You just described Discontinuous Staging (tm) which is in my AIR-3 report included in all clustered and staged kits. I used it in scale competition in an Aerobee 350 which has a staging structure between the Nike and the Aerobee. Mine was BT-60- to BT-70 and both stages recovered by parachute. I flew it and copies of it at many scale contests including Sunnyvale (Barber judge) and Phoenix (Stine and barber judge), High thrust composite E to D12-3.

Jerry

http://v-serv.com/crp/monographs.htm

Since the subject of the thread has changed fromgap staged recovery to straight gap-staging:

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Edmonds Aerospace CiCi Stage 2 is a kit that was released that relied on gap staging, and the booster section recovered by gliding. There was also a 24mm thunder version of this kit.

kj

We have the 2225 and 2650 in stock and Apogee (or U.S. Rockets) has the 3100 in stock. All use direct gap staging with a mixing chamber.

1002 Hi-test-2225 $49.95 http://v-serv.com/usr/kits/hi-test2225.htm
1001 Hi-Test 2650 $99.95 http://v-serv.com/usr/kits/2650.htm
1074 Hi-Test 3100 $109.95 http://v-serv.com/usr/kits/3100.htm
1033 Triple Trouble $39.95 http://v-serv.com/usr/kits/tripletrouble.htm

These are unbelievably reliable clustered staged rockets that accept popular 18mm, 24mm, and 29mm BP motors. They can also use composite APCP motors with either Discontinuous Staging (tm) or electronics actuation, or pad departure actuation.

Tech Jerry

Funny, I've had multiple inquiries at the range asking whether my Centuri was a 2-stager.


...and probably only about 3 seconds of actually seeing it.

Those motors have propellant with a light smoke trail. Heavier delay smoke. I saw my E6-0 to E6-8 flight to 1991 M in Sunnyvale (1980's) to apogee and recovered all parts. It was optically tracked at a NAR contest.

Bundick has my permission to post the flight cards from that event! Especially all my flights.

Jerry

Jerry,

A little history, please. How did you come up with that arrangement? Had you had failures with direct cluster staging or was this a pre-emptive design to prevent failures? Did you ever do any ground tests with just two booster motors and 3 sustainers to see if they all lit. Just really a novel and clever appearing arrangement I've not seen elsewhere, so I'm curious.

Steve

You've brought up something else that would be great for scale realism, especially for scale models of boosted single-stage sounding rockets such as the Aerobees (I like the cut of your modeling jib, tbzep! That's a much nicer booster than the original MMI one!) and the Iris, HYDRA-Iris, Cuckoo-boosted Skylark, INTA-255, and Boosted Arcas I, although it would likely be difficult to do *reliably* without an electronic, accelerometer-triggered sustainer ignition system:

Such scale models in which the booster and the sustainer fired in parallel would provide high launch acceleration (plus realistic "in-line" double exhaust plumes and smoke trails, as with the full-scale vehicles), yet the sustainer could--if desired--use a low-thrust, long-burn motor. Not only would this also be realistic for scale models of some boosted single-stage sounding rockets (the INTA-255 and the Boosted Arcas I had relatively low-thrust, slowly-accelerating sustainers [after their boosters dropped away following burnout]), but such models could reach high altitudes using lower-impulse, cheaper sustainer motors (because they wouldn't reach top speed immediately, then waste it fighting drag soon after launch).

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Our open air gap staged Aerobee Hi flights were 100% successful. The particular photo is the third flight staging at low altitude with an A8-0 to B6-4. No enhancements needed, no fuses, no electronics.
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It was simply an intuitive design that in practice worked out. I don't think I ever did a single ground test until I made my first motor. Always flight tests. Why waste the motor? That particular configuration was first tested in my Enerjet 2650 which came 1 stage but I added a stage to it so I could fly 3x F100-0 to 3x F100-10. After many such flights I later did 3x F67 to 3x F67 and 3x F67 to 3x G76. Once I did the U.S. Rockets version of the 2650 in circa 1980 I was able to obtain H motors as well. Once I made motors I was able to "obtain" J motors as well. Probably my most satisfying flight with a U.S. Rockets 2650 was 3x H240 to 3x J160.

The 2225 came along almost a year later along with a bevy of U.S. Rockets kits, about a dozen with BT-70HD I call BT-22.

The Hi-Test 2225 was one of the most popular rockets at LDRS-1. There were several Hi-Test 2650's as well.

Jerry