Launching in wind

[Blast it Tom!]

Gang, I don't have a lot of time for searching but am trying to gear up for a launch tomorrow with the grandkids. Now usually I waiyt for as calm a tine as possible, but scheduling these things when I can get everyone there is almost like herding cats. So we are supposed to have a nice afternoon tomorrow, but the time frame is usually breezier than earl evening. I've seen videos of launches here where flags are almost standing out and I'm like, "How the dickens do you launch in wind like that and even hope to get your rocket back?"

So that's the question. I think part of the answer is launching slightly downwind instead of into the wind, so the natural weathercocking keeps you a little more over the pad. But this is whoosh-pop-drop, chutes out at apogee, and then you're at the wind's mercy. Any better advice than that? Much thanks, I gotta get out and mow while the weather's nice, I'll check back later. keep those cards and letters coming, folks!

 

[Bill S]

Downgrade your parachute if you can. Instead of an 18", put in an 15". Or an 9" instead of an 12"... If you don't have smaller chutes, in a pinch, you can make them from plastic shopping bags (Target in particular is red and easier to see). Some people like to "reef" the shroud lines with something to keep the chute from fully opening, but I haven't tried that yet.

If the rocket is fairly lightweight, consider trying an streamer in it. Ordinary crepe paper from Walmart will do. Make the streamer at least 10x the width of the crepe paper. Depends on which rockets you are flying of course, as some aren't suited for streamer recovery.

Downgrade the planned motors. Instead of an C, put in an B. Or an A instead of an B. If the rocket doesn't go as high, it will probably drift less.

You can angle the rod with the wind a bit and it'll help keep the rocket flying more or less straight up, but then you risk it drifting further downwind. If you angle into the wind, you may get an lower apogee and a closer touchdown site. But if you add too much angle, you may get ejection right before the rocket hits the ground. Its also a good idea to shorten the delay if you can... Instead of say an C6-5, try an C6-3, etc.

Also looking to see what others have to say.

 

[smstachwick]

I concur with adjusting the recovery system to the field. Another option in addition to removing the streamer is to remove the recovery device entirely and just blow the nose if the rocket is highly visible in the air and on the ground. You may accumulate some more damage or lose sight of it on the range, but at least you’re far less likely to have it drift off the range. Keep some superglue handy and maybe assign one of the kiddos as a “recovery specialist” to keep an eye on it from a far downwind position.

Another recommendation I find myself handing out all the time is to start with the smallest recommended motor for your airframe(s) and work your way up. If recovery on a 1/2A is easy and an A is a close call, scratch the B on that rocket and use it in a heavier, draggier one that won’t go as high or drift as far. This is why having a fleet is so helpful, you can match a flight to the range much more easily if you have good options.

I wouldn’t try to angle the rod too much, I’d say adjusting it more than single-digit degrees is asking for trouble. Getting it wrong presents a high risk of loss or, worse, ballistic return to earth causing damage or injury. I’d say it’s better to go straight up and adjust the “up” and “down” parts of your rocket to minimize drift than it is to play around with your GSE and get it to drift where you want it. If you miss, you might be in trouble, so just make missing harder.

 

[Back_at_it]

If at all possible fly with streamers for better chance of recovering. As for flying into the wind vs with the wind, that really depends on the rocket.

Rockets that are over stable or rockets with a lit of fin area tend to weather cock more. For instance, I'd fly something like the Alpha into the wind where something longer like the Vapor I'd fly with the wind. I've learned that short fat rockets like to be flown with the wind as well. My Big Daddy's will make a U-Turn and head back into the wind.

 

[kuririn]

NAR recommends:
Not launching in winds more than 20 mph.
No more than 30 deg. rod deflection from vertical.

Strategies for mitigating wind drift:
Sub a streamer for a chute
Sub a smaller chute
Cut a spillhole in the chute.
Reef the shroud lines to shorten the effective length and prevent full unfurling of the chute.
Sub a smaller motor.
If the rocket is big enough use a chute release.
Don't launch.

 

[rharshberger]

NAR recommends:
Not launching in winds more than 20 mph.
No more than 30 deg. rod deflection from vertical.

Strategies for mitigating wind drift:
Sub a streamer for a chute
Sub a smaller chute
Cut a spillhole in the chute.
Reef the shroud lines to shorten the effective length and prevent full unfurling of the chute.
Sub a smaller motor.
If the rocket is big enough use a chute release.
Don't launch.

To add to Kuirins post, if you do launch into the wind, reduce the delay length by 1 step, if you normally fly the rocket on a B6-4, switch to a B6-2 that way it pops closer to the top of where it weathercocks and has less chance of a zipper. We fly a lot in 10-15mph winds here in Eastern WA.

 

[JimByrne]

You may have lower winds at certain times of the day.
We launch in the early morning since the wind comes up late morning in our area.

 

[Blast it Tom!]

Well, gang, much thanks to all! We may have to scrub tomorrow, there are supposed to be strong winds ahead of a front. I learned a few more things from y'all, and maybe someone else happening along will learn, too! Now of course, since my progress in the hobby makes a snail look like meteor, I had completed the kids' rockets about a year ago with no thought to making the parachutes swappable. Yes, I own some snap-swivels now. Three of them, though, the 'chute matches the rocket - Duck Dodgers, Marvin the Martian, and Porky Pig as the Space Cadet, so you wouldn't want to swap them, just cut down on the engine/delay. Even with the rated engine, though, they're only supposed to go a couple of hundred feet. Heavy and slow, I guess.

Yes, we do have calmer winds morning and evening. We usually go out in the late afternoon.

<Sigh> Been retired over a year and still can't figure it out...! We work like crazy around here! But winter is coming and I do have some lightweight ripstop nylon downstairs and a Solidworks pattern for a 12 gore semi-elliptical 'chute that I can size to whatever diameter I want (I won't need anything bigger that would require more than 12 gores for a while). Hopefully my beloved and I will get going on them soon... And I'm not at all averse to streamers.

I'll probably compile all of this into a list of notes.

 

[BABAR]

My experience with angling the rod to adjust to winds is that, all other things being equal, the rocket does whatever the heck it wants to. I have far more frequently wished I had simply launched straight up after angling the rod then wished I’d angled the rod when I launched straight up.

In the absence of a very large flat mowed field (or an onboard tracker), never launch a rocket (or a rocket containing expensive equipment) that you are not willing to lose in significant winds, and absolutely don’t launch in winds over 20 mph. Stay home and build or plan your next rocket.

 

[tsmith1315]

Reef the shroud lines to shorten the effective length and prevent full unfurling of the chute.

This is an easy thing to try, you can use a little bit of masking tape around the lines. Not permanent, and effectively increases your stock of parachute sizes a bit. Adjust at the field to current conditions when preparing your flight.