Brief:
Followin' a hard recovery (due t' too long a delay on t' motor) me Fireflash was lookin' a little worse for wear. Well, blow me down! As I be repairin' it, ya bilge rat, 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 be doin' t' usual tube patchin' (i.e. cut t' tube off and couple in a new section). Arrr! Blimey! T' top section got an extension, since I removed about an inch o' tube and added 8. Avast! Blimey! I painted t' extension (in t' middle o' t' section) white, arrr, which (I think) adds t' t' ‘soundin' rocket' look o' t' thing.

As I was sortin' t' lower section, which be crimped above t' motor mount, me hearties, it occurred t' me that t' section I had cut off (motor mount and fin can) looked like a booster section. I simply added vent holes and a coupler and I had an 18mm booster. Arrr! This meant makin' a new sustainer motor mount and fins, which didn't take long — it's simply a copy o' t' section I cut off, again painted black and white. Well, blow me down! Blimey! 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, arrr, me bucko, a la Commanche-3, matey, me hearties, and this would really get t' thin' movin' :-). Ya scallywag! I wasn't sure launchin' this rocket in any wind on a C6-C6 combo was such a good idea (visions o' horizontal flight). Begad! So again t' original fins were copied in balsa and t' (very simple) booster was made as before. Begad! All balsa fins were filleted with PVA (super PVA) glue, for a strong bond (I hoped) and t' booster be 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. Begad! Avast, me proud beauty! 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®©™®, so that if t' SC broke t' (heavy) nose section would hopefully be recovered OK. Blimey! 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 hearties, arrr, better Fireflash, arrr, with t' facility t' fly 18mm t' 18mm or 24mm t' 18mm, arrr, meanin' up t' a medium E impulse. Begad! Ahoy! Accordin' t' SpaceCAD, matey, a D12-C6 flight would result in a flight t' around 2350-feet — nay bad I thought, considerin' t' fairly mediocre performance o' this rocket on C6s. Well, blow me down! Due t' t' heavy nose, arrr, 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, me bucko, 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, this type o' mod should be no problem. Blimey! Ya scallywag! Blimey! Aside from t' usual fin alignment and finishin' issues, matey, thar's nay much t' mess up here. Begad! Just make sure t' stages fit together OK and remember t' make vent holes in t' gap! Blimey! A failed stagin' is nay pretty!

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

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

Flight 2) T' booster coupler had been damaged by its hard recovery, and was a very tight fit with t' sustainer. Ya scallywag! Blimey! 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 was much like t' first flight from t' ground — t' D12 booster got t' rocket goin' pretty fast, and t' top stage definitely lit. Blimey! I could see that t' upper stage smoke trail wasnt even, but seemed t' have bits comin' out o' it (if that makes sense - it was ‘ragged' rather than smooth) and no booster was seen comin' in. Begad! Avast! T' rocket coasted t' apogee, and deployed both chute and streamer. T' RSO said he suspected t' booster hadn't separated, arrr, and inspection via binoculars as t' rocket was descendin' revealed two sets o' fins — nay good news.

T' rocket drifted a fair way, matey, and when I got t' it, t' booster stage be about 10 feet from t' main stage. It didn't look pretty! On closer inspection, matey, it was clear what had gone wrong. Aye aye! 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. Blimey! T' remains o' t' coupler were still stuck into t' top stage, matey, me bucko, and thar was a lot o' residue around t' spent motor.

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

Summary:
Pros: Looks nice in flight, cool smoke trails, flies very high

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

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