(Contributed - by Bill Eichelberger - 05/29/05)
This is a stock Estes Firehawk (the BT-60 based version) with a 3x18mm cluster
in place of the standard single 18mm engine. The Firehawk was an auction win
from eBay and was initially purchased with an eye toward using the nose cone to
a National Aerospace Plane. That all changed after I realized what a
unique looking bird the Firehawk was and that it was BT-60 based and would lend
itself easily to clustering.
Ever since rediscovering the remains of my half built Estes Super Vega in 2001,
realizing that most of it wasn't salvageable and therefore ripe for
modification, I've had a thing for clustering BT-60 based rockets. For the
Firehawk project I had a cluster mount already completed and gathering dust on
my desk, which was a major factor in the decision to turn it into a cluster.
Having the mount already built made just made it easier. I'd probably have
clustered it anyway. Aside from the cluster, the only other change that I made
was the now standard anchoring of the Kevlar
shock cord into the upper centering ring. Everything else about the build went
just as specified in the instructions, which are fairly easy considering that
the Firehawk is just an oversized 3FNC rocket.
The parts list:
- BFS-40L (1/8" balsa)
- BT-60R (5")
- BT-60 (18")
- JT-60C tube coupler
- 3 BT-20J engine tubes
- 3 RA-2050 centering rings for engine blocks
- 2 RA-2060 centering rings
- 2 LL-2B launch lugs (3/8")
- 12" nylon parachute (from Thrustline Aerospace)
- 36" Kevlar
shock cord (from Thrustline Aerospace)
- 36" 1/8" sewing elastic shock cord
- 2 large snap swivels
Although a fairly large rocket, the Firehawk was surprisingly simple to finish
in large part due to it being built in two separate sections. Once I had
securely glued the engine mount into the fincan and plugged all of the
potential exhaust leaks, I attached the fins and used thinned Elmer's Fill 'n'
Finish to eliminate the tube spirals and balsa grain. This was where not
connecting the sections in a rocket like this pays dividends. After priming the
whole rocket with Valspar primer, I took an section of scrap BT-60, slipped a
tube connector into the fin can, and used the scrap BT-60 as a paint stand. I
sprayed the fin section with several coats of Testors Bright Red Gloss, which
was an incredibly bad choice. It took five coats and a whole can of the Testors
paint to do the small fin section because of the paints inability to cover
well. It wound up being a good color choice, but I don't think I'll be buying
any more Testors paints in the future. The top section was painted in the same
way as the bottom as far as the tube connector and scrap of BT-60, but the
Valspar gloss white covered in two coats. When the two sections were dry I
glued them together using the tube connector and prepared to apply the decals.
I didn't think this would be a problem because I considered the Firehawk a kit
of fairly recent vintage. At the time I didn't know that it was produced only
in 1989-90, which made the decals fifteen years old at the minimum. This became
obvious as they started to come apart as soon as I tried to slide them off of
the backing paper. The Firehawk isn't overly laden with decals as there are
only three, but it took me over two hours to get them on and looking decent.
From a distance the mess isn't evident but please try to be no closer than five
feet if you're looking it over.
While far from my first cluster, the Firehawk was easily one of the most
impressive. Despite encountering my age old launch lug bugaboo and have to
super glue a set on just before I took it to the pad, I was optimistic about
it's first flight and loaded it with a trio of C6-5s despite the windy
conditions. Unlike my previous, bulkier attempts at clustering, the Firehawk
really screamed off the pad--a truly "now you see it, now you don't"
flight and definitely one too quick for my meager launch picture taking skills.
It cocked into the wind and was just a dot when the ejection charges fired but
it was pretty obvious that ejection happened early. As usual, the windcocking
was a blessing in disguise as recovery took me out almost to the dog park with
it. (A straight flight might have left the park altogether.) The long walk did
allow me to recover several rockets that flew after mine, so at least someone
The second flight came two weeks later and was also done on a trio of
C6-5s. The flight was as impressive as the first one had been and looked to be
quite a bit higher, but the ejection seemed to come quite a bit early. It was
after the flight that the real adventure began. The flight had been quite high
and the winds came on strong just before the Firehawk was launched. It
windcocked somewhat but lacked the fin area for it to be enough when it came to
recovery. We watched it as it drifted to the east and out of the park. Having
learned from past mistakes, I saddled up the van and drove over to the site but
found nothing. I climbed the park fence and followed the path along the area
that we had sighted from the pad and still came up empty. I decided to make one
more pass along the edge of the subdivision across from the VOA before I gave
up but this was turning up nothing as well. I had literally just thought that
the search was a lost cause when a lady came out of a house and asked if I was
looking for the rocket. I had been within twenty feet of it the whole time but
it had nestled into the grass perfectly so that it wasn't visible from any
vantage point. It was barely even visible as I stood almost on top of it.
PROs: The Firehawk is a great looking bird when built and finished in the
factory scheme. The forward swept fins look great and the BT-60 size makes for
a satisfyingly large and sturdy finished product. Great performance with the
CONs: Wimpy 18mm power for a rocket of this size when built stock. At the
very least this one should have been D powered. Decals didn't age well.