So I got a Hawk as a bonus on an order last year, and despite my poor results with gliders, I built it anyway. Wednesday I flew it for the first time, and it nose dived. So... what do I do to fix that?

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NAR # 115523
Once upon a better day... SAM #0076
My site: http://rocketry.gonnerman.org

Nose dived in boost or in glide?

If glide, add some weight to the tail.

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Bob Harrington
NAR #62740 L1
AMA #46042
CMASS & RIMRA Member

Add weight to the tail? I'm assuming that you trimmed it out before flight.

My understanding is that the Semroc Hawk performs best when built without sanding sealers, paint, or primers that weigh it down.

I finished mine using permanent markers.

OK, now listen carefully.

This is from years of trimming stick and tissue rubber band airplanes.

When making adjustment for glide make one and only one change per trial!

I cannot stress this enough. Otherwise it will just be another lesson in frustration.

Add or subtract weight, do several test tosses to see what it does remembering what you just adjusted.

If that does not work go back to the original setting, if you added weight take it off.

Then try one more adjustment either ellevon, rudder, weight whatever but ONLY ONE change!

If that doesn't work go back to the previous sett.

After a while you will get the hang of it but you have to keep going back to your original setting almost every time.

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"I'm a sandman. I've never killed anyone. I terminate runners when their time is up." Logan from "Logan's Run"

http://sandmandecals.com/

Sandman's trimming info mirrors my own, and some of you on here *KNOW* how that can be!

What I'd suggest for such a small glider is to use an 'easy' trimming weight, most likely a small paper clip. From the sound of your post, just place this over the tail, preferably on the underside of the rudder. Test toss....multiple times. If the bird is now stalling, move the small clip to a point more forward. Test again.

You should likely 'hit' what looks like a good trim point soon enough. Im also assuming that you *DO* have some decalage in the stab, right? If not, and it is a 0-0 config, then you may have unmitigated h*ll trying to 'lock in' a valid trim. If you seem to be stuck between stall and dive with only the slightest weight shift, then you are in this boat.

One 'hack fix' for such a deal is to add VERY SMALL elevon tabs to the stab, one on each size. Just use tape, fold it over itself, leaving no more than 1/8" extending beyond the aft edge of the stab. Bend these up slightly, and toss. You may find you need that small paper clip now as NOSE weight, and this is actually preferred. IN no case should you have to bend the 'elevonettes' up much at all, or youll throw off the boost for sure.

Now, if you really want to build a no frills cannot miss glider, please dig up my SkyDart LV plans and info on this Forum. Slap one of these together and you will wonder where stuff like this has been for so long.....

Totally agree with the advice from Sandman.
ONLY make one change at a time...otherwise you will never know which change made the difference.
Gliders are not THAT hard...you just have to be patient with them and always trim before first flight.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.

That would be a bad assumption.

Seriously, I suck at gliders. The last two I built, both of which are now lost, I killed hours trying in vain to trim... probably because, despite the best of explanations, I really don't understand what I'm doing.

Up I do good. Parachutes I do good. Gliders I suck at.


I took that to heart with my Tinee... and I don't have it anymore. Not that it glided... it nosedived, actually, right into a beanfield.


Gah. STILL a lesson in frustration. As I mentioned, I spent a lot of time trying to trim two other gliders. Admittedly, one was a Sparrow, which I'm told is hard to trim. Paradoxically, it actually sort of glided, though not well, and was lost on its second flight.


Hmm. I might just have to do that.

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NAR # 115523
Once upon a better day... SAM #0076
My site: http://rocketry.gonnerman.org

Here's a spot with some clear tips / hints:

http://www.gryffinaero.com/models/f...ps/hlgtips.html

Or look at stuff for catapult gliders like the attached PDF.

Attached Files

catapult.pdf (14.2 KB, 300 views)

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A dark night in a city that knows how to keep its secrets. But high above the quiet streets on the 12th floor of the Acme Building, one man is still trying to find the answers to life's persistent questions. Guy Noir, Private Eye.

Sounds like the motor failed to eject.

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Nah, I saw it eject, and it was absent when the rocket was on the ground.

Guy, I printed out that web page, but I haven't had time to read it over yet. Thanks!

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NAR # 115523
Once upon a better day... SAM #0076
My site: http://rocketry.gonnerman.org