Flying at Blue River Airpark today 10-4 or so. Cloudy and a few showers but low winds and pleasant temps.
Two mid-airs in one flight… what fun!!
This last Sunday… July 27th… was our club airshow. We’ve been doing a public airshow as a way to make money for the club for about 7 or 8 years now. Our acts vary but there are usually group flights from various eras or types like WWI, WWII, electric foamy, etc… as well as a buddy box session or two, some scale helicopter, 3D helicopters, giant scale aerobatics and of course 3D airplanes. This year we even had a 3D act that mixed a 3D heli and a 3D giant scale aircraft. The two pilots even swapped transmitters during the middle of that one! Its a ton of work to put on but we have some fun too. One of the acts that is a perennial favorite is the glider chase and this year was a good one.
Our glider chase is just what it sounds like. We have a trainer plane that carries an RC glider (really just a large foam glider converted to rudder and elevator only) up several hundred feet and then several of us with whatever we have that is disposable will go and try to crash into the defenseless glider. The crowd loves it and participating in it is always a blast. There are few rules other than keeping the “battle” out away from the crowd, and no attacking the carrier plane. This year we had, I think, 6 chasers out on the flight line and more chasers always makes for more excitement. The usual result is that the glider gets away cleanly (even though the glider pilot is generally not trying to get away!) and the chase pilots often aren’t so lucky. One of the first things you figure out is that making your plane hit another in flight when you intend it is much harder than when you aren’t trying!! Another is that you can’t begin to keep everyone else in sight so you are forced to watch your plane and the target plane… there just is no way to watch everyone else at the same time. It helps to have a spotter as well to get you in the neighborhood of the glider when you overshoot and aren’t sure which plane is the target!
The more common scenario is that the chase planes collide while trying to get close to the glider as all the planes try to occupy the same small box of airspace. I always tell folks that if you fly a plane in this event and land it without damage you have just received the gift of a free plane! You have to write off your plane on takeoff and just hope to find the wreckage to recover your electronics. Anything more is a gift. Of course the high level of attrition is why the crowd loves it. Here’s my experience during one such flight last Sunday.
I took off immediately after the carrier plane and circled up slowly to try to stay in the same altitude range as the glider and preserve fuel. The Duraplane I fly for this has a small tank and sometimes the glider stays up a while and most of the action is at high throttle so fuel preservation is key. I stayed a good distance away from the carrier plane in order to not endanger it. When the release was called out on the PA my spotter directed me toward the glider. Shortly that area of the sky got crowded with planes darting in and out of my vision field. My rule is never pull away from other planes as I attack. If they get between me and the target they are going down! After a couple passes I had dropped below the glider and pulled up toward the target just as another plane dove past. An audible “pop” occurred as he passed and I saw a strip of something fall away from the right wing. After a near miss with the glider I circled once to check controls and all seemed OK so I turned back into the fray. I was (apparently) unharmed. Probably just a slapped wing and a little lost covering. Since my wing is mostly foam I figured it was OK. I could tell it was my right wing that had been hit but apparently nothing serious.
Here is the actual damage that occurred on the first mid-air:
This is the right 1/3rd of my wing and you can see the strip of aileron that is missing is about 1/3rd of the total on that side. Looks like a prop got into it and did some carving. I saw something fall away but couldn’t tell it was part of my airplane and the plane seemed to handle OK.
A few minutes later the glider is down to about 50 feet and the announcer calls “knock it off” as we are getting close to the crowd and the runway. One plane has already gone into the Corn when he failed to pull up quite quick enough after a vertical dive at the glider. As I pull out and turn down the runway I see another plane coming head on at high throttle… about 6 feet away!!! There was no time to react. A loud thud and lots of pieces go flying but my engine is still running. I have a vague recollection of seeing “the other guy” dropping away into the corn and then I realize I may have an issue of my own. Ailerons are totally non-responsive… rudder is working and there is some dihedral in the wing so turns are possible but sluggish. I call out that I have no ailerons and ask for a clear field. The landing is fairly uneventful and I taxi back to look at the plane. Now the wing has a bit more damage.
Here is the other wingtip:
That white gash in the wing goes all the way through where the prop of the 25 size glow plane cut through it. The other end of the prop came down on the right aileron and now it is pretty much trash as well. The servo and linkage for the ailerons sits atop the wing and the wingtip of the other plane (after hitting my prop I expect) hit that and broke the servo arm causing the linkage to depart and leaving no control at all over my ailerons. His wingtip was pretty much mulch for several inches.
There was quite the buzz in the crowd when this occurred and both I and the other pilot knew what we were getting into. No harm, no foul. In fact, it was a lot of fun and a real crowd pleaser. I was amazed to have had two midairs in one flight and even more so that I landed the airplane successfully and with as little damage as it has.
Drat that glider… I’ll get my revenge… next year.
P51 Mustang Red Tail – Latest Updates
In the last 2 weeks I’ve had the Mustang up on 6 flights and put it back in “race ready” condition just in time for our annual Tim Mills Derby Days RC Airshow. This is just a little wrap up of the updates I’ve made and issues I’ve had since building up a new wing and electrifying the Robart retracts. I will come back and edit this post with a few added photos in the coming days.
Working more or less chronologically, I got the wing built up and the retracts installed along with installing the retractable tail gear in the fuselage. All seemed to be working pretty well so I went out for the first flight. It went well, with “Drag Racer 2” going through her paces just I remembered. She flies heavier than anything else I fly but with no real handling problems or bad habits other than needing a lot of speed to handle well. Fairly much what you’d expect from a big war bird. Maybe the ailerons could be dialed up a bit but the rolls are probably pretty close to scale… maybe a second or a bit more to complete a roll?? I’ll have to check that and consider increasing throws on those.
This first flight, I kept the gear down and the landing was fairly uneventful with the exception of a tendency to turn right as the roll out got slow. Nothing that the rudder couldn’t correct. The landing gear took the shock on landing better than I expected. A pleasant surprise.
Second flight a half hour later was a bit more exciting… After the first couple laps I hit the retract switch and all three disappeared into the bottom of the airplane as planned. So far so good, except the plane wanted to climb rapidly. At first I didn’t understand but soon the reality of removing drag and closing the majority of the large pockets in the bottom of the tail and wing set in. The plane is just getting more lift and experiencing less drag… which equates to the tendency to climb. That’s generally a good thing so why fight it. Eventually, a couple flights later, I trimmed it for level flight with the gear up and just got used to pulling a little up when flying with the gear extended.
After a few high speed passes I decided it was time to land and went for the retract switch again. A quick pass to check gear down and… uh-oh… only 1 main is down! While having all sorts of awful thoughts about how a Mustang would land on no gear (22 lbs of airplane on the scoop… yikes!) or even worse with only one main gear I tried cycling the gear a couple times. Eventually I had the two mains down and locked. The tail gear also managed to jam part way down but I decided to live with that and brought it in smoothly again. No damage and now it is obvious that the gear door is pivoting on the strut and getting caught on the edge of the wing inset.
Back in the shop to tighten and re-glue the doors and come up with a solution for the tail wheel jam issues. The problem seemed to be that the cables that steer the wheel go slack when retracted. This allows the tail wheel to pivot around in flight and get caught against the side of the plane when the command comes to move. After some consideration, I added some rubber bands to the assembly to hold the wheel straight when no servo linkage pressure is being applied. This keeps the axle and wheel from contacting the insides of the fuse OR the landing gear doors when coming down.
Back at the field a few days later and it was time for flight 3 and 4. These two flights went well and it was during these that the trim got adjusted to account for the wheels up “slick” condition of the airframe in normal cruising mode. As I flew, I got more and more comfortable with the airplane and made some “photo” passes in near knife edge and about 20-50 foot altitudes as well as fast low passes, immelmans, loops, split S(s), aileron rolls… Pretty much anything you’d expect a Mustang could do. Both landings were smooth with comments from a pilot who owns this same ARF (not modified and with the wire gear on) to the effect that I was making him look bad by coming in to land so smoothly. I love to see a big bird do a nice landing so I spend extra time and effort to make mine look good when I can.
Also during these flights I noticed just how much slicker the plane is with the gear up. I was expecting 2-3… maybe 5 mph increase in speed. What I got was 10-12! In a couple of cases the GPS on board said I had hit 113, almost 114 in a shallow dive toward the field. Before anyone comments on the inaccuracy of GPS speed, I can tell you I have tested the GPS versus the Pitot tube type instrument and they are very consistently within 1-2 mph of each other. Engine RPMs hit somewhere around 7500 at their highest which didn’t seem to harm the DA-50 at all.
Those flights went very well and the landings were nice with full flaps and just a click or two of power on landing. Back in the shop I painted the mounting blocks to match the struts and added the guns to the leading edge. Two .50 cal in each wing in this B/C model (unlike the 3 per wing in the D). The guns I did a bit different this time. I cut circles out of flat black and then circles out of those big enough for the gun barrels. I then ironed these covering “donuts” onto the leading edge at the appropriate spots and then drilled in the donut hole so the gun barrels could be expoxied in place. After all was complete, a little flat black paint to cover up the brass tubes from which they are fabricated and all is ready to go. There seems to be quite a variance in gun installations in different Mustang models so these look good enough and much better than the factory glue on pieces.
About the only thing left for this bird is more flights and some added epoxy on a couple of cowl screw inserts that are walking out. I’m actually getting past the knee knocker factor of flying this bird and starting to enjoy it for what it is. Not my favorite or best flying aircraft, but very impressive in the sky with plenty of wow factor for the crowd.
Flying today noon to 7 or so. Mustang and Telemast…
Flying today noon to 7 or so. Mustang and Telemaster/Jumper are on deck.
Float flying at Roy Wilson pond. Beautiful day and…
Float flying at Roy Wilson pond. Beautiful day and successful flying with T28 and the Beaver.
P-51 Mustang Redtail finally in the air again!
Finally finished up getting the wing rebuilt and ran out of excuses to not fly the Redtail. Perfect weather and the looming airshow at the field where I am expected to fly this bird were the final straws so the Mustang went to the field for the first flight with the new wing.
This time, the retracts were electrified instead of tied down in the extended position, the tail gear doors had been installed and the wing was short a few .50 caliber guns but otherwise just like the last time it flew. The difference being that last time it flew I was coming off of about 10 successful flights, not the off-field landing that caused the need for a new wing in the first place. Also that was toward the end of last flying season… it seems like a long time since I flew it last and I was having my doubts. Not about the plane of course, but the pilot was another matter.
There were lots of questions bouncing around in my head. Did I remember how to land this bird? Which switch was the kill and which retracts and which one just made Tim salute?? Here are pictures from the two evening flights. (All pictures courtesy of Steve Howard)
Tail up and just about to lift:
First pass with wheels still down…
A few passes later… checking to see if the gear retracted as planned. Looks good and you can even see the green “ignition on” indicator light!
Then, of course, a high speed pass was called for. After all, it hadn’t ever been this aerodynamically clean before!
And finally, you have to do a photo pass! You can see the rudder working in this shot.
In all, two very successful flights. There is a laundry list of issues to address. First the right gear is rotated a bit outboard, causing a right turn as the plane slows to a moderate speed after landing. Also, on the second flight the right main gear door got caught so the right main would not immediately come down! I considered belly landing (ouch… ouch… ouch…) but a few cycles freed it up and landing was fairly uneventful after that. The tail gear got caught a couple times going up and down. Going to have to find a way to self center that when the cables that steer it go slack during retraction… Later, also realized that a couple of cowl screws need some attention. The inserts seem to be pulling out. Perhaps from vibration where the exhaust rubs the cowl. Seemed like with the gear up the plane wanted to climb!? Just from a cleaner airfoil or what I’m not certain but may have to mix some down with the gear up position to smooth that out. A crop of small issues like this always seems to occur after the first flight or two so back to the shop for this bird. All in all, I’m calling it a win with the retracts performing a bit better on ground handling and shock absorption than I expected them to.
Once all that is cleaned up I can install the guns back in the wings and do some other cosmetic work on the tail gear door hinges (white is not a good color for those). The landing gear door blocks on the mains are natural wood color at the moment also. Those will get some paint as well. I’d really like to get a half dozen more flights before the big show on the 27th. If the weather cooperates this week I hope to be able to be show ready by then.
Two flights on the mustang tonight with no big iss…
Two flights on the mustang tonight with no big issues. Host of small issues to work out. Can start breathing again.
Xion Wing Lock – Pt 3 – Can’t recommend
After another couple flights on my Wild Hare Slick on Saturday I have lost a second wing lock. Once again, no harm as I have clips on my anti-rotation pins and they once again stopped the wing from sliding out far enough to cause any issues. I had the wing locks very snug and I believe installed these correctly so I can’t account for how they managed to exit the airplane.
Because of this, I can’t recommend this system. While I love the idea of quick connect and disconnect and somewhat easier installation than the nylon bolts I was using…. I can’t positively identify why mine have now twice been lost in flight. If these had been the only thing holding on my wings I would have trashed an airplane… twice now.
I’ll have noticed the studs from Xion seem very sloppy in the blinds that are in my wing so maybe this is somehow contributing to the problem. Is this just a case of cheap blinds with to much play in them? I don’t know but I’m done risking my plane to find out. If you use these successfully I’d love to hear about what you did to make them work but I’m done with them for now.
For my earlier posts on this item, please see:
and
Planning to try to do some flying on Sunday. Maybe…
Planning to try to do some flying on Sunday. Maybe 12 to 6 then home for dinner and shop time in the evening.
Parkzone T-28 – My 3rd
I picked up a new PZ T-28 to replace the one I retired a couple months back. I started having motor issues and had at least one servo starting to chatter, plus the foam was showing a lot of wear. Additionally it was the US Air Force color scheme which is beautiful up close but very hard to see under anything but perfect lighting conditions. I like to fly this plane near dusk and sometimes far up and out at times and poor visibility is an unnecessary limiting factor so I had been wishing to get back to the Navy scheme since about 2 days after I bought the last one!
Since I was pulling a new ARF out of the box anyway I thought I’d post some comments. First, it seems that PZ really knows how to pack an airplane. The packaging kept the plane very secure and I found no dents or dings at all. As you can see here, its very nicely packed.
Second, the manual (which I didn’t need, since I’d done this twice before) is well written, apparently by a native US/English speaking person (at least the US/English portion, I can’t comment on the rest of the languages) which I find refreshing compared to some I’ve seen. No offense intended to those who are native speakers of other languages but I would expect a product sold in a particular country should have a manual that is written clearly in the native tongue of that land. Everything seemed to be present and accounted for so assembly was pretty quick.
Looking the airplane over there are some drawbacks. The paint job suffered from a bit of over spray and the decals have quite a few wrinkles and bubbles. While I still like the overall look of the airplane, it could look better with a bit more care in production. Here is an example.
That aside, I have now flown the new plane a dozen flights or so and just as I remember it is a hard to beat little airplane. Somehow it seems to fly bigger than it is. While not capable of unlimited vertical… no hovering for this bird… the plane has enough power to climb rapidly and quite a bit of aerobatics are within its flight envelope. Even better, the plane flies super stable (without needing a stabilization system) and can handle a lot more wind than you would imagine for a 2 pound foamy. I can fly around all day doing knife-edge or simply putt along making wide sweeping turns and making low passes and it will do either equally well. It just flies great. It also will fly with a wide variety of battery packs. I’ve flown them with everything from 1500-2200 3S packs from 15C to 45C discharge rates (static testing showed about 14A, so 15C is sufficient) and any of them will work. Lower capacity batteries which are lighter and high C rated packs improve performance but the lower end (cheaper) batteries work well and keep costs down so suit yourself!
In the past I had typically hand launched the T-28 as the small wheels are not always conducive to upright landings and smooth takeoffs. I have been a proponent of getting rid of the wheels from the beginning as it also lightens the plane up a bit… always good in an airplane that doesn’t have unlimited vertical anyway. This time, however, I decided to get back to some wheels takeoff and landings so decided to put them on. They were a problem on our grass field. Not intolerable but occasional flip overs and difficulty taking off with anything less than full throttle and full up elevator. I like a nice easy takeoff and upright landings so I recently changed them out for some Dubro lightweight wheels that I’ve seen others use on the other similar size PZ aircraft. Here is a comparison of the old (smaller) wheels and the newer, larger set. (Dubro 250MS)
Here is the complete set installed. The existing axle caps unscrew and so can be reused but I did need some wheel collars to add inside the wheels to keep them from rubbing the wires. I also had to drill the wheels out to 7/64ths to fit the wire axles.
I flew at the local field using these the other day and it really makes a difference. Much easier to roll on the grass and landing went great. The nose occasionally will dip as the landing gear bends back but not a big issue and I think extending the nose gear just bit will help with that as well.
One final construction note. I have noticed in the past that the wing tends to rock just a bit when installed, even with the machine screw at the front nice and tight. In order to keep the wing snug, I add some wing saddle tape to the body before I install it. This tightens things up remarkably.
Since I had an extra Telemetry receiver lying around…. I had to install it, and an altitude module, and… well I’m still working on the rest! Don’t know how long I’ll leave it in there but it’s fun to gather some data.