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I was curious if my Aerovee powered Waiex could get anywhere close to the service ceiling stated on Sonex's website or if that number was a bit optimistic, so a few weeks ago, I decided to see how high it would go. My airport is at 720 ft elevation and it was about 80 degrees out. I think the density altitude was about 2000 ft. I stayed directly over the airfield and just flew a pattern at a cruise climb. I wanted to see how stall characteristics were at higher altitudes during the flight, so once I reached 10,000 ft, I did a power-on, no flaps stall and was very surprised that the stall felt almost exactly the same as it does at 5000 ft, and it stalled at an IAS of 38 mph. Recovery was smooth and only took about 150 ft. After that, I kept climbing to see how high I could take it. I reached 11,500, but it took about 55 minutes to get that high. I think it still could have climbed a bit higher, maybe to 12,000, but I'd be surprised if it would get higher than that, at least on that day.

So I figured I'd see how high some of you have taken your Sonex/Waiex aircraft, especially those of you flying behind an Aerovee.

Here's a shot of my altitude just before the stall I did.


That's downtown Dayton way down there.

Very impressive Tom! That’s some great performance for an AeroVee! Personally the highest I’ve had mine is 9500’ MSL with the turbo but I don’t have a transponder so I’m limited to below 10,000’. Without the turbo, I’ve only been to around 7500’ or so. I get too bored with climbing at only 100-200 fpm at those altitudes!

On my second flight I got to 10,650ft MSL measured by GPS. My field elevation and the weather were almost exactly the same as yours.

At the rate I was climbing near the end, I think I could have made it close to 12,000, but it would have easily taken at least another 15 minutes. I'm pretty sure someone with a climb propeller could probably get quite a bit higher. I was only getting about 2800 rpm while climbing. Considering the slow rate of climb I'd be surprised if the level flight RPM would have been much over 2900 rpm.

Were you seeing similar RPMs? For comparison, what propeller were you using? I was using a Prince 54x46.

During my flight testing I got up to 10,000' msl with my AeroVee and AeroInjector. I could have kept going but that was my target, and the puffy clouds were so much fun to fly around!

11,500msl over the Bob Marshall Wilderness in Montana on my way back to KKLs from KOSH. Had to get over all the smoke from the forest fires. Didn't have enough visibility to land at one of my planned fuel stops so had to divert to alternate. Could have gone higher but that was all that was necessary.

15,000ft as I flew over the top of Pikes Peak, 14,110ft. Only 890ft AGL.
https://www.youtube.com/watch?v=cTYV3BZCQVk
But it took some ridge wave work to get it.
The jabiru pretty much didn't want to give me anymore.
Gary Motely did a lot of high altitude work in his Aerovee powered sonex.

gammaxy wrote:On my second flight I got to 10,650ft MSL measured by GPS. My field elevation and the weather were almost exactly the same as yours.

At the rate I was climbing near the end, I think I could have made it close to 12,000, but it would have easily taken at least another 15 minutes. I'm pretty sure someone with a climb propeller could probably get quite a bit higher. I was only getting about 2800 rpm while climbing. Considering the slow rate of climb I'd be surprised if the level flight RPM would have been much over 2900 rpm.

Were you seeing similar RPMs? For comparison, what propeller were you using? I was using a Prince 54x46.

That's about what I was seeing with my RPMs as well. even at full throttle for recovery after I did the power on stall, it took a minute to get my airspeed back up to the 75 IAS I was slowly climbing at. I'm using a 54x44 Sensenich wood prop. Once I leveled off at 11,500, I was seeing IAS of 80 mph, but my GPS ground speed was showing about 75 kts into the wind and 110 kts with the tailwind. I think that works out to about a 92 kts (110 mph TAS), which I think was pretty respectable for a naturally aspirated Aerovee at that altitude.

fastj22 wrote:15,000ft as I flew over the top of Pikes Peak, 14,110ft. Only 890ft AGL.
https://www.youtube.com/watch?v=cTYV3BZCQVk
But it took some ridge wave work to get it.
The jabiru pretty much didn't want to give me anymore.
Gary Motely did a lot of high altitude work in his Aerovee powered sonex.

You sure had some incredible views in that video. 15,000 ft is pretty remarkable. I'm sure it helps to have the Jabiru with the added hp. I'm curious what the service ceiling of my Aerovee would be at gross weight. I know climb rate is much slower even down low when flying with a passenger, so I'd be surprised if I could even get it to 10,000.

17,500 is possible with a Jabiru 3300 (FL180 was only a legal barrier!).

I’ve had mine to 13,500 ( Jab 3300). Jeff Shultz took it to 15,000 in phase 1


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