Flight Log for 24 March 2001, 60 Acres Park, Redmond, WA

Overcast appr. 3000' AGL, wind SW 5-10, changing to partly cloudy and wind variable 2-5
Model Flt 
#
Recovery Type Motor Comments
Luna 2-18 Express
7
18" plastic parasheet
2x Estes B6-4
First flight of the day, rod angled to compensate for the wind.  Both motors lit right up, and the boost and coast were nominal, but the parachute (packed in my flight box for more than a year before being swapped in to replace the Quest 14" that stripped on the last flight) failed to fully open; the resulting partial parachute brought the model down pretty sharply and again hinged the one radiator fin that had been hinged previously.  I was able to get some CA at make a field repair a little later.
BBBertha!
21
12" plastic parasheet
Estes B6-4
By way of demonstrating that the 2-18 Express flies much like a Bertha, but with two motors instead of one, I launched my BBBertha! on a single B6-4 -- and sure enough, it flew much the same.  The Bertha goes a bit higher, but not very much, and the recovery walk was similar.
Astron Cobra
15
18" nylon X-form
3x Estes A8-5
Using up the last of my A8-5 motors before they expire from certification at the end of June.  All motors lit immediately and the boost was spectacular, if short -- the sound of 3 A8 motors all burning at once warms the cockles of my heart.  Coast and recovery were nominal, and a short walk ensued.
Astron Cobra
16
18" nylon X-form
3x Estes B6-6
The first flight was so good I had to do more -- so loaded up some B6-6 and off she went again.  Once more, ignition was prompt and simultaneous; this time the rocket went higher and faster, of course, but still landed back on the field without any problems.
BBBertha!
22
12" plastic parasheet
Estes D12-5
Conditions were improving, so I decided to give the Bertha a ride on the motor it was really built for.  Loaded up, touched it off, and watched it streak skyward -- as opposed to arcing downrange as expected; it seems the higher velocity gave it a similar amount of downrange travel as on the B motor, but much more than twice the altitude.  Even so, the rocket comes down smartly on the 12" parachute, and recovered only a few feet into the (closed) soccer fields across the road from the launch site; had we been set up on the south edge of the field, as we normally are, instead of the north edge, which was accessible with the field drive closed, recovery would have been on field.
Cherokee-D (2)
26
12" plastic parasheet w/ spill and vents
Estes C6-5
I suppose this shouldn't have come as a surprise, given the age of this model, but the shock cord pulled out of its mount on ejection of this flight, resulting in a lot of drift for the nose cone (which was, however, recovered) and the body streamlining in from several hundred feet.  Fortunately, BT-55 is sturdy stuff, and the rocket was so stable that it landed perfectly aligned with its velocity; as a result, the body tube took a neat core sample of the soft ground rather than crumpling.  Only a new shock cord mount will be required.
Luna 2-18 Express
8
18" plastic parasheet
2x Estes B6-4
I looked for C6-5 motors, but could find only one remaining in my stash -- I obviously need to reorganize my motors and make a shopping trip to buy more.  I loaded with what I had, and sent the 2-18 Express off again.  This time, the two motors didn't light quite simultaneously, and the rocket again coned strongly as the anhedral in the main wings converted what might otherwise have been a pinwheel flight into a survivable, if somewhat low excursion.  Recovery was completely nominal, with the parachute opening fully and the rocket descending gently, no new damage.
BBBertha!
23
12" plastic parasheet
Quest C6-0/Estes C6-7
I wanted to try something different, so I set up to stage the Bertha by taping the motors together -- I've done this several times before with good results.  This time, disaster struck.  The nozzle in the C6-0 was defective, eroding or chipping almost instantly on ignition and resulting in a very low thrust burn; the rocket staggered into the air, instead of lifting smartly, turned over and started to cruise missile, and I found myself hoping for a staging failure -- but no such luck.  Upper stage ignition was successful, with the rocket pointed about fifteen degrees below horizontal; the result was my first power prang as BBBertha! slammed into the base of a blackberry bramble at near maximum speed.

The impact was enough to shatter the nose cone (I think it struck a rock), as well as driving the base of the cone deep into the recovery compartment, tearing both the compartment and the main airframe tube.  In addition, the motor mount detached, failing the rear centering ring (again).  I don't expect to rebuild this rocket, though I may salvage the fins and motor hook.

I plan to contact Quest to report the failure of their motor, and assuming they offer me a replacement rocket, I'll probably get either a Big Betty or a Courier -- and order a couple bulk packs of A6-4 and B6-4 while I'm on the line.  I've already filed a MESS form with the NAR.



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