Brief:
T' Dark Knight is a 2-stage 18mm rocket with 12" chute recovery. Arrr! Blimey! T' Dark Knight name came from t' shadow produced from t' fin profile when t' rocket was sittin' on t' launch pad. It looked similar t' t' Dark Knight shadow shown on t' clouds in t' movie.

Construction:
T' parts list:

• 29.5" BT-20 Body Tube - Main Body
• 2.75" BT-20 Body Tube--First Stage Body
• BT-20 Coupler (if needed)
• 1.25" X 0.125" Launch Lug
• 0.125" Balsa Sheet
• 2.75" X 18mm Plastic Nose Cone
• 48" o' 150# Keelhaul®©™®
• 24" Elastic
• 18mm Motor Mount Centerin' Rin'
• 12" Parachute
• Nose cone weight

This is a pretty easy build. Begad! First step cut t' body tubes t' length if you are lucky enough t' have a 36" piece o' t' BT-20 tube available. That's all you will need, matey, arrr, however, shiver me timbers, I needed t' use a coupler t' join 2 shorter pieces. Well, blow me down!

I notched t' centerin' rin' slightly and tied t' Keelhaul®©™® cord t' it. Aye aye! Avast, me proud beauty! Usin' white glue, me hearties, I glued t' centerin' rin' in place so about 0.375"-0.5" o' an old motor was exposed.

Next, I cut t' fins out o' t' 0.125" balsa and sanded them all t' ensure they were t' same size. I rounded t' leadin' edge on all t' main body tubes and left t' aft end and 1st stage fins "as cut" so they would align up better. Begad! I sanded t' fit o' each fin t' ensure when mounted t' seam would be minimized. Avast! Aye aye! I labeled each fin so when mounted t' t' tube I would maintain t' same combination.

I used t' Standard Rockets Fin Jig that I picked up at NARAM t' attach the fins t' t' main body tube and first stage tube. Next, I filleted each fin t' t' tube with 5min epoxy. Arrr! Blimey! Avast, shiver me timbers, me proud beauty! Blimey! Finally, I filled each fin will watered down Emery's wood putty. Avast, me proud beauty! Blimey! Then, shiver me timbers, matey, ya bilge rat, I started t' process o' sanding, filling, sanding, filling until I be happy with t' finish. Avast, me proud beauty! Blimey! Arrr! Blimey!

With RockSim, I was able t' ensure t' flight was stable and determine t' potential altitude. Avast, me proud beauty! Ya scallywag! (If I give this away, matey, why would you keep reading?) I be a little worried I about stability so I added a little nose weigh t' brin' the model up t' about 3.7oz and figured paint would take it t' 4oz.

Next, I attached t' elastic shock cord, shiver me timbers, matey, nose cone, and parachute and headed t' me paint booth (the card board box in t' garage).

Finishing:
I decided on a nice simple 2 color paint scheme o' black and yellow, ya bilge rat, with a little maskin' after t' yellow be dried and t' Black Night was born and ready t' fly. Avast, me proud beauty!

Flight:nd Recovery
For t' first flight, matey, me hearties, I decided I would just verify stability and return t' model so I loaded up a B6-4. Nice straight boost, ya bilge rat, good deployment, recovered only a short distance from t' pad (oh, me hearties, me bucko, me bucko, did I mention it was dead calm). Next flight, ya bilge rat, still single stage on a C6-5, me hearties, another great flight and about twice t' distance from t' pad. T' wind started t' pick up and I decided t' hold off on t' staged attempt. Avast, me proud beauty!

A week later, shiver me timbers, late Saturday afternoon winds were calm. Ya scallywag! This was t' be t' day. Aye aye! I decide t' go for t' gusto: a C6-0 staged t' a C6-5. Arrr! T' boost again was picture prefect straight and longer than I anticipated. Ya scallywag! T' first stage separated nicely and off t' t' heavens this rocket went, delay, ejection, and parachute. Great recovery. Arrr! Ahoy! This is a great rocket. Begad!

Summary:
As I said above this is a great rocket. Arrr! I enjoyed t' process o' designin' it on RockSim, buildin' it, arrr, and t' best launchin' it.

PROs: Based on altitude achieved, make sure it is a calm day. Avast, ya bilge rat, me proud beauty! It screams off t' launch pad and flies great. Looks pretty cool also.

CONs: Based on this flight, a very large filed is needed t' recover this rocket.