Entry speeds / how to do.... basic aerobatics Waiex?

entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 7:37 am

by gyroron

Trying to understand what maneuvers I can do, and how to do them in my Waiex.

I have done many barrel rolls… Typically starting at around 120-130 mph, bring the nose up 30 - 40 degrees, then full stick either left or right, comes around fairly quick and ends close to level attitude with minimal altitude or speed loss.

I have done a few Split S’s… Typically, starting around 100 mph, simply chopping power to idle, nose level, roll to the right or left to inverted and pull a little back pressure on the stick to come around. Probably not pulling enough on the downline as I am seeing lots of altitude loss and speeds approaching 175 mph.

Yesterday I was going to attempt my first loop… Had no idea what speed to enter it at. Was at full throttle in a slight dive, at around 150 mph I started to pull back, Did not look out at wingtip like I should have… Got plane pointed likely to about vertical and chickened out, reduced power and stomped hard right rudder and did a hammerhead / wingover type of maneuver…

Not sure why I am scared to loop the plane. I had a Vans RV-4 and would loop and roll it often. Had a titan Tornado and would loop and roll it quite a bit. And have owned several Phantom ultralights and loops and rolls were done on almost every flight in those.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 8:11 am

by GraemeSmith

In my 80hp AeroVee Sonex I shallow power dive to 125KIAS as the entry speed. Smooth 3-4G pull at full power, smoothly lessening the pull and G on the way up and about 1G over the top to keep the oil pressure on. Airspeed over the top is about 40KIAS - though there is probably some calibration error there. The plane is still flying well. Retard throttle as she comes over the top and pulling it smoothly and hard to 3-4G at the finish. Never so “light” over the top as to “float” or go negative G. Little left rudder on the way up and she is level when inverted. A little right rudder on the way down to come out level. I lean slightly before the pull into the loop as the Aerocarb seems to rich and stumble slightly on the initial pull.

If I get good smooth 4 G pulls at start and finish without an accelerated stall I don’t lose altitude. If I only pull 3G at start and finish it costs about 300-500ft of altitude.

I find the loop the easiest of all the maneuvers to do and of course - hard to do WELL.

This sequence starts with a loop and finishes with some loops to form a cloverleaf - though my ear went haywire and I didn’t complete the cloverleaf. Skip ahead to 1:28

YMMV!


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 8:47 am

by XenosN42

Hi Ron,

Here’s a video of a Sonex doing some aerobatics showing the airspeeds. Hope it helps!

https://www.youtube.com/watch?v=nWH4UZ6ntTo


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 10:37 am

by hickej

Please everyone, get instruction before venturing into aerobatics. The barrel roll went very wrong for a friend of mine in a Waiex who did not neutralize the stick before applying full aileron. He ended up diving at the ground inverted because he was still applying up elevator. He pulled it out just in time.
Safe flying - it’s the only thing left to do!
-Jim


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 11:46 am

by sonex1374

GraemeSmith wrote:In my 80hp AeroVee Sonex I shallow power dive to 125KIAS as the entry speed. Smooth 3-4G pull at full power, smoothly lessening the pull and G on the way up and about 1G over the top to keep the oil pressure on.

Graeme is spot on here. To achieve a good loop you need to pull hard enough at the beginning. A 3-G pull is about the minimum needed to keep the speed from bleeding off too rapidly over the top, and a 4-G pull works even better. It may seem like pulling less G is easier on the airplane, but it’s counter productive. The plane can handle it just fine, and the bigger danger is falling out of the loop over the top and barreling down toward the ground in the resultant recovery. That’s a way to build a lot of speed, and a lot of G’s, and that can definitely hurt the plane!

My recipe is simple: 130-140 mph entry speed, pull to 3-4 G’s, release the back pressure to float over the top, and then bring the G’s back in on the backside during the pull out. If you pull too hard on the backside you’ll feel the elevator “shudder” a bit as the wing nibbles at a secondary stall.

A final thought about the inverted portions of our simple aerobatics. We all know that our planes don’t have inverted fuel and oil, but so long as even a little positive G is on the airplane, things still work just fine. I do this all the time in rolls by pushing just a touch of down elevator while inverted (just enough to get to maybe 1/2 or 1/3 G, definitely not zero or negative G’s). The engine never misses a beat, and the oil stays in the engine and not out the breather. I’ve even filmed these with my GoPro just sitting on the glareshield (not attached to anything) - it stays put just fine.

Jeff


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 6:59 pm

by mike.smith

Pretty much the same as Graeme and Jeff, except I think Jeff’s Jabiru can do it from level flight. With a VW you have to start by going downhill to gain speed. In doing so you can over-rev the engine. I do everything in knots… 130-140 kts. Throttle back on the downhill to not over rev. Pull back on the stick (not abruptly, but firmly and with conviction). Increase to WOT on the way up. Feed in a little left (for a VW) rudder. Lighten the pressure on the stick before the apex, and let the plane go over the top and get its nose going down hill on it’s own. Right as I start the back side of the loop I throttle back to keep from over-reving. Decrease the pressure on the rudder as you finish. How much depends on what you see as you look at the horizon. Pull the stick smoothly back until you’re level again. I’ve never needed any right rudder, only left rudder.

If you don’t lighten the back pressure at the top, not only will it be egg shaped, but you’ll likely exceed the critical AOA and stall. I did that several times when I was first looping the Sonex (my training had been in a different aircraft type). The plane just mushed out and rolled upright on its own, more or less.

For a split S, or reverse half Cuban, I don’t exceed 70 kts, so the throttle is always retarded when I start. I’ll throttle back a little more on the down line if it looks like I’m carrying excess speed. Otherwise you can easily get past Vne in a hurry.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 02, 2020 8:57 pm

by Rynoth

My loops have been 130KT decending entry full power (Aerovee Turbo climb prop), no issue with RPM keeping max cruise power setting (35" MAP). 2-3 g’s on entry if my g-meter was correct.

I will say that my Lift Reserve Indicator (~AOA) was my primary instrument nearing the top of the loop, I was able to keep 1 eyeball on it and adjust back-pressure accordingly to stay just shy of the stall buffet. I LOVE that instrument.

https://www.youtube.com/watch?v=n6uxv3ie2dw

On my first loop I looked overhead for the horizon, which was a bit disorienting and obviously made my headset fall off. Subsequently I watched the wingtip and my LRI and it was much more comfortable.

Make sure you chop the power as the nose slices down through the horizon, as the g’s set in very quickly once you’re pulling back up and away from the earth and airspeed quickly builds.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Apr 03, 2020 11:19 am

by Sonerai13

hickej wrote:Please everyone, get instruction before venturing into aerobatics…

I wholeheartedly agree with this. The Sonex line of aircraft are all very clean from a drag standpoint, and when you get them pointed at the ground the speed builds up FAST. This can be very dangerous because seeing the ground appearing to rush up at you at that rate generally causes and almighty pull on the stick and VERY rapid rise in G loads. The airplane will likely stall before it breaks, but that can lead to its own set of problems, especially as altitude rapidly diminishes. This is not for the faint of heart. Instruction is really the only safe way to do this.

And if I read y’alls descriptions right, what you are calling a “barrel roll” is actually and aileron roll (sometimes called a “ballistic roll”). A true barrel roll is performed more like a loop, with aileron added in. It is in effect an elongated loop and takes time and altitude to perform. It doesn’t happen fast like an aileron roll.

The bottom line is that aerobatics are fraught with peril and should not be undertaken without proper training, especially in a “slippery” airplane that can get you in BIG trouble in a big hurry.

Be safe!


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sat Apr 04, 2020 7:08 pm

by mike.smith

I did my aerobatic training in a Decathalon, which is a much draggier airplane. I had to learn the numbers that worked for my Sonex. So when people ask for things like entry speeds and techniques fore a Sonex, I’m happy to share my experiences. I just have to assume they’ve gotten proper training before doing aerobatics in their Sonex. Incidentally, I start all my aerobatics at 5,000’ AGL, and 3,000’ is my personal hard deck as I lose altitude doing multiple maneuvers.

I also have a laminated 6x5 piece of a sectional in the side pocket, with all the legal aerobatic areas delineated. I make sure I’m in those areas when doing aerobatics. Busy airspace near Boston. Having ADSB (in) is nice to get an initial read on the local traffic shortly after take-off, to decide which area I’m going to head for to practice in.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 05, 2020 6:44 pm

by Arjay

All you acro guys are making me drool. I have not yet been able to do any acro in My Sonex. It has an 80 hp aerovee with aerocarb. A couple of years ago my mechanic was out for a test flight, pulled the airplane up into the start of a loop and the engine died. He could not get it re-started and was forced to land on a 4 lane divided highway near the airport. (of course this made the international news, primarily because of the airplane markings, but that’s another story). Since then I have not been able to do any acro in my Sonex, and I am dying to try it out.

After investigation, my mechanic determined that the reason the engine died was that the g load in the pull up to the loop caused the fuel to be too rich, flooding out the engine. He figures the only way to cure this condition is to install a fuel pressure regulator ahead of the TBI. Upon looking around in the engine compartment there is not enough room on the firewall to mount the regulator, so he thinks he will have to weld a bracket on the motor mount on which to attach the regulator.

Questions: 1. Have any of you guys experienced engine flooding out doing acro? If so, what did you do to cure that problem?
2. Is installation of a fuel pressure regulator necessary?
3. If it is, would it be ok to weld a bracket to the motor mount (cross piece going side to side) to hold the regulator?

Any input you guys have would be appreciated. I am getting too old to keep waiting for my acro fix.

Ron, legacy Sonex taildragger, aerovee with aerocarb, based at KlZU

Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 05, 2020 7:01 pm

by Rynoth

I haven’t had any engine issues yet during aerobatics. Aerovee Turbo with a stock 2.5 needle in an Aeroinjector. Started all my maneuvers with mixture leaned for max-continuous power cruise flight. I don’t have a fuel flow meter, I do have a gascolator.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 05, 2020 7:16 pm

by Sonerai13

Arjay wrote:1. Have any of you guys experienced engine flooding out doing acro? If so, what did you do to cure that problem?

Yes. Most all throttle body injectors like we use on the VW conversions (AeroInjector, POSA, etc.) will go rich due to the g loading during a high G maneuver. I had a POSA on my Sonerai and did acro with no problem. Same with the Sonex and Onex. I have never had one go so rich as to kill the engine though. Had a couple of stumbles on occasion, but was expecting them so didn’t get worried.

As others have mentioned, leaning to best mixture for the altitude will minimize the issue.

Arjay wrote:2. Is installation of a fuel pressure regulator necessary?

In my experience, no. As always, YMMV, but on all the airplanes I’ve flown there was no problem doing acro with the AeroInjector (or the POSA).


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 09, 2020 11:18 pm

by Fastcapy

Arjay wrote:Questions: 1. Have any of you guys experienced engine flooding out doing acro? If so, what did you do to cure that problem?
2. Is installation of a fuel pressure regulator necessary?
3. If it is, would it be ok to weld a bracket to the motor mount (cross piece going side to side) to hold the regulator?

Any input you guys have would be appreciated. I am getting too old to keep waiting for my acro fix.

Yep, I experienced it multiple times when pulling positive G loads. Engine would go way rich and sputter. Luckily a quick push over kept it running. I also realized that was the cause of the stumble I experienced on takeoff. With the fuel pickup at the rear of the tank the rearward fuel movement and increased head pressure would cause it to go rich and “burp”. Dangerous, but hey just fly through it they say…

I tried an Aeroinjector and then an Aerocarb and both had the same issues. I finally bought a Rotec TBI and have not had an issue with it since. I actually feel comfortable flying behind it now. With the aeroinjector/carb I felt like the motor was going to quit at any minute. Best thing I ever did for my plane was throw the aeroinjector/carb in the trash.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Apr 10, 2020 11:02 am

by sonex1374

I fly acro often and my AeroInjector handles the G’s well. Like Joe Norris and others have reported the mixture may temporarily enrichen, but if I’m leaned appropriately for my altitude it’s an insignificant effect. I’ll try going to full-rich next time and see how that affects the engine. I’m very happy with the AeroInjector, but I don’t have any experience flying Sonex acro with anything else either (e.g. Rotec TBI, Ellison, Zenith Carb, Bing, EFI, etc… so many choices!)

Jeff


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Apr 10, 2020 12:00 pm

by gammaxy

My experience is similar to Jeff’s. I adjust the mixture lean for smoothness while gently pulling G’s during the clearing turn and find the mixture to be fine throughout aerobatics. Otherwise, it will bog down.

I had a fairly regular stumble like Mike’s on takeoff and when applying power rapidly to end a descent. I ended up training myself to advance the throttle slowly to avoid it. I decided to try out the burp tube others have mentioned and haven’t had a stumble since. My theory was vapor bubbles were in the fuel line and the engine was going lean, though. The one big catch is I definitely want to shut off the fuel with the fuel valve (and wait a while for the engine to shut down) or else the entire contents of the burp tube will slowly drain through the Aeroinjector after shutdown.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Apr 10, 2020 8:43 pm

by mike.smith

FWIW, I’ve never had so much as a hiccup flying acro with the AeroInjector. The engine RPMs may slow a bit when I get closer to 0-g’s (lower head pressure), but other than that I’ve never had a burp or stumble. It runs the same a 4.5 g’s as is does at 1g.

My acro involves, aileron rolls, 4 point rolls, loops, spins, Cuban 8’s, hammerheads, and variations thereof.

I’ve also rolled a Waiex with a Viking engine (thanks, Max!). No issues there, either.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sat Apr 11, 2020 8:24 am

by gyroron

I went up the other day, climbed to 5000 feet, and did several rolls, a few split s, steep turns, etc… just couldn’t get the courage to do a loop. Not sure why I am scared to do it. Somehow I feel concerned I might get too slow at the top and end up in a inverted spin… or some other weird thing will happen. Or I will pull too hard and overstress the tail or something.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sat Apr 11, 2020 9:47 am

by Rynoth

gyroron wrote:Or I will pull too hard and overstress the tail or something.

Do you happen to have a G-meter? If not there are some apps for phones that can give you a ballpark figure. I never went over 3g’s in my loops, and even that felt fairly uncomfortable to my body. I think the plane can handle a lot more G’s than I can. Also, G’s probably aren’t going to stress the tail nearly as much as the main wings. Over-speed on the other hand, might.

If you’ve never done a loop in any plane though, I’d go back to what Joe said. Find an aerobatic instructor and take some lessons first.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sat Apr 11, 2020 10:35 am

by Arjay

Mike wrote:

“I tried an Aeroinjector and then an Aerocarb and both had the same issues. I finally bought a Rotec TBI and have not had an issue with it since. I actually feel comfortable flying behind it now. With the aeroinjector/carb I felt like the motor was going to quit at any minute. Best thing I ever did for my plane was throw the aeroinjector/carb in the trash.”

Mike:

Some questions: What motor do you have? What model Rotec? How does the Rotec mate to the stock Aerovee intake manifold–is it a direct match, or require modification? Does the Rotec require carb heat? Air filter? What kind of connections are required for fuel input, throttle, mixture, etc.? Where can I get the Rotec?

Thank you for your input

Ron


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 12, 2020 8:30 am

by gyroron

Rynoth wrote:

gyroron wrote:Or I will pull too hard and overstress the tail or something.

Do you happen to have a G-meter? If not there are some apps for phones that can give you a ballpark figure. I never went over 3g’s in my loops, and even that felt fairly uncomfortable to my body. I think the plane can handle a lot more G’s than I can. Also, G’s probably aren’t going to stress the tail nearly as much as the main wings. Over-speed on the other hand, might.

If you’ve never done a loop in any plane though, I’d go back to what Joe said. Find an aerobatic instructor and take some lessons first.

The plane has one of those E1 electronic multi function instruments, and one of the settings is a G meter. Not sure how accurate it is.

I have looped before.

Have looped several Phantom ultralight airplanes, Looped the Titan Tornado I used to own many times, and Looped the RV-4 I used to own many times.

Its just one of those things… Its like back in my younger days, there was a bridge going across a cove in the lake we used to boat on. Wanted to jump off that bridge into the lake. Just couldn’t get the courage to do it. Finally one day ( after several beers ) a few friends and I swam off the boat to the shore and climbed up to the road and walked out on the bridge… and after a few of them jumped in, I followed. And after that I would jump off that bridge without hesitation.

I was nervous to roll this plane the first time. Took several flights in the plane before I said to myself, Lets just do it already… And I pitched the nose up about 30 degrees, stopped the climb, threw the stick hard over to the right and it rolled right around no problem. Now I have no issues, no fear to roll the plane at all. I just need to say to myself, F it, we are looping this thing today and just go do it. I am sure once I pull off a clean loop or two I will be over my fears and be willing to do them all the time.

Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 12, 2020 8:34 am

by gyroron

And speaking of aerobatics… I tried yesterday to spin the plane. Flaps up, at 5000 feet, I set throttle to idle and let the airspeed bled off to stall. Tried doing that with full right rudder, and full left rudder. Plane buffet pretty bad, but it would just mush, not break off into any kind of spin. What do you do to get a Waiex to spin?


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 12, 2020 8:45 am

by Rynoth

gyroron wrote:And speaking of aerobatics… I tried yesterday to spin the plane. Flaps up, at 5000 feet, I set throttle to idle and let the airspeed bled off to stall. Tried doing that with full right rudder, and full left rudder. Plane buffet pretty bad, but it would just mush, not break off into any kind of spin. What do you do to get a Waiex to spin?

Good question, I haven’t been able to get mine to spin yet either, though I only tried a couple times. Might have to do an accelerated cross-controlled stall to get it started, and/or go full power. I’m waiting for my new headset to give myself some more headspace to the canopy before I try again.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 12, 2020 9:47 am

by tx_swordguy

not sure about the waiex but model a sonex with a jab will spin quickly if you go flaps retracted nose high to slow down to about 40ish (right at stall) then hard left stick and left rudder. Have not done a right spin which is against the propeller affect in a jab. I was taught in a champ to use opposite flight controls to spin and that just didn’t work in the sonex. I just tried an exaggerated steep left turn right at stall speed (just as you start feeling the wing stop flying) engine at idle and it snapped into the spin. It was surprising since I had tried it several times unsuccessfully in the past with the cross control method (all it did is buffet and shake alot). My sonex with full flaps single person doesn’t seem to stall. It just seems to mush down in a nose level-to high attitude at a 1000+ fpm decent. Maybe I have just not gotten the correct environment factors to make it stall at full flaps (it may stall that way in a MTOW configuration)
Mark


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 12, 2020 10:02 am

by GraemeSmith

Well - 101 - spin recovery - because if you mess up acro - you will probably end up in a spin… Right? Sure… Like capsize drill in a sailing dinghy. So let’s practice before Acro…

Legacy Sonex with AeroVee

Darned if I can KEEP mine in a spin. I can stall it nose high, cross control it and it flips over into a very recognizable incipient spin. But it won’t stay there. The nose flops downhill and she either just mushes downhill or develops a dangerous accelerating spiral. No matter how I abuse, cross control or hold controls “pro-spin” - yes she will flip into it - but she just wont stay there. I guess I could load her more aft CG and see if I can get it to flatten some - but I’d have to load her out of CG range. And if I was to do that - I’d want a spin recovery parachute.

I’ve also put the plane in a full crossed slip and raised the nose to stall her and see what happens. In high wings I’ve flown - the plane falls into the slip on it’s side and rotates in an axis about its wings. In the Sonex - as the plane mushes into the stall the rudder wins and she rolls away from the slip but doesn’t spin.

Base to Final “rudder it round excessively” to get the inner wing to stall and drop into the killer spin - nope - she falls off in a mush. You probably wouldn’t have enough height to recover - just like a real spin - but she won’t flip over and really spin.

And the power on departure spin where you get nose high, slow and apply too much rudder to counteract ‘P’ factor. Usually the plane will flip on it’s back and spin. Nope - she just mushed and falls off onto the direction you have the rudder applied.

I do miss spinning…


entry speeds / how to do… basic aerobatics Waiex?

Posted: Tue Apr 21, 2020 11:00 pm

by Fastcapy

Arjay wrote:Mike wrote:

Mike:

Some questions: What motor do you have? What model Rotec? How does the Rotec mate to the stock Aerovee intake manifold–is it a direct match, or require modification? Does the Rotec require carb heat? Air filter? What kind of connections are required for fuel input, throttle, mixture, etc.? Where can I get the Rotec?

Thank you for your input

Ron

Hi Ron. Sorry for the delay in the response.

I have an Aerovee. Rotec 34-R. I was able to mount the 34-R right to the intake manifold the same way as the aerocarb. Carb heat isn’t really needed anymore than would be needed with an aerocarb. I run the same air filter (actually the K&N version of the stock one). It only took minor changes to throttle, mixture and fuel connections, however you will need to add a primer control. But it is easy and cheap. You can get it from Rotec, just good Rotec TBI.

Sent from my LM-G710 using Tapatalk


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Wed Apr 22, 2020 12:25 pm

by Arjay

Mike: thanks for your input. I just ordered a new Rotec to replace the aerocarb.
Getting anxious to have some fun. Will try to keep everyone updated when we get it installed.
Ron


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Apr 23, 2020 8:35 am

by gyroron

Well finally sacked up and did a loop. Then did like 4 more… was actually a pretty easy maneuver and drama free. Started out at about 3500 feet agl, slight nose down with about 80 percent power ( jab 3300)… once I saw 150 mph I brought the nose up to about 35 degrees somewhat gently then hauled the stick on back and titled my head back to watch it come around. Slight reduction of power on the downside. Airspeed never got below about 95mph and no real build up of speed. Fastest I came out of any of them was maybe 105 mph. Was fun. Glad to add another “ trick “ to the list with this fun little plane


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Mon Apr 27, 2020 7:06 am

by gyroron

https://www.youtube.com/watch?v=1ylsE4147QI


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Mon Oct 25, 2021 1:13 pm

by Arjay

My mechanic Fred and I need some help from you guys flying acro in the Aerovee Sonex. When we had the aerocarb installed the motor would load up (too rich) and stop when Fred pulled up to about 3 g’s. It even caused him to make an emergency landing on the highway. Since then we changed the aerocarb to a new Rotec tbi. It took a few runs to finally get the tbi tuned to where the motor would start up and run smooth. Now we have the throttle stopped so that the slide in the tbi will not open the last 1/8 inch or so. In that configuration it runs well straight and level, gets about 3150 rpm on takeoff run and, a little more, about 3250, on climbout. The problem is it kills the motor when pulling any g’s, just like before with the aerocarb.

Any suggestions?

You guys flying regular acro with the Aerovee can you describe your fuel system setup?
Carb type?
Gascolator?
Fuel pressure regulator?
Fuel pump?
Burp tube?
Leaning ritual?

We are considering taking the Rotec tbi apart to see if we can find anything obviously wrong inside. But we don’t have a service manual, don’t really know what to look for, and can’t get any response to our many requests for help from Rotec.

Any words of wisdom from you guys with experience would be greatly appreciated. Help!,

Ron
Legacy Sonex td, aerovee


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Mon Oct 25, 2021 5:28 pm

by GraemeSmith

Legacy Sonex
Aeorvee 2.1
AeroInjector with 2.5 needle - tuned per the book. Slide is FULLY open at WOT. Idles at 800-900 once warmed up.
K&N High pass air filter.
Fuel tank vent line has a one way valve to let air in from outside and keep fuel in the tank.

Fuel Tank → finger strainer in tank → Fuel Cock → Firewall → Hi-Pass Gascolator immediately after the firewall → dead straight slight downhill shortest run to Aeroinjector with armored flexible hose. All silcone/fibreglass firesleeved and covered again with fibreglass aluminized tape. Gascolator is taped over with the fibreglass aluminized tape.

Exhausts are fibreglass insulted full length to tail pipes just before they exit the cowl.

No burp tube.

No pressure regulator or pump.

No problem at idle - I have an outside air inlet pointed directly at the air filter.

Generally - lean for best power.

Just before acro - ensure leaned for best power.

Sharp 3G - 5G pulls with no problems. If there IS a slight hesitation on the engine with the pull - lean a “smidge” more.

It’s about as simple as I can make it (some might argue about the gascolator) and it works.

Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Oct 28, 2021 8:44 pm

by mike.smith

Legacy Sonex, AeroVee 2.1. Fuel tank w/ finger strainer → Braided fuel line → Firewall → In-line fuel filter → Braided fuel line to AeroInjector (technically it’s not called a “carb”). I think I have a #2.5 needle. No gascolator. No outside air to the air filter; all air from under the cowl per Sonex plans.

All fuel lines from the firewall on, are insulated with fire sleeve, hot water pipe insulation, and reflective heat tape. Fuel lines are mostly straight shots, except for the 90 deg turn from the tank to the firewall, and the 90 deg turn into the AeroInjector inlet.

Vent goes vertical from the tank, above the cowl, then 180 deg back down to vent at the bottom of the cowl. The aluminum tubing at the bottom of the cowl is bent slightly to face into to the wind (to prevent negative pressure from air across the tub).

Have never had any issues whatsoever with the AeroInjector, and have never even had the engine hiccup during aerobatics. At high Gs the engine runs perfectly normally. Approaching negative G’s the RPMs will begin to slow down a bit, but not a whole lot. The only throttle adjustments are to control airspeed and RPMs. I’ve never needed to work the throttle to keep the engine running.

Maneuvers: rolls, 4 point rolls, loops, 7-turn spins, hammerheads, Cuban 8’s, etc.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 09, 2023 4:58 pm

by Bryan Cotton

Hey all,
Your input and videos on entry speeds were really helpful. Question for the Aerovee acro pilots: What do you use as RPM limits? I noticed in my spin/roll video that I got a little over 3600 during the dive to 120. Redline in the manual is 4000 RPM. Are you working hard to keep it under 3400 RPM, or just under 4000?

Thanks!


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Sun Apr 09, 2023 6:15 pm

by GraemeSmith

I set redline at 3,400 and try and stay under 3,200 when going downhill on a loop. It’s too easy to overspeed. I work the throttle - like I do in other acro planes.

My fuel is a straight “uniform grade” (for want of a better description) downhill run from the bottom of the tank to the AeroInjector. There is a large gascolator on the firewall on the way. All covered with glass/silicone firesleeve - or taped over with layers of glass/aluminum reflective tape. Even the Gascolator bowl.

Exhaust pipes are wrapped with glass tape - full length.

ENSURE AIRCRAFT IS <950lb GROSS
CG in Aerobatic Range

MONITOR G Meter on EFIS All speeds KIAS

Aileron Rolls 3G 80-130
Barrel Rolls 3G 120-130
Chandelles 69-95

Hammerhead 100-110
(AVOID TAIL SLIDE)
Loops / Cloverleaf 3G 125-140
Lazy Eights 69-109
Horizontal Eights 125-140
Snap Roll NOT RECOMMENDED

Spins 35-40
Split S 60-70

Stalls <40
Whip Stalls PROHIBITED
Wing Over 78-95


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Tue Apr 18, 2023 7:56 pm

by mike.smith

Graeme’s numbers are pretty close to mine (for aileron rolls I prefer not being slow, so 120 kts for me is the usual pull up speed). You do have to watch the revs and work the throttle on the downhillls.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Wed Sep 13, 2023 9:37 am

by Bryan Cotton

I posted this video in my photo thread:
https://youtu.be/ZjJ2CCP6KVk?si=AJUgcO0tI_TEAcYx

The loop around 2:20 in the video - totally forgot to push the throttle in on the way up. I have to pull out a lot of power to keep the RPMs below 3400 in the dive to 140. Tells me two things:

  1. 140kts entry is probably enough to make it around the loop without power
  2. The contribution of the 80hp engine is minimal

Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Dec 14, 2023 12:53 pm

by Bryan Cotton

Hey all,
I tried my first hammerheads in the Waiex today. They were pretty ugly! Kept ending up inverted rather than straight down. It has been a long time since I’ve done hammerheads, but have done them in an F28A and a Pitts S2A. I figured that maybe I was pulling back on the stick by accident or something, and then tried to make sure I didn’t do that. Do you guys go forward stick on the kick over? I sort of remember doing that with the Pitts but I thought it was a subtle thing and used for style points, i.e. keeping it perfectly vertical through the pivot to the downline. If anybody had experience in the Waiex or Sonex they want to share I’d like to hear it. I am not sure if the conventional tail feels the same as the Y tail in this maneuver.

I did my pullup at 140kts, same as my loop entry speed. I know in this thread that some do them at lower speed but I figured that would give me more time in the vertical to figure out when it was time.

It was still fun, and the champions of our airshows and aerobatic competitions are safe from me for a little longer.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Dec 14, 2023 1:51 pm

by Bryan Cotton

I am wondering if maybe I was subconsciously putting in some right aileron when I kicked in right rudder. Would make sense for what was happening.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Thu Dec 14, 2023 9:59 pm

by Bryan Cotton

https://youtu.be/gPbcODcmFfc?si=nKzv5fwgU5l3XR-w


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 10:20 am

by Tnhelm

It appears to me that when you start the turn/pivot on top with the rudder, the airspeed is still high enough to cause more lift from the outer wing than the inner, resulting in the roll to inverted. When I taught basic aerobatics in the Citabria, it was frequently necessary to apply near full opposite aileron the keep the pivot on the top vertical, as indicated by the inside wing visually slicing backwards in reference to the ground. In fact that was my reference when making the reversal, watching the inner wing slice backwards and controlling the roll tendency with opposite aileron.
I have done the hammer head turns in my OneX which turned out well, although one got a little slower than desired on top and the airplane just barely pivoted around to downward. That was too close for me in avoiding a vertical tumble or tail slide. It probably looked good from the outside.
Tnhelm
Onex 0137


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 10:35 am

by Bryan Cotton

Thanks Tnhelm, good description. Makes sense.

In the Pitts I was taught to wiggle the ailerons a little on the up line, and when they went unresponsive that was a sign the airspeed was low enough to kick over. I’m wondering if this technique would also work in the Waiex. You need that goldilocks airspeed on top - not too fast, not too slow. I probably erred on the too fast side.

Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 12:15 pm

by Area 51%

Maybe you don’t have time to look, but does the oil pressure fluctuate at all when all the oil is in the back of the engine?
Do you notice any extra oil coming from the rear seal?

Looks like a lot of fun!


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 12:30 pm

by Bryan Cotton

Area 51% wrote:Maybe you don’t have time to look, but does the oil pressure fluctuate at all when all the oil is in the back of the engine?
Do you notice any extra oil coming from the rear seal?

Looks like a lot of fun!

Definitely fun. I am not very good at looking inside when I am doing aerobatics. Next time I plan to mount both cameras inside, one looking forward and one looking back. The forward looking camera will let me see the position of the controls and also give me a 3% chance of reading the oil pressure. There is also a red blinky light on the MFD that blinks if the oil pressure is too low. But it also blinks for low airspeed so I expect it to blink.

As far as noticing extra oil, that would be hard. There is oil everywhere even if we just fly straight and level.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 3:36 pm

by rizzz

Bryan Cotton wrote:Thanks Tnhelm, good description. Makes sense.

In the Pitts I was taught to wiggle the ailerons a little on the up line, and when they went unresponsive that was a sign the airspeed was low enough to kick over. I’m wondering if this technique would also work in the Waiex. You need that goldilocks airspeed on top - not too fast, not too slow. I probably erred on the too fast side.

https://youtu.be/MArvKledKYk?si=1iyOHdZ1947LA1FB

Hammerhead at 0:45, I don’t use the stick very much at all during this manoeuvre, just kick full rudder when the speed drops to about 40kt and maintain full throttle till the plane is pointing downward again.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 4:02 pm

by Bryan Cotton

Nice video Michael, and thanks for the contribution to the thread. How do you figure out when you are at 40kts?


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 4:44 pm

by rizzz

Bryan Cotton wrote:Nice video Michael, and thanks for the contribution to the thread. How do you figure out when you are at 40kts?

I should have stated this differently, I kick full rudder when I see my airspeed indicator approach the 40kt mark. Not sure what airspeed I am actually doing at that point and whether the indicator is reliable at all during such a manoeuvre.
You can actually see my airspeed indicator and how quickly the speed drops pretty well in the video.


Re: entry speeds / how to do… basic aerobatics Waiex?

Posted: Fri Dec 15, 2023 4:53 pm

by Bryan Cotton

rizzz wrote:I should have stated this differently, I kick full rudder when I see my airspeed indicator approach the 40kt mark. Not sure what airspeed I am actually doing at that point and whether the indicator is reliable at all during such a manoeuvre.
You can actually see my airspeed indicator and how quickly the speed drops pretty well in the video.

Thanks, that answers the question. Wasn’t sure if you were eyes in to see it pass through 40 or if you used other cues.