Wing Loading P51, Too Heavy??
10-14-2014, 12:56 PM
#26
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Hi Corey,
My mustang ( a D version bye the way ) flew very well. It is difficult to assess these things, but there were times when it didn't feel as rock solid as other P51's I had flown. I suspect the Wing airfoil is not as forgiving as others.
However, do not be concerned, for this feeling I had didn't translate into any bad vices or habits. The most difficult part of the flight for me was taking off. Needed all the righthand rudder. Normal flight was great. Landing was ok, a breeze with the nose slightly down, power on , full flap configuration. Don't wallow or it will bite. I dead sticked once and was surprised how well it handled the slow flair coming of a fast approach.
Hope this helps, and feel free to ask more . Cheers Merlin Man
My mustang ( a D version bye the way ) flew very well. It is difficult to assess these things, but there were times when it didn't feel as rock solid as other P51's I had flown. I suspect the Wing airfoil is not as forgiving as others.
However, do not be concerned, for this feeling I had didn't translate into any bad vices or habits. The most difficult part of the flight for me was taking off. Needed all the righthand rudder. Normal flight was great. Landing was ok, a breeze with the nose slightly down, power on , full flap configuration. Don't wallow or it will bite. I dead sticked once and was surprised how well it handled the slow flair coming of a fast approach.
Hope this helps, and feel free to ask more . Cheers Merlin Man
10-15-2014, 05:07 PM
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The Weigh in and CG
Dry weight as in pictures 16.28 lbs, GREAT, unfortunately its going to take 2 lbs of lead on the motor mounts to CG correctly 
for all up weight of 18.25-18.50 lbs + fuel Sure wish I could get some weight out of the tail end and not add any nose weight at all it woudl be PERFECT but shes finished and too pretty to hack on, damn physics. I am hoping those big flaps help with the landings 
A GREAT guy here on RC universe had the plans and forwarded me some pictures of the plans and info, finished weight per info on plans is 14-18 lbs, so I am hoping being its close to design its not turned back into kit form on first flight.
No wonder shes so heavy, all hinge and control points hidden, scale looking Robart air retracts mains and tail wheel sequenced gear doors even on the tail wheel, full cock pit with sliding canopy that is air cylinder operated, nav lights, panel lines, rivits and simulated screws, would need a pilot to make it complete for flying, I'm seeing 19-19.5 lbs here on take off ?????
What do you guys think???
for all up weight of 18.25-18.50 lbs + fuel Sure wish I could get some weight out of the tail end and not add any nose weight at all it woudl be PERFECT but shes finished and too pretty to hack on, damn physics. I am hoping those big flaps help with the landings A GREAT guy here on RC universe had the plans and forwarded me some pictures of the plans and info, finished weight per info on plans is 14-18 lbs, so I am hoping being its close to design its not turned back into kit form on first flight. No wonder shes so heavy, all hinge and control points hidden, scale looking Robart air retracts mains and tail wheel sequenced gear doors even on the tail wheel, full cock pit with sliding canopy that is air cylinder operated, nav lights, panel lines, rivits and simulated screws, would need a pilot to make it complete for flying, I'm seeing 19-19.5 lbs here on take off ?????
What do you guys think???
10-15-2014, 05:16 PM
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Hi Lancr,
That is a really great looking P51, but I find it hard to believe that it will need 2lbs. on the motor mount ! . I cannot remember having to put ANY nose weight in any of my Mustangs. It must have an extremely heavy tail?!. I presume you have the correct Cof G ?.
Cheers,
Merlin Man.
That is a really great looking P51, but I find it hard to believe that it will need 2lbs. on the motor mount ! . I cannot remember having to put ANY nose weight in any of my Mustangs. It must have an extremely heavy tail?!. I presume you have the correct Cof G ?.
Cheers,
Merlin Man.
10-15-2014, 06:27 PM
#29
Your wing loading at 18 pounds is 43.6 ounces per square foot. That is high for a plane that size but it’s not fatal. Use the flaps and keep your speed up when landing. It's the retractable tail wheel that's killing you. I wouldn't add any more weight than what's necessary. Dan.
10-15-2014, 11:04 PM
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I wish the tailwheel was really the primary issue. I've been corresponding with the OP, because I have one that I also bought partially finished. Refer to this thread: http://www.rcuniverse.com/forum/rc-w...ng-advice.html
It simply looks like they build tail heavy ... which is why they don't get finished ... once the builder realizes the mistake, he gives up. If the builder doesn't take precaution to lighten the material in the tail (I have the manual addendum which specifically addresses the need to do this), then they wind up like the OP's ... and mine. To get mine to balance required three pounds of lead in the nose, but I was trying a ST 2500. The heavier engine he is using probably accounts for the difference. For this reason, I shelved it until I can work up the courage to get out a RotoZip and start hacking.
Before someone jumps on me and says that the plane CAN be flown this heavy ... don't. I know it could be done, I simply refuse to put that much weight up there without trying to deal with it in the tail. I got my plane for $30, so I think the effort and risk is reasonable.
Hey, lancr, give me another call ... perhaps we can use my less complete version as a test article to see what you MIGHT be able to do to drop the weight in the tail. However, consider this ... to get a pound out of the nose, we need to get four to five ounces out of the tail. This is roughly equivalent to pulling a 3/8x4x36 sheet of balsa out of the tail. There is "lite" ply in the tail, but ... geez. And we need ... TWO pounds out.
Here's one hint - the rudder itself is incredibly heavy. Mine was not hinged, so I could weigh it, and I've never seen anything quite like it. That means the elevator, and stabs are problems too. This is where the pink addendum sheet told the builder to swiss cheese the balsa. I'm sure mine is not, and even if it was, we are still looking at three sheets of balsa plus ribs in the construction of these components. I fear I may have to hack them off and do a better, lighter, job (there are some other problems in the construction of mine back there that make that option a good one).
Stay in touch please, and let me know if you decide to move forward and fly it - again, it probably CAN be flown this way - I've simply chosen not to do so - putting weight up front is not something I do unless I've tried everything else first.
It simply looks like they build tail heavy ... which is why they don't get finished ... once the builder realizes the mistake, he gives up. If the builder doesn't take precaution to lighten the material in the tail (I have the manual addendum which specifically addresses the need to do this), then they wind up like the OP's ... and mine. To get mine to balance required three pounds of lead in the nose, but I was trying a ST 2500. The heavier engine he is using probably accounts for the difference. For this reason, I shelved it until I can work up the courage to get out a RotoZip and start hacking.
Before someone jumps on me and says that the plane CAN be flown this heavy ... don't. I know it could be done, I simply refuse to put that much weight up there without trying to deal with it in the tail. I got my plane for $30, so I think the effort and risk is reasonable.
Hey, lancr, give me another call ... perhaps we can use my less complete version as a test article to see what you MIGHT be able to do to drop the weight in the tail. However, consider this ... to get a pound out of the nose, we need to get four to five ounces out of the tail. This is roughly equivalent to pulling a 3/8x4x36 sheet of balsa out of the tail. There is "lite" ply in the tail, but ... geez. And we need ... TWO pounds out.
Here's one hint - the rudder itself is incredibly heavy. Mine was not hinged, so I could weigh it, and I've never seen anything quite like it. That means the elevator, and stabs are problems too. This is where the pink addendum sheet told the builder to swiss cheese the balsa. I'm sure mine is not, and even if it was, we are still looking at three sheets of balsa plus ribs in the construction of these components. I fear I may have to hack them off and do a better, lighter, job (there are some other problems in the construction of mine back there that make that option a good one).
Stay in touch please, and let me know if you decide to move forward and fly it - again, it probably CAN be flown this way - I've simply chosen not to do so - putting weight up front is not something I do unless I've tried everything else first.
10-16-2014, 01:37 AM
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Hi Corey,
My mustang ( a D version bye the way ) flew very well. It is difficult to assess these things, but there were times when it didn't feel as rock solid as other P51's I had flown. I suspect the Wing airfoil is not as forgiving as others.
However, do not be concerned, for this feeling I had didn't translate into any bad vices or habits. The most difficult part of the flight for me was taking off. Needed all the righthand rudder. Normal flight was great. Landing was ok, a breeze with the nose slightly down, power on , full flap configuration. Don't wallow or it will bite. I dead sticked once and was surprised how well it handled the slow flair coming of a fast approach.
Hope this helps, and feel free to ask more . Cheers Merlin Man
My mustang ( a D version bye the way ) flew very well. It is difficult to assess these things, but there were times when it didn't feel as rock solid as other P51's I had flown. I suspect the Wing airfoil is not as forgiving as others.
However, do not be concerned, for this feeling I had didn't translate into any bad vices or habits. The most difficult part of the flight for me was taking off. Needed all the righthand rudder. Normal flight was great. Landing was ok, a breeze with the nose slightly down, power on , full flap configuration. Don't wallow or it will bite. I dead sticked once and was surprised how well it handled the slow flair coming of a fast approach.
Hope this helps, and feel free to ask more . Cheers Merlin Man
i will make a flight plan befor my first flight.
10-16-2014, 01:46 AM
#32
I have a TF P-40 (.60-size) that has a 40 ounce wing loading. It flies fine, but it has to have plenty of airspeed for takeoff and landings. If you have an old sport plane sitting around, you can add ballast, at the cg to that plane until it has a 40 ounce loading as well and use it to practice with til you are more comfortable with a plane like that.
This practice has been used for years and will help you be more comfortable with a heavier plane.
Best regards.
This practice has been used for years and will help you be more comfortable with a heavier plane.
Best regards.
01-10-2016, 10:36 AM
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No, unfortunately have not worked on her since last Dec, my Dad died a year ago today Found him frozen in his drive way on a minus 15 degree morning, it appeared he was out looking for the Sunday paper around 5AM and the cold must have induced a heart attack or something. And to top it off then early May on the night of my daughters over the top wedding after a grand reception party my baby brother of only 25 went home and decided he had enough of his ex girl friends torture with their child and he would never have the happiness of the day he just experienced and we found him dead the next morning with a pistol in his hands. I have not flown or worked on models at all this past year Its been hard to just about do any thing let alone any thing fun. Setting 2 tomb stones this month, one next week on which would have been my Dads 81st B-day and on his sons right next to him at the same time, life has not been the same. Hoping to maybe get back on the horse and do some practice welding in the near future and at least finish the exhaust before spring, maybe fly a foamy or something. I'm going to be a Grand Pop for the first time in February some time, as one family member left this earth the same night another was created, weird how life works. I'll post some thing some day about both, the 51 and my new grand daughter 
Found him frozen in his drive way on a minus 15 degree morning, it appeared he was out looking for the Sunday paper around 5AM and the cold must have induced a heart attack or something. And to top it off then early May on the night of my daughters over the top wedding after a grand reception party my baby brother of only 25 went home and decided he had enough of his ex girl friends torture with their child and he would never have the happiness of the day he just experienced and we found him dead the next morning with a pistol in his hands. I have not flown or worked on models at all this past year Its been hard to just about do any thing let alone any thing fun. Setting 2 tomb stones this month, one next week on which would have been my Dads 81st B-day and on his sons right next to him at the same time, life has not been the same. Hoping to maybe get back on the horse and do some practice welding in the near future and at least finish the exhaust before spring, maybe fly a foamy or something. I'm going to be a Grand Pop for the first time in February some time, as one family member left this earth the same night another was created, weird how life works. I'll post some thing some day about both, the 51 and my new grand daughter
01-10-2016, 02:34 PM
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Very, yery sorry to hear of your losses, and the circumstances were really tough. We are pulling for you - it takes at least a year to get past this sort of thing - it sounds like you have the strength to push on. Let us know how we can help, if even to just listen.
Rikk
Rikk
01-10-2016, 03:20 PM
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THANKS ALL!!! Today was a rough day, I'm sure unfortunatly there will be a few more as another anniversary comes, the day of my brothers demise on my daughter's first wedding anniversary none the less but hoping the summer after has outings that don't include walking around Cemetary after Cemetary browsing tomb stones for the just the right ones and fighting for child visitation rights and paying all the bills related to it all
Yep, the day it does fly it will be with a 2 blade woodie for sure, there is a couple of them out in the shop already collecting dust waiting for the day they get their "turn". The $150 4 blade beauty will hopefully get a turn some day too if all goes as planned !
Today was a rough day, I'm sure unfortunatly there will be a few more as another anniversary comes, the day of my brothers demise on my daughter's first wedding anniversary none the less but hoping the summer after has outings that don't include walking around Cemetary after Cemetary browsing tomb stones for the just the right ones and fighting for child visitation rights and paying all the bills related to it all Yep, the day it does fly it will be with a 2 blade woodie for sure, there is a couple of them out in the shop already collecting dust waiting for the day they get their "turn". The $150 4 blade beauty will hopefully get a turn some day too if all goes as planned
!
01-10-2016, 03:23 PM
#39
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Rikki you ever get yours in the air yet?
What engine did you finally fit her with?
Some pictures or good news would surely help get the juices flowing again
What engine did you finally fit her with?
Some pictures or good news would surely help get the juices flowing again
01-10-2016, 04:18 PM
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Naw, I had a spell of bad luck myself that took my productivity down the last year and a half ... stress induced seizure dropped me in a hardware store, leading to a hard number of whacks on the noggin, which caused moderate traumatic brain injury. Brain bleed, etc. You learn about what you have deep in yourself getting through these things - you are in the crucible too. I'm good now, and back in the game myself. Working on a ziroli P-38 though, along with a helping some other guys with trainers and all.
So mine is still in primer. I also came into a Platt 1/5 FW190 that had never been flown so I got to get that going too - it is not as well tricked as your P51, but it is needs the same amount of work yours does to get airborne. Maybe if we beat each other up to get them in the air, maybe we'll get there faster, eh? You know ... you are right off I-80, and I routinely have to drive my daughter to Washington DC for college from sunny Wisconsin. I could get mine done ... and stop along the way and we could fly 'em together. Now that would be motivation! P51 vs FW190 ...
So mine is still in primer. I also came into a Platt 1/5 FW190 that had never been flown so I got to get that going too - it is not as well tricked as your P51, but it is needs the same amount of work yours does to get airborne. Maybe if we beat each other up to get them in the air, maybe we'll get there faster, eh? You know ... you are right off I-80, and I routinely have to drive my daughter to Washington DC for college from sunny Wisconsin. I could get mine done ... and stop along the way and we could fly 'em together. Now that would be motivation! P51 vs FW190 ...
