Category: Gas

This is my Wildhare Slick 540.  The basic stats are as follows:

Wing Span 88″

Length  ~82″

Weight ~18 lbs

Powered with a DLE-55 and Pro-Flow Cannister and turning a Falcon 23×9 (or sometimes a Xoar 23×8 laminate).  Here’s what it looks like at the moment.

Here’s a shot of the inside which has a few interesting features as well.  As you can see I’m running one of the water bottle type tanks.  This one is manufactured and pre-assembled by B & E Graphix.  So far it has been a great tank.  It’s significantly lighter than the standard type tank and the (I think felt) clunk does a great job of sucking up every drop available.  Moving back behind the wing tube there are two A123 2300mah 2S packs for extremely stable power.  On top of them at the top of the photo is my ultra IBEC from Tech-Aero and nearer the bottom is my TM1000 Telemetry module.  Hooked to that and velcro’d to the top of the wing tube is the attached GPS sensor (there are other sensors including temp, ignition voltage, and 3 Axis G Force).  Further back is my Spektrum 9110 PowerSafe receiver with all 4 remotes scattered about.  Behind that you can see the pull-pull system for the rudder which is handled with authority by the Hitec 7955TG

This is without question the best flying plane I own or have ever owned.  It’s completely honest with no bad habits and is as close to a “go where you point it” flyer as anything I’ve ever seen.  The combo is reasonably quiet and has plenty of power thanks to the engine, prop and canister combo.  It will climb straight up forever and fly at least sportsman level IMAC on 100 plus degree heat index Indiana summer days…  It may be able to do more but it needs a better pilot for that.  😉

Like every aerobatic airplane I’ve ever seen or heard about, it benefits from a few of the standard mixes to perfect it’s capabilities but unlike some I’ve flown, it can fly quite well without any of them.

Unfortunately Wildhare like others in the market, quit ordering and stocking the big planes due to the slow economy in the past few years.  That downturn appears to be reversing, so hopefully they will get back in the market soon before the market moves on to other folks who are already shipping new competing products.

 

Continued the investigation tonight.  Set the body in my trusty PVC holders on workbench #1 and started examining from the front.  Pulled the cowl and found a couple minor issues… One cowl screw insert coming loose, ignition box moving a bit, but no smoking gun under the cowl.  Even pulled the plug and examined.  It actually looks like I have heard it should.  Sort of uniform dark grey.  Gap looks fine and no carbon buildup obvious.  Top of the piston still nice and shiny as well.  All linkage and tubing plus the telemetry sensors and wiring looked OK.  I then decided to skip an actual ignition spark test for the moment and moved on back into the wing saddle area.  Again nothing obvious so I turned on the plane and started looking to see if (as I thought) the ignition voltage sensing is beyond the kill.  The plane died quickly like that occurred but the telemetry didn’t show the ignition voltage loss.  This all worked as expected but it brought to mind the idea that maybe I had a throttle curve that brought the throttle below idle or some sort of misconfiguration of a mix that would cause that.  Looking at the radio yielded nothing but when I moved the throttle back and forth I saw some odd movement and looking more closely I found the culprit.  Here is the problem:

With this screw backed out this far the adjustable arm can end up extending enough to cause the throttle to bottom out and shut down the engine.  As you can guess, I will be coming up with a different type of connection.  I know, some folks will say this type of connection in a big gasser is just stupid to start with, but with so little force required to move the throttle I was not worried about torque causing slippage or the arm bending or any of that.  What I obviously should have been concerned about was vibration loosening the screw!  I will probably replace this linkage with a standard threaded clevis (once I solder on a threaded coupler) and a standard servo arm… non-adjustable this time…  A drop of something to keep the screw in place might be used as well.  Perhaps nail polish or the like.  I don’t think thread lock works on nylon!

Obviously its hard to be happy about a crash but the good news is the damage seems to be limited to my pride and the wing.  My pride will recover… its a nasty bruise but they heal.  The wing is not that difficult to replace, and not very expensive in the grand scheme of things.  The better news is that I now know what caused the crash and it is easily rectified.  I was hating the thought of fixing all the damage and not being able to figure out a cause.  That would really make me paranoid and give me no confidence to fly the plane again.  Now I’m back to looking forward to it!

 

Pulled the landing gear and servos out of the wing this evening.  Port side gear bay and main spar and ribs took the brunt of the damage.  Cracks and buckling apparent.  Would be difficult to fix.  Would need to re-manufacture at least one rib and remove and re-web the main spar.  I imagine parts of it are cracked or broken as well.  The other side the top sheeting and some of one rib is crushed.  I am fairly sure I will just order a new wing this fall and reconstruct over the winter.

Both retracts had some flexing/bending of the mounting ears.  The starboard side was bent worse as you can see here.

Some hammering against the anvil/vise seems to have straightened those out pretty well.  I don’t expect the retracts are actually hurt at all.  They seem to operate smoothly and the struts compress as before.  Best I can tell everything is pretty straight again now.

I need to carefully inspect the fuselage but on first inspection it looks unhurt.

First look through the telemetry data has nothing significant to help pin down a cause.  Both the pack voltage and ignition voltage stayed in range both before and after the engine quit.  Overlaying the altitude and RPM graphs it is pretty easy to see when the engine plummeted in RPMs over a few seconds, ending at zero!  I will have to carefully examine the wiring beyond the sensor, check the ignition itself as well as the plug, the hall sensor and of course the fuel system to see if I can determine a cause.  The log showed no signs of problems and even if it had gone to failsafe the throttle would have simply gone to idle.  I will confirm that too but don’t believe it would have quit if I took a hit and it doesn’t appear I did anyway.  There was plenty of fuel in the tank when it quit so will be sure to check the plumbing as well.  Still a mystery for today.

Due to a flame out at a very bad time the P51 made a landing in the bean field 20 feet off the end of the runway.  Analysis is underway to try to determine a cause and assess damages.  Quick guess is the wing will need to be replaced due to landing gear attachment point damage.  More to follow when I have time to work on it. Will be looking at telemetry data as well for info leading to reasons behind the failure.

Three more flights today on the P-51 today.  I think they were number 10-12 on this bird.  She flies well with adequate power from the DA-50 and with full flaps the landings are getting to be smoother all the time.  No appreciable bounces today and 2 landings that were totally greased in.  I may have to start saving to modify the retracts to electric power and consider installing them if I keep this up!  The Top Flite is a really nice flying model.  Once you get the flaps dialed in with a little up elevator mix on deployment it isn’t too bad to land.

On the skydiver front, George had a bad day.  After a successful early jump, the next two were ugly.  First, the release mechanism didn’t and he stayed firmly attached and then on the next attempt he did a “hanger” and simply drug along behind all tangled up and just to add injury to insult his arm busted off when I landed… 🙁

He has already been repaired and is ready for the next attempt.  Also had a scare with misplacing his “static line” that attaches to the plane and allows his parachute to open upon his exiting the airplane.  I eventually found it but it has inspired me to build a second one as a spare.  If I can find a little cheap metal spring hook I think I will be in business.  The rest is easy… just a release pin in the middle and small patch of hook and loop on the end and I’m in business.

 

Put up 3 more flights today… about 7 minutes each.  Total battery usage was around 480mah so the average looks like ~25mah per minute of flight.  Even less than last time but probably less “on-time” between flights etc… so more typical of actual flight times.

Finally got my flap mix to elevator about right I think and all three landings were good.  1  bounce or less and no really anxious moments.  Just greased’em in!  One flight I got a reported 96mph so I think maybe 100 is going to be the top speed if I get in a nice long full throttle dive unless I make some changes.  I can’t complain about that.  It seems reasonable enough.  I’m not seeing any excessive temps… around 230 I think is about normal peak which seems on the cool side so I’m not going to complain.  Flight pack voltage is very steady with the two A123 packs supplying a nice and fairly steady 6.5 or so volts if I recall correctly and the IBEC is locked in at 5.2V.

Did some nice, slightly high, photo pass/knife edge passes and some sub 30 foot high speed passes along with a few Immelmans, Split-S, loops and plenty of rolls and combinations.  Stall turns are fairly easy and I am having few problems with orientation.  All in all, its shaping up nicely.

After the 3rd flight I sat and made a few adjustments in the radio.  As is my usual method, I started with dual or triple rates configured for each of the main flight surfaces and once I narrow down throws and expo settings I like the rates go away and all are set to the same settings so there is no chance of problems due to improper switch settings.  Ailerons are pretty much dialed in and rudder is comfortable though I may need to fine tune a bit.  Elevator is nice for landing but the plane can snap if I pull too hard.

I’ll have to decide if a bit less elevator is still good enough for landing but other than that I’m getting pretty comfortable with the Red Tail.