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RV-12iS - Does Anyone Find The RV-12iS Brakes are Less Than Powerful

J

jackking123

Well Known Member
Patron
I flew an friends RV-12iS and found the brakes kind of weak from other planes I am use to.
Airplane brakes are not car brakes to be sure. They are not power assisted.
Does not feel spongy, stops plane, but seems less than powerful, Is that normal? *

In my case I had seat a tad too far back, for ideal brake actuation for my leg length. Owner is taller.
I could get full rudder, but more extended than I'd like in retrospect. Need to move up a few notches.

First time flying this plane it seemed to have less than spectacular brake power. I think PUSHING
harder is the cure, just asking?

*Not a low time or inexperienced pilot; not new to RV's, but newish to RV-12iS, I ask this dumb question to get feedback from RV-12iS pilots.
 
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Amadeus said:
Ugh. Not again. You HATE the RV12; we get it.

Just avoid ever flying in one and certainly turn down all maintenance requests for them.
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Wow, that was sure some quick snark. jackking123 asked a reasonable question about as politely as possible. Turn it down a notch dude.

I usually operate my 12 off of grass so the brakes don’t get used much. Thinking about asphalt runways they may be a little on the weak side. Certainly not overpowering. But the landing distance is so short it’s not like I’m going to run off the end of anybody’s runway. And there is plenty of brake for me to neatly pirouette wherever I need to.
 
Amadeus said:
Ugh. Not again. You HATE the RV12; we get it.

Just avoid ever flying in one and certainly turn down all maintenance requests for them.
Click to expand...
I should not reply, but with respect you are wrong. I don't hate the RV-12iS. The rest of your comment means nothing to me?

I inspected brakes, MATCO (good quality brand) with 65% pad thickness and expected more stopping power in such a light plane. That is all Amadeus. I have limited time in the RV-12iS. Trying to learn Amadeus.

As far as maintenance, I flown many planes, including RV's I built, flew and maintained. I'm considering bleeding brakes. No hate, just cautious. The common issue as I understand is trapped air in the cross-over tube which is at a high point. No hate. Looking for information. ugh. :rolleyes:
 
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jackking123 said:
As far as maintenance, I built and flew two RV's, owned 3 other Part 23 planes, maintained all of them. I'm considering bleeding the brakes. No hate, just cautious.
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bbaggerman said:
Wow, that was sure some quick snark. jackking123 asked a reasonable question about as politely as possible. Turn it down a notch dude.
Click to expand...

Nah, he asked almost this same question already. He does this over and over. People will make suggestions, he will go have AI craft arguments to explain why they everyone is wrong. He will ignore good advice, fail to fix the problem, and say it's the RV-12 fault.

It happens over and over. There's a few of them. It's like a pandemic here.
 
N8DAV8R said:
Nah, he asked almost this same question already. He does this over and over. People will make suggestions, he will go have AI craft arguments to explain why they everyone is wrong. He will ignore good advice, fail to fix the problem, and say it's the RV-12 fault.

It happens over and over. There's a few of them. It's like a pandemic here.
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What are you talking about? When did I ask this question before? Show me. You say I asked over and over? show me? Where did I say everyone is wrong? Show me? You are making up ad hominins. Again I don't hate the Rv-12iS. I think it is a cool LSA.

What GOOD advice did I ignore? Show me. If I disagree with a suggestion that is OK. For example, I asked what is best RPM to dynamic prop balancing a RV-12iS? One suggestion was use cruise RPM 5200-5500 RPM. That is above static RPM, so impossible. I replied thank you, good advice but not possible with fixed pitch prop, but with constant speed prop can do cruise RPM. I did the balance at 4700 RPM and cut the initial vibration down x4 after final permanent weight installed and final verification.

Read my replies I'm very thankful and appreciate of advice, even if I decline the opinion, suggestion. Saying I hate the RV-12iS is a false. Period. If you snipe and badger me, that is on you... "Why did you bring up Lycoming..."

Where did I say it is the RV-12iS's fault? I never said that. It has standard MATCO brakes and is a very light plane (thus LSA). To repeat myself I suspect my seat position was poor (less leverage on brakes). Also air in cross over tube (as I said) is possible. I see no bubbles. Making up false accusations, being personal is poor form. I'm trying to get the "feel" for the RV-12iS brakes, pun intended. If you can't say something nice.... :)
 
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bbaggerman said:
Wow, that was sure some quick snark. jackking123 asked a reasonable question about as politely as possible.
Click to expand...
Viewing this question by itself it certain would appear so.

Have a look at the RV12 Forum and you will understand.
 
jackking123 said:
I flew an friends RV-12iS and found the brakes kind of weak from other planes I am use to.
Airplane brakes are not car brakes to be sure. They are not power assisted.
Does not feel spongy, stops plane, but seems less than powerful, Is that normal? *

In my case I had seat a tad too far back, for ideal brake actuation for my leg length. Owner is taller.
I could get full rudder, but more extended than I'd like in retrospect. Need to move up a few notches.

First time flying this plane it seemed to have less than spectacular brake power. I think PUSHING
harder is the cure, just asking?

*Not a low time or inexperienced pilot; not new to RV's, but newish to RV-12iS, I ask this dumb question to get feedback from RV-12iS pilots.
Click to expand...
Compared to most on this forum I'm probably considered a low time pilot. My only experience with RV's is with the 12. The only other make I have any significant time in would be Cessna (172 and 140). Personally I'm happy with the brake performance. Not once have I found myself wishing they were more powerful. In fact, up until this post I hadn't really thought about the braking performance at all. Which I suppose means they behave exactly as I would expect.

I do have the Grove brakes (not the Matco). I don't know if that makes for any difference in performance.
 
The brakes are simple enough, if they aren't spongy and are otherwise well maintained it's hard to see much room for improvement there.

I think the less powerful feeling may be a result of the short distance between the brake lever and its pivot. Less mechanical advantage for the toes than other pedal designs.
 
After recent high speed taxi runs to break in my brakes per the manufacturer’s recommendations, my brakes are no less effective than those that were on my RV7. I actually locked a tire up at one point during the process.
 
My RV12iS brakes are good. When filling them I did spend a lot of time getting rid of air bubbles in the brake lines. I could only see the air bubbles because I was using the original nylon brake lines, except for the short ones between the bottoms of the gun-drilled legs and the brake assemblies. Some builders use braided brake lines throughout. IMO that's a bad idea because you can't see where the air bubbles are.
 
jackking123 said:
I flew an friends RV-12iS and found the brakes kind of weak from other planes I am use to.
Airplane brakes are not car brakes to be sure. They are not power assisted.
Does not feel spongy, stops plane, but seems less than powerful, Is that normal? *

In my case I had seat a tad too far back, for ideal brake actuation for my leg length. Owner is taller.
I could get full rudder, but more extended than I'd like in retrospect. Need to move up a few notches.

First time flying this plane it seemed to have less than spectacular brake power. I think PUSHING
harder is the cure, just asking?

*Not a low time or inexperienced pilot; not new to RV's, but newish to RV-12iS, I ask this dumb question to get feedback from RV-12iS pilots.
Click to expand...
I don't see much difference between the 7A I built and the RV12iS. Sounds like you need to build yourself your own 12iS.
 
OP here, after several more flights, 5000 RPM runup, you got to grab the horse's reins (push on brake pedals harder). For taxi, runup (4000 rpm), takeoff, landing it is satisfactory, acceptable. I am use to it.

Looking at the RV-12iS brakes in totality, thanks to insight from answers given above, thank you, the brake lines use un-reinforced plastic so they may give a little. The moment arm of brake pedals is short, mechanical advantage of foot pressure to braking is lower than other planes I have flown. However they work.

This is a LSA and there are compromises for weigh. It may be a design choice, to lower the chance of wheel lock up. In the early 90's flying as a CFI-I-ME in a large fleet of planes, among them C-182's and C-182RG's. The C-182 did not have an issue as much as the RG with pilots flat spotting the tires. The RG used "low profile" tires at higher pressure so they fit into the fuselage when retracted. The heavy plane, smaller tires and powerful brakes lead to more flat spots. NOT having overly powerful brakes can be good. If you have to LEAN on the brakes to not run off the end of the runway, U DONE ALREADY messed up Son.

PS I do not need an RV-12iS Build, built a RV-4, RV-7 and working on 2nd RV-7. I am good. 😊
 
I used to own a Cardinal RG and did indeed make a flat spot one day. Thank you for explaining why, many years later. (y)
 
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