Loadstar II Failure and Crash (REPAIRED)

Well....dang.....The attempt was for NARTREK Silver Payload.

Last month the Loadstar flew perfectly....Booster separated as sustainer ignited....booster fell within 50' of the pad and rocket made a perfect flight to apogee deployment of recovery gear....floated back to Earth with payload intact and undamaged.

Not today....

I don't know what happened....winds were a little gusty but not out of limits or bad, really...rockets were weatehrcocking and arcing over, but the winds would carry them back to us. I had a C6-0/C6-7 loaded up. Just like last month. Payload was different though as I had to make a NAR Competition Payload (70x19mm, 28g). Rocket lifted off and immediately weathercocked into a steep arc, like 45 degrees. As soon as the booster burned out and the sustainer ignited, there was a "pop" and the booster/C6-7 separated from the rocket. The C6-7 went ballistic, flying by itself to an adjacent field, starting a fire. (kinda scary) The rocket coasted to apogee then came in ballistic, destroying the plastic payload bay, payload and transition section. The booster was found later, after I left, so I haven't had a chance to inspect it.

Not sure what went wrong. I think the payload shifted when the rocket weathercocked, increasing the angle. Don't have a clue about the motors....it was like I had them switched...the C6-7 in the booster and the C6-0 in the sustainer...but I know that wasn't the case....I was VERY careful putting them together with a single strip of clear tape. I'm curious if the booster was found with a motor in it......

I can repair the rocket....just needs a new transition and clear payload tube......

Wow! That sucks bud! At least its repairable. Nice paint job on that one!

ereinert said:

Wow! That sucks bud! At least its repairable. Nice paint job on that one!

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Thanks....I sent Estes a note telling what happened and asked about getting replacement parts. All I need is the clear payload tube, BT60 size and the transition piece, from BT55 to BT60. Everything else is good to go.

I talked to the folks with my booster today. They'll bring it to the HPR Launch in 2 weeks....so I'll get that back as well. This rocket is my only payloader. The booster is in good shape, undamaged....and there was no motor in it. Should have been, unless someone removed it.

All things considered...I think, maybe, the tape I used was too strong.

The only problem with ordering parts from Estes is there shipping charges. I was going to order another coupler for my Leviathan so I could make a baffle and went to there website and found the coupler for around $4.00, I said cool and added it to my cart and at checkout they wanted over $10.00 for shipping.. "Empty cart!"

Fred,

Sorry about your rocket.

One idea for replacing the clear tube... instead of going out and buying the assorted clear tubes from Estes... You can go to Home Depot and get a Lithonia Lighting 4 ft. Fluorescent Tube Protector. 4' of clear tubing... Enough to do several rockets with payload sections (plus accurate upscales in the BT-60 tube size), and still have enough leftover to make a 168% upscale of the Cherokee D as a phantom kit.

NOTE: use a scrap of BT-60 to shim the clear tube as the tube is slightly bigger than the stock Estes parts.

ereinert said:

The only problem with ordering parts from Estes is there shipping charges. I was going to order another coupler for my Leviathan so I could make a baffle and went to there website and found the coupler for around $4.00, I said cool and added it to my cart and at checkout they wanted over $10.00 for shipping.. "Empty cart!"

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I'd point you in this direction for DIY tube couplers: Make Your Own Tube Coupler. When it comes to ordering parts, nowadays I either have my LHS order them for me, or I go to Semroc (free shipping).

I'm hoping Estes will send me the parts free.....as far as buying them....I can buy a whole new Loadstar II for $13....I'd go that route.

I like the parts suggestions...that's good for bench stock for repairs and scratch built.....

If you don't absolutely have to have a clear payload section, you can substitute a 5" piece of BT-60 for the PST-60R. You can get a balsa adapter from Semroc or BMS (TA-5560). Did the upper stage motor mount come loose during the flight, or was the motor pulled out of the tube during staging?

One note, I equipped my Warp II with 3/16" lugs so payloads could be lofted with less rod whip than a 1/8" rod. I normally use my Warp II to loft an reverse Astrocam. The lens hood points to the aft end of the rocket and takes a picture during staging.

Fred Garvin said:

I'm hoping Estes will send me the parts free.....as far as buying them....I can buy a whole new Loadstar II for $13....I'd go that route.

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Yeah. I pulled the classic move of leaving the nose cone on the back of my car while building my Patriot and then forgetting about it. Until I heard the crunch next time I backed out of the garage. I ended up buying another Patriot kit for the nose cone. The thrust ring I used on, coincidentally, a Loadstar II to replace one I mis-installed and had to remove destructively, and I'm now using some of the other parts on a scratch build. Thinking about using the fins on a Goony Patriot.

mwtoelle said:

If you don't absolutely have to have a clear payload section, you can substitute a 5" piece of BT-60 for the PST-60R. You can get a balsa adapter from Semroc or BMS (TA-5560). Did the upper stage motor mount come loose during the flight, or was the motor pulled out of the tube during staging?

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That's a good idea....I don't have to have a clear payload bay......easy fix.....

The C6-7 pulled out of the mount....no damage...right at staging...

Multiple points to consider:

1) You could not have had the motors switched because if you did, the upper stage would not have ignited until after the C6-7 (erroneouosly put in the booster) had completeed thrusting and after the seven second delay time when the ejection charge would go off and ignite the C6-0 (erroneously put into the upper stage). I doubt that happened and you can tell by looking at the motor casing in the booster and at the point of origin of the fire.

2) If the payload was already off center, it would make the rocket fly at a bad angle.
3) if you used the standard Estes launch pad with way too short launch rod (30 inches) then this heavy rocket would never have been able to build up enough speed to fly in the direction the rod was pointed. It MUST leave the rod going very fast so that any cross wind is a tiny fraction of the airpeed in the direction you have ppointed the rod. Use a 4 foot 1/8" diameter steel rod or a 5 foot 3/16" diameter steel rod.

4) Were the motors Estes or Quest (obviously the C6-7 was Estes). A Quest C6-0 has decent peak thrust (after a few tenths of a second.....) but the sustaining thrust if VERY low and heavy rockets will fall out of the sky or arc over badly. They are GREAT in lightweight rockets.

5) How were the fins oriented between the two stages? In other words, were they "interdigitated" so that they were spaced far apart, or were the aligned or semi-alinged between stages? Attempts to align multi stage fins can be DISASTROUS as even the tiniest misalignment can create a HUGE aerodynamic force as the air flows between the aft end of the upper fin and the leading edge of the lower fin and creates a massive amount of "lift" just like a flap on an airplane wing (or the vane on the flap of an airplane wing).

6) Short rockets are horrible for stability. Long slender rockets are better and (again) they need a motor and launch pad/rod/rail that can get the rocket up to HIGH speed before it leaves the rod/rail.

2. I should have secured the payload better. It was a NAR Competition Payload that I built...a cylinder measuring 70x19mm and 28g. Plenty of room for it in the bay. Should have cushioned it with some wadding.

3. Club supplied launch equipment. 1/8" rod...probably 36".

4. Both motors were Estes.

5. Interdigitated. Always fly the booster with fins in clean air.

Made this same flight last month and it was textbook perfect. The only differences:

Tape - use Scotch tape (thin, Magic) last month, cheap clear tape this time.
Payload - 5g difference, unsecured. Last month flew my little Apollo Astronaut figure; he fits snug, 23g.
Winds - No winds (or barely a breeze) last month; this launch breezy, with gusts to maybe 15 mph....most of the rockets were weathercocking.....

I'm really leaning toward the tape....cheapo clear tape I just tossed in the kit....upon closer inspection, it's thicker and pretty tough...hard to tear, almost like box packing tape. Last time I used Scotch Magic...really thin, easy to burn through and tear....the C6-7 was pulled out of the sustainer at booster separation and flew by itself. I'm trying to get my head around just how that happened....

Was the C6-7 secured in the sustainer mount with masking tape for a friction fit or did it have a motor hook?

It should not have come loose from the mount if it was firing correctly. Was there any sign on the casing of a cato sich as a burn through of the casing (in this case, a thin channel on the inside of the casing that would allow a small jet of flame to shoot forward and ignite the ejection charge)? if the ejection charge fired early, then the wadding would be scorched. if the C6-7 really fell out of the upper stage, then there would be no wadding scorching of any kind.

Fred Garvin said:

2. I should have secured the payload better. It was a NAR Competition Payload that I built...a cylinder measuring 70x19mm and 28g. Plenty of room for it in the bay. Should have cushioned it with some wadding.

3. Club supplied launch equipment. 1/8" rod...probably 36".

4. Both motors were Estes.

5. Interdigitated. Always fly the booster with fins in clean air.

Made this same flight last month and it was textbook perfect. The only differences:

Tape - use Scotch tape (thin, Magic) last month, cheap clear tape this time.
Payload - 5g difference, unsecured. Last month flew my little Apollo Astronaut figure; he fits snug, 23g.
Winds - No winds (or barely a breeze) last month; this launch breezy, with gusts to maybe 15 mph....most of the rockets were weathercocking.....

I'm really leaning toward the tape....cheapo clear tape I just tossed in the kit....upon closer inspection, it's thicker and pretty tough...hard to tear, almost like box packing tape. Last time I used Scotch Magic...really thin, easy to burn through and tear....the C6-7 was pulled out of the sustainer at booster separation and flew by itself. I'm trying to get my head around just how that happened....

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Yes, the C6-7 was friction fitted with a bit of masking tape. I do not have the booster in my possession but was told it is undamaged and recovered with no motor(s).

The sustainer has no burn damage at all. The wadding is untouched. Looking up the motor tube, it is clean. (and intact) It's as if the C6-7 fully separated from the sustainer, ignited and took off on it's own.

In order for the C6-7 to separate it would need to be improperly friction fitted and/or there would need to be a large force applied directly to the front of the motor casing pushing it backward. Nothing would 'push' the rocket upward away from the motor when it was taped into the mount.

A complete mystery unless there is evidence of a burn channel in the inside of the C6-7 casing.

Fred Garvin said:

Yes, the C6-7 was friction fitted with a bit of masking tape. I do not have the booster in my possession but was told it is undamaged and recovered with no motor(s).

The sustainer has no burn damage at all. The wadding is untouched. Looking up the motor tube, it is clean. (and intact) It's as if the C6-7 fully separated from the sustainer, ignited and took off on it's own.

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Entirely possible the friction fitting for the C6-7 was not adequate. There is no burn damage to the sustainer and the C6-7 is lost.

The Loadstar II has multiple friction fittings:

C6-0 is fitted into the booster, which has a thrust ring at the aft end.
C6-0 is taped to the C6-7
C6-7 is friction fitted into the sustainer, which has a thrust ring at the fore end.
Booster is friction fitted to the sustainer, further holding the taped C6-0/C6-7 motor combo.

In order for the booster to separate, the C6-7 must ignite and push it away. The thrust of the C6-7 burns through the tape and pushes the C6-0 and booster away from the sustainer. (hence, the thrust ring aft on the booster) The forward thrust of the C6-7 "should" have forced it against the foreword thrust ring in the sustainer, holding it in place, no?

I did not find the boooster, but I was the first one to get to have a look at it. The C6-0 was not in the booster when it was brought back to the RSO table.

I didn't notice anything strange about the C6-7 casing when I picked it up after making sure there wasn't a fire (no fire, just tracking smoke). I didn't give it a thorough inspection, but did check it as long as I could hold it. I don't remember there being any masking tape or similar for friction fitting, but again, I wasn't trying to conduct a post-mortem.

The tremendous pressure and heat of the forward end of the booster motor propellant rupturing will be more than enough to melt the tape and push the booster away, even if the upper stage motor never ignites.


This is called "pop and stop" staging.

Tiny motors produce less oomph out the top of the booster. The 1/2A3-0T was pretty weak and would not always ignite upper stage motors with tiny nozzles (like the 1/2A3-4T). A C6-0 has a larger surface area and less volume, so it will pressurize big time. A D12-0 will produce an astounding amount of flaming plasma and pressure.

Fred Garvin said:

In order for the booster to separate, the C6-7 must ignite and push it away. The thrust of the C6-7 burns through the tape and pushes the C6-0 and booster away from the sustainer. (hence, the thrust ring aft on the booster) The forward thrust of the C6-7 "should" have forced it against the foreword thrust ring in the sustainer, holding it in place, no?

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AlfaBrewer said:

I don't remember there being any masking tape or similar for friction fitting, but again, I wasn't trying to conduct a post-mortem.

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I have to wonder if what I'm remembering is friction fitting the C6-0, taping them together....and omitting the friction fit on the C6-7....that would make sense.....

In that case, as the booster thrust started to drop off and before it burst through the tape and ignited the upper stage motor, the drag from the booster fins would hold the booster and attached motors back while the upper stage mass (heavy payload) kept it moving because of it's momentum. The booster would then 'drag separate' from the bupper stage and then a split second later the upper stage motor ignited and flew off on it's own.


Staging is called the "train wreck".

Fred Garvin said:

I have to wonder if what I'm remembering is friction fitting the C6-0, taping them together....and omitting the friction fit on the C6-7....that would make sense.....

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shreadvector said:

In that case, as the booster thrust started to drop off and before it burst through the tape and ignited the upper stage motor, the drag from the booster fins would hold the booster and attached motors back while the upper stage mass (heavy payload) kept it moving because of it's momentum. The booster would then 'drag separate' from the bupper stage and then a split second later the upper stage motor ignited and flew off on it's own.


Staging is called the "train wreck".

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Given the post-mortem described thus far, this was my independent conclusion. The ballistic coefficient of the upper stage, especially with the near 1-ounce payload, far exceeded that of the booster. Combine this with a loose booster and 2nd stage motor and the booster drag separated taking the 2nd stage engine with it.

TheAviator said:

Given the post-mortem described thus far, this was my independent conclusion. The ballistic coefficient of the upper stage, especially with the near 1-ounce payload, far exceeded that of the booster. Combine this with a loose booster and 2nd stage motor and the booster drag separated taking the 2nd stage engine with it.

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Thanks guys for the analysis and thinking about this.....helps me to know what most likely happened.....

shreadvector said:

In that case, as the booster thrust started to drop off and before it burst through the tape and ignited the upper stage motor, the drag from the booster fins would hold the booster and attached motors back while the upper stage mass (heavy payload) kept it moving because of it's momentum. The booster would then 'drag separate' from the bupper stage and then a split second later the upper stage motor ignited and flew off on it's own.

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I like this theory, but my Loadstar II separates much more easily at the nose/sustainer break than at the sustainer/booster break. Accepting the assumption that the momentum of the payload and the drag on the booster's fins causes a separation event to occur (while ignoring the potential drag contribution of the sustainer's fins compared to the booster) and assuming that Fred's Loadstar came out similarly to mine with respect to separation friction, wouldn't it be more likely for the nose cone to have come off during the staging event than extracting the sustainer motor from the sustainer airframe if this mechanism were the cause of the failure?

Fred - At which break did your Loadstar II separate more easily?

(Not trying to be argumentative, just trying to understand the all the forces at work in this theory in the hope that I can avoid a similar fate for my Loadstar.)

I'm the other Fred, not the model owner.


You are correct in your assumptions and your questions. The nose coming off during the "train wreck" is the most common multi-stage failure I observe.

We'll see if he added tape to the shoulder or if he commonly has a bit of the shock cord or shround lines crammed between the shoulder and the inside of the body tube.

KevinM said:

I like this theory, but my Loadstar II separates much more easily at the nose/sustainer break than at the sustainer/booster break. Accepting the assumption that the momentum of the payload and the drag on the booster's fins causes a separation event to occur (while ignoring the potential drag contribution of the sustainer's fins compared to the booster) and assuming that Fred's Loadstar came out similarly to mine with respect to separation friction, wouldn't it be more likely for the nose cone to have come off during the staging event than extracting the sustainer motor from the sustainer airframe if this mechanism were the cause of the failure?

Fred - At which break did your Loadstar II separate more easily?

(Not trying to be argumentative, just trying to understand the all the forces at work in this theory in the hope that I can avoid a similar fate for my Loadstar.)

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I have always been leery of taping motors together when it comes to staging and I never do it. In fact in the early days, Estes instructions had taping as a standard method until they started encouraging "pop & go" staging. This would be without taping the motors together. And I can honestly say that I have never had a problem with pop & go. I just had to make sure my stages fit but not too tightly.

The payload bay tube to transition section was extremely tight and could be considered a permanent connection.

The nosecone was snug and the access point to the payload bay. It needed no tape on the shoulder.

The transition section to body tube was fitted well. No tape on the shoulder. It would stay in place when held by the nose, but would pop with slight effort to deploy recovery gear. No issues there, and if part of the shock cord or chute lines got caught you'd have to apply quite a bit of force to get it together. Certainly didn't happen.

The booster section was a very snug friction fit. So much so I sanded the collar down quite a bit to get it loosened up. Even so, it was still a snug fit.

The rocket proofed perfectly last month on a C6-0/C6-7....booster separated and tumbled back within 50' of the pad. Rocket staged and continued, deploying recovery at apogee and floating back to ground a couple hundred feet away. It was a great flight. I bet Sam remembers it.

Fred Garvin said:

The booster section was a very snug friction fit. So much so I sanded the collar down quite a bit to get it loosened up. Even so, it was still a snug fit.

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Sounds just like mine - the point I was getting at above is I think it more likely that the "train wreck" would have caused it separate at the payload transition/sustainer break than at the booster/sustainer break. That doesn't mean that's not still what happened, I admit it's an elegant explanation. I just don't understand why it would have happened this way given that it was more likely to separate someplace else.

Fred Garvin said:

The rocket proofed perfectly last month on a C6-0/C6-7....booster separated and tumbled back within 50' of the pad. Rocket staged and continued, deploying recovery at apogee and floating back to ground a couple hundred feet away. It was a great flight. I bet Sam remembers it.

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I've never used that combination myself - I've used B6-0 in the booster many times, and D12-0 once (using my Loadstar 2.5 booster) but never the C6-0. Even with the D12 booster however I'm still only using a C6-5 sustainer motor and I've only got a 10g altimeter as a payload.

I had a NAR Competition Payload.

The booster separated from the rocket. The C6-7 separated from the booster and the rocket, and flew by itself. The rocket remained intact until impact with the ground.

I have a payload section and transition if you want.

Yes please, and thank you. I responded to your PM with my info....