May 17, 1997 - Launch Report
We had some friends along to see the fun. They wanted to witness the maiden flight of the freshly primer'd Shadow. Biggest rocket anyone in this area has seen. We don't have a lot of rocketry going on around here, so it doesn't a whole lot to wow 'em.
The soccer fields were empty - YES! The weather was smiling upon us with clear skies, 70 degrees and only a 2 -5 mph breeze. I put up the Plumbers Delight launch pad for only the second time. It is a nice big platform that gets the end of the launch rod up out of harm's way.
First we sent up Big Bertha on a B6-4 to get everyone in the mood. She flew straight up and behaved as a perfect lady, drifting to touchdown some 300' away on her 12" chute with spill-hole. Hmm, I'll use the 15" x-form chute for the next flight, to be C6-powered for checking the above-the-trees winds. Got Bertha prepped again with the C6-5, changed chutes, angled the launcher a few degrees into the breeze and fired! Straight flight on the exact line of the launcher, no weather-cocking at all. Nosed-over somewhere around 700' and drifted to nearly the exact same landing spot as the first flight.
Okay - no jetstreams lurking up there - confidence is high!
We have a go for the launch of The Shadow.
I had completely prepped the first cluster in the motor canister before leaving home. The dual D12-5's were in place with ignitor wires twisted in parallel. The 12V nicad camcorder battery was being used for ignition on 25' of 18 gauge speaker wire with alligator clips for connection. I kept the battery in my jacket pocket while clipping the leads to the ignitors. I know this doesn't sound exactly according to the NAR safety code, but in most respects it's at least as good. My "launching switch" is momentary-contact leads that only complete the circuit when carefully positioned on both battery terminals. When I let go, the leads positively break contact. The "removable safety interlock in series with the launch switch" is the entire battery assembly. Without it, nothing is going to happen. If anything, this is safer than a launch controller.
If someone spills a soda on the controller box while you're connecting the ignitor clips, it may short out completely and you're likely gonna get a nasty surprise. If someone spills a soda on the bare wire leads while I'm connecting the clips at the other end, nothing happens.
Check the wiring continuity with the Estes launch controller - shows OK. Get the camcorder battery out and yell "HEADS UP!". Everybody stand back! Stand way back! The Shadow checks out as super-stable with VCP (3 calibers between CG and CP), but this is the first flight of a substantially modified kit (to me anyway).
The family and friends are excited... but I'm a basket-case. Will both of the motors fire? I had hand-picked the ignitors as the best I had. Will the self-designed baffle protect the chute, yet allow the NC to eject? Am I nuts? Look at the size of that thing! On the launcherpad, it's over 6' tall!
Well, everyone is waiting. Check the field - the only other people there are 200' feet away and stopping to watch too. Check the sky - it's clear, the breeze has actually dropped to nearly non-existent. I have no excuses.
5-4-3-2-1
Mash the wires Dean! Big Whoosh!
Both motors fired and up went The Shadow. Beautiful liftoff! Nice and slow,
acceleration about the same as Big Bertha on a C6-5. Nice straight flight to
about 600'. Lotsa smoke in the calm conditions. She's just
tipping over when the nosecone pops and the chute deploys just like its
supposed to. Okay... I can start breathing again.
Yahoo - I feel good! The recovery team (my son and his friends) bring The Shadow back - complaining of the strong sulphur smell in the smoke that's still wafting out both ends of the BT. The 4 sheets of wadding I used for extra peace of mind are still in there and only looking a little greyish from the smoke. The baffle worked flawlessly. Whew - D motors do stink!
We sent up the SuperShot next on a B6-4 while I got The Shadow ready for her next mission. The fast acceleration of the SuperShot surprized the neophytes in the audience. I had a hard time convincing them that it was the same motor as Bertha's first launch.
Next flight of The Shadow: all ready to go and checked out.
Mash the wires Dean! Whoosh?
This doesn't look right... she's climbing much slower than before. Agghh!
Only one motor has fired! Checking my pulse, OK - no heart attack yet.
But this is first-hand proof of just how stable this rocket really is. Other than lifting slower, she's tracking straight up with only one motor that's about 5/8" off-center. The eject occurs frightening past the very low apogee (maybe 200'), but the chute deploys and brings her in tail-first but kinda hard.
Don't know why the 2nd motor didn't fire, I'll have to examine it later and see if there's any evidence that the ignitor even burned. Well, the heavy aluminum pie-plate I bought for a blast deflector now has a small hole burned right through from the slower liftoff.
Uh-oh... There's very slight BT damage just forward of the main fins. Nothing
serious, but an extra inch in length of the motor cartridge thrust ring
would've prevented this completely. Rats! The BT wrinkle is right in the 1"
gap I left between the motor cartridge thrust ring and the stuffer
tube's funnel reducer. If I'd had a continuous internal structure right up
to the funnel, it would have been strong right up to the top of lower bodytube
coupler. Have to rectify that.
Shadow Motor Mount Details
There's a lot of questions from everyone as to what went wrong. I have to admit that I don't know for sure. But likely the ignitor failed, or I didn't have it in place when I inserted the plastic plug. (BIG white ones for D's)
Meantime, we send Bertha up again on a B6-4. That close call with The Shadow has me nervous. Bertha behaves herself and I start to get my confidence back.
This is the last flight of the day for The Shadow. I only bought two packs of D's. The Shadow is back on the launcher and all ready to go again.
Mash the wires Dean! Big Whoosh!
Straight up - beautiful. This is more like it. She tips over, the NC pops and
the chute doesn't come out...
THE CHUTE DOESN'T COME OUT?!?!
No, wait... there it is - right at the throat of the bodytube. Whats's it doing there? Get out the end!
The Shadow is now on her way down and picking up speed.
Pull the chute out.
Pull the chute out.
I'm feeling sick. It ain't pulling it out. I can see the chute, stuck right
in the top of the tube. What the... why won't it come out?
This is bad, very bad - and then in slow motion and as if screaming "HELP ME!". The Shadow has angled its descent right at me. Okay, don't panic. Do I try to catch it? HEAVENS NO, just moooove!
Whizz - thump! Augered in not 5 feet away.
Waaaaahh! My lovely rocket! On its first day!
Pulling it out of the well-used, not-so-soft soccer field. The top section of bodytube is hopelessly crumpled. The slight wrinkle ahead of the main fins is now worse.
Sniff... I'll be okay.
There's the chute, still right at the top of the bodytube.
WHY? Cripes, I can't even pull it out. What's going on here?
With all the mods I made to this kit, and everything else worked great... the thing I screwed up was the LOC-style shockcord mount. I can't believe it. An end of the nylon cord was projecting out of the epoxy just enough to snag a couple of the chute's kevlar shroud lines and completely prevent deployment. Grrr!!!
But, I think it's repairable. A whole new top tube is needed above the upper baffle-coupler. I also need to straighten and reinforce the lower bodytube by extending the MMT thrust ring right up to the stuffer reducing funnel. More filling, sanding and painting - I hope The Shadow will fly again this summer.