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I have THE fastest RV-9/9a

I believe the Sensenich prop has that 2600 rpm max when used with the O320. Doesn’t apply to the O360.

Just a little clarity, the Sensenich prop for the O-320 is a certified prop. The O-360 prop is NOT!
 
So much has been discussed about Vne relative to TAS that I’m pretty sure we all understand the distinction.

Unfortunately, I don’t believe that is the case.

No one wrong here, but seriously...Vans could publish a bulletin here tomorrow, supported by full page ads in the magazines, and "TAS for VNE" still won't register with all RV operators. Not everyone reads magazines or VAF, and some folks just don't care.

Want to make a long term impact? Have a placard made for the panel stating the VNE and specifying "TRUE AIR SPEED". Chances are it will still be spreading the word long after we're all gone.
 
Sorry, but I disagree. Vans has been very quick to recommend numerous service and safety bulletins related to their kits, and builders of their kits. I think it’s important to recognize that Vans Aircraft manufactures kits, not airplanes. We, as builders, are the manufacturers of these airplanes.

... The flight limits (flutter) are determined by the manufacturer - you and me during Phase 1. ...
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This is simply unrealistic. Builders are not test pilots and haven't been to test pilot school and don't understand the procedures, science or engineering involved to create the data, interpret that data and set reasonable limits with industry standard margins for safety. This is why almost EVERY kit manufacturer does that testing and provides safe guidelines to the builders. Sure, the builder can set whatever they want, but most simply aren't foolish enough to not follow those guidelines.

If you flew once to 250 kts in your phase I and didn't experience flutter, I certainly hope that you wouldn't set your VNE at 250, as I am confident that there is MUCH more to it than that. You could have been one knot from flutter and that limit becomes VERY DANGEROUS with the slightest touch of the stick setting off flutter. Following your logic, maybe next you well tell us we should be setting our own Va based upon our testing. Do you really expect 1000's of untrained folks to do that also? Do you expect builders to be doing stalls at 6 G's to get this data when we know that the designer has done all of the work and provided us guidelines to use? I could be wrong on how Va is tested for and set, but that is kind of the point. I haven't had any training on how to do this and have no idea HOW to properly set limits like this. One of the reasons that I bought a kit from someone who has done this work and demonstrated proven safety results within those set limits.

Did you do the testing to set the G limit on your plane also? You are the manufacturer, right? Pretty sure that requires pushing the structure to the point of damage and therefore impossible for a builder to perform even if they had the know how and tools to do it. You can't just stress it to 6G, observe no damage and call it a day. That is not how it is done, unless you disagree with having standard safety margins.
 
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Speed ion the table

How much speed are we leaving on the table with the 2600 rpm restriction with this prop?

When at altitude some of us run the full 2700 rpm with other competitor props.

Tim
 
9A speed

I can't view the link either. You list the speed but not the altitude?? I have a 9A but really have done any speed testing yet...lol. I've been flying it locally but not on any trips or at altitude (other than practicing approaches and keeping the speed down). I will soon just to find out.
 
I can't view the link either. You list the speed but not the altitude?? I have a 9A but really have done any speed testing yet...lol. I've been flying it locally but not on any trips or at altitude (other than practicing approaches and keeping the speed down). I will soon just to find out.

Dan, we should get together some time and check speeds. That is if the clouds and wind ever go away!
 
30 hours into Phase 1

Really happy with the performance but most importantly when you pull the throttle back you can really go fast and burn little fuel. This wing loves altitude! 175Kts straight and level 8000ft but it drinks fuel at that setting. Have to respect the TAS VNE though it doesn't take much to get it there.

IO-360 Thunderbolt - Ground Adjustable Sensenich 2 blade composite - Dual PMags

This plane is an amazing design - speed up high and really forgiving and stable down low and slow.
 

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efficiency at max speed

I cruise at 7.1 GPH at 148 KTAS, so roughly 24 MPG at 170 MPH (160 HP).
If I run the Hartzell CS prop at 2700 RPM at 8500', it gets up to 170 KTAS, but at 11.5 GPH, that is only 17 MPG. Only done that for 10 minutes at a time. Move the CG aft to the limit if you really want to go fastest.
 
I can't view the link either. You list the speed but not the altitude?? I have a 9A but really have done any speed testing yet...lol. I've been flying it locally but not on any trips or at altitude (other than practicing approaches and keeping the speed down). I will soon just to find out.

It seems I can reach a higher TAS at lower altitudes, but then fuel burn drops off as I go higher, while TAS remains about the same. For example, I can do 162 to 165 KTAS at 4500 feet, but then at 8500 feet, the KTAS is still 162. At 12,500, I can only get 155-158 KTAS, but the fuel flow is around 7GPH.. much better. This is on a RV-9a, O-320 160HP, Hartzell CS prop.

For a comparison, this -9a seems to run out of power above 12,500. My O-360 fixed pitch -4 gets up to 17,500 pretty easily, without a struggle. Makes me think I would rather have the bigger engine in the -9, perhaps it wouldn’t run out of steam up high. Maybe a Fixed pitch 360 is better than a CS 320?
 
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I cruise at 7.1 GPH at 148 KTAS, so roughly 24 MPG at 170 MPH (160 HP).
If I run the Hartzell CS prop at 2700 RPM at 8500', it gets up to 170 KTAS, but at 11.5 GPH, that is only 17 MPG. Only done that for 10 minutes at a time. Move the CG aft to the limit if you really want to go fastest.

I'm more or less, +/- 2 kts, the same as Jim, with a fixed Catto. About 150kts TAS at 7gph is my flight plan for economy cruise. If I get above 10,000 MSL, however, the speed can go up significantly for the same fuel burn.
 
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