Performace

25 posts in this topic

Posted

I have a Mark IV, it doesn't preform anywhere like the factory spec's say that it will. Can't tell that the flaperions are down in landing, coming in at 80mph,4000rpm and upon landing cutting power to 2000rpm, idle. Take off is apx 70 and stol is 60. Is this normal?? What happened to 40 or is it my plane????

Share this post


Link to post
Share on other sites

Posted

I have a Mark IV, it doesn't preform anywhere like the factory spec's say that it will. Can't tell that the flaperions are down in landing, coming in at 80mph,4000rpm and upon landing cutting power to 2000rpm, idle. Take off is apx 70 and stol is 60. Is this normal?? What happened to 40 or is it my plane?huh.gif

What engine do you have? What wings do you have? Too many unknown facts to help you. We need more info. Russ.

Share this post


Link to post
Share on other sites

Posted

What engine do you have? What wings do you have? Too many unknown facts to help you. We need more info. Russ.

Ok, Have 582, wingspan is 30 ft, were speedwing but added the factory option of the 35 1/2 inch extension to each wing. New Power fin three blade prop, set pitch to .025 as per Power Fin, has apx 45 hrs on it now but has alwas been like this, just don't get the slow speed performace that I wanted, wanted short take off and landings but don't get them. Total weight is 1034 so isn't weight. Thought that this might be an ongoing thing with all of them.

Share this post


Link to post
Share on other sites

Posted

Ok, Have 582, wingspan is 30 ft, were speedwing but added the factory option of the 35 1/2 inch extension to each wing. New Power fin three blade prop, set pitch to .025 as per Power Fin, has apx 45 hrs on it now but has alwas been like this, just don't get the slow speed performace that I wanted, wanted short take off and landings but don't get them. Total weight is 1034 so isn't weight. Thought that this might be an ongoing thing with all of them.

What is your empty weight? what is your CG? both these are the biggest things in performance. I can fly my buddies extended speed wing just as slow as my HH and get in and out just as short. Incaft I think I can get out in his quicker than I can on mine!

:BC:

Share this post


Link to post
Share on other sites

Posted

What is your empty weight? what is your CG? both these are the biggest things in performance. I can fly my buddies extended speed wing just as slow as my HH and get in and out just as short. Incaft I think I can get out in his quicker than I can on mine!

:BC:

Total empty is 530 and the cg is +12.05. Orginally, the plane with the speedwings was to be a aerobat. All this should have made it more like a heavy hauler but doesn't seem like the wing extension did anything but increase DRAG. Doesn't seem to make any difference if the flaperions are down or not.

Share this post


Link to post
Share on other sites

Posted

Total empty is 530 and the cg is +12.05. Orginally, the plane with the speedwings was to be a aerobat. All this should have made it more like a heavy hauler but doesn't seem like the wing extension did anything but increase DRAG. Doesn't seem to make any difference if the flaperions are down or not.

move your CG back... like to 15 or 16" by putting divers weights on the tail wheel. It will really make a difference in the slow speed flying. I can fly my buddies all day long at 42 MPH indicated and backed up by the GPS on various courses. Have you tried to disconnect the static port on the ASI to make sure it is not getting a bum static and showing speeds way off? my normal approach is to maintain speed with elevator and vary descent rate with power if I want to drag it in short. I have seen Mark get off the snow in under 150' and sometimes closer to 100'.

What is your stall speed power on and off. I cant fathom not noticing a huge difference with the flaperons, you should have a pronounced pitch down and need to really haul back on the stick to keep the nose up. On wagonmasters, it makes a real big differnece in trems of getting in and out to use the flaps!

:BC:

1 person likes this

Share this post


Link to post
Share on other sites

Posted

move your CG back... like to 15 or 16" by putting divers weights on the tail wheel. It will really make a difference in the slow speed flying. I can fly my buddies all day long at 42 MPH indicated and backed up by the GPS on various courses. Have you tried to disconnect the static port on the ASI to make sure it is not getting a bum static and showing speeds way off? my normal approach is to maintain speed with elevator and vary descent rate with power if I want to drag it in short. I have seen Mark get off the snow in under 150' and sometimes closer to 100'.

What is your stall speed power on and off. I cant fathom not noticing a huge difference with the flaperons, you should have a pronounced pitch down and need to really haul back on the stick to keep the nose up. On wagonmasters, it makes a real big differnece in trems of getting in and out to use the flaps!

:BC:

I have checked the speeds with GPS and it is right on. No there is no big difference or any difference in all when you go flaps down. There is a bolt that keeps you from putting the flaperions all the way down that is on the seat. I have removed the bolt and the flaps really go down but how much is too much? This bolt is screwed in all the way so to shorten it, it would need replaced if that is what it is. Stall speed power off is apx 60 mph and about the same when stall in a climb. I approach at apx 80 with 4000 rpm and when I noses up, back to 2000 rpm which is idle with the 582 Rotax.

Share this post


Link to post
Share on other sites

Posted

Wow, Those numbers seem extremly high, I dont have an Avid but from what I have read the stall speeds should be in the 30,s and approach speeds more like 50. You might ask Joey or Leni what there speeds are at.Im not sure but the top speed is not too much over 80 to 90 MPH, so coming in on final at 80 sure seems like alot.I would definately get it figured out before trying to slow up too much on landing.The guys on this forum have lots of experience with these type of aircraft so there is a lot of trial and error knowlege out there so you are on the right track. Good Luck Randy

Share this post


Link to post
Share on other sites

Posted

Wow, Those numbers seem extremly high, I dont have an Avid but from what I have read the stall speeds should be in the 30,s and approach speeds more like 50. You might ask Joey or Leni what there speeds are at.Im not sure but the top speed is not too much over 80 to 90 MPH, so coming in on final at 80 sure seems like alot.I would definately get it figured out before trying to slow up too much on landing.The guys on this forum have lots of experience with these type of aircraft so there is a lot of trial and error knowlege out there so you are on the right track. Good Luck Randy

I agree, that is why I got an AVID, it was suppost to be a short take off landing fun slow plane. I am glad that I have an instructor that is experienced but this also gets him. Everything that he has been reading, it doesn't do. Know that those guys put lots of time in theirs in that enviroment should know about the stol and all. It is my dream to some day fly to Alaska, been there several times, would be the ultimate trip. But I have got to get this problem figured out. It may be the flap adjustment isn't just right or something, gone over the books time and time again to no advail. It is very responsive and on the ground, is kind of short coupled but is built to fly.

Share this post


Link to post
Share on other sites

Posted

I agree, that is why I got an AVID, it was suppost to be a short take off landing fun slow plane. I am glad that I have an instructor that is experienced but this also gets him. Everything that he has been reading, it doesn't do. Know that those guys put lots of time in theirs in that enviroment should know about the stol and all. It is my dream to some day fly to Alaska, been there several times, would be the ultimate trip. But I have got to get this problem figured out. It may be the flap adjustment isn't just right or something, gone over the books time and time again to no advail. It is very responsive and on the ground, is kind of short coupled but is built to fly.

If you dont have a pronounced pitch down when you pull on the flaps, something is not right. You should have 15 degrees of flap when you pull them on. Set reflex to maybe -2 degrees. I know you can go as much as -6 but when you do the stick gets heavy in cruise and I just dont like the feel. -2 is about right (imagine that the designer actually knew what he was doing :lol: ).

Wagonmasters plane is the same as yours. 582, same approximate weight, same speed wing, same extension. The difference is I can fly his all day at 40-42. Stall power on with flaps comes real gentle at about 38-39 with no major wing drop. It is a real joy to fly and very sporty feeling.

I am leaning towards the forward CG and perhaps the flaps not dropping down far enough.

:BC:

Share this post


Link to post
Share on other sites

Posted

If you dont have a pronounced pitch down when you pull on the flaps, something is not right. You should have 15 degrees of flap when you pull them on. Set reflex to maybe -2 degrees. I know you can go as much as -6 but when you do the stick gets heavy in cruise and I just dont like the feel. -2 is about right (imagine that the designer actually knew what he was doing :lol: ).

Wagonmasters plane is the same as yours. 582, same approximate weight, same speed wing, same extension. The difference is I can fly his all day at 40-42. Stall power on with flaps comes real gentle at about 38-39 with no major wing drop. It is a real joy to fly and very sporty feeling.

I am leaning towards the forward CG and perhaps the flaps not dropping down far enough.

:BC:

Ok, I will check the flaps but it may be a day or two, the wind blowing here and the plane is 20 miles away so will get back when I check this out. Will read the book on setting the flaps. Yes, I would like to be able to fly that slow, would help on soft landings and take offs. I need all the info that I can get. Thanks

Share this post


Link to post
Share on other sites

Posted

Reading this it kind of has me baffled. I think Leni is on the right track but with the empty wt and cg numbers you have it should perform better than my plane. I have a 629 lb empty wt and 11.2 cg, but mine will still take off at around 35 mph solo and stalls about the same. The flaperons make a big difference on the low end but even without flaps I have never had to approach at 80. Mine will just make 80+ in cruise and I can comfortably fly it at 60 without flaps and 40 with flaps on. You may have done this already but it is good excersise to get to altitude and really explore how slow you can fly the plane and manuver it. Although my airspeed indicated is off at the low end and high angle of attack; It will still fly and manuver at 20 mph indicated. I know it helped me get a lot more comfortable with landing it at the slowest speeds.

Like Leni said, when you pull your flaps full on it should feel like you are standing the plane on its nose; very pronounced. There is a limit to the flapperon deflection though or Avid warns of flaperon reversal; so don't just get rid of hte limit bolt. For a while I had a problem with mine not getting full flap deflection and finally determined that I had some interferance with the actuator tube hitting my bunges at the very last of the travel. It didn't seem like much off of the limit but when I fixed it, that last little bit of travel seemed to have as much affect on the flaps and the airplane as the first 3/4 of the flap travel; so be sure you get full travel to the limit per the manual.

Randy

Share this post


Link to post
Share on other sites

Posted

Reading this it kind of has me baffled. I think Leni is on the right track but with the empty wt and cg numbers you have it should perform better than my plane. I have a 629 lb empty wt and 11.2 cg, but mine will still take off at around 35 mph solo and stalls about the same. The flaperons make a big difference on the low end but even without flaps I have never had to approach at 80. Mine will just make 80+ in cruise and I can comfortably fly it at 60 without flaps and 40 with flaps on. You may have done this already but it is good excersise to get to altitude and really explore how slow you can fly the plane and manuver it. Although my airspeed indicated is off at the low end and high angle of attack; It will still fly and manuver at 20 mph indicated. I know it helped me get a lot more comfortable with landing it at the slowest speeds.

Like Leni said, when you pull your flaps full on it should feel like you are standing the plane on its nose; very pronounced. There is a limit to the flapperon deflection though or Avid warns of flaperon reversal; so don't just get rid of hte limit bolt. For a while I had a problem with mine not getting full flap deflection and finally determined that I had some interferance with the actuator tube hitting my bunges at the very last of the travel. It didn't seem like much off of the limit but when I fixed it, that last little bit of travel seemed to have as much affect on the flaps and the airplane as the first 3/4 of the flap travel; so be sure you get full travel to the limit per the manual.

Randy

One important note; weight makes a HUGE difference. You will not get the slow flight numbers if you are at max GW, so you will not see them flying dual but you should still be able to approach at 60 and land at 50 and the flaperons should still have the same big affect on the plane.

Share this post


Link to post
Share on other sites

Posted

One important note; weight makes a HUGE difference. You will not get the slow flight numbers if you are at max GW, so you will not see them flying dual but you should still be able to approach at 60 and land at 50 and the flaperons should still have the same big affect on the plane.

In Wagonmasters Extended speed wing Mk IV dual, take off is at 45-50 and climb out at 60-65. Cruise is around 90 to 92. I fly approach at 50-55 with touch down around 42-45 full flaps. This is if I want to get it in short. It is nothing to fly approach at 70 then on short final pull flaps, chop the power and damn near instantly you are at 50-55 and coming back in with the power to get the sink rate you want.

:BC:

1 person likes this

Share this post


Link to post
Share on other sites

Posted

In Wagonmasters Extended speed wing Mk IV dual, take off is at 45-50 and climb out at 60-65. Cruise is around 90 to 92. I fly approach at 50-55 with touch down around 42-45 full flaps. This is if I want to get it in short. It is nothing to fly approach at 70 then on short final pull flaps, chop the power and damn near instantly you are at 50-55 and coming back in with the power to get the sink rate you want.

BC.gif

Ok, Guys, had the Bird up yesterday and going in the morning unless the wind is 9--O !!!!!! Will check the angle of the flaperions tomarrow to see if they are 15 degrees. I have stalled it in the air and it stalls at 60 mph..... No, I will not remove the bolt, it acts as a stop and yes, the control is clear of the bungee cords. It has been a long windy spell here. My local airport is 3702 feet according to the chart so may be altitude has anything to do with it ??? But will know much more tomarrow I hope. Want to say thanks to ya'll for the help. All the info has been processed and has been checked out. I don't rule anything out !!!!!!!! Talked to Brent, new Airdale owner that bought out Avid and he is full time now, said that if I would put heavy hauler wings on it, it would help greatly but also said that they would fit the fat avid when I got ready.... from what he talked, there is a lot more room inside the cabin of it but I don't plan on living in it. Anyway, so much for the BS. Will get back tomarrow or tuesday. Thanks

Share this post


Link to post
Share on other sites

Posted

Ok, Guys, had the Bird up yesterday and going in the morning unless the wind is 9--O !!!!!! Will check the angle of the flaperions tomarrow to see if they are 15 degrees. I have stalled it in the air and it stalls at 60 mph..... No, I will not remove the bolt, it acts as a stop and yes, the control is clear of the bungee cords. It has been a long windy spell here. My local airport is 3702 feet according to the chart so may be altitude has anything to do with it huh.gif But will know much more tomarrow I hope. Want to say thanks to ya'll for the help. All the info has been processed and has been checked out. I don't rule anything out !!!!!!!! Talked to Brent, new Airdale owner that bought out Avid and he is full time now, said that if I would put heavy hauler wings on it, it would help greatly but also said that they would fit the fat avid when I got ready.... from what he talked, there is a lot more room inside the cabin of it but I don't plan on living in it. Anyway, so much for the BS. Will get back tomarrow or tuesday. Thanks

Ok, was flying this morning and the wind was 11 knots and gusting. Checked the degree of the flaperions and it was eight so will get a shorter bolt today I hope and will tell you what it does later in the week when I go again. Thanks

Share this post


Link to post
Share on other sites

Posted

8 with the flaps up or down? 8 positive or 8 negative? Don't get wrapped up on the flaps. They do very little on my airplane. I use them on takeoff to get the tail up faster but that's about it. I rarely touch them on final because it causes so much nose down pressure. I'm at 533lbs empty with STOL HH wings and I stall at 36. I fly around comfortably at 55-60 while yanking and banking through the trees. I think that unless you switch over to STOL wings your going to never get the type of performance your looking for. I've never talked to anyone yet who liked the speed wing.

Share this post


Link to post
Share on other sites

Posted

8 with the flaps up or down? 8 positive or 8 negative? Don't get wrapped up on the flaps. They do very little on my airplane. I use them on takeoff to get the tail up faster but that's about it. I rarely touch them on final because it causes so much nose down pressure. I'm at 533lbs empty with STOL HH wings and I stall at 36. I fly around comfortably at 55-60 while yanking and banking through the trees. I think that unless you switch over to STOL wings your going to never get the type of performance your looking for. I've never talked to anyone yet who liked the speed wing.

Dont knock it till ya fly it... I am guessing you did not read any of my posts. I can fly wagonmasters MK IV extended speed wing just as slow as my HH. If you dont think the flaps do much for you then you dont have them dropping all the way. They make a pretty damn big difference when used.

:BC:

Share this post


Link to post
Share on other sites

Posted

Ok, was flying this morning and the wind was 11 knots and gusting. Checked the degree of the flaperions and it was eight so will get a shorter bolt today I hope and will tell you what it does later in the week when I go again. Thanks

What we could be dealing with here is a case of elevator authority or a lack thereof.Gap seal the elevator horiziontal stab gap and put some vg's on the underside of the tail. Don't skimp on how many you put on.I went with cci vg's and used most of a full kit on the tail.If your plane has an elevator trim tab then you have a true mk 4 elevator size wise if not then your elevator is around 15% smaller.Of course, getting the cg back to 16 or more will help the elevator work more effectively.

Mike

Share this post


Link to post
Share on other sites

Posted

What we could be dealing with here is a case of elevator authority or a lack thereof.Gap seal the elevator horiziontal stab gap and put some vg's on the underside of the tail. Don't skimp on how many you put on.I went with cci vg's and used most of a full kit on the tail.If your plane has an elevator trim tab then you have a true mk 4 elevator size wise if not then your elevator is around 15% smaller.Of course, getting the cg back to 16 or more will help the elevator work more effectively.

Mike

Will look into this, it is a true Mark IV. For a fact, the indicator doesn't work but the switch does and you can really tell when you set it in the air. Haven't gotten it back in the air yet to see what the flaperions are doing with the new setting but the weather here has been raining every day which is unusual here, we get about 15 to 17 inches a year but we get planty of wind. Maybe monday..... or tuesday, looking forward to seeing what difference it will make and yes, some was saying that they used a tape to seal the elevator. To put it on the bottom with the elevator up and then when it is in the down position, put it on and see what it will do. Will try about anything..... Thanks Needing all the help that I can get to solve what is going on.......................

Share this post


Link to post
Share on other sites

Posted

Its been 5 years.  What did you find the problem to be?  I'd be afraid to fly that plane knowing something was wrong. 

Share this post


Link to post
Share on other sites

Posted

If I recall gross weight is 911# on a MkIV with speed wing while doing aerobatics, and 1050# without aerobatic maneuvers.   At 1034# your flying around fully loaded, unless I read something wrong, which is often the case. 

Share this post


Link to post
Share on other sites

Posted

hi, are you sure of the wing covering? may be the skin let pass air...

Share this post


Link to post
Share on other sites

Posted

I can fly at 60 all day long with my feet out the door. Something is seriously wrong. 

Share this post


Link to post
Share on other sites

Posted

Back during my airline days we once had a pilot tell me that the airplane he was flying felt like it was  on the edge of a stall the whole flight.  It was a 727 that we had just leased.  So after reading a bit in the maintenance  manual, I went to take a look.  Sure enough, the leading edges of the wings were rougher than a cob.  How are your leading edges?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now