hi there

[woodysr2 14]

Hi there just joined

I have bought an Avid mk4 Aerobat but it had the stole's extensions fitted in 2014.

I bought this plane sight unseen as I was in hospital at the time and was looking for  good wing fold aircraft unfortunately this one isn't as good as I was led to believe, either that or I have been flying all wrong for the last 15 years lol.

The plane seems to be flying tail down and behind the drag curve elevator trim is sitting around 35 to 40 degrees down when set to Neutral????

Plane flying at 60 knots at 2300 rpm (jabiru 2200) and descending obviously mushing all over the place

any help ideas would be most appreciated

 

[1avidflyer 1983]

I have over 500 hrs flying an Avid MK IV with a jabiru engine.  I usually cruise at 2800-2850.  You are running the engine way to slow in my opinion.  The Jabiru redline is 3300, so at 2300 you are running at only about 2/3 rpm of what is perhaps available.  Ever try to fly a 65 HP continental at 1550 rpm.  About the same thing.  Run higher rpms and see what that does for you.  Also, try adding just a touch of flaps if the increased rpm isn't giving you what you want, that will push the nose down.  And by the way, welcome to the group.  Got any pictures?  JImChuk

[woodysr2 14]

Turns out one flapper was 9 degrees off level,

weight and balance is out apparently needs 4lbs of weight in the tail

but nose seems way light bouncing all over the place when taxying on slightly rough ground.

which would make you think it was tail heavy

[1avidflyer 1983]

A good way to set, or check the flaperon setting is clamp a board to the bottom of the flaperons close to the fuselage sticking back maybe 18" - 24".  Make a mark on both boards same distance back from the flaperon.  With the plane level side to side, put the stick all the way to one side.  Measure from your mark on the boards on both sides down to the floor.  (floor should be level side to side as well)   Then  put the stick all the way to the other side and measure from boards to the floor.  If the flaperons are adjusted correctly, both up and down measurements should be the same from one side to the other.    The boards just exaggerate the dimensions to see the difference easier.  Unlikely that it's tail heavy, most Avids tend to be nose heavy.  If you are doing the W&B correctly, math don't lie....  JImChuk

[woodysr2 14]

Thanks for the reply Jim

That is what is screwing with what little grey matter I have left lol. When I was sitting in the plane one of my mates came over put two fingers on the spinner and tipped the plane back on its tail with virtually no force required???

yet when I took it up for its last flight after levelling out the flapperons I was fighting to get the nose up and had to put elevator trim full down to relieve the pressure, so unless flappers are set at the wrong angle ie: flaps down it will need more weight in the tail. Already 4lbs there and another 4 to go there.

To the best of my knowledge it has always been a nose wheel but has had an engine swap 582 to Jabiru but that was years ago.

the plane has had the big fin heads fitted and new pistons and rings but wouldn't think that would account for the handling issues or imbalance.

going to double check aileron/flapperons this evening and inspector coming down again Sunday need this sorted before the end of the month lol.

weight and balance done by inspector I have lead strips to fit if required

William Russell

[1avidflyer 1983]

Do you have the correct main landing gear?  There is a difference from taildragger to trike.  JImChuk

[woodysr2 14]

to be absolutely honest I don't know

I do think it has been a trike all its life from the pictures I have seen of the plane.

I did see that there is a different nose wheel (a casting one) this one is linked

but the gear seems to be very short coupled ie. nose wheel distance to mains

inspectors coming on Sunday but there are only 50 in the uk so not a lot of knowledge this side of the pond.

William

[1avidflyer 1983]

Here ae a couple of pictures of Avids from the side.  Notice on the trike version, the wheel is centered between the front and rear mounting points for the landing gear on the fuselage.  On the taildragger version, the wheel is actually just a bit ahead of the front mounting point for the landing gear.  That means that if you use the wrong gear, the wheel will be about 6" away from where it should be, forwards or backwards.  JImChuk

[wypaul 448]

Posting some pictures will really help.  I think you need to get one of those 50 owners to come take a look.  Unfortunately W/B can be correct but if the gear is not right you will have the ground handling issues you describe.  Best to get it sorted before it causes an problem.

[woodysr2 14]

I posted a couple of pictures in the picture section the other day.

I would say mine looks pretty much the same as first pic but huge spats fitted lol

I will take more pics today when/if I get to the hangar.

I did notice elsewhere on the forum that there is a castoring nose wheel version that looks like it would take the nose wheel a good distance further forward extending the wheel base.

[flywise 169]

Thanks for the reply Jim

That is what is screwing with what little grey matter I have left lol. When I was sitting in the plane one of my mates came over put two fingers on the spinner and tipped the plane back on its tail with virtually no force required???

yet when I took it up for its last flight after levelling out the flapperons I was fighting to get the nose up and had to put elevator trim full down to relieve the pressure, so unless flappers are set at the wrong angle ie: flaps down it will need more weight in the tail. Already 4lbs there and another 4 to go there.

To the best of my knowledge it has always been a nose wheel but has had an engine swap 582 to Jabiru but that was years ago.

the plane has had the big fin heads fitted and new pistons and rings but wouldn't think that would account for the handling issues or imbalance.

going to double check aileron/flapperons this evening and inspector coming down again Sunday need this sorted before the end of the month lol.

weight and balance done by inspector I have lead strips to fit if required

William Russell

I would redo the weight and balance for sure, certainly don't assume anything. If any doubts redo it....how long ago was it done by the way ??

[woodysr2 14]

I added the 5lbs of weight to the tail it now fly's hands off with the trim just about neutral.

so lovely and light controls however after taking a spat off it certainly looks like wheels need to go back at least 6 inches

as the nose is far too light due to wheelbase

William

[1avidflyer 1983]

Looks like tri gear set up to me.  Did you actually do a proper weight and balance?  May not be wise to just guess at it, cause it feels right.  JImChuk

[woodysr2 14]

yes proper weight and balance was done and weight added now flying just about hands off a tiny amount of trim to raise the nose for straight and level at 2800 but looking at the position of the main gear it is actually just in front of body mass and under the centre of the wing.To me the wheels should be four or five inches further back under the wing struts.

Just my thoughts but more than happy to be corrected if wrong

William

[1avidflyer 1983]

I have no experience with tricycle gear on the Avid, but it does look like you have the Avid factory gear set up.  I think the Avid designer of the tricycle gear knows more then I do, so if CG is right, I would think things are as they should be.  Hope that doesn't sound snarky, I don't mean it like that.  JImChuk

[woodysr2 14]

no not snarky at all

thanks for the response

I have been told by a previous pilot that the plane is now flying pretty much the way it was.

I can wheelie the plane along the runway almost from a standing start. So now looks like it is just getting used to it.

I would prefer the main gear to be 4 or 5 inches further back so C of G is forward of the main gear which would keep the nose on the deck lol

Regards

William

 

[ChrisBolkan 130]

I have a million hours in the tricycle gear Avids. (not really but a LOT) You want the gear exactly where it is! It's perfect. That easy wheelie is EXACTLY what you want for perfect smooth landings! It is so wonderful. Makes the trikes able to land in really rough places without concern for taking out the nose wheel. Takeoff rolls consist of giving it gas, lifting the nosewheel a bit and rolling along with the nosewheel lifted until it flies. Landing do just the opposite. Land nose high and ride on the main wheels with the nose up (just like you taxi it now) until you have rolled over the rough stuff enough to put the nose down and safely apply brakes. I land my little trike in some very rough places. Pretty short too. Can't quite get the hard braking on as quickly as with a TW, so can't get stopped quite as quickly, but super respectable.

The balance of gear placement Dean did was amazing and genius IMHO . Makes the little Trike do almost as well as TW versions in the rough shit. Plus it's sort of auto calibrated to know if your CG is too far aft when you have it all loaded up for camping. If the tail won't stay up you need to move some weight forward.

[woodysr2 14]

Thanks for the reply Chris 

I will get a few more hours in on it and see how I go 

I have a tail wheel coming so will fit that to stop the tail touching the grass

will post pics when it arrives

 

[jbmaridon 0]

Happy 4th of July. I am new to this forum. My name is Joe Maridon. I recently purchased an Avid Catalina project that was purchased in 1995 and never completed. I am on a fast track to get it flying and have and will have questions that I hope others on this site will be able to help me with.     My project has the forward swinging gear and and engine munt for the Rotax 912. I have purchased a used 100 HP 912 and awaiting delivery. I have not yet selected a propeller. That is one area I would like to get some input. The project is well along. It is on the gear and all controls are installed. I just finished covering the wings. I particularly need help with canopy details and the removable enclosure below the engine.

I am located in Spokane, WA and there are many lakes to operate from.

I am a retired mechanical engineer, I have a commercial pilot license, A&P and IA. I have built and restored a few airplanes and currently fly a Cessna 150 Texas taildragger with a 150 HP Lycoming 0-320 and a long list of other modes. 

I will post some pictures in the future

[1avidflyer 1983]

Welcome to the group Joe.  I have no experience with the Catalina myself, but others here have.  It seems like Warp drive makes a very durable prop for seaplane applications.  JImChuk

[flywise 169]

Happy 4th of July. I am new to this forum. My name is Joe Maridon. I recently purchased an Avid Catalina project that was purchased in 1995 and never completed. I am on a fast track to get it flying and have and will have questions that I hope others on this site will be able to help me with.     My project has the forward swinging gear and and engine munt for the Rotax 912. I have purchased a used 100 HP 912 and awaiting delivery. I have not yet selected a propeller. That is one area I would like to get some input. The project is well along. It is on the gear and all controls are installed. I just finished covering the wings. I particularly need help with canopy details and the removable enclosure below the engine.

I am located in Spokane, WA and there are many lakes to operate from.

I am a retired mechanical engineer, I have a commercial pilot license, A&P and IA. I have built and restored a few airplanes and currently fly a Cessna 150 Texas taildragger with a 150 HP Lycoming 0-320 and a long list of other modes. 

I will post some pictures in the future

Welcome...I have a 912 powered cartalina. 69inch Koolprop/Nr prop 2 bladed sabre.  Happy to help you ....I am 1Hr from Vancouver/canada.

here some pictures for you 

https://1drv.ms/f/s!AvMw5i-09AkLmURmKBSU8uAlC3IR

https://1drv.ms/f/s!AvMw5i-09AkLrBtSxvtsC_MQNeYT

https://1drv.ms/f/s!AvMw5i-09AkLmyLHNPdIaLSnwTWe

https://1drv.ms/f/s!AvMw5i-09AkLmyLHNPdIaLSnwTWe

 

Edited 4 Jul 2021 by flywise

[jbmaridon 0]

Supermotive, I am building an Avid Catalina. I can not help you with your nose gear issue.

[marcusofcotton 51]

I have a question. I am configuring a nose wheel setup on my MKIV, and I need to set the fuselage angle. I just receive one of the catering nose wheel setups, and I am getting ready to configure a main gear setup. I have some flexibility on the main gear. If I wanted to maximize the attitude of the fuselage, at rest on the ground, what would be the attitude (the angle of door sills [or floor] to level ground). Would the door sills be parallel with the ground, or would the front of the door sills be a few degrees above level giving a  nose up attitude, and if so, how many degrees nose up? I can't find this information in any manual.

If you maximize angle of attitude at rest on the ground, I'm guessing you're doing so by use of shorter main gear. Doing so reduces your useable angle of attack on the ground by not allowing as much rotation of the fuselage during take off and landing. Put it up level and put a skid on where the tailwheel would mount - my skid is square tubing filled with lead to help CG.

This should probably be in a different thread.

[Supermotive 49]

macusofcotton, you are right, I moved the conversation to: General Category /Avid Flyer General Hangar /Avid Model IV /Setting Fuselage Attitude with Nose Wheel Trike Configuration