We are considering getting a 2548 class going down here and as such I have a few questions regarding survivability and performance.
Some of the 2548's use fibreglass/composite fuselage construction. How well do they survive a midair? Are they easily repairable or is it a chuck away and build again thing?
Do you find the flight performance equivalent to current SSC aircraft or is it faster/slower?
Have you found an airfoil that is a good all round performer in this class ie one that offers stability and maneuvrability without snapping?
What's the survival prospects for a 2548 aircraft in a midair/dirtnap?
I am chasing facts, not opinions. If anyone has any hard data or personal experiences to relate thats fine. I just don'e want to turn this thread in to a rant on what's good/bad about 2548
Composite fuselages and 2548 performance data
Moderator: hbartel
Zeek,
I have built 2 2548 birds one p-51c and a p51d.
The c-model has 10 rnds and a dozen or so one on one practice sorties on it. It is a solid foam fuse with two rails down the inside of the fuse. It is covered in bi-di tape with coro tail. In its 10 rnds I have had 3 midairs. other than a small prop cut under the tail and some flaked off paint there has been no damage.
The d-model has yet to see action, I am still doing some adjusting on it. It has a hollow foam fuse with 4 1/8 inch fiberglass rods down the center.
I can tell you that these birds are a ball to fly. Even when I am just sport flying I always bring one and put a couple of flights on it. Most of the club members stop and watch anytime it is in the air. they always call for low passes down the runway.
The speed is close to SSC but they don't have near the turning ability. You really have to plan and work for your cuts.
If you could get 4 or so people to build one you will have a ball.
If you want to give it a try, Mike Fredricks has a p-51d (I built one of these) and a Zero. They are a pretty easy build.
Try to keep your weight 3.5 lbs or under and you will have a great flying bird.
Hope this helps a little.
I have built 2 2548 birds one p-51c and a p51d.
The c-model has 10 rnds and a dozen or so one on one practice sorties on it. It is a solid foam fuse with two rails down the inside of the fuse. It is covered in bi-di tape with coro tail. In its 10 rnds I have had 3 midairs. other than a small prop cut under the tail and some flaked off paint there has been no damage.
The d-model has yet to see action, I am still doing some adjusting on it. It has a hollow foam fuse with 4 1/8 inch fiberglass rods down the center.
I can tell you that these birds are a ball to fly. Even when I am just sport flying I always bring one and put a couple of flights on it. Most of the club members stop and watch anytime it is in the air. they always call for low passes down the runway.
The speed is close to SSC but they don't have near the turning ability. You really have to plan and work for your cuts.
If you could get 4 or so people to build one you will have a ball.
If you want to give it a try, Mike Fredricks has a p-51d (I built one of these) and a Zero. They are a pretty easy build.
Try to keep your weight 3.5 lbs or under and you will have a great flying bird.
Hope this helps a little.
-
Ed Kettler
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Hi Zeek,
The guys I know who have flown 2548 in contests with a molded composite fuselage are Bender (Serg Gaidamakov) who has P-40s and IL-2 and IL-10s, Naes (Sean Galt) with a Ta-152 and Chris Handegard. If you go to http://www.georgiacombat.com/Dixie_Nats_2005.html you can see Bender's and Chris' planes. Bender sells kits of his P-40.
Performance varies, and weight is important. The first generation birds we built were pretty heavy, but flew well enough to prove the concepts. Some were in excess of 4 pounds. Dane McGee has three P-51Ds that are right at 3.25 pounds and are very good fliers. The lighter planes accelerate better and climb faster, but top speeds appear to be similar. We put an Eagletree flight data recorder in one of the planes, and the average top speed reported was 55 mph. My impression are they are slightly faster than the average SSC plane.
Survival for the foam/crutch method of building has been good. I've probably built the most 2548 planes at this point, and the ones I've written off have been through several hard landings and midairs with mostly field/overnight repairable damage. I built and equipped enough planes to be loaners at contests, so they were "well used and abused". With two, the weight gains from several minor repairs just made the plane weigh too much. One of my favorites had its ply crutch fractured after going in due to a battery failure, and it was more of a pain to rebuild it than build a newer/lighter version.
As Mad points out in his post, the planes do not turn anywhere near an SSC rate, which makes for mostly pursuit flying.
Hope that helps.
Ed
The guys I know who have flown 2548 in contests with a molded composite fuselage are Bender (Serg Gaidamakov) who has P-40s and IL-2 and IL-10s, Naes (Sean Galt) with a Ta-152 and Chris Handegard. If you go to http://www.georgiacombat.com/Dixie_Nats_2005.html you can see Bender's and Chris' planes. Bender sells kits of his P-40.
Performance varies, and weight is important. The first generation birds we built were pretty heavy, but flew well enough to prove the concepts. Some were in excess of 4 pounds. Dane McGee has three P-51Ds that are right at 3.25 pounds and are very good fliers. The lighter planes accelerate better and climb faster, but top speeds appear to be similar. We put an Eagletree flight data recorder in one of the planes, and the average top speed reported was 55 mph. My impression are they are slightly faster than the average SSC plane.
Survival for the foam/crutch method of building has been good. I've probably built the most 2548 planes at this point, and the ones I've written off have been through several hard landings and midairs with mostly field/overnight repairable damage. I built and equipped enough planes to be loaners at contests, so they were "well used and abused". With two, the weight gains from several minor repairs just made the plane weigh too much. One of my favorites had its ply crutch fractured after going in due to a battery failure, and it was more of a pain to rebuild it than build a newer/lighter version.
As Mad points out in his post, the planes do not turn anywhere near an SSC rate, which makes for mostly pursuit flying.
Hope that helps.
Ed
Zeek, if you want a composite fuse combat plane or an arf for 2548 I would recommend Bender's P-40. I started to fly 2610 last year with one of his earlier yak arfs and it got me through the season. The p-40's that he has are better than anything I've seen from the major manufacturers. I like to build from scratch but I know may rc pilots don't. For those that do like to build from scratch I would reccomend Chris Quinn's method of twin aluminum rails which he used last year in an experimental 2610 plane. I documented that construction of a P-40 waiting for test flight. The thread was posted I think in February.
<<Some of the 2548's use fiberglass/composite fuselage construction. How well do they survive midair? Are they easily repairable or is it a chuck away and build again thing?>>
Nice question thanks for asking.
We have working on adjusting composite technology to combat purposes since 2002. I have a lot of data and statistic. (Also I keep collection of damages composite and foam models for analysis).
True is: Direct comparison aluminum (or HDP) enforced foam fuselages with composite fuselages might be not absolutely correct.
Classic composite fuselages usually significantly lighter (and have better surface quality). It might be more strong VS foam if put extra fiber on it, but it looks like composite is more expensive vs foam (Stay on foam design if you do not counting your working time).
In real life additional factor play an important role. For instance: How often-technical standards are changing. (Artificial increasing of minimal weight sound funny for most classic style modeler. It works against technical progress but it is real).
We will see who will dominate in a time. (SIG generate the rules. Rules dictate direction for selection). (Ops, it is illegal subject).
Bottom line is: composite models appropriate for combats are exist. Anybody who wants to try is very welcome!
To make clean experiment we need to build two fuselages with identical weight using different technique and crash it.
Volunteers?
For combat purposes stronger fuselage are required VS classical model aviation. My answer is: There is no problem at all. Technology allowed doing it. It is only question of demand and question of time. If you need it sooner - makes custom order for much stronger fuselages and get it.
Visit www.benderplane.com for order composite KIT or ARF scale models P40 (scale 2548), p39 (scale 2610), Yakovlev 9 (scale 2610, open-B and SSC), Ilyushin10 (scale 2610).
Nice question thanks for asking.
We have working on adjusting composite technology to combat purposes since 2002. I have a lot of data and statistic. (Also I keep collection of damages composite and foam models for analysis).
True is: Direct comparison aluminum (or HDP) enforced foam fuselages with composite fuselages might be not absolutely correct.
Classic composite fuselages usually significantly lighter (and have better surface quality). It might be more strong VS foam if put extra fiber on it, but it looks like composite is more expensive vs foam (Stay on foam design if you do not counting your working time).
In real life additional factor play an important role. For instance: How often-technical standards are changing. (Artificial increasing of minimal weight sound funny for most classic style modeler. It works against technical progress but it is real).
We will see who will dominate in a time. (SIG generate the rules. Rules dictate direction for selection). (Ops, it is illegal subject).
Bottom line is: composite models appropriate for combats are exist. Anybody who wants to try is very welcome!
To make clean experiment we need to build two fuselages with identical weight using different technique and crash it.
Volunteers?
For combat purposes stronger fuselage are required VS classical model aviation. My answer is: There is no problem at all. Technology allowed doing it. It is only question of demand and question of time. If you need it sooner - makes custom order for much stronger fuselages and get it.
Visit www.benderplane.com for order composite KIT or ARF scale models P40 (scale 2548), p39 (scale 2610), Yakovlev 9 (scale 2610, open-B and SSC), Ilyushin10 (scale 2610).
After you setup the initial mold, the speed at which you can layup and finish a fuse. Once I have it all figured out I'm going to tackle putting the firewall and servo crutch inside before closing it all up. The weakness that I have discovered for combat so far is the nose section and wing saddle area. Adding more glass has not added significant weight yet so I'm going to keep adding the beef until it's rock solid.
As far as repairs go, it's pretty easy. You just put a patch over the slice if it's a prop cut from the inside about 1/2" oversize. To replace a chunk you can iron monokote onto thin balsa and form it over the outside of the skin and tape it down, then put a patch from the inside oversized by about 1" on all sides. Peel off the balsa/monokote form after curing and light sand and paint. It's really that simple.
Sometimes you get deadly hits that aren't worth rebuilding but the only problematic areas are the fuselage exploding from haveing too much rubberband pressure from too many rubberbands. When a hit comes from the top over the wing saddle, the fuse rips open. I switched to nylon bolts and so far is looking good.
Speed IMO is faster with glass because it's smoother. If you pay attention to clean aerodynamics you will definitely see a speed increase. I promise you this.
HTH, NAES
As far as repairs go, it's pretty easy. You just put a patch over the slice if it's a prop cut from the inside about 1/2" oversize. To replace a chunk you can iron monokote onto thin balsa and form it over the outside of the skin and tape it down, then put a patch from the inside oversized by about 1" on all sides. Peel off the balsa/monokote form after curing and light sand and paint. It's really that simple.
Sometimes you get deadly hits that aren't worth rebuilding but the only problematic areas are the fuselage exploding from haveing too much rubberband pressure from too many rubberbands. When a hit comes from the top over the wing saddle, the fuse rips open. I switched to nylon bolts and so far is looking good.
Speed IMO is faster with glass because it's smoother. If you pay attention to clean aerodynamics you will definitely see a speed increase. I promise you this.
HTH, NAES
While I haven't had much time to work on my 2548s I have managed to build one of Bender's P-40s. It is extremely durable.
By this I mean it has taken some very major damage and is still repairable and flyable.
Its first flights were with a CG too far forward and a bad prop / muffler combination for up here at 5325' of elevation. Got a good overhand heave from my brother for a downwind launch but ended up doing a snap roll directly into the asphalt, straight down. Winds didn't change at all, but after a prop and spinner change the same thing happened. The fuse did split a bit and had some pieces that split off, but it was repairable even though the impact the second time sheared offf the prop stud from the engine.
The flight conditions were simply poor, not the airplane. However, taking two big nose dives into the asphalt might have totalled other planes, but this one is ready to fly again at 53oz after repairs.
By this I mean it has taken some very major damage and is still repairable and flyable.
Its first flights were with a CG too far forward and a bad prop / muffler combination for up here at 5325' of elevation. Got a good overhand heave from my brother for a downwind launch but ended up doing a snap roll directly into the asphalt, straight down. Winds didn't change at all, but after a prop and spinner change the same thing happened. The fuse did split a bit and had some pieces that split off, but it was repairable even though the impact the second time sheared offf the prop stud from the engine.
The flight conditions were simply poor, not the airplane. However, taking two big nose dives into the asphalt might have totalled other planes, but this one is ready to fly again at 53oz after repairs.
My scale 2548 p40 http://benderplane.com/galleries/contes ... 0604BF.htm
Fly very well with CG about 35 mm from leading edge in the middle of wing. Total flight weight was 3.5 Lb with propeller 10x4 and standard OS-max-25fx 13700 rpm.
I have never had trouble with launching.
So my suggestion try this combination for first flight.
What I believe is very important: do not try launching yourself. Ask somebody assistance for first flight. Keep model under control from the very beginning. First moment is more important. After trimming it is not problem to work without helper, but for first flight I am sure it is important.
We did not try makes more tail-heavy variant. Might be it possible, but I was pretty happy with such CG (35 mm from leading edge). Model was stable and maneuverable.
I have flown it two round during NATS2005 before midair with Kirk. In midair model was damaged, but it survive. I will repair it soon.
After midair: http://amocs.com/gallery/contests/NATS_ ... 0715DH.htm
BTW look on color scheme it is simplest variant for bonus model.
http://amocs.com/gallery/contests/NATS_ ... 0715BX.htm
Good luck to you on contest.
Fly very well with CG about 35 mm from leading edge in the middle of wing. Total flight weight was 3.5 Lb with propeller 10x4 and standard OS-max-25fx 13700 rpm.
I have never had trouble with launching.
So my suggestion try this combination for first flight.
What I believe is very important: do not try launching yourself. Ask somebody assistance for first flight. Keep model under control from the very beginning. First moment is more important. After trimming it is not problem to work without helper, but for first flight I am sure it is important.
We did not try makes more tail-heavy variant. Might be it possible, but I was pretty happy with such CG (35 mm from leading edge). Model was stable and maneuverable.
I have flown it two round during NATS2005 before midair with Kirk. In midair model was damaged, but it survive. I will repair it soon.
After midair: http://amocs.com/gallery/contests/NATS_ ... 0715DH.htm
BTW look on color scheme it is simplest variant for bonus model.
http://amocs.com/gallery/contests/NATS_ ... 0715BX.htm
Good luck to you on contest.
Well, after taking a centerpunch just aft of the wing saddle I was left with a lawn dart. This was my very first one I laid up so durability was yet untested. This is a layer of .75oz and a layer of 4oz glass with a couple CF tow stringers that didn't go past the canopy. Very flimsy and not nearly as stiff as my last layup.
HTH, NAES
HTH, NAES