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Volume of rain an O-320 RV can fly through?

BMW_X6M

Active Member
On one of my flights back from OSH I flew through a brief light shower.

What is the volume of rain when you would get concerned?
Should I close the carb heat flapper valve?
I assume at some point water will go through the engine?

Overall I remain hesitant to fly through anything but a light shower when absolutely necessary and with ADSB showing the local severity on the screen.
 
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On one of my flights back from OSH I flew threw a brief light shower.

What is the volume of rain when you would get concerned?
Should I close the carb heat flapper valve?
I assume at some point water will go through the engine?

Overall I remain hesitant to fly through anything but a light shower when absolutely necessary and with ADSB showing the local severity on the screen.

I have flown through some relatively heavy rain in my 6 / IO-320 (IMC). Don't see how any meaningfull amount of water can get through the filter. Light amounts that can vaporize are almost beneficial and do no damage. Water injection has been used for decades to help reduce detonation potential, typically to allow greater ignition advance increased turbo boost or higher compression. I don't see how the carb heat flapper would help. More important to be sure that your FAB has a drain hole for the water to escape. Without this, I could see a real problem with water ingestion.

Larry
 
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On one of my flights back from OSH I flew threw a brief light shower.

What is the volume of rain when you would get concerned?
Should I close the carb heat flapper valve?
I assume at some point water will go through the engine?

Overall I remain hesitant to fly through anything but a light shower when absolutely necessary and with ADSB showing the local severity on the screen.


Once upon a time I flew in moderate to heavy rain for over an hour. The engine performed fine I am sure it ingested some water. I have a tipup canopy and my cockpit was flooded with carpet soaking wet. I had drainage holes in the floor but they were not large enough to relieve the water. I throttled down to lessen wood prop erosion but leading edges were beat up. I fly through the rain relatively often and engine performs the same. Flawless.
 
I've had some rain where the engine developed a slight non-uniform miss, I pulled the carb heat closed and it cleared. Pulling the carb heat in heavy rain may be beneficial. I have limited testing for heavy rain.

but this tape helps keep water out. doesn't need to be this wide in the aircraft axial direction. extends slightly beyond the hinges.

IMG_20171011_192141_zpsdc72ifzf.jpg
 
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Flying back from Minnesota a week after OSH I flew for over an hour in rain that was a bit more than moderate at times. Engine performed flawlessly. I have a slider canopy and did not get one drop of water in the cockpit. My Catto three blade also came out unscathed, no damage to the paint.
 
Heavy Rain = Low Visability

The biggest limiting factor for heavy rain has been visibility for me. IFR Cherokee 140 flight. Looked like a wall of water underneath a very dark/black cloud.

I always apply carb heat and reduce RPM. Asked Craig at Catto about rain, he said to reduce below 2200 rpm.

Picked-up/purchased my RV-6 at Jackson, CA; homebase for Catto. He taped my leading edges before I departed for home. Have an early RV-6 Catto two blade without the metal leading edges.

Best regards,
Mike Bauer
 
I have a ram-air inlet, similar to a Bower inlet, with alternate air going through a conical K&N filter. Unlike the Bower inlet, my alternate air source is taken off of the #2 cylinder cooling ramp.

I have been in thunderstorm rain so heavy that it became hard to maintain a horizon (although still pretty clear which way was up from the dark cloud base). I have on occasion selected alternate air, closing off the direct ram air. But I have never noticed any adverse effect on engine running, even with the ram air on, which must gulp a fair bit of water.
 
The biggest limiting factor for heavy rain has been visibility for me. IFR Cherokee 140 flight. Looked like a wall of water underneath a very dark/black cloud.

I always apply carb heat and reduce RPM. Asked Craig at Catto about rain, he said to reduce below 2200 rpm.

Picked-up/purchased my RV-6 at Jackson, CA; homebase for Catto. He taped my leading edges before I departed for home. Have an early RV-6 Catto two blade without the metal leading edges.

Best regards,
Mike Bauer

I have a catto and applied the leading edge tape. I fly at 2700 in all kinds of rain with no damage/erosion. I think his caution is for props without the tape.

Larry
 
I've flown twice this year in heavy rain, as long as 20 or so minutes. My setup is similar to Steve's with a forward facing scoop into a conical filter. It ran smoothly through all of it. I did get a little paint erosion on the prop tip paint and on the baffles in front of the #1 and 2 cylinders, but other than that, nothing. I didn't even get any leakage into the cockpit or forward baggage.
 
Question about the airframe:

Have you guys every had any damage to the wing, tail, etc. leading edge paint from heavy rain?
 
I use carb heat through rain if the engine is equipped. I haven't seen much effect from rain in the injected planes I've flown, but I wouldn't fly in heavy rain conditions.

Paint wise, rain damage will be determined by the quality of paint job on the plane.

Vinyl wrap doesn't do too well in rain as I found out, but is easy to patch.
 
If you have a wood prop that is something to worry about with any rain. Aluminum props can get eroded in rain. That is why you keep the pain on it. The fancy composite props have SS leading edge but not the surfaces. Slow down and reduce RPM helps.

Paint on leading edge. I keep min waxed. But yes rain at 190 mph can cause erosion of paint... but if high quality paint it is not an issue. That is why you see jets have unpainted leading edges among other reasons.

Engine should run fine in rain... Not sure what the worry is about? If any water somehow makes it past the filter into the intake it will turn cook off the water.
 
A little

Every time I fly through appreciable rain I'll find a new pinhole in the paint on the leading edge. Paint is 12 years old at this point, for what that's worth.

My Warrior used to develop pinholes on the wing leading edges AND it lost paint on the point of the spinner. No paint loss on the RV spinner so far, for whatever reason.

My Hartzell has tape that seems to have borne the brunt of any damage thus far.

Question about the airframe:

Have you guys every had any damage to the wing, tail, etc. leading edge paint from heavy rain?
 
Rain damage

Being from Central Florida I fly through rain quite often. On occasion moderate to heavy. My injected IO-320 seems to lose a little RPM when heavy rain.
I have a Catto nickel leading edge prop and have not seen any damage to the leading edge. I did however lose one of the Catto stickers on the prop that is covered by a coat of clear paint.
I also have small chips in the paint on my horizontal stab where the fiberglass meets the aluminum. It appears I could have done a better job blending this in but I blame it on rain.
 
I've only been in light rain a couple times. Didn't have any engine issues but water was dripping on my legs. My worry is the water being sucked in from apparently everywhere and blowing on my avionics on the back will cause problems. I avoid rain!
 
I've had some rain where the engine developed a slight non-uniform miss, I pulled the carb heat closed and it cleared. Pulling the carb heat in heavy rain may be beneficial. I have limited testing for heavy rain.

but this tape helps keep water out. doesn't need to be this wide in the aircraft axial direction. extends slightly beyond the hinges.

IMG_20171011_192141_zpsdc72ifzf.jpg

How did the tape last when opening and closing canopy? Now I need to find some Blue tape.
 
How did the tape last when opening and closing canopy? Now I need to find some Blue tape.

I change it about once a year but it is still OK after a year. note: I place pipe teflon tape over the seam and then cover with vinyl tape.
 
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I once inadvertently ended up in very heavy rain. It was scary. The result was that my Catto composite prop had the leading-edges torn up. I've since replaced the prop with a Catto prop with Nickel lead-edges. This prop is much better in the rain.
The more scary part of the story is that I got water in my pitot tube and lost airspeed indication. At the time I didn't realize that was the problem and had a very stressful couple of minutes without airspeed indication and not knowing why. If I'd turned on my Pitot heat, that might have helped. That was about 8 years ago - I learned some very important lessons on that flight!
 
Looks like I'm late to the party, but I too can attest that an O-320 can ingest a huge amount of rain that you would never want to fly through!
 
The reality is the engine will fly through far more rain than you will ever want to fly through yourself!

As Phil mentioned, every time we push a little deeper into the operational envelope we experience new things happening. Sometimes good things. Sometimes bad things. We just need to be prepared to deal with them.

Rain getting inside the airplane is the one thing that challenges me the most. Sometimes, no matter how good the weather seal is, water, driven by 150+MPH wind, drives past the seals. Sometimes it gets in places where you can't seal it out. That's when drains in the low points of the floors come in particularly handy!
 
that's why I'm working on the combination uninator-drainiator. for those heavy rains when you need both.
 
Engine effects of rain . .

1. combustion - that has been discussed
2. cooling of barrels and heads - -

The sudden cooling of the barrels particularly rapidly reduce the diameter, but if the engine is built with the factory clearances, then it is a non issue. Sudden heavy rain has been known to shrink and stop/destroy an engine, but that possibility is well known to Lyc and Conti and designs now accommodate. Piston/cylinder and ring gaps will rapidly get reduced with the shrinkage of the barrel.

With proper clearances, it is a non-issue for any other engine effect. On the plus side, it will produce a touch more power, and it will clean the combustion chambers to a like new condition.
 
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