Revision to Tripoli Rule Regarding Wireless Remote Switches

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Status
Not open for further replies.
Cameron, if I may ask. What alt's do you fly that need programming before the flight. I do mine once and they are good. Do you switch out alt's between rockets?

I do switch out altimeters between airframes, but generally I prep rockets the week before a weekend launch so all i do at my prep table is attach a fresh battery, do one final power up test, then fly.

My primary altimeters are Raven 4s, Marsa 33, and AIM XTRA 2s and 3s. I fly RRC2+ as my dedicated backups.

Generally I don't have enough flights planned to require switching and reprogramming at the field but there are times where I fly a small two-stage (so I use Ravens) and then want to fly a small MD airframe (also Raven) so I will need to download the previous flight data and reprogram.
 
I'm not saying walk around with a rocket powered up (I don't think anyone would say to do that) - all that movement might trigger the launch logic then you absolutely will have a bad day. Here is my process...

1. Program altimeter
2. Test e-match continuity
3. Prepare pyro charges
4. Verify charge continuity
5. Install altimeter and connect all power and charges
6. Power up altimeter to verify continuity/altimeter self-test
7. Turn off altimeter
8. RSO, power off
9. Off to the pads

Your process is dangerous. I reprogrammed it for you.

1. Program altimeter
2. Test e-match continuity
3. Install altimeter and connect all power and charges e-matches
4. Power up altimeter to verify continuity/altimeter self-test
5. Turn off altimeter/power
6. Prepare pyro charges and close up e-bay
7. RSO
8. Off to the pads
9. On the pad, power up electronics and then insert igniter
 
Last edited:
Your process is dangerous. I reprogrammed it for you.

1. Program altimeter
2. Test e-match continuity
3. Install altimeter and connect all power and charges e-matches
4. Power up altimeter to verify continuity/altimeter self-test
5. Turn off altimeter/power
6. Prepare pyro charges and close up e-bay
7. RSO
8. Off to the pads
9. On the pad, power up electronics and then insert igniter
Genuinely asking here, which step/process do see as dangerous and why? (Not trying to be combative, I like a good discussion and you could very well have a genuine concern i haven't thought of)

Why do the step 4 test without pyro circuits attached? The point of a prep table full-up test is to mirror flight conditions so I'm not that asshole trying to troubleshoot a bad pyro connection on the pad while everyone else is burning cameras and altimeters while I remove plastic rivets and shear screws to fix an error that could have been identified prior?
 
Genuinely asking here, which step/process do see as dangerous and why? (Not trying to be combative, I like a good discussion and you could very well have a genuine concern i haven't thought of)

Why do the step 4 test without pyro circuits attached? The point of a prep table full-up test is to mirror flight conditions so I'm not that asshole trying to troubleshoot a bad pyro connection on the pad while everyone else is burning cameras and altimeters while I remove plastic rivets and shear screws to fix an error that could have been identified prior?

In your check list you power-on after installing BP, not good. If you look at my step 3., piro e-matches are connected, just not with BP installed in the cans. This allows for a complete power on system check in step 4. and no need to power-on after BP is placed in the charge can. Powering on after BP is in the can is not a good idea while in the pit. At power-up, anomalies sometimes do occur . The best/safest way to power-up after BP is installed, is with the rocket on the pad and upright. The other option, although not ideal, is at a designated prep area forward of the LCO.
 
In your check list you power-on after installing BP, not good. If you look at my step 3., piro e-matches are connected, just not with BP installed in the cans. This allows for a complete power on system check in step 4. and no need to power-on after BP is placed in the charge can. Powering on after BP is in the can is not a good idea while in the pit. At power-up, anomalies sometimes do occur . The best/safest way to power-up after BP is installed, is with the rocket on the pad and upright. The other option, although not ideal, is at a designated prep area forward of the LCO.

Powering up an altimeter with just initiators (e-matches or such only, and no BP) just checks e-match continuity (which I do before I add BP to ensure I don't make a bum charge). Adding powder, handling e-matches, running pyro leads...all these things manipulate e-matchs and have the potential to crimp and short out leads. Installing primed e-matches in an airframe is where most of my disconnects or breaks in continuity come from which is why I check everything at the table before I head out.

You said anomalies occur during power up...I agree this is a possibility (remote) but how many issues are user-induced and how many are actual altimeter failures? People reverse polarity, cross-connect leads, attach batteries with switches in the "on" position...none of that is the result of an altimeter failure and no amount of sequencing will fix stupid. I have never seen a legit altimeter failure at power up nor have I ever heard of someone correctly handling, pre-flighting, arming, and powering an altimeter only to have it randomly pop chsrges at power up. Every failure I have seen was caused by negligence so whether it is on the pad or at the prep table, people mess up will mess up.
 
Powering up an altimeter with just initiators (e-matches or such only, and no BP) just checks e-match continuity (which I do before I add BP to ensure I don't make a bum charge). Adding powder, handling e-matches, running pyro leads...all these things manipulate e-matchs and have the potential to crimp and short out leads. Installing primed e-matches in an airframe is where most of my disconnects or breaks in continuity come from which is why I check everything at the table before I head out.

You said anomalies occur during power up...I agree this is a possibility (remote) but how many issues are user-induced and how many are actual altimeter failures? People reverse polarity, cross-connect leads, attach batteries with switches in the "on" position...none of that is the result of an altimeter failure and no amount of sequencing will fix stupid. I have never seen a legit altimeter failure at power up nor have I ever heard of someone correctly handling, pre-flighting, arming, and powering an altimeter only to have it randomly pop charges at power up. Every failure I have seen was caused by negligence so whether it is on the pad or at the prep table, people mess up will mess up.

Wether it's altimeter failure, which does happen, or any number of bone-head mistakes you mentioned, all the more reason, if BP is installed, to not allow power-up checks in the pit area or before placing the rocket on the pad. Let's face it, our hobby has the potential risk to cause injury to people and property. It's all about risk management. I hope this helps your understanding.
 
Wether it's altimeter failure, which does happen, or any number of bone-head mistakes you mentioned, all the more reason, if BP is installed, to not allow power-up checks in the pit area or before placing the rocket on the pad. Let's face it, our hobby has the potential risk to cause injury to people and property. It's all about risk management. I hope this helps your understanding.

When it comes to risk, you have to evaluate two things...frequency and severity.

We don't insist on armoring our rockets in case they are hit by meteors because, even though such an event would be catostrophic, it is so I likely an event as to not need consideration.

We can debate the severity of unintentional BP detonation, but we can agree it does happen (for a variety of reasons). Aside from ringing ears or maybe a slight burn, the severity of accidental BP ignition is low for the user and for anyone more than 3 feet away is limited at annoyance.

The most common cause is user error and the most minor cause is powering up a properly configured and maintained altimeter. I would say that frequency is very low and severity is lower still. All that together means it is a non-issue. People like to take the extreme position and throw the word "safety" around as a reason (or excuse) for doing something or prohibiting, but are we really mitigating risk by not powering up altimeters in a controlled environment? Or, as I content, are we adding another useless prohibition (which is where this entire thread started with TRA BOD's making a capricious and arbitrary switch rule, ignoring current technology and its capabilities)?
 
When it comes to risk, you have to evaluate two things...frequency and severity.

We don't insist on armoring our rockets in case they are hit by meteors because, even though such an event would be catostrophic, it is so I likely an event as to not need consideration.

We can debate the severity of unintentional BP detonation, but we can agree it does happen (for a variety of reasons). Aside from ringing ears or maybe a slight burn, the severity of accidental BP ignition is low for the user and for anyone more than 3 feet away is limited at annoyance.

The most common cause is user error and the most minor cause is powering up a properly configured and maintained altimeter. I would say that frequency is very low and severity is lower still. All that together means it is a non-issue. People like to take the extreme position and throw the word "safety" around as a reason (or excuse) for doing something or prohibiting, but are we really mitigating risk by not powering up altimeters in a controlled environment? Or, as I content, are we adding another useless prohibition (which is where this entire thread started with TRA BOD's making a capricious and arbitrary switch rule, ignoring current technology and its capabilities)?

Severity??? Obviously, you have never seen the results when an inadvertent charge goes off in the pit area and drives a nose cone or upper body tube assembly through a car window or worse. There is no debate to it. BTW, the prohibition on powering up of BP charges in the pit area and before arriving at the pad, with the rocket in the upright position is a well established safety practice. If you wish to violate good safety practice, good luck. If you ever launch at MDRA, I'll be sure to make sure you are on the up and up.:)
 
Last edited:
We can debate the severity of unintentional BP detonation, but we can agree it does happen (for a variety of reasons). Aside from ringing ears or maybe a slight burn, the severity of accidental BP ignition is low for the user and for anyone more than 3 feet away is limited at annoyance.

BP does not detonate.

1-2 grams of loose BP igniting while being prepared is not a large threat to anyone. Light some on a piece of paper and it just goes poof. Once it is contained, it is a little more dangerous, but still not a huge threat, and of little threat to anyone more than a few feet away.

The real danger comes when it is contained and the nose cone is in place. Now it is a threat to anyone close enough to be struck by the flying nosecone or booster. I might be annoyed if a plastic BT-50 nosecone hit me, but a larger metal tipped fiberglass nosecone could cause injury or property damage. This is why we take care and why I think fully prepped rockets should only be armed when pointed up on the pad or in a safe place where the only person in harms way is the person responsible for the rocket.
 
Severity??? Obviously, you have never seen the results when an inadvertent charge goes off in the pit area and drives a nose cone or upper body tube assembly through a car window or worse. There is no debate to it. BTW, the prohibition on powering up of BP charges in the pit area and before arriving at the pad, with the rocket in the upright position is a well established safety practice. If you wish to violate good safety practice, good luck. If you ever launch at MDRA, I'll be sure to make sure you are on the up and up.:)
Again, it is a capricious rule that in no way improves safety or efficiency.
 
BP does not detonate.

1-2 grams of loose BP igniting while being prepared is not a large threat to anyone. Light some on a piece of paper and it just goes poof. Once it is contained, it is a little more dangerous, but still not a huge threat, and of little threat to anyone more than a few feet away.

The real danger comes when it is contained and the nose cone is in place. Now it is a threat to anyone close enough to be struck by the flying nosecone or booster. I might be annoyed if a plastic BT-50 nosecone hit me, but a larger metal tipped fiberglass nosecone could cause injury or property damage. This is why we take care and why I think fully prepped rockets should only be armed when pointed up on the pad or in a safe place where the only person in harms way is the person responsible for the rocket.
But why are you asserting there is a risk associated with powering up an altimeter with pyro circuits attached? Do your altimeters wantonly fire off charges when they are powered up? If so, you might want to talk to your vendors.
 
What about applying power to an electronic device designed to take in and safely distribute electricity to pyro events is unsafe?

It depends on the design. The devices in question here from Eggtimer while they do switch both power rails they use a single device (micro-controller) to do that. Exposing you (and those around you) to single point failure modes.
 
But why are you asserting there is a risk associated with powering up an altimeter with pyro circuits attached? Do your altimeters wantonly fire off charges when they are powered up? If so, you might want to talk to your vendors.

Due regard.

An altimeter should not fire a deployment charge when it is powered up. What it a failure occurs and it does? Assuming that the deployment charge does fire when you don't want it to, what is the safest position for the rocket to be? Where you do want to be if this happens?

Aside from rocketry, I set up and shoot public firework displays. We use firing systems and hand fire the shells depending on the show. An ematch should not ignite when not attached to the firing system, but they can and have. The safest method is to load the shell and attach the e-match so of it does ignite, the shell lifts and performs as it was designed to. The only consequence here is your ears ringing and maybe minor burns from the muzzle blast if you weren't wearing PPE. Likewise when we connect the e-matches to the firing system, it is powered off. The field is cleared when it is powered on and during continuity checks. This is all to ensure safety to us from an inadvertent electronics failure.

Rocketry and pyrotechnics are cousins and similar safety practices are followed.
 
Last edited:
It depends on the design. The devices in question here from Eggtimer while they do switch both power rails they use a single device (micro-controller) to do that. Exposing you (and those around you) to single point failure modes.
I have one Eggtimer Proton that was built by a friend and I have never flown so I am utterly ignorant of its function and design. I have used Eggtimer wifi switches in situations where mechanical switches were impractical so I'm familiar with their function but not their design. I have also used Featherweight magnetic switches which were banned under the older prohibition.

As to single points of failure, I am not familiar enough with the wiring and functioning of enough altimeters to make a comparison about safety inhibits on their designs. I can safely assume no major altimeter designer is engineering weak links into their systems. They want them to be safe, reliable, and affordable.

To the original point, is a single point of failure, or looked at another way, a single point of protection sufficient when it comes to altimeter design? Since altimeters aren't randomly blowing charges all over when they're powered up, I'm going to assume that is an intentional design protocol so single point systems are indeed sufficient.
 
I agree with Fred, one should avoid activating a device that could injure bystanders if there is any fault in the system. If you just put only yourself in peril, well it's a free country.
 
Due regard.

An altimeter should not fire a deployment charge when it is powered up. What it a failure occurs and it does? Assuming that the deployment charge does fire when you don't want it to, what is the safest position for the rocket to be? Where you do want to be if this happens?

Aside from rocketry, I set up and shoot public firework displays. We use firing systems and hand fire the shells depending on the show. An ematch should not ignite when not attached to the firing system, but they can and have. The safest method is to load the shell and attach the e-match so of it does ignite, the shell lifts and performs as it was designed to. The only consequence here is your ears ringing and maybe minor burns from the muzzle blast if you weren't wearing PPE. Likewise when we connect the e-matches to the firing system, it is powered off. The field is cleared when it is powered on and during continuity checks. This is all to ensure safety to us from an inadvertent electronics failure.

Rocketry send pyrotechnics are cousins and similar safety practices are followed.
What can I say? Opinion noted, wrong as it is. I guess, I have been around long enough and exposed enough to know better.
[/QUOTE
What can I say? Opinion noted, wrong as it is. I guess, I have been around long enough and exposed enough to know better.
I love the old timer attitude that permeates TRF and the hobby as a whole.

Anything anyone calls "safe" is immune from further discussion. It's the sign of an intellectually weak point.

That is how we ended up with the BOD (who cut their teeth on breakwire timers soldered in their garages and have the audacity to question technology they don't understand) passing a bogus wireless switch rule.
 
I have one Eggtimer Proton that was built by a friend and I have never flown so I am utterly ignorant of its function and design. I have used Eggtimer wifi switches in situations where mechanical switches were impractical so I'm familiar with their function but not their design. I have also used Featherweight magnetic switches which were banned under the older prohibition.

As to single points of failure, I am not familiar enough with the wiring and functioning of enough altimeters to make a comparison about safety inhibits on their designs. I can safely assume no major altimeter designer is engineering weak links into their systems. They want them to be safe, reliable, and affordable.

To the original point, is a single point of failure, or looked at another way, a single point of protection sufficient when it comes to altimeter design? Since altimeters aren't randomly blowing charges all over when they're powered up, I'm going to assume that is an intentional design protocol so single point systems are indeed sufficient.
Frequency versus severity.

A 4" fireworks shell going off with you next to it is orders of magnitude worse than an e-match with BP.

If I were dealing with fireworks I would reconsider my position accordingly.
 
Frequency versus severity.

A 4" fireworks shell going off with you next to it is orders of magnitude worse than an e-match with BP.

If I were dealing with fireworks I would reconsider my position accordingly.

The e-match with a bundle of BP on it, sure. The same bundle of BP when loaded into a rocket with a nosecome that can become a projectile, and I'd take my chances with a 4" shell. Having had a 4" shell break on the ground next to me, the burning stars are less dangerous than the nosecone with a much higher mass.
 
I think I'll go get my shine box. All this frequency and severity stuff is to much for me to handle, being an old timer and such.:D:rolleyes:

At 38 its only the second time I've been called an old timer, the the other is just some of the 21 year olds at work making jokes.
 
I don't know you, but I'll take your concern under advisement.:D Just as I was told, "Critical thinking...use it.", contributed to the conversation.:(
threats do not contribute - u don't have to know me to understand that
 
yes it was, you are singling him out for "special" treatment at a launch.. that is a threat
 
I think I'll go get my shine box. All this frequency and severity stuff is to much for me to handle, being an old timer and such.:D:rolleyes:
How scandalous right? Using current industry safety terms and evaluation criteria in seeking to determine truly effective and safe operational protocols. The nerve.
 
Status
Not open for further replies.
Back
Top