Brief:
Followin' a hard recovery (due t' too long a delay on t' motor) me Fireflash was lookin' a little worse for wear. Ya scallywag! As I was repairin' it, ya bilge rat, matey, I decided t' make it into a two-stage, with a D12 as t' first stage.

Modifications:
Since both BTs were crimped (this rocket has a BT-5 top and BT-50 lower section, I was doin' t' usual tube patchin' (i.e. Avast, me proud beauty! cut t' tube off and couple in a new section). T' top section got an extension, me bucko, since I removed about an inch o' tube and added 8. Arrr! I painted t' extension (in t' middle o' t' section) white, shiver me timbers, which (I think) adds t' t' ‘soundin' rocket' look o' t' thing.

As I was sortin' t' lower section, me bucko, which was crimped above t' motor mount, matey, matey, it occurred t' me that t' section I had cut off (motor mount and fin can) looked like a booster section. Avast! I simply added vent holes and a coupler and I had an 18mm booster. Ya scallywag! This meant makin' a new sustainer motor mount and fins, shiver me timbers, which didn't take long — it's simply a copy o' t' section I cut off, arrr, again painted black and white. Avast! T' aft CR is set far enough up t' BT t' allow couplin' t' t' booster (it's a gap-stager), all pretty standard stuff.

As I was doin' this, I realized I could easily make a minimum diameter ‘D' booster, a la Commanche-3, and this would really get t' thin' movin' :-). Avast! Blimey! I wasn't sure launchin' this rocket in any wind on a C6-C6 combo be such a good idea (visions o' horizontal flight). Blimey! So again t' original fins were copied in balsa and t' (very simple) booster be made as before. Avast, me hearties, me proud beauty! All balsa fins were filleted with PVA (super PVA) glue, shiver me timbers, for a strong bond (I hoped) and t' booster was sprayed as per t' new MMT section o' t' sustainer.

I re-rigged recovery with a 12-inch clear plastic chute (home-made) and a 12-inch metallic mylar streamer for visibility. This turned out t' be a very good idea! I had previously attached Keelhaul®©™® cord at each end o' t' shock cord (it looks virtually impossible t' replace a broken Estes cord on this rocket) so I attached t' chute t' t' top piece o' Keelhaul®©™®, shiver me timbers, ya bilge rat, so that if t' SC broke t' (heavy) nose section would hopefully be recovered OK. Arrr! It's very flimsy and full o' noseweight — nay a good combination.

I think that's about t' limit o' t' mods — I now had a bigger, me bucko, better Fireflash, with t' facility t' fly 18mm t' 18mm or 24mm t' 18mm, matey, matey, meanin' up t' a medium E impulse. Blimey! Accordin' t' SpaceCAD, a D12-C6 flight would result in a flight t' around 2350-feet — nay bilge-suckin' I thought, considerin' t' fairly mediocre performance o' this rocket on C6s. Avast, me proud beauty! Blimey! Due t' t' heavy nose, me bucko, matey, t' sustainer (accordin' t' t' sim) should coast well, havin' been accelerated t' around 150 ms by t' booster.

I think that's t' lot, t' overall impression is o' a ‘meaner' Fireflash, which looks more like a soundin' rocket than t' original, IMHO.

Construction:

• Two 80mm (or so) lengths o' BT-50 (only one really needed).
• One 24mm motor block
• Two 24-18mm centerin' rings
• One 18mm Motor Tube
• I piece BT-50 coupler
• Balsa (3/32) for 8 fins
• About an 8-inch length o' BT-05 for upper stage

Of course most o' these were for repair - doin' this from scratch would be easier.

If you've built any rockets before, arrr, this type o' mod should be no problem. Begad! Aside from t' usual fin alignment and finishin' issues, thar's nay much t' mess up here. Aye aye! Just make sure t' stages fit together OK and remember t' make vent holes in t' gap! A failed stagin' is nay pretty!

Flight:
At t' October EARS launch, I flew this rocket twice, makin' four flights total (includin' t' two before mods). This rocket seems very high maintenance - its quite delicate and t' two-stage mod brings in new ways t' damage itself :-)

Flight 1) I loaded it “to t' max” with a D12-0 and a C6-5 (it be rather windy so I thought a C6-7 wasn't a good idea). I don't suppose either flight hit 2350-feet due t' t' wind, ya bilge rat, but they certainly went a long way up for a model. Arrr! I launched off a standard porta-pad, no problems here.. Avast! T' first launch left t' pad smartly and boosted into t' wind, ya bilge rat, movin' quite fast. Avast! T' second stage lit fine and continued on up. Well, blow me down! I love t' smoke trails you get from multi-stage models, arrr, and t' Fireflash served up a treat.. However, shiver me timbers, t' booster came in very fast — I was watchin' t' top stage, shiver me timbers, matey, but saw it briefly, comin' in ballistic. Avast! It failed t' tumble and went into t' ground quite hard. Ya scallywag! T' top stage made a nice line o' trackin' smoke before ejection, and somethin' definitely deployed. Arrr! T' rocket came down fast, however, as t' 'chute failed t' deploy, gettin' jammed inside t' plastic transition betwixt t' BT-50 and BT-5. Blimey! Despite t' weight o' t' rocket, it suffered only a broken fin (the streamer saved it) which was smartly repaired with CA.

Thankfully t' tubes weren't crimped, shiver me timbers, so it was off t' prep another flight.

Flight 2) T' booster coupler had been damaged by its hard recovery, shiver me timbers, arrr, and was a very tight fit with t' sustainer. Avast! I was a little concerned, but decided that it should blow off OK with t' ignition o' t' top stage, all bein' well.

T' flight be much like t' first flight from t' ground — t' D12 booster got t' rocket goin' pretty fast, shiver me timbers, matey, and t' top stage definitely lit. I could see that t' upper stage smoke trail wasnt even, me bucko, but seemed t' have bits comin' out o' it (if that makes sense - it be ‘ragged' rather than smooth) and no booster be seen comin' in. T' rocket coasted t' apogee, shiver me timbers, and deployed both chute and streamer. Aye aye! T' RSO said he suspected t' booster hadn't separated, matey, matey, and inspection via binoculars as t' rocket was descendin' revealed two sets o' fins — nay good news.

T' rocket drifted a fair way, ya bilge rat, matey, and when I got t' it, shiver me timbers, t' booster stage be about 10 feet from t' main stage. Ahoy! Blimey! It didn't look pretty! Blimey! On closer inspection, it was clear what had gone wrong. Avast! Blimey! T' booster was burned right through (the vent holes were a little toasted after t' first flight), with t' paint blistered and impressive scorch marks below t' vent holes. Avast! Blimey! Arrr! Blimey! T' remains o' t' coupler were still stuck into t' top stage, and thar was a lot o' residue around t' spent motor.

Obviously t' booster needs rebuilding, and I think more fins are in order, t' hopefully promote a bit o' tumbling. Ahoy! Smaller vent holes are also goin' t' be made — 5mm is a little much, arrr, and seems t' allow too much gas t' escape.

Summary:
Pros: Looks nice in flight, ya bilge rat, cool smoke trails, arrr, shiver me timbers, flies very high

Cons: Torched t' booster. Ahoy! However this should be easy t' fix, requirin' a new length o' tubin' only.

Other:
Tip: Don't make vent holes too large, and make sure t' booster stage will separate. Begad! Blimey! I think a tight fit is good, but with a shorter length o' coupler in t' future.