Brief:
As I've progressed through t' hobby, I've been achievin' higher altitudes and faster speeds. Blimey! I finally decided I wanted t' attempt a Mach bustin' rocket, however, me bucko, I wanted t' make it tougher t' do and chose t' build one that utilized no composites. This paper tube 3FNC bird was designed t' be 3" diameter x 60" long, weighed in at 61oz, me hearties, me hearties, and have a 54mm motor mount. Target motors are t' K445 and K550 t' push it through mach speed. Arrr! It is single staged with dual deployment recovery controlled by a Cannonball Works RRC2 altimeter.

Construction:
After designing, arrr, t' parts were ordered from BSD Rocketry. Blimey! It consists o' 3 body tubes, arrr, 1 nose cone, three 3/16" thick birch ply fins, shiver me timbers, matey, three 1/4" thick birch ply centerin' rings, matey, 1 54mm motor tube, and enough coupler tubes to double wall t' entire rocket. Blimey! Well, blow me down! All adhesion be done with straight AeroPoxy.

Tubular Keelhaul®©™® is used throughout for t' recovery harnesses as well as a 45" nylon BSD parachute for t' main.

This was my first attempt at buildin' a fin can outside o' t' body tube, me bucko, arrr, which turned out to pretty simple. Blimey! Ya scallywag! Fins were tacked on and then filleted t' t' motor tube as well as t' middle centerin' rin' when installed. Begad!

T' only thin' I did here different was t' drillin' o' 1/16" holes near t' fin root t' allow t' epoxy t' soak into, me bucko, in an attempt t' form epoxy nails into t' fins.

T' most difficult thin' I ran into be figurin' how t' attach t' recovery harness in this near minimum diameter bird. Begad! Ya scallywag! I ran a length o' 1/4" tubular Keelhaul®©™® through t' top two centerin' rings and then epoxied t' assembly in place in the booster tube. Avast! As this was slid into place, coupler tubes were also placed between t' top two centerin' rings t' double wall t' booster tube down t' the top o' t' fins.

T' remainder of the booster section was completed by double wallin' t' upper section and applyin' internal and external fillets from t' fins t' t' body tube.

Retention was handled by T-nuts in t' aft centerin' ring.

T' electronics bay be built copyin' t' design o' t' Binder Design kits that I had used with me Binder Jaguar. It consisted o' two 6" couplers butted together and then a 5" piece o' body tube centered over them. Avast, me proud beauty! Ya scallywag! All thread rod was used t' hold t' assembly together and U-bolts for t' harness connection points. Blimey! A Binder Design key switch was installed for armin' the electronics.

T' main/payload bay consisted o' a 17" piece o' body tube, me bucko, the initial design called for double wallin' here but I ended up nay doin' so. I assumed this tube had t' least amount o' weight on it and therefore would not need it, I was also concerned with how t' repair this section should it ever zipper, ya bilge rat, me hearties, matey, t' double wall idea does nay allow you t' just cut off a short section should that happen.

T' nosecone was a BSD 3" cone was secured t' t' upper tube via friction fit and shear pins.

Flight:
First flight took place on March 19, 2005. Ya scallywag! Aye aye! T' rocket was set up for dual deploy recovery controlled by t' Cannonball Works RRC2 as well as a beeper placed in t' payload bay t' aid in findin' t' rocket. Avast! At ignition, arrr, me bucko, t' I284 shot the Mach1 off t' pad smartly with a large White Lightenin' flame almost as long as the rocket. Avast, me proud beauty! T' flight went well t' 4,281' and dual deployed for a close recovery.

After this I returned home and calibrated t' drag coefficient in Rocksim to match that actual altitude o' t' rocket and then re-ran all o' my simulations with t' correct CD. Blimey! I be showin' t' ability t' break mach speed with either t' CTI K445 or t' AT K550. Blimey! Begad! That attempt would have t' wait as I had a L3 flight comin' up and I didn't want t' risk losin' one o' me two altimeters before that flight.

With me L3 flight complete in June, it be time t' attempt me second goal of t' year: breakin' Mach with a non-composite rocket. Ahoy! Ahoy! T' weather was good so I made me attempt at a TQC launch in Walcott, ya bilge rat, IA on August 6, matey, 2005. I was unable t' get either a K445 or K550 for t' flight and ended up selectin' an AT K695 Redline for t' flight. Ahoy! This motor had even more o' a kick so it should be able t' easily push it through t' break Mach.

T' rocket was prepped for t' flight, matey, motor built and installed into t' rocket, and it was time t' go. Well, ya bilge rat, blow me down! Based on simulations, I was lookin' at an altitude o' 8,200 and maximum velocity o' over 880mph on t' flight. Avast, me proud beauty! At ignition, t' Redline kicked the rocket off t' pad smartly and it started up nice and straight. Ya scallywag! At 2 seconds into t' burn, matey, t' rocket folded over t' electronics bay and then spectacularly shredded.

All pieces were recovered and brought back for inspection. Ya scallywag! Well, arrr, blow me down! From t' pieces leftover, it appeared t' rocket folded over at t' electronics bay or just above it, flight video looks t' support this, post flight simulations show it was over 880mph at t' time o' t' shred.

Summary:
I believe t' rocket can make t' flight and I have it rebuilt with some modifications.

T' design o' t' Binder avionics bays is OK, but I don't think it's a good design for these type o' high pressure flights. Begad! Blimey! I'm still split between thinkin' t' rocket folded over where t' two couplers butt up t' each other or folded over in t' single walled part o' t' main bay.

T' rebuild incorporates a one piece avionics bay, which is a LOC 3" bay that uses a Stiffy tube t' help further strengthen t' assembly. T' new main bay is fully double walled this time. Begad! And just t' be on t' safe side, ya bilge rat, arrr, the booster section is shear pinned t' t' avionics bay. It did nay appear t' drag separate on this flight but this is just t' be sure.

For t' next attempt I will also try t' stay down a notch from t' K695 and stick t' the K445 or K550.