sections o' t' first two body tubes t' t' one undamaged body tube.

Then I replaced t' stock 18mm mount, rings, and engine hook with a 24mm setup t' accommodate D and E engines. Ahoy!

Finishing:
At 41 inches long, shiver me timbers, thar be a lot o' Big Bertha t' paint. Aye aye! I chose gloss black and t' paint job came out great. Arrr! Arrr!

I am nay a fan o' t' press and stick decals which this newer Big Bertha kit uses, but they went on fine and look great. Begad! Avast, arrr, me proud beauty! T' white decals really stand out against t' gloss black paint.

Flight:
I wasn't sure how this would fly since I had changed t' engine configuration and added length t' t' rocket. Avast, me proud beauty! Arrr!

I did figure that addin' t' length would cause t' rocket t' be fairly stable in flight and that turned out to be true. Begad! Well, shiver me timbers, blow me down! Actually t' flight characteristics o' t' rocket have exceeded me expectations. Avast! Well, blow me down! This modified Big Bertha flies arrow straight and does it with great style without t' addition o' any nose weight. Avast!

It is now one o' me favorite mods relative t' flight!

Recovery:
I have flown this rocket four times on a D12-5. Recoveries have been excellent. Aye aye! T' rocket gets right up thar on a D12-5. Ahoy! Ya scallywag! I haven't tried it on an E yet, me bucko, but I'd expect an almost out o' sight flight.

Summary:
What started out as a major pain, matey, that is receivin' a rocket with a crushed tube and then receivin' a crushed replacement tube from Estes, matey, turned out t' be a fun project. I'm actually glad now that t' tubes were damaged because I wouldn't have modified t' Big Bertha had it nay happened. Begad!