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B Rocket Glide

For NARAM-51 the Rocket Glide event is for B engine class.

Rocket Glide combines the challenge of building and flying a glider which remains in one piece for the whole flight, which can boost relatively well (and hold together) on rocket power, and transition to a long gliding flight.

In Rocket Glide, the glider must remain in one piece for the whole flight. Nothing can come off - no pop-pods, no parasites, no ejected engine. It cannot be staged. The glider must be returned for one of the two flights allowed.

Flex-wing (Rogallo/hang glider) type gliders are not allowed.

For the full rules for this event, please see the Rocket Glide Rules on the NAR web page.

Scoring - For Rocket Glide, the scoring is the total of two flights allowed, but at least one of those flights must have the glider returned.

Design considerations - Difficulty of making and flying a glider that does not have any parts come off in flight (Often with a design that uses some sort of moving parts like a sliding wing or sliding pod). Trade-offs of high glider performance and visibility with surviving rocket boost, and trying to get at least a reasonable boost altitude.

Rocket Glider designs are more specialized than Boost Gliders, so it is not recommended for newer fliers to try to design their own. Best to go with a kit such as those below, or a plan. With experience, you might later develop a knack for designing your own gliders, but it's best to learn from something proven first.

A list of plans and kits is included further down on this page.

Designs - Many basic design approaches have been used for Rocket Glide. Here are a few:

Slide-Wing - The wing is mounted in a manner that allows it to slide along the fuselage, so the wing is towards the back for launch (moving the CP rearward), then at ejection moves forward for glide. They tend to boost very straight. The wing slide mechanics are somewhat more difficult to build than others, but it is usually worth it.

Slide-pod - A long engine pod about the length of a normal pop-pop is used. The pod is forward on boost (making the CG forward like a normal pop-pod B/G) then at ejection slides back so that the CG is where it needs to be for glide. It is a reasonable approach which usually boosts OK, and is easier to build than a slide-wing. Well-made slide wings tend to perform better than well-made slide-pods. Slide-pod models use a telescoping external tube glued to the pylon, such as 20mm telescoping tubing, for a BT-20 sliding pod tube to freely slide inside of.

Auto-Elevator - A design which does not move the wing, or move the CG, but changes the angle of the elevator (or canard). The elevator has to be flat (straight) for boost so there is no incidence angle between the wing and tail, so the model will boost straight. For glide, the elevator moves up (or canard trailing edge moves down). This is often one of the simplest and easiest rocket glider designs to use. Although depending on the particular model design, the performance potential might be compromised.

The Xebec-B is an auto-elevator design, which is easy to build as R/G's go. But it is somewhat finicky as to how straight it boosts, varying from model to model (and sometimes modeler to modeler). Usually it if does not boost straight, it pitches up a bit onto its back, due to unintended slight up elevator angle.

Swing-Wing - Originally a definitive early design for Rocket Gliders, the wings pivot from rearward for boost to forward for glide. They are neat to see fly and deploy, but tend to be too heavy and complex to be competitive other than in the higher engine classes. For B engine class, it's not very competitive.

No Moving Parts - A special design that, as it's name says, has no moving parts. So, it is about the simplest Rocket Glider to build (That has wings, anyway). This approach was tried when the event was first created, but only experts had any decent success trimming their models to boost straight and transition to a glide. More recently, Kevin Wickart has come up with a design called the "Mediocre Fred", which is not as finicky as the early designs, but must be built exactly as described. It was a plan in Sport Rocketry magazine, and also is available online on the WOOSH website. It is designed for D power, but can be flown on a B6-2. Ideally, for B class it should be scaled down.

"Backslider" Superroc Rocket Glider - Bob and Peter Alway wrote a winning R&D report resulting in the "Backslider" plan. It is a type of super roc rocket glider, which is basically a long skinny "normal" rocket going up, that glides down backwards using lift from the long body tube and fins (read the report to understand how). It does not glide very well compared to normal R/G's, but has been used by some for qualified flights and "return" flights. And in some smaller contests has taken places when used as the primary (or only) model a competitor flew. Depending on the resulting CG due to the parts used and assembly, a given Backslider model might require a little bit of clay (not too much) to be added to the root of one fin to make sure it glides backwards, rather than falling horizontally (which is not a glide).

Some Stiletto Slide Wings built by Jim Stum, Chad Ring, and David Woebkenberg:

Deployment magic - The above R/G designs (excluding the Backslider and No Moving Parts designs) use the ejection charge only as a starting point to cause the design to go from rocket boost mode to glide mode. Usually rubber bands are used to make the wings slide, pods slide, wings swing, or elevator to move. What keeps them from moving until ejection? Usually a burn-thread which is rigged to hold the model in boost mode. At ejection, the thread burns, allowing the rubber bands to do their thing.

Burn Thread Prep at Nose

Slide-Wing Prep

Slide-Pod Prep

Swing-Wing Prep

For Auto-Elevator prep, see the Xebec-B plan. Only a light pull is needed to make the elevator pop up: instead of a rubber band, elastic thread tied into a loop of the proper length should be used. A too-strong pull might make it difficult to force the elevator flat for boost.

The burn thread needs to be thin so it will burn easily. The button and carpet type of thread that Estes uses for shroud lines is too thick for anything short of a D12 ejection charge to burn. So use a finer thread. I prefer to use white elastic thread, which will snap free when it burns.

The rubber bands need to be selected carefully. Do not grab just any rubber band and try to force it to stretch really far, as it might cause the model to actually break itself when the band force causes the model's parts to slam into each other too hard at ejection. Look for rubber bands with 1/16" cross sections, in various lengths, at Office Supply type stores. Look for the classic pale brown latex bands, colored bands tend to not stretch as much. While the band should not be stretched so much that it causes excessive force, it should not be relaxed at the end of travel so that there is slack, as it might not deploy the wings, pod, etc, 100% as it needs to. This is not hard to get right, just it can cause trouble if it's overlooked.

Building Gliders - Jeff Vincent's Nocturne Slide-Wing Rocket Glider plan includes a lot of useful instructions on how to build, trim, and fly a Rocket Glider. It also includes some information on how to rig up the thread and rubber band system, useful to know for any slide-wing. The written article is here, and the 11 x 17" plans are here.

Ed LaCroix created some fantastic instructions for the Maxima A Boost Glider kit, from the time when Ed owned and ran Apogee. The instructions are so in-depth that they are a must-read for anyone wanting to learn more on how to build, trim, and fly rocket boosted gliders of any kind. Please note that the Maxima is a BOOST Glider, not a Rocket Glider, so that design is not legal for this event. But the general "how to build and fly glider" information in those instructions is very useful.

Kevin Wickart wrote a nice short article on how to do quick and easy airfoils, on the WOOSH section's website. Click here to read it.

A VERY nice sanding block, useful for gliders, helicopter, and any rocket really, is an all-metal 2-piece clamp-type sanding block made by Red Devil, carried by most Ace Hardware stores (look near where they stock sandpaper). It has a 1/8" foam rubber backing sheet, which ought to be removed since it allows rounding things too easily in 3-D when you usually want to shape in 2-D at a given time (as with a wing). So, remove the rubberized portion. That sanding block holds a 4.5 x 5.5" sheet of sandpaper (quarter of a 9 x 11" sheet), with a 3.5 x 4.5" sanding surface area on the block. This works far better in most cases than a narrow sanding block. Of course, the wings (or fins) should be shaped and finished before they are glued to the fuselage or model.

When doing very rough shaping for wings, 80 to 120 grit sandpaper is good to grind off a lot of wood in a short time. Don't over-do it though by sanding off too much. Then go to finer grit like 180 to 220 for finer shaping. Beyond that, 280/320 paper, is sort of a cross between final shaping and setting up for a final finish. A final finish for bare balsa is to use 400 grit paper. Get the "black" type wet or dry sandpaper, it sands better and lasts longer than the reddish types. If you use any clear dope, use 320 to 400 grit paper before and after.

Glider Finish - Never use paint on a contest type glider. For newer fliers, no finish is usually fine. You don 't want to weigh the model down too much and maybe having warpage problems. If you want to improve the finish, use some thinned clear dope in one or two light coats, sanding before and after with 240 and 400 grit sandpaper. The idea is not to add significant weight or cause the wood parts to warp. Some fliers like to use a Japanese tissue finish, but that is more for experts and to an extent is overkill for B R/G's.

Coloring - OK, so bare balsa (even with clear dope) is not easy to see in the air or on the ground. Use a large black magic marker to color the bottom of the wing and tail surfaces black, as that shows up against the sky pretty well. Use a large red or orange magic marker to color the top surfaces. If you can find true fluorescent markers (not to be confused with wimpy fluorescent highlighters), an orange or red/magenta fluorescent color is highly recommended.

Glide trimming - It is an understatement to say that it is very important to trim the glider to glide properly. It's not easy to describe just how to do so.

One mostly universal tip is to have the tail of the glider and the wing to not be parallel to each other (zero incidence). There ought to be a little bit of "up elevator" angle in the tail, relative to the wing, to make the nose pull up a bit. Some plans/kits may be quite specific, and in those cases go with what they say (for example the Xebec-B auto-elevator design requires absolute zero incidence for a straight boost, then up elevator for glide). Note that free flight model airplane experts sometimes prefer zero incidence, but they are deeply experienced (usually) to have just the right touch and experience to get away with it.

The above being said, one of the simple ways to achieve slight up elevator effect (without adding too much) is to build the model zero-zero (wing and stabilizer parallel to each other), then warp the trailing edge of the stabilizer up. Make sure that the fuselage itself is not warped "down" - if it is warped at all, better to be warped "up" relative to the wing and stabilizer.

Special trimming notes for Rocket Gliders -

  • Always trim with a burned-out engine casing in the model, using the same engine type you will fly it with. If you trim with no engine, or an unfired engine, the CG you try to trim for will not be where the real flight's glide CG will be.
  • For Slide-Wing models, do not glue the forward wing stops on before going out to do some basic trimming. Use tape to hold the wing from sliding along the fuselage, and do a few trim throws to see if you have the wing in the right ballpark location. If the model seems tail heavy, move the wing back a bit, and re-tape. If it seems nose heavy, move the wing forward a bit, and re-tape. When it seems to be in the right spot, use a pencil or pen to mark on the fuselage exactly where the wing should stop, then later glue the stops on at that location.
  • For Slide-Pod models, do not glue on the glide position stop ring (near the front) to the slide pod until you've done a similar series of rough glide trim tosses as described above for slide-wings, in order to determine where the slide pod should stop for glide.
  • For Auto-Elevator models, the trimming is unique. The elevator needs to be absolutely flat on boost, so the model will boost straight. Auto-elevator models tend to be designed a bit nose-heavy, so there should be no need to add any noseweight. So the way to trim an auto-elevator model (at least as far as pitch trim), is to adjust the elevator angle until it glides properly. If it stalls, adjust for less elevator. If it goes into a shallow dive or just feels like it is gliding too fast, adjust for more up elevator.

General trimming tips from a number of different sources:

Estes Boost Glider Technical Report, written by Tom Beach (pdf file from Estes Educator website). An excellent article with many illustrations, that cover a wide range of areas involving Boost Gliders and Rocket Gliders, including trimming. HIGHLY RECOMMENDED.

Kevin McKiou's Basics of Design and Trimming of B/G's and R/G's. Items 1 thru 5 are useful only if you are designing your own, or modifying an existing plan/kit. Items 6 thru 9 are useful for trimming gliders for optimum glide performance.

Again, Ed LaCroix's instructions for the Maxima A Boost Glider has trimming tips.

Hand Launch Glider trimming tips for beginners, from a British Free Flight model airplane site. The latter portions about hard throws (necessary for contest HL gliders) is not too relevant for rocket boosted gliders (since the F/F HL glider fliers's hard upward throws are their equivalents to our rocket "boosts"). Note the basic glide trim info and illustrations at the top of the page.

Launching - Set up the glider on the pad so that it faces into the wind. This means the wing bottom faces upwind, and the wing top faces downwind. Actually the dihedral effect will usually try to make the glider face that way.

Some people prefer to make their own glider launcher that has the launch rod mounted onto a 3/8" or 1/2" dowel, so that the whole rod can be used for guidance.

A classic launch problem is for the micro-clips to fall at ignition to grab onto the glider wing or tail, causing damage or even disaster. Some prefer to tape the clips to the rod so they can't fall, which is effective but a bit messy. Others like to use an umbilical approach. They arrange for a separate launch rod, dowel, or other structure to hold the micro clip wires away from the glider, so when the clips fall they will not fall straight down, but swing away in an arc from the glider. A simple umbilical is to use a piece of 1/4 x 1/4 spruce 18" long or so, and cut the bottom at a very sharp angle that is about 30 degrees from vertical. Then glue a launch lug to the angled part. That way, the spruce umbilical can be slipped over the launch rod, umbilical angled at 30 degrees from the rod, ready for the micro-clips to be attached to it. Put your name on it, since the next person to use that pad will probably want to remove your umbilical.

Clips attached to an umbilical

More Information:

Engine recommendation for B Rocket Glide:     

B4-2 (Most R/G designs need low thrust to reduce boost stress, and a short delay)


B6-2 (Heavier R/G's that can take a B6, such as an R/G designed for C6 power)


B6-4 (Backslider Superroc type R/G's only)

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Model Plans & Kits



Nocturne Slide-Wing R/G article (NAR website)
The accompanying 11 x 17" plans are here)

Plan by Jeff Vincent, of ASTRE

Competitive slide-wing plan. Article has a lot of generally useful information beyond the plan itself.

Stiletto-B Slide wing plan (pdf file)

Plan by George Gassaway

Competitive slide-wing plan

QCR - "Easy Slide" slide wing and slide pod kit series by Ken Brown

Kits by Ken Brown - QCR - Qualified Competition Rockets

Competitive kits. See QCR's website for the various slide wing and slide pod designs they offer.

Future B R/G kit by Edmonds Aerospace

Kit by Rob Edmonds - See notes at right

Rob Edmonds is working up a B R/G kit for NARAM-46. When it comes out, this page will be updated.

Xebec-B auto-elevator plan (pdf file)

Plan by George Gassaway

Easy to build plan that can be a bit touchy on boost.

XP-2 Swing Wing R/G plan (pdf file) NAR site

Plan by Chris King, based on Al Nienast's design

Swing wings are not as competitive as some other designs. But if swing wings interest you more than the others, this is a good one to build.

Backslider Superroc Rocket Glider plan
(Internet Archive of Peter's old AOL site)

Plan by Bob & Peter Alway

From their winning R&D report. Not a competitive model, but the simplest to build R/G that there is.

    1 meg pdf file

Great glider instructions by Ed LaCroix.

The Maxima is not legal for R/G. But the instructions are a must-read for how to build, fly, and trim any rocket boosted glider

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Last Updated  6/30/2009