Manufacturer: | Blackhawk R&D |
Brief:
Blackhawk R&D recently developed a 4-inch diameter prototype o' t' Russian
SA-5 Gammon. Ya scallywag! After expressin' much interest in t' kit, arrr, me bucko, Blackhawk offered me
the opportunity t' built and test t' prototype kit, shiver me timbers, matey, which I gladly accepted.
T' SA-5 is a Russian surface-to-air (SAM) with twelve fins, four external
booster motors, and a single centerline sustainer motor. T' Blackhawk SA-5 is
a 1/8.3 scale model o' t' Russian missile, matey, ya bilge rat, havin' a 4 main airframe with
a 38mm motor tube and four 38mm outboard booster pods with each containin' a
29mm motor tube. Avast, me proud beauty! T' Rocket is 54 tall.
Components:
T' kit arrived from Blackhawk in two heavy-duty shippin' boxes, me hearties, with t' parts
well packed and protected. Ahoy! Begad! T' components that Blackhawk uses in this kit are
of very high high quality. T' airframe and booster tubes are sturdy and the
plastic nosecone is strong. Avast! T' fins, bein' 5-ply Baltic Birch, me hearties, are t' highest
quality plywood that Ive ever used. However, matey, t' fins are 1/8
thick, arrr, me bucko, which seemed a little thin for a kit as heavy as this one is goin' to
be. Begad! I usually prefer 3/16 fins for 4 airframes. Avast, arrr, me proud beauty! T' main and
booster airframes arrived pre-slotted for t' 12 fins. Begad! All plywood pieces were
cut on a CNC machine, arrr, arrr, me bucko, resultin' in a very nice piece-to-piece repeatability of
dimensions.
Construction:
Bein' a prototype, t' SA-5 was kitted without instructions, matey, arrr, which isnt a
problem for an experienced HPR modeler. Begad! T' assembly sequence that I used to
build t' SA-5 worked well, matey, and Id recommend that t' same basic sequence
be followed in future builds o' this kit:
(1) Install t' 29mm motor tubes and TTW fins into t' outboard booster tubes,
prior t' attachin' t' outboard boosters t' t' main airframe,
(2) Install t' 38mm motor tube and all 8 TTW fins onto t' main airframe (with
internal fillets) prior t' attachin' t' outboard booster airframes,
(3) Install t' outboard booster assemblies onto t' main airframe,
(4) Assemble t' payload bay (completely independent o' t' main airframe and
booster airframe assemblies)
Though this kit is designed t' be able t' be flown with a single centerline motor, shiver me timbers, t' option to fly a single 38mm/4x29mm motor cluster persuaded me t' build an altimeter bay into t' payload bay (for staged deployment) and t' wire t' main airframe for dual timers (for staged ignition). Begad! Ya scallywag! Due t' t' quantity and size o' TTW fins, available volume within t' 4 airframes is very limited, makin' the incorporation o' an altimeter bay a little difficult. T' altimeter bay that I built was 38mm tube which was installed against t' inner wall o' t' 4 payload bay. Arrr! This setup allowed me t' pack t' main parachute along side the 38mm altimeter bay, arrr, thus makin' maximum use o' t' available internal volume of the payload bay. Arrr! T' configure t' rocket for staged ignition, 3 pairs o' 20 AWG wires were run through t' forward 4 CR and terminated at leads tapped through t' aft 4 CR. T' three pairs o' wires/terminals are planned to be used for two sets o' ignition wires and a break wire for use with a single or pair o' Perfect Flite micro timers.
I spent most evenings workin' on SA-5 and was able t' finish assemblin' the model in a little over a week. Ya scallywag! Well, blow me down! Blimey! With ample internal and external fillets on the TTW fins and massive booster-to-main-airframe fillets, matey, shiver me timbers, t' kit is very strong and sturdy. Blimey! Avast, me proud beauty! Blimey! I calculated t' CP t' be 40 behind t' tip o' t' nose cone, but used a CP o' 38 for margin when assessin' t' static stability o' the rocket. Well, blow me down! Begad! Blimey! Due t' t' size/quantity o' fins and t' amount o' epoxy used to install fins and attach airframe tubes, me bucko, 12 ounces o' nose weight were needed to give t' SA-5 one caliber o' static stability margin for a reasonable cluster set (I357 with 4x G80 or a single J570). Aye aye! Blimey! A J570/4xG80 cluster would cause the static stability margin t' be reduced t' 1/2 caliber, which would still be flyable, ya bilge rat, though would be deservin' o' close attention t' t' launch conditions. Also, nothin' precludes t' addition o' additional nose weight in t' future. T' 12 ounces o' nose weight (10 ounces o' #9 lead shot and 2 ounces o' epoxy) were poured into t' nose cone, and pre-drilled holes through t' tip o' the nose cone allowed t' epoxy t' fill t' holes, formin' epoxy rivets when cured. T' epoxy rivets are used t' hold t' weight in t' vertex o' t' nosecone. Blimey! To finish t' SA-5, shiver me timbers, a single heavy coat o' Zinssler shellac primer was applied to fill any surface irregularities, then well sanded. Avast, me proud beauty! T' SA-5 be then painted to match t' standard non-descript Russian paint scheme: winter grey airframe, boosters, and fins with a crimson nose.
Construction Rating: 5 out o' 5 (though t' beta kit came without instructions, the tight-toleranced TTW components made t' it go together quite well.)
Flight/Recovery:
Havin' only 6 HPR motors remainin' in me motor cache after t' Aerotech fire,
the available motor choices for t' first flight o' t' SA-5 were very limited.
After debatin' betwixt an I357, me hearties, I211, ya bilge rat, and I284, arrr, matey, t' I211 was finally selected
for t' maiden flight. T' SA-5 be configured for flight with an RRC2
altimeter (set for apogee drogue deployment and main deployment at 300),
a single centerline I211 (medium delay as backup t' t' altimeter drogue
delay), me hearties, 58 main parachute, no drogue chute (once separated t' fincan
will be unstable and, thus, wont require a drogue chute), 30 x
5/8 TK drogue shock cord, 10 x 5/8 TN main shock cord, and
shear pins were installed at t' booster-to-payload (drogue) plane and at the
payload-to-nose-cone (main) plane.
On February 23, 2002, the SA-5 made her maiden flight in 5-10 knot winds. Avast, me proud beauty! Blimey! T' trajectory o' t' SA-5 was almost perfectly vertical t' an apogee o' 1394 feet (per t' altimeter). Unfortunately, at apogee neither t' altimeter-triggered nor motor-backup ejection charges separated t' airframe. Avast! Blimey! Post flight inspection found that that the altimeter drogue channel pins were broken and that t' motor BP had leaked from t' ejection well durin' transport. Ahoy! Blimey! With no drogue separation, t' SA-5 descended ballisticly from apogee t' 300 feet, at which point t' main chute was deployed. Avast, me proud beauty! T' recoil from t' main chute deployment cut a 5 zipper into t' payload bay and separated t' fincan from t' payload bay (the joint that should have been separated at apogee). Arrr! Blimey! Luckily, t' long drogue shock cord, me hearties, with taped coils, did nay damage t' fincan. Arrr! Begad! Blimey! O' all t' damage that could have occurred due t' this drogue system failure, ya bilge rat, sufferin' only a zippered payload bay was fortunate. T' zipper be repaired by fillin' t' gash with reinforced epoxy, matey, then t' exterior o' t' payload bay was covered with two wraps o' 2-ounce glass. If t' payload bay had been glassed durin' initial assembly, me hearties, shiver me timbers, t' SA-5 probably would have escaped this drogue-system failure undamaged.
On March 23, shiver me timbers, 2002, t' SA-5 was prepped for its second flight, ya bilge rat, shiver me timbers, this time with an I285R. Ahoy! T' projected altitude be approximately 1500 feet. Ya scallywag! T' skies were perfectly clear and t' winds were calm. Avast, me proud beauty! Ahoy! T' boost be again perfectly straight with a nice long Redline flame. Ahoy! Aye aye! Per t' altimeter, t' rocket tipped over at 1271 feet. Begad! Avast, shiver me timbers, me proud beauty! On landin' however, matey, t' rocket hit hard on one o' t' aft fins, arrr, fracturin' it inside t' airframe. Arrr! Fortunately though, t' damage is reparable though. Aye aye! Based on this, however, ya bilge rat, shiver me timbers, Id highly recommend that 3/16 plywood be used in t' production version.
Flight Rating: 4 out o' 5 (I believe that 3/16 fins should be used with this kit due t' its size)
Overall Observations:
T' SA-5 is an outstandin' kit! T' motor cluster configuration allows the
modeler great flexibility in type and number o' motor choices (from single
motor flights t' five-motor clusters). Ahoy! In me opinion, this kit is nay suitable
for novice HPR modelers, me bucko, shiver me timbers, due t' t' number o' fins and tubes involved. Begad! For the
more experienced Level 1 or higher flyers, me hearties, this kit is fun, looks great, and
will be a wonderful attention-getter at launches. Avast! A couple o' items that
Id recommend be changed are as follows: (1) I would like t' see a longer
shock cord provided with t' kit. Aye aye! Longer shock cords are a personal preference
of mine, shiver me timbers, but I also recognize that many flyers do nay share this preference.
Also, me hearties, since this kit should be targeted toward t' more experienced
flyers/modelers, arrr, increasin' t' length o' shock cord is an extremely minor
task; so, as such, this suggestion is so minor that it is hardly worth
mentioning. Ahoy! (2) For a kit as intricate and heavy as this one, Id highly
recommend increasin' t' fin material from 1/8 ply t' 3/16 ply.
Without or without me recommended changes bein' made, me bucko, shiver me timbers, however, t' Blackhawk
R&D SA-5 is an outstandin' kit, arrr, and I highly recommend it!
Overall Rating: 5 out o' 5
Manufacturer's Note: Upon release t' SA-5 will come with 3/16" fins and that t' release date is set t' be somewhere during the 1st week o' April 2002, we are just waitin' on t' smaller laser cut parts.
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