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What design mods would you make to the RV-12?

Top Cat

Well Known Member
I have a 2014 RV-12 SLSA and love it.

However, if I had my way there are a few things I'd change to improve (for me) on the design. Just wondering what you folks think?

I'd make all RV-12 have fixed wings and just offer the removable wing as an option,

Then I'd have a 12 gallon fuel tank in each wing. Bit like the Rans S19, but I'm
not sure if metal or plastic (like Rans). This also stops fuel spills from cracking rear 'perspex' panel.

I'd look into sliding canopy like the Rans S19

A small door to the baggage area with a box shape to store tools, qt oil etc

An access panel on the wheel fairings near the strut. Press button it springs out to allow pre-flight inspection of brakes and much easier tire press check.

map pockets standard.

Built in shutter on oil cooler for cold weather ops, instead of using metal tape.

Moveable rudder pedals to adjust for pilot height as well as improved seat adjustment.

Just some things I thought of after flying it for 18 months!!
 
At OSH this year, the ESLA folks asked for suggested mods. I emailed them this list. Several have been incorporated!
++++++++++++++++++
Kaitlyn - it was a pleasure meeting you at Oshkosh. I bet you are tired!
It was mentioned to send suggested improvements to the RV12 to you.

You may be familiar with the Van's Air Force website - vansairforce.com - the best user community in all of aviation. There are sub-forums for each type of RV plus other topics. Major focuses include builder assistance and modifications. Mods for the RV12 are not nearly so prevalent, but they do exist and one forum thread (link below) contains most of them. VAF was invaluable for me in my RV12 build.

The VAF RV-12 sub-forum
http://www.vansairforce.com/community/forumdisplay.php?f=73

The RV-12 Modifications thread in that forum - generaly all the mods have pictures.
http://www.vansairforce.com/community/showthread.php?t=64145

The best modifications in my opinion are (not in any order):

1. Split rear bulkhead and floor cover plate to avoid tank removal. See my Post #126 in themodifications thread. Also #164 & 166.
2. Quick drain immediately below the tank coming through one of the lower inspection plates. Post # 76 and 145.
3. Slotted center panel piece with backer plate, to allow the control cables to be dropped down and removal of the panel center plate for modification - WITHOUT having to pull the throttle and choke and heater cables completely out of the plane and then reinstalling them (a nasty job also requiring resetting all the carb adjustments!) See Post #163.
4. The "Bender Baffle" to improve cabin heat in the winter. Post 191 and some links.
5. Nutplates on the tank filler neck attachment flange to the outside skin.
6. The Moeller tank fuel gauge is now standard but it needs a gasket, not Proseal!
7. For many of those of us with Rotax engines with the engine mounted Honeywell oil pressure sensor - we got a kit from Lockwood with an extension hose that lets us mount that sensor off the engine and on the firewall. The hose has an orifice fitting. Engine vibration would give that $400 sensor an early death. (Post 32 shows the concept but also is shown replacing the sensor, not just moving the existing one if it still works. Also note comments in several posts after that.)
8. Canopy lock. (Post #5 for one method, post #63 and 93 for another - that is the one I did.)
9. Clips on oil door to hold the cap while you check the oil (post #6)
10. The USB port that sticks straight down from the instrument bay bottom is not a good idea. There are reasons to leave a memory stick in it all the time, not just for updates. Nor would it be good if it stuck out the instrument panel pointing aft. To take an in-flight Dynon screenshot you need a USB stick in that port, also to download log files after a flight. In the current position you could break it off with your knees. I took a short USB extension cable, and routed it to an opening in the glove box - and I leave a USB stick inserted there. Another option would be to use the same kind of cable extension but cinched up with cable ties on the underside bottom of the avionics bay, facing aft. With the USB socket far enough forward that a memory stick in it would not protrude past the plane of the panel. Similar to post #218.
11. The Ray Allen grips and transmit buttons are better than the bicycle grip idea with those current pushbuttons. Post 146.
12. REMOVABLE RIGHT STICK! In-flight removeable and replaceable with those little holes with those protruding click-type buttons (such as are used on the Van's tow bar.) All that is needed is a little piece of curved inside pipe at the cut, and a quick disconnect for the radio transmit wire, and a plastic cap for when removed. The geometry of the stick is such that it needs to be cut for removal in the curved section.
13. Post 45 discusses lower cowl hinge pin creep. I had that on one side but just fixed it with tape at each install of the lower cowl.
14. Nutplates instead of metal nuts in one place, post #46.
15. Many people want a fuel pump switch. I just pull the fuse if I need to have the master on, like for Skyview updates.
15. Post 66 - headset straps - these are optional if you remember to ask Abby at Flightline for them, also stick and flap handle boots and a velcro pocket for the center under-panel sloped surface. Some put headset hanger hooks on the structural member running aft of the canopy handle, above the baggage compartment.
16. I think the -12 needs an inline fuel filter upstream of the pump.
17. The wireway above the rudder pedal crossover is terribly crowded. It needs more room for all the wires - perhaps more than one wireway.
18. Tank return fitting lock plate. Really needed! See post 147 and 171 - I think something like this may be incorporated on current kits.
19. Improved ground for engine and voltage regulator. Post 240.
20. Several alternatives for better regulator cooling, starting about post #246 to #253.
21. Post #258 - eliminating finger-pinching from the flap handle pushbutton.
22. PLEXIGLAS - NOT LEXAN REAR WINDOW! Mine is already fuel crazed and I will have to replace it sooner or later.
 
Bill_H wrote:
10. The USB port that sticks straight down from the instrument bay bottom is not a good idea. There are reasons to leave a memory stick in it all the time, not just for updates. Nor would it be good if it stuck out the instrument panel pointing aft. To take an in-flight Dynon screenshot you need a USB stick in that port, also to download log files after a flight. In the current position you could break it off with your knees. I took a short USB extension cable, and routed it to an opening in the glove box - and I leave a USB stick inserted there.

Not trying to hijack this thread. Bill re USB stick, is the tiny profile "SanDisk Cruzer Fit" sort of USB a help in ameliorating the problem?

John
 
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Any very short USB drive would be OK. But my bottom-mount USB port was initially intermittent, as was a replacement sent from Stein. (And we thoroughly checked that those 4 wires were going to the right pins on the Skyview.) Others have reported this too. No problem ever with the extension cable.
 
John -- The short memory stick in the factory-spec location works fine. I leave my Seattle Avionics chart stick in place all the time. -- David
 
I agree on getting the fuel tank out of the passenger compartment.

Or at least compartmentalizing the fuel tank with additional structure (perhaps not the ideal way to do it).

Who wants to be the first pilot to have a minor accident, like running off the side of a runway, only to find the tank has ruptured and sprayed fuel all over the cabin? (Note that when a tank ruptures, it inherently is pressurized due to whatever g's are causing the loads to fail it.)

This is one issue that is keeping me from buying an RV-12.

Best Regards,

-Paragon
Cincinnati, OH
 
Risk management...

I agree on getting the fuel tank out of the passenger compartment.

Or at least compartmentalizing the fuel tank with additional structure (perhaps not the ideal way to do it).

Who wants to be the first pilot to have a minor accident, like running off the side of a runway, only to find the tank has ruptured and sprayed fuel all over the cabin? (Note that when a tank ruptures, it inherently is pressurized due to whatever g's are causing the loads to fail it.)

This is one issue that is keeping me from buying an RV-12.

Best Regards,

-Paragon
Cincinnati, OH

For a talk about my RV-12 build at our EAA chapter a few weeks back I did a search of the NTSB database for RV-12 accidents. Found 6 up to the end of August (one was incorrectly labelled Rans RV-12 BTW). All non-fatal (although I had read of at least one fatality in Australia a while back possibly the result of a "cowboy pilot" on the aircraft's first flight)

06/24/2010 LOC on takeoff (first flight by pilot in make/model)
08/29/2011 LOC hard landing on aborted takeoff due to open canopy (fuel tank rupture)
11/10/2012 Midair collision in pattern
12/10/2013 LOC on crosswind landing. Post impact fire
04/03/2014 Collision on landing. Hit aircraft on takeoff roll
06/20/2015 Impacted terrain on landing. Pilot distracted.

Small sample, but as expected most (if not all) were pilot error. Tank ruptured in one and probably two of the accidents but I believe these occurred before the recent tank mods were rolled out by Vans. I'm not qualified to analyse accident data, but after looking at this, I'm personally more concerned about a mid air collision that I am about the fuel tank placement. Given the spectacular visibility that we have in a RV-12 (and ADS-B traffic in many cases as backup) I was somewhat surprised that these were some of the most common events. (again small sample size)
 
I agree on getting the fuel tank out of the passenger compartment.

Or at least compartmentalizing the fuel tank with additional structure (perhaps not the ideal way to do it).

Who wants to be the first pilot to have a minor accident, like running off the side of a runway, only to find the tank has ruptured and sprayed fuel all over the cabin? (Note that when a tank ruptures, it inherently is pressurized due to whatever g's are causing the loads to fail it.)

This is one issue that is keeping me from buying an RV-12.

Best Regards,

-Paragon
Cincinnati, OH
Just FYI, there have been two Service Bulletins to address this risk. This is not to say that your concern is not justified - just passing along a tidbit of additional info.
 
For a talk about my RV-12 build at our EAA chapter a few weeks back I did a search of the NTSB database for RV-12 accidents. Found 6 up to the end of August (one was incorrectly labelled Rans RV-12 BTW). All non-fatal (although I had read of at least one fatality in Australia a while back possibly the result of a "cowboy pilot" on the aircraft's first flight)

06/24/2010 LOC on takeoff (first flight by pilot in make/model)
08/29/2011 LOC hard landing on aborted takeoff due to open canopy (fuel tank rupture)
11/10/2012 Midair collision in pattern
12/10/2013 LOC on crosswind landing. Post impact fire
04/03/2014 Collision on landing. Hit aircraft on takeoff roll
06/20/2015 Impacted terrain on landing. Pilot distracted.

Small sample, but as expected most (if not all) were pilot error. Tank ruptured in one and probably two of the accidents but I believe these occurred before the recent tank mods were rolled out by Vans. I'm not qualified to analyse accident data, but after looking at this, I'm personally more concerned about a mid air collision that I am about the fuel tank placement. Given the spectacular visibility that we have in a RV-12 (and ADS-B traffic in many cases as backup) I was somewhat surprised that these were some of the most common events. (again small sample size)


Brent,

Thank you for the NTSB accident information. One has to look up both "RV-12" and "RV12" in the NTSB database to get everything.

There were two nosegear collapses. The NTSB lists one cause as, "The pilot's selection of unsuitable terrain for a precautionary landing, which resulted in a nose over."

Where it alternatively might have said, "Pilot chose grassy field for landing, nosegear collapsed due to nosegear design digging into terrain, resulting in a noseover."

So another request for RV-12 improvements: More rugged nosegear design, with the swivel bearing base raised above the wheel centerline to minimize odds of digging in.

The good news from these accident reports is that the LSA philosophy of low stall (& landing) speeds appears to work, resulting in non-fatal accidents for these various mishaps. There may have been a different result in aircraft with stall speeds of 60+ kt instead of 41 kt.

-Paragon
Cincinnati, OH
 
There may have been a different result in aircraft with stall speeds of 60+ kt instead of 41 kt.
The severity of a crash goes up with the square of the speed. The damage done at a speed of 60 is not 1.5 times that at a speed of 40, as one might expect. Instead, the damage at 60 is twice that of 40. Another way to look at is if the engine gets pushed back 2 feet at an impact speed of 40, then it will get pushed back 4 feet at a speed of 60.
 
Brent,

Thank you for the NTSB accident information. One has to look up both "RV-12" and "RV12" in the NTSB database to get everything.

There were two nosegear collapses. The NTSB lists one cause as, "The pilot's selection of unsuitable terrain for a precautionary landing, which resulted in a nose over."

Where it alternatively might have said, "Pilot chose grassy field for landing, nosegear collapsed due to nosegear design digging into terrain, resulting in a noseover."

So another request for RV-12 improvements: More rugged nosegear design, with the swivel bearing base raised above the wheel centerline to minimize odds of digging in.

The good news from these accident reports is that the LSA philosophy of low stall (& landing) speeds appears to work, resulting in non-fatal accidents for these various mishaps. There may have been a different result in aircraft with stall speeds of 60+ kt instead of 41 kt.

-Paragon
Cincinnati, OH

Over generalized opinion (in my opinion)

There has actually been quite a few (I haven't actually counted them, but I am aware of ~ 6) RV-12 accidents that have resulted in nose gear failures and none of them resulted in a flip over (other than this one, which I was not aware of).

If anyone thinks that a nose gear can be designed to actually prevent a trigear airplane from ever flipping, I think they are mistaken.
 
I think that tiny wheels/tires are a bigger factor in flip-overs in off-airport landings than the gear will ever be. It's just part of the design to keep RVs light and reduce drag. You just have to accept the risk, keep those 5-point belts cinched tight and aim for something soft and inexpensive if the fan ever stops.
 
Agree

Think that the only airplane design that absolutely never will flip nose over in the event of an emergency landing in a rough field is the one that we drove around as a child - had pedals to make it go and was great fun. Tipped over sideways tho.:cool:
 
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