Explanation of terms please

[JAL3]

I'm not a glider guy so I am not really conversant with all the nuances of the terms. I would like some clarification if you please for the following:

boost glider
parasite glider
rocket glider

I have an idea in my own mind for the definitions but that is based on obervation an not paying a lot of attention.

boost glider: a glider with a rocket pop pod like the Semroc Swift BG

parasite glider: a rocket with little glider thingies that fall off at apogee such as the Estes Shuttle XPress

rocket glider: a glider where the motor housing stays with the glider for the entire ride like the Squirrel Words Red Baron

Are these accurate conceptions?

 

[jsdemar]

Your descriptions are correct!

 

[JAL3]

Your descriptions are correct!

Thanks!

 

[BobH48]

rocket glider: a glider where the motor housing stays with the glider for the entire ride like the Squirrel Words Red Baron

The Squirrel Works Red Baron ejects the motor so it's a boost glider also but you have the concept correct.

A rocket glider is where the motor casing stays with the glider the entire time.

 

[JAL3]

The Squirrel Works Red Baron ejects the motor so it's a boost glider also but you have the concept correct.

A rocket glider is where the motor casing stays with the glider the entire time.

I was making the motor housing the distinguishing feature as opposed to the motor casing. Based on what I understand from you, the Baron would be a boost glider although it does not have a pop pod?

 

[AstronMike]

To be certain, a Boost Glider is *anything* that involves *something* separating from whatever boosted upwards together - this would even include the subset of Parasite Gliders.

You mentioned about the pop pod on a Swift BG, but bear in mind that rear ejection pods fall under this too (and I of all people should know!), as does any other ejection based 'thing' that makes something eject or otherwise separate in order for the rest of the vehicle to glide back.

Even the types that eject a forward section and glide back, with no onboard moving parts, count here - look up the Astron Triple Eagle, which BrianC here and myself fly incessantly to good effect.

Now, to muddy the water a tad on "Parasite Gliders"......what if you take two gliders that normally fly on their own and add them to a central carrier which then hauls both of them up and dumps them at apogee? I still consider the aformentioned two gliders in this case as 'parasites' even though they can and do fly independently - very few true parasite gliders can do this.

The term "Rocket Glider" has been thrown around and abused forever. Of course, this only refers to something that goes up - and then glides down - without ejecting or separating anything whatsoever.

And finally, what do you call a vehicle that consists of a large SkyDartish glider with a rear ejection pod that upon ejection winds up becoming a flexie glider of its own? Did the internal glider eject the 'outer' one or vice versa?

And, please do not ask me about 'Flexie Rocket Egg Glider', or I will turn into Shreadvector II with my explanations! :surprised::eyepop::eyepop:

 

[JAL3]

I was afraid of this.

I asked the question mainly to better organize the gallery section. It seems it will be less simple than I thought or hoped.

 

[MrGneissGuy]

I am not well versed enough to answer your question but did do some research on what it would take to add rc control for the descent of a boost glider and (not to add to the confusion but...) there is apparently a difference between BOOST gliders and boost GLIDERS. I won't even tryto explain that as I'm not sure I get it fully.

 

[JAL3]

I am not well versed enough to answer your question but did do some research on what it would take to add rc control for the descent of a boost glider and (not to add to the confusion but...) there is apparently a difference between BOOST gliders and boost GLIDERS. I won't even tryto explain that as I'm not sure I get it fully.

Your kindness is appreciated.:cyclops:

 

[AstronMike]

I was afraid of this.

I asked the question mainly to better organize the gallery section. It seems it will be less simple than I thought or hoped.

Gallery section??

Are you going to put subsections there for posting gliders under the main three 'areas'? Still workable if you do that, and if/when I can add to those, would choose the closest category nonetheless.

Or just create an 'AstronMike's Gliders' separate one to eliminate any confusion :wink:

 

[AstronMike]

there is apparently a difference between BOOST gliders and boost GLIDERS. I won't even tryto explain that as I'm not sure I get it fully.

BOOST gliders, in that sense, refer to any gliding vehicle that tends to be designed for 'sport flying' and not so much for all out BTC duration stuff. The vast majority of my stuff falls here, but also bear in mind, that I have some nonstandard stuff that glides a LOT better than you'd expect from such 'clunkers', although I am not currently an all out duration first sort.

boost GLIDERS tends to refer to the standard conventional aircraft with front motor pop pod, ala Swift or other such beings, as these are/were designed for maximum performance and duration. Used to fly the heck out of these things but rapidly got tired to watching gliders I could barely see thermalling off....not to mention losing track of where its small pop pod ended up.

What I tend to do is design 'clunky' sport gliders but then try to optimise them, particulary in weight savings, to end up with stuff that is very large but very light for a given motor type, and the result is an overall nice flyer. Those of you who frequent TTRA launches can vouch for this.

 

[kjohnson]

For your purposes, boost gliders and parasite gliders are the same thing- a rocket powered model that separates into 2 (or more) parts, one of which glides. That could cover A whole lot of different modle types that have a motor pod that contains the motor (either front montes like the Swift, or rear mounted like the Scissor Wing Transport) or just ejects the motor (Red Baron or Falcon) or where you have a glider attached to a larger rocket.

Rocket gliders are rocket powered models that do not separate I to multiple parts, and the whole model descends by gliding. This covers a lot of different types of models that can change geometry (slide pods, slide wings, swing wings, flop wings, pop up elevators, etc) or not. It also covers rc models like FAI S8 models as well as my Cosmos Mariner and SpaceShipOne conversions.

They are all rocket boosted gliders.

 

[gpoehlein]

NAR definitions of these items boil down to:

A Boost Glider is any glider that is boosted vertically and transitions to glide flight after ejection. All gliders are covered by this category, but under NAR rules, flexwing gliders are excluded from competition in the Boost Glider category. Flexies are still technically boost gliders.

A Rocket Glider is any boost glider that does not shed any portion of itself when it transitions to glide flight. Thus, rocket gliders include any variable geometry models (swing wings, flop wings, slidewings) and backsliders. The Red Baron (or Flying Jenny) is not a rocket glider because it must eject its motor to transition. Rocket Gliders must bring their motors back with them and cannot lose anything like pop pods. An example of this would be the Estes Tomcat (2086):

https://www.ninfinger.org/rockets/nostalgia/96est34.html

Parasite gliders are not given definition under NAR rules, but are generally considered a glider that is hanging on the side of a regular rocket that would be capable of flying without the glider. Good examples are the Estes Firefly (1280):

https://www.ninfinger.org/rockets/catalogs/estes79/79est24.html

and Multiroc (1329):

https://www.ninfinger.org/rockets/catalogs/estes79/79est44.html

Actually, I would break down Boost Gliders into Motor Ejectors (such as the Red Baron or the Estes Falcon), Pop Pod Models (such as the Quest Flat Cat), Internal Pod Models (such as the Sky Dart or Bomarc) and Pure Flexies (that spit or eject the flexwing glider out of the front of the model). The Scissor Wing Transport and Soaring Eagle, although using variable wing geometry and flew wings respectively, would be IMHO primarily Internal Pod models.

Hope this helps.

 

[BobH48]

Another method that rocket gliders employ are wing flaps like on the Nova Salamander 5.

The flaps are held down by elastic bands (photo 2). When prepping the rocket for flight, a piece of thread is tied to the flap actuator and strung through the small loops on the fuselage and then brought down through the holes in the motor tube. When the flaps are in launch position (about 45 degrees up flap) the thread is pulled tight and taped to the motor tube (see MMX version in photo3).

The rocket is launched facing up about 20 degrees from vertical. The asymetrical thrust wants to push it upward and the wing flaps try to counter it with downward pressure . If (and it's a big if) you have the flap angle correct and the launch angle correct, during the power portion, the upward push is stronger and during the coast portion the downward push is stronger and the model flies upward in an "S" shape.

The model should be almost pushed over horizontally when the motor ejection charge burns the thread and the flaps are pulled down into glide position.

 

[JAL3]

Gallery section??

Are you going to put subsections there for posting gliders under the main three 'areas'? Still workable if you do that, and if/when I can add to those, would choose the closest category nonetheless.

Or just create an 'AstronMike's Gliders' separate one to eliminate any confusion :wink:

This is the first: https://www.rocketryforum.com/showthread.php?t=17434

Take a look at the guidlines in the index. Its a work in progress.

 

[JAL3]

For your purposes, boost gliders and parasite gliders are the same thing- a rocket powered model that separates into 2 (or more) parts, one of which glides. That could cover A whole lot of different modle types that have a motor pod that contains the motor (either front montes like the Swift, or rear mounted like the Scissor Wing Transport) or just ejects the motor (Red Baron or Falcon) or where you have a glider attached to a larger rocket.

Rocket gliders are rocket powered models that do not separate I to multiple parts, and the whole model descends by gliding. This covers a lot of different types of models that can change geometry (slide pods, slide wings, swing wings, flop wings, pop up elevators, etc) or not. It also covers rc models like FAI S8 models as well as my Cosmos Mariner and SpaceShipOne conversions.

They are all rocket boosted gliders.

I guess I am drawing a distinction, in my mind at least, between vehicles that I consider rockets which may deploy a glider (The thing would fly just fine without any parasites) and those gliders that use a detachable pod to provide the boost (you could not fly the pod by itself; the glider makes it stable).

That is the distinction in my mind and how I am inclined to classify things but I will be the first to admit, gliders are not my thing.

I am learning. Slowly, painfully, I am learning.

 

[InFlight]

Another example, the Mach 10 is a rocket glider as the motor casing will stay in the model during the glide and landing stage.

Mach 10 Plans

.

 

[gpoehlein]

Another example, the Mach 10 is a rocket glider as the motor casing will stay in the model during the glide and landing stage.

Mach 10 Plans

.

Technically, it is classified as a Boost Glider and not a Rocket Glider since it ejects a weighted nose cone with a streamer. Contest legal for Boost Glider but not for Rocket Glider.

 

[kjohnson]

I guess I am drawing a distinction, in my mind at least, between vehicles that I consider rockets which may deploy a glider (The thing would fly just fine without any parasites) and those gliders that use a detachable pod to provide the boost (you could not fly the pod by itself; the glider makes it stable).

That is the distinction in my mind and how I am inclined to classify things but I will be the first to admit, gliders are not my thing.

I am learning. Slowly, painfully, I am learning.

In the end it's your sandbox and you can organize it how you see fit. I looked in the "Rocket Glider" gallery, and all of them are what I would call "Boost Gliders" because they all either eject the motor casing, or detach from their carrier rockets.

kj

 

[RoyAtl]

I was afraid of this.

I asked the question mainly to better organize the gallery section. It seems it will be less simple than I thought or hoped.

No, Mike's fine-chopping of the subject doesn't affect the basic correctness of your initial assumptions.

Just generalize your boost-glider description to include anything where something is thrown off the glider to allow the glider to glide! And understand how a parasite glider is a certain form of boost glider.

And rocket gliders are everything else that boosts upwards, and glides down that's not a boost glider.

 

[InFlight]

Technically, it is classified as a Boost Glider and not a Rocket Glider since it ejects a weighted nose cone with a streamer. Contest legal for Boost Glider but not for Rocket Glider.

Is that a local club rule?

I don't see anything that says that in the Rocket Glider Duration Competition contest rules...
Rocket Glider Duration Competition rules

37.2 Disqualification
Any entry that descends with parachute and/or streamer recovery device(s) attached shall be disqualified.


Although, the Boost Glider Duration Competition rules say you can have the model separate into multiple pieces.

Boost Glider Duration Competition rules

36.1 Scope
Boost Glider Duration Competition comprises of eleven events open to any model rocket, one portion of which returns to the ground in stable, gliding flight supported by aerodynamic lifting surfaces which sustain that portion against gravity. If the entry is staged, the gliding portion must be part of the uppermost stage, and must not be deployed until that stage has burned out. The entry may separate into multiple pieces; only the gliding portion is timed and only the timed gliding portion needs to be returned to satisfy Rule 15.10. Models whose gliding surfaces are made of flexible materials (e.g., plastic film or cloth) are prohibited from this event. The purpose of this competition is to achieve the longest flight duration time.


Am I over looking something? you know, when you post a comment like that you should really back it up with some information so the rest of us can learn something.

.

 

[kjohnson]

Am I over looking something? you know, when you post a comment like that you should really back it up with some information so the rest of us can learn something.

Yes.. you are not taking into account the wording of 37.1-
a rocket glider (per NAR contest rules) is "any single-staged model rocket that returns to the ground in stable, gliding flight supported by aerodynamic lifting surfaces which sustain it against gravity"

That means the whole rocket needs to be supported by the wings- not a part of the rocket supported by the wings and another part on a streamer or parachute, or tumbling.

36.1 says that a boost glider may sep into mutiple parts-
"any model rocket, one portion of which returns to the ground in stable, gliding flight supported by aerodynamic lifting surfaces which sustain that portion against gravity" and "The entry may separate into multiple pieces."

The differentiation is based on the NAR contest rules. If you haven't flown contests or don't fly the BG and RG events, the distinction may not make a big difference to you, but it has lead to this general rule of thumb-

If it drops any parts (nose cone on a streamer, pop pod, motor casing, carrier rocket, etc) then it's a boost glider.

If it stays in one piece and everything that left the pad comes down in one piece gliding, then it's a rocket glider.

But they are all Rocket Boosted Gliders

kj

 

[gpoehlein]

And I should add that, in most NAR competitions, you can fly a rocket glider in the boost glider duration events, but not the other way around. And any kind of flex wing is prohibited in either.