Galaxy Chute Aft of Firewall?

skelrad · #1 09-13-2022, 10:44 AM

I know this question will probably just end up generating negative responses to the idea of putting a chute in a plane, but I'll risk it... (I've got my reasons for considering a chute. No need to "open my eyes" to how unnecessary it is.

)

I've looked at the BRS solution, and I really don't love their decision to put it so far aft. That got me looking at other options, specifically Galaxy. I know I've heard of someone installing a Galaxy chute aft of the firewall before, where it sits on the passenger side and exits vertically. If this is doable, it sure seems like it would solve most of the CG concerns that come with the BRS setup (I'd give up the heavy constant speed setup).

I'm just getting ready to start my fuselage kit, so haven't wrapped my head around the build yet. Does the space just aft of the firewall typically get filled up with equipment for the panel, or what is the likelihood of being able to carve out enough room for a chute pack? Are the ribs in that area set in stone, or can they be moved around a bit? This will be a tip-up. I'm not sure of specific dimensions of the chute yet - still waiting to hear back from Galaxy on the proper size chute (looks like either 140 or 175 sqm).

Just pondering options at the moment. I may end up just writing it off, but if it's doable, I know I'd have a happy passenger.

mfleming · #2 09-13-2022, 11:41 AM

The area aft of the firewall may get crowded with electronics depending on how you lay out the LRUs. BUT, even without the added electronics, this area has quite a few structural elements that would take some serious engineering to safely make room for the BRS.

hiline · #3 09-13-2022, 03:02 PM

I have a RV9 complete BRS set up that is like new and will sell cheap if your interested?
Let me know,I took it out of my 9 when i sold it last year.
Tony
916-813-7210

DanH · #4 09-13-2022, 06:02 PM

Brandon, the wild card is the cable(s) or strap(s) which attach the chute to the airplane. It really doesn't matter very much where you locate the pack, or which direction you fire the rocket, because it's impossible to predict the attitude of the fuselage at deployment. You do want to carefully consider where the cable/strap might go when the chute opens...because it has the potential to decapitate.

Specific to this application, a slider incorporates a roll bar into the windshield frame. No guarantee, but it would go a long way toward keeping the suspension system out of the cockpit. A tip up would concern me.

The related concern is where to place the airframe attachment. The chute folks should have a pretty good estimate of G at opening, thus the required strength. They may wish to help with the structure, and you may wish to get an independent review.

Ed_Wischmeyer · #5 09-13-2022, 06:20 PM

Another point has to do with the landing gear. I don't know how stout RV gear is for this purpose, but on other planes, the gear is beefed up to absorb the impact of landing under parachute. If the gear doesn't absorb the impact loads, your spine will.

So a chute by itself is only half the answer...

skelrad · #6 09-13-2022, 06:21 PM

Great points to consider. I seem to remember that the guy who did this in his -7 routed the cables for the rear down through the wing root fairings. I wish I could find the reference to it. I think he said his install was supervised by Galaxy, so I've emailed them to see if they have any documented guidance. I'm lucky to have a family member who is an A&P and aeronautical engineer for one of the big biz jet brands, and could help out with design if I were to go this route.

It may not end up being worth the effort, but I want to do my homework for my wife's sake before nixing the idea. She's fine with flying in small planes, but I know her comfort level flying over the mountains around us would improve with a chute. BRS is an option, and the CG can still be dealt with, but definitely not ideal. This may all ultimately be a mental exercise. I sure like the idea of a forward mounted chute though.

Southern Pete · #7 09-14-2022, 06:58 AM

Dan has made a very valid point. Take a look at other aircraft that include a parachute and look at how the suspension cables are attached. They are thick cables. Also think about how to extract the parachute for repacks and how to replace the rocket. Not required that often but you must include a means to extract both of them. Often the suspension cables are attached to the chute risers with a large carabiner so figure that in. If you are building it will be possible to locate the avionics elsewhere, that is no factor.

rv8ch · #8 09-14-2022, 07:32 AM

Quote:

Originally Posted by skelrad

... This may all ultimately be a mental exercise. I sure like the idea of a forward mounted chute though.

May sound crazy, but I think what would be best would be a chute up front that suspends the aircraft from the engine mounts, and lets the aircraft land on the tail vertically. You'd need headrests to avoid neck injury. You'd also need to ensure that the prop was stopped before the lines get tangled in there.

Full aircraft parachutes have saved a lot of people, and it would be great to have them incorporated into the design. I think it will be easier with the RV-15, but no idea if that's being looked at.

Plenty of room in the front baggage area of the -8, if that's an option for you.

Another crazy option - wear parachutes when flying rather than counting on the full airframe parachute. Probably the simplest and cheapest option.

rocketman1988 · #9 09-14-2022, 07:42 AM

"...Full aircraft parachutes have saved a lot of people..."

That is a whole other can of worms, based on marketing and an incomplete data set.

The great thing is that in experimental aviation you can build whatever your heart desires, so if the chute idea works for you, go for it...

Just one question, though...how are you going to test it?

skelrad · #10 09-14-2022, 09:36 AM

Quote:

Originally Posted by rocketman1988

Just one question, though...how are you going to test it?

Yep, without deep pockets to play around with rocket testing on a specific airframe, you're left trusting in the engineering. Sometimes we just have to be okay designing to mitigate risk vs having a certainty that there is no risk at all though. In the end whether or not I pursue this will mostly depend on what the requirements end up being and what an engineer says. I'm fine with that, since I'm not trying to go this route "at all costs." It's a nice-to-have solution, but not required for my build by any stretch. I really appreciate all of the comments about design considerations though.