Guidance Control now legal?

[firemandivi]

I got into model rockets over 20 years ago and with the whole ATF explosive license requirements and having kids, well I've out of the hobby for quite a while. I know we won the court case against the ATF which was nice to see. The reason for my post is the other day I was cruising youtube and saw video with a person working on a control unit for his rocket motors that would change the motor direction with servos to help control pitch and yaw. I very clearly remember back in 2000 that you couldn't do that and anything that could control the rocket was illegal. I have dones some searching and it seems the laws may have changed over the past couple of decades. as I see more people doing something similar. Can anyone point me in the direction as to what is legal for controlling the pitch and yaw of a high power model rocket? Any help would be greatly appreciated. Thank you.

 

[Titan II]

I very clearly remember back in 2000 that you couldn't do that and anything that could control the rocket was illegal.

Source? It was never illegal that I am aware of.

 

[boatgeek]

I got into model rockets over 20 years ago and with the whole ATF explosive license requirements and having kids, well I've out of the hobby for quite a while. I know we won the court case against the ATF which was nice to see. The reason for my post is the other day I was cruising youtube and saw video with a person working on a control unit for his rocket motors that would change the motor direction with servos to help control pitch and yaw. I very clearly remember back in 2000 that you couldn't do that and anything that could control the rocket was illegal. I have dones some searching and it seems the laws may have changed over the past couple of decades. as I see more people doing something similar. Can anyone point me in the direction as to what is legal for controlling the pitch and yaw of a high power model rocket? Any help would be greatly appreciated. Thank you.

It depends on what you mean by control. If you're using controls to keep the flight vertical or on a particular bearing, all is well and good. That was never illegal either. If you're controlling to point at a point on the ground for destructive purposes or in the air, that was and is illegal.

There is some gray area of legality of controls under descent. Some people have said that using a guided/RC-controlled parachute isn't legal, since you're guiding it to a spot. I'd say that's no different than an RC boosted glider. A more compelling argument is that the FAA restrictions on remote control aircraft would apply to rockets descending under onboard or radio control.

 

[cerving]

You can't "target" a location on the way up, but you can actively stabilize your rocket. Typical methods involve the use of steering fins (typically canards in the nose), or thrust vector control (however that only works while your motor is firing). Those are exciting new developments... welcome back to the hobby!

 

[OzHybrid]

With modern RC electronics being capable of waypoint guidance, the genie is out of the bottle. Vertical trajectory assistance has been allowed but not guidance to a GPS point that's set vertically above the rocket. The fact that parachute guidance is happening is a tricky one, that unless it's formally codified in the NAR or Tripoli rules, leaves us wide open to legislation prohibiting it. Without it in our rules, so we can say we're doing this safely, it would be difficult to defend a legal case against any legislation that may happen.

 

[boatgeek]

With modern RC electronics being capable of waypoint guidance, the genie is out of the bottle. Vertical trajectory assistance has been allowed but not guidance to a GPS point that's set vertically above the rocket. The fact that parachute guidance is happening is a tricky one, that unless it's formally codified in the NAR or Tripoli rules, leaves us wide open to legislation prohibiting it. Without it in our rules, so we can say we're doing this safely, it would be difficult to defend a legal case against any legislation that may happen.

To be fair to NAR and TRA, it doesn't matter what their rules are if a national authority decides to make a law or regulation. That said, I would very much like NAR and TRA to petition FAA to allow RC flights over 400 feet AGL within a waiver cylinder if the waiver holder allows. That would resolve virtually all of the questions about guided descent.

 

[OzHybrid]

To be fair to NAR and TRA, it doesn't matter what their rules are if a national authority decides to make a law or regulation. That said, I would very much like NAR and TRA to petition FAA to allow RC flights over 400 feet AGL within a waiver cylinder if the waiver holder allows. That would resolve virtually all of the questions about guided descent.

Allowing guidance at an organised, approved rocket launch vertically above the launch on ascent and to a designated landing area would solve the problem.
Not sure there's a will to confront that discussion. It's certainly doable with pretty much off the shelf equipment.

 

[VTS SkunkWorks]

Source? It was never illegal that I am aware of.

I have been designing and flying VTS (Vertical Trajectory System) rockets since 1995. It is not permitted to "Aim a rocket at a target", however, it has never been illegal to design a rocket to go straight up. There were flyers that pre-date my 1995 flights as well. David Ketchledge actually coined the VTS title in the early 1990's. The photos are from 2002 at Blackrock and show a 4" dia rocket using cold gas thrusters for Yaw and Pitch control.

 

[firemandivi]

Just to clairfy my original question was to speifiy controlling the rocket so it has a straighter lift off and not controlling it to go sideways or anything. From reading everyone's posts it seems that it is allowable but does anyone have a reference to a law or regulation that states what is allowed for this or not? Is it just vector thrust control, can you use fins with actuators, can this only be done during thrust, is there a time limit, etc. etc.

 

[Rschub]

If you are waiting for a law that approves technological advancements or innovation before participating, you will be waiting a long time. Such regulations always follow innovations.

I guess if you are waiting for "government approval" for an activity, that is the safest bet. Everyone will judge risk/reward differently.

The "That's not approved" mindset never appealed to me personally. YMMV

 

[boatgeek]

Just to clairfy my original question was to speifiy controlling the rocket so it has a straighter lift off and not controlling it to go sideways or anything. From reading everyone's posts it seems that it is allowable but does anyone have a reference to a law or regulation that states what is allowed for this or not? Is it just vector thrust control, can you use fins with actuators, can this only be done during thrust, is there a time limit, etc. etc.

What's not prohibited is allowed. The rules regarding flying at targets are "don'ts." As long as you don't do those things, then you're free to use any technology you wish to aim vertical. Of course, you'll have to get RSO approval to fly at a club launch, but that's a club issue not a legal issue.

 

[firemandivi]

Thank you boatgeek. In my line or work I have many rules, laws and regulations I have to follow and I just was hoping there was something saying what was legal or what wasn't allowed so I could be sure what I did was legal. I will check with the RSO and see what they have to say about vertical stability controls. Thank you everyone for your responses.

 

[VTS SkunkWorks]

Here's what I found:

NFPA 1127 4.17.1​

No person shall ignite and launch a high power rocket horizontally, at a target, or so that the rocket’s flight path during the ascent phase is intended to go into clouds, directly over the heads of spectators, or beyond the boundaries of the launch site, or so that the rocket’s recovery is likely to occur in spectator areas or outside the boundaries of the launch site.​

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And from TRA board discussions:​

Vol 29 No 3 Summer 2018 Page 08 TRA BOD Activities​

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Active Stabilization​

We should support its use in a research sense. However, it should not be used for certification attempts. Certification is to prove you understand the basics. Currently more unknowns than knowns and we need to continue to closely monitor progress.​

Seems like Active Stabilization or VTS is fine for launches other than certification attempts.

 

[Art Upton]

I have been designing and flying VTS (Vertical Trajectory System) rockets since 1995. It is not permitted to "Aim a rocket at a target", however, it has never been illegal to design a rocket to go straight up. There were flyers that pre-date my 1995 flights as well. David Ketchledge actually coined the VTS title in the early 1990's. The photos are from 2002 at Blackrock and show a 4" dia rocket using cold gas thrusters for Yaw and Pitch control.

George Gassaway Sun Seeker rockets would fly to the sun. He would wait until it was overhead. Way Back in the Day 1988 NARAM R&D

http://georgesrockets.com/GRP/RandD/Sunguidance.htm

 

[VTS SkunkWorks]

Awesome Sun guidance link, thank you!

 

[VTS SkunkWorks]

Larry Lynch-Freshner flew the Futaba 2-axis horizon sensor (Pilot Assist Link PAL) in the tip of a nosecone around 1998 I think, to test for Yaw and Pitch control.

 

[VTS SkunkWorks]

 

[burkefj]

Another notable Gimbaled Engine project was by Scale expert John Pursley. He used on in a Mercury Redstone Model in 1998. He perfected it more since then. It makes use of a combination of model airplane type Gyros and horizon Sensors (modified). An onboard computer gave the gyros priority for the initial climb phase, then switched over at a certain point of the flight to the Horizon Sensors. This is because Horizon Sensors are not as reliable below 50 feet of altitude or so, and model plane type gyros drift pretty fast and cannot hold the course of a rocket flight over time. So, John's solution to use the strengths of both was quite brilliant.

 

[cls]

ARA Press still offers Steve Ainsworth's "Vertical Trajectory Systems" (2017) as an e-book

https://www.arapress.com/e-books/

(and they have a bunch of other nifty stuff too...)

 

[VTS SkunkWorks]

A good reason for using VTS is that you can fly much higher on a given total impulse.


Apogee Rockets Newsletter 471 Optimal Altitude