Mariner 40 Water Flying

Lanier Mariner Water Flying



November 25, 2006

Probably the last water based flight of the season. First flight with the new Tower .46, but I’m still struggling with engine outs and mixture problems. I may want to replace the fuel tank to see if that makes a difference. This aircraft is still bad luck, but still in one piece and a lot of fun when it’s all working!

Photos from the day:






This is what happens when your engine dies on you in flight …




The following 3 images are all from the same picture.











April 15, 2005

First flight of the season: I took off, but the engine started to lean out too much. It was surging and almost quiting. I landed immediately, richened the mixture a bit, took off, and it was roaring perfectly. I did a couple passes, a couple aerobatic tricks, and then the engine quit abrubtly. I dead sticked it in towards the shore, it carried long when it got into the sheltered area out of the wind, it touched down and skimmed on step much longer than I expected, and then settled in and decelerated to a slow drift about 2 feet short of the shore. (whew!)

Upon inspection on shore, I discovered the entire needle valve assembly was shed in flight and is now at the bottom of the lake. (grrrr.) This grounded me the rest of the beautiful weekend. (double grrrr.)

I am now working on getting a replacement part or replacement engine, which ever comes first.

September 17, 2004

I took Friday off work, loaded up the car with my Mariner and with Hannah, and went up to my parent’s place to fly.

Here we are taxiing out for the first flight. It was a bit of a breezy day. Winds were probably about 15mph with a bit higher gusts. But the Mariner seemed to handle the winds just fine. My parents live on the south end of the lake and the wind was from the south, so thankfully we were a bit sheltered and I didn’t have to deal with white caps breaking over the top of the airplane.





This is the take off run. The Mariner 40 gets out of the water quickly powered by a Magnum Pro 45.



Here is a variety of in-flight shots. They are not particularly compelling, but hey, it flies. πŸ™‚ One thing I discovered that is fun to do is spins. The Mariner has enough elevator authority that you can pull it into a stall/spin at just about any speed or orientation. In full speed level flight, full up elevator will put you into a “horizontal” spin. You continue to travel horizontally and forward, but you are in a spin. It almost looks like a standard roll, but is caused by one wing generating a lot less lift than the other.

Even more fun is to pull the aircraft into a vertical climb at full throttle, then hit full up elevator and full aileron and full rudder simultaneously. This also puts the plane into an aggravated spin, except you are still going straight up as you are spinning! As you decellerate, the spin get’s flater, but that big engine is still pulling and you can almost (but not quite) hang on the prop. It’s quite impressive at the apex of the manuever when you are basically tumbling/spinning/hanging on the prop all at the same time.














Here I am bringing her in for a landing:



Landed. Touch down and transition from on-step to slow taxi is really cool with a seaplane, as is transition to step and take off.



Taxiing out for the next flight:




Turning into the wind:



Lining her up:



And here we go. Notice we are up on step and about ready to lift off:


IMG_1995 Lifting off:



One last water taxi shot:




July 9 – 10, 2004

WARNING: See my maintenance log note on this date about the wing hold down bolts stripping out! Important story!

Ok, with that issue resolved, I was finally ready to take my Mariner 40 skyward! There wasn’t a breath of wind … perfect maiden test flight conditions.




Well … almost, I started the engine, ran it up, was satisfied it would go, placed the aircraft in the water, taxied for a minute so that I could at least say I played for a while if the take off went badly.







So, ready to try my first water take off … I gunned the throttle and the engine immediately quit. !$#@$!



After some fiddling around on shore, I determined I had a bad glow plug. Luckily I had a spare, so I installed that and was able to proceed.

So, now a bit more cautious, I started to slowly add throttle…



… but I noticed that just above idle taxi speeds the engine started to eat spray so I switched to the gun and go approach. That worked well and I was airborn very quickly.


Just so you know, this plane is slightly weird because the engine is mounted on a pod/pylon above the wing. Thus, full throttle causes the aircraft to want to pitch down … which isn’t usually the direction you want to go when you cram full throttle. So, until I got used to this and got the aircraft trimmed out in the pitch direction, I was kind of up and down a lot and a bit shakey in the pitch dimension.

Fortunately it flew off the building board close to perfectly in trim for ailerons/rudder so I only had a squirrelly pitch problem to worry about.

Other than that (and once I got a handle on the pitch behavior) it was incredibly smooth and stable in the still late evening air … beautiful to watch and a joy to fly. Take offs were easy and fairly short with a Magnum .45. Touching down on the water was gorgeous, and watching it come down off step and sink into the water and resume a slow/idle taxi was *really* cool. Seaplane flying is the greatest thing ever!

I flew a couple flights again this morning in slightly windier conditions. I observed that once I had the aircraft trimmed up reasonably well in pitch, the pitch changes due to throttle changes became much less noticable. The pylon thrustline is designed with just about the right amount of down thrust (aka up pull) to compensate for the asymetric thrust. I found that at a single trim point, the plane flew great at full throttle and then when I cut the throttle to idle for approach, slowed right down and had almost the perfect approach pitch/speed … they must have worked on the thrust lines a bit before they kitted the plane. πŸ™‚

The ARF is on the pricey side, but I’m really happy with it, and *really* happy with how it flies.

Oh, one other story to relate … I wouldn’t try this near the city where I live, but since I was flying way out in the boonies and have never seen an aircraft near this lake, and the weather conditions were crap for full scale flying anyway (low clouds due to a dense fog layer starting to break up with the mid-morning sun.) Anyway, I noticed I seemed kind of close to one of the low broken fog/cloud chunks a couple hundred feet AGL (or should I say ALL, above lake level) so I decided to keep climbing and aim for it. After a bit of climbing my plane started to get a bit “fuzzy” and suddenly disappeared entirely … right into the cloud. I cut the throttle expecting to pop right out again, but I didn’t. It turns out I flew in from the side, not the bottom, hard to tell from the ground perspective, and I only say that because my plane didn’t just pop right back out. So with the throttle idled I put it in a tight spiral … and waited … and waited … still no plane … finally, after about an eternity and a half, it popped out, happy as could be … I recovered from the spiral and resumed normal flying …

So let me just say that sea plane flying is a blast. The Mariner 40 is a great option … looks awsome, flies awsome, pretty good quality arf. I ran into a couple issues with it as noted above, but nothing insurmountable.

If I thought there was a small chance my wife wouldn’t shoot me, I’d quit my day job and go into flying seaplanes full time!

And finally one in flight movie (low quality):

May 19, 2004

Happy Birthday to me! Don’t ask how old. I feel the same as I did yesterday. πŸ™‚ It’s time to start looking for a nice day (which can sometimes be hard to find in Minnesota.) I have to factor in a drive to a lake someplace so I don’t know when this will happen … I will update this page after I fly.


Sig Rascal 110 #2 Results

Sig Rascal 110 #2 – UMN UAV Project

IMG_4073 Purchased August 24, 2005.

This is the second Rascal 110 purchased by this project. It comes with a Zenoah G26 gas 2-stroke ignition engine. The engine seems to be a very nice match for the aircraft. With an 18×8 prop, it will idle at about 1800-2000 rpm and tops out at about 7000 rpm. This isn’t quite the 10k rpm that our OS 1.60FX would turn (with the same prop) on our first Rascal, but it is more than enough power for this aircraft.

October 25, 2006.

Pictures from our morning at Jensen field. We were flight testing to collect data from our 3-gps carrier phase differential attitude determination system.

Warmups on the ground …



Fly by’s …





Landing approaches …






Some of the ground crew helping out …


Taxiing …



Closeups of the instrumentation …




Detail of one of the wing gps antennas mounted internally …


Overview of the airframe …



July 11, 2006.

Here is an article written about our project: sensor-0517.pdf.

Here are the raw (color) photos.




May 31, 2006.

Today was a beautiful day. Temps in the upper 70’s. Wind about 5mph out of the N and NE. Our mission for today was to collect good MIDG data. We have had problems with our aerocomm radio modem link so Greg rigged up a little gumstix unit to record the data directly on board. We lose our real time link for this, but we get solid data with no drop outs. We want solid data for another little adventure.

This was our first outing of the season. We put in two flights today and the Rascal flew beautifully. The engine ran great and was rock solid. I even spotted my landings on the runway, although with the extra weight, she rolled out a little long onto the grassy area which is no big deal. The Rascal handles mowed grass with no problems.

Here are a couple new pictures of the Rascal with Greg and I.




December 12, 2005.

Movie time.

Here’s a word of explanation. On 10/26/05 we did a test flight and captured the live video stream from the onboard camera as well as the data stream from the onboard IMU/GPS/INS unit. (See the entry for 10/26 below.) We replayed the data stream in FlightGear with overlayed instruments (this can also be done in real time as the data is captured) and saved that out as a movie. Then we edited the two streams together in two different ways: side by side, and blended overlay. The result is interesting. You can see at the start of the flight where the IMU was pretty far out of whack … as much as 5-20 degrees off in yaw. But as the flight progresses you can see the error diminish and later in the flight the match can be quite good.

Both videos are about 50Mb to download. You will need DivX6 to play them. Linux or open source people might find they can play these with xine or mplayer. Windows people might need to go download the DivX6 runtime codec from

Blended Overlay

Side by Side

November 30, 2005.

Minnesota! This here is what we live for! We put up with above freezing temps, oppressively humid summers, terrible mosquitos for a few months of the year, and high taxes, but days like today are the payoff: Standing outside in +20F temps (and often colder) freezing our butts off or playing hockey, or both. πŸ™‚

Today we flew Rascal #2 at Jenson field. Temps were about +20F. Winds were some where between calm and very light. We probably had about 2″ of snow on the ground … right on the borderline for operating with wheels. The first takeoff run was a little “S” shaped and we had one nose over on a landing (zero damage) but other than that everything worked fine as I adapted to the conditions. We also tested our new video capture hardware.

Just look at these picts and see what you folks in sunny warm climates are missing out on. Oh yeah, and these pictures look dark for good reason. The sun barely cracks the horizon up here this time of year. And when the sun is up (or not up) it’s usually cloudy.





November 11, 2005.

img_3142 Here is a diagram of some of the Rascal 110 dimensions.

October 26, 2005.

Today we flew Rascal #2 at Jensen Field. Weather was perfect, winds were light and out of the east. Our primary goal was to test the live video and live synthetic view right next to each other to verify they track each other as they should since both reflect live data. We also practiced flying over specific objects and buildings to see if we could recognize things from the live video in flight.

Here are two pictures taken nearly at the same time. The first is from the onboard video camera, the second is the FlightGear based synthetic view:



October 17, 2005.

Paw and Greg fixed our radio modem / RC system interference problem so now we get excellent range checks. We setup down at “Jensen field” in Rosemount, MN.

Here is a picture of the field and the row of hangars:


Our ground station is basically setting up our equipment on a picnic table in the shade:



Here are some pictures of our aircraft posing:







Our wireless video camera refused to work so we flew without that. Our primary objective though was to flight test our “synthetic visual system.” This consists of a MIDG-II IMU/GPS/INS transmitting data to the ground via an aerocom radio modem. On the ground we have some custom software that reads the MIDG-II binary data and sends the results over to FlightGear for real time rendering. Ted built us a “photo-real” model of the area that was compatible with FlightGear.

We were disappointed with the data rate we were getting (maybe 5hz.) This prevented us from doing any serious flying under the hood. But I think we validated our approach and when we track down our data rate issues we will have a very powerful remote piloting tool.

I made a short movie of an approach and touch down. I replayed the data on my laptop so it is smoother than in real time because the replay code can easily interpolate between data points. I pointed my little digital camera at the laptop’s screen and here is the result, low quality, but you can see things in action. Notice the live working instruments at the bottom of the display. We are landing to the west and have a pretty stiff turbulent wind coming from the NW and rolling over the hangers. I’m not showing off my piloting skills here, but the touch down was nice ad gentle. πŸ™‚

Click on the following “text” link to view the movie:


October 3, 2005.

All our instrumentation was moved over to Rascal #2 so today we flew a series of test flights to make sure the plane flew well with it’s payload. We couldn’t pass the range check test with our radio modem on so we scratched our heads for a while, but couldn’t come up with any clever ideas so we unplugged the power and grudgingly continued with no telemetry data.

We were very happy with the aircraft’s performance and handling with the load. We seemed to be getting solid video with our patch antenna. We also wanted to put more time on our buddy box/safety pilot system so we did one flight where we switched off control to each other.

Finally, happy with how everything was working, we walked over to the ground station and took turns flying “under the hood” with video only. Our camera points 45 degrees down which gives a good view of the ground, but not the horizon. We were able to hold a reasonably straight line via video alone, but turns were very difficult because you couldn’t see the horizon to get a good judge of bank angle and pitch angle. This is where the synthetic view would have been really nice … but no telemetry data.

Next up is to figure out our interference problems and get back to where we can fly with telemetry turned on.

September 26, 2005.

Friday and today we have been working on extracting our instrumentation from Rascal #1 and testing it to verify everything still works after our crash. We need to do a bit more testing, but we are reasonably confident at this point that everything survived intact (minus our radio modem which had it’s antenna sheared off.)

Today I continued to modify my MIDG-II replay software so I can read the live incoming data directly from the serial port and pass it to FlightGear. This gives us a live, real time, synthetic view that should match the real aircraft very closely. This should allow us to insert things like restricted airspace, important objects, mission goals, flight route, etc. into the synthetic view. We even have the capability of setting up a virtual ILS for our landing approach. Our sensors are not good enough to allow us to do a full stop landing, but they could assist us in lining up and flying most of the approach.

In addition, the synthetic display can be viewed from inside a live virtual cockpit with working instruments, from a chase plane, or from a tower view. This should be really cool!

September 21, 2005.

After crashing Rascal #1 we decided to take Rascal #2 up for it’s maiden flight. Everything worked great and the plane flies just as beautifully as Rascal #1. I think we get a lower idle and more braking action from the prop on approach, so Rascal #2 is easier to spot in on the landings. Also, there is much more fined grained precision on the low end of the throttle range with the G26 which means a notch up or down of power actually gives you a notch up or down of thrust. This makes controlling the rate of decent on approach work just like the text books say it should. (With smaller glow engines you typically have poor precision on the low end and seem to have not enough or too much power on approach with no fine grained control.)

One small bit of strangeness did occur in our 2nd flight. I think we had the idle set a little too low so when I pulled power for a slow fly by, the engine quit . I was downwind, but way to high to make a good approach to the runway. I kept the wings level and touched down on the extreme far end of our mowed grassy area. I bounced back up and sailed into the farm field (alfalfa???) bounced one more time in the field and the nosed over and went tail high. Zero damage, not a scratch, but it ended up *inches* from where Rascal

Sig Rascal 110 #1 Rebuild

Sig Rascal 110 #1 – UMN UAV Project

Next steps …

  • Come up with a better solution for securing the tank.
  • Redo top nose cover job?
  • Cut and fit cowl.
  • Purchase replacement windshield (?)

October 20, 2006.

This morning I re-maidened Rascal #1. I had to work through some minorhardware issues, but the structure and rebuild all held together well,and the airplane flew straight and true and as good as it ever has.I’ve very happy with the outcome, and very glad to have this airplaneback on active flying status.

October 19, 2006.

This evening I ran the engine for the first time after the crash. Everythingseemed to perform well. I think I may try to re-maiden tomorrow if the weather is ok.

October 2, 2006.

The battery and reciever and crystal arrived today. I tested to makesure they all work. I brought the aircraft home this evening andmounted the receiver, battery, and volt-watch unit. I still need to secureantenna. I’m running out of things I can think of todo before test flying!

September 29, 2006.

Begin putting the damaged right wing back together. I epoxied thewing joiner box back together so it is secure again and then a rebuiltand sheeted the first inboard section of leading edge back to the mainspare. Finally I sanded and covered it and (tada!) the wing is done!


We are *really* close to being ready to fly! Just waiting on thereceiver and battery now. I will cut and fit the cowl after wesuccessfully test fly and after I’ve regained my confidence in thisengine.



September 28, 2006.

Mixed up some epoxy and sawdust and used that to fill in the shatteredend of the right wing strut. I sanded this down to shape, redrilledthe hole, and threw a quick coat of white paint on it. Good asnew. πŸ™‚ Here are before (damaged) and after (fixed) shots.



September 27, 2006.

Installed the engine and muffler.Reassembled and installed the main gear. Cleanedup the wings in advance of inspecting and repairing them. Inspected thedamaged wing strut and determined it is fixable.


September 26, 2006.

I recovered the front of the fuselage in white monocote. The top of thenose didn’t turn out nearly as well as I had hoped so I may cut that offand redo. We ordered a receiver and battery. I reinstalled the tailwheel assembly and the canopy.



September 25, 2006.

Test mounted the engine and rigged the throttle linkage. Next step is tocover the front of the fuselage.

September 22, 2006.

Worked on installing the fuel tank. Routed the throttle linkage housing.

September 19, 2006.

Secured the front wing support (where the wing dowls plug into.) Gluedin forward cabin support rods.

September 18, 2006.

Epoxy seal/paint the outside firewall.Filled in some of the gaps/cracks with balsa filler.

September 15, 2006.

Today I glued in the top nose support stringers. Then starting with thecracked up nose sheeting from the original, I drew a rough template of theshape the sheeting needed to be. I transfered that to 1/16th sheeting anddid some test fitting and trimming. Finally I squirted it up with windex which was what I had on hand and the sheeting pretty much melted around the curve …cool. πŸ™‚ The final results looks better on the left side than on the rightbut I guess that just means I need to do a little filling and sanding.



Posing with the cowl and the cabin support rods.


September 14, 2006.

Reinforce left front nose side splice internally with some hardwoodsquare stock.

Finished sheeting both sides of the front fuselage (i.e. sides of the nose.)



September 13, 2006.

Reinforce wing leading edge bulkhead reinforcements. I’m compensating herefor an earlier mistake where the bottom portion of these reinforcments didn’tget clamped in where they should have been and thus there is some ugly gaps.It will be non-visible when the fuselage is all sheeted, but I just wanted tomake sure it’s solid structurally.

I installed (and tack epoxied) the engine mount blind nuts onto the backside of the firewall. These are a horrible pain to deal with once everythingis sheeted in … probably the hardest part of assembling the stock Rascal.So they are installed now and I don’t have to worry about them later.


Finally, I cross sheeted the bottom of fuselage forward of the main gearblock. This adds a surprising amount of rigidity to the nose section whichis what I was hoping/planning. I also attached the original sheeting to therear of the main gear block. (Little details …)


September 12, 2006.

Today I spent a few moments fabricating and installing the firewall sidereinforcements. I also fabricated the nose top stringers.



September 11, 2006.

Today I glued in the main landing gear block and supporting structure.I also dug around the shop and found the hardwood stringers I’ll needto support the balsa sheeting on the top of the nose section. When Itest fit the cowl, she’s actually starting to look a bit like her oldself again! Maybe there is hope after all. πŸ™‚


September 8, 2006.

I spent a few more minutes fiddling with the fuselage. I foundseveral cracks and splits in the cabin roof where the wing dowlsinsert, specifically the sheeting forward of that.

I also secured several more cracks and splits in the bulkheads andvarious places I found them. I epoxied the split off pieces back ontothe landing gear mounting block.

I glued the cracks and splits in the right side forward nose section(shown in test fit configuration in IMG_3993 in the Sep. 7 entry.) Ifinalized my scheme to splice in the left side nose piece to theoriginal. It will involve a number of doublers, some beefy squarestock, and a big mess of epoxy.

Finally, I began to reassemble the nose section.


September 7, 2006.

A week ago I scored a new replacement cowl from a very kind fellow modellerwho was willing to donate his spare to the cause.

Today I did some work gluing the split clamshell that was the fuselage backtogether. From the wing trailing edge foward split out like a big clam shell.From the wing leading edge forward is just splinters. After today I shouldmostly have the wing leading edge back to the tail all fixed up and solidagain.

Yes, it still looks pretty ugly, but an amazing amount of rebuild progresshas actually been made:





May 30, 2006.

Today I made a replica of the fuselage bulk head that is between thecabin and the firewall. I also started tracing out the piece for the leftside of the nose (which exploded in the crash.) It is important to get thesize and shape just right so the firewall has the proper amount of right anddown thrust. I think I’ve got it, but it’s something I have to be carefulabout. I’m not 100% sure yet how I will fit/splice the new piece into theold one, but once I figure out how to get the side pieces glued on in a structurally sound way, I’m home free for this rebuild I think.

The replacement firewall:


The replacement rear fuel compartment bulkhead:


The replacement "instrument panel":


The replacement left side of the nose area:


May 26, 2006.

I pieced together the shattered bits of the original firewall and usedthat as a pattern to trace out a new firewall. The firewall is two layersof 1/8" light ply, so I made two copies, and sandwiched them together withepoxy.

My goal is to use the original bits as patterns to build new pieces when theoriginal is just too shattered. There is still some thought that needs togo into how best to proceed in some areas, but I’m making progress.

May 19, 2006.

Happy birthday to me. πŸ™‚ I spent the evening cleaning up the engine.The dirt was surface only, nothing even made it into the carb. The carb wasslightly shielded by the cowl and the engine wasn’t running when it hit.There was a small amount of dirt/grit inside the veturi, so I popped offthe carb and blew everything out from the backside with carb cleaner. Hopethat doesn’t attack the rubber gaskets (not to mention my fingers.) Thealuminum spinner appeared to have no damage, the engine seemed to turn well,the motor mount was 100% intact. The only thing that shattered was thefirewall. I’m going to have to build me another one of those.

May 17, 2006.

Some of the parts fit together, some don’t. Some pieces are just not thereanymore.








May 16, 2006.

Today I started laying out the parts to try to piece them together. I madea lot of progress figuring out what goes where, but haven’t glued anythingback together yet. Some pieces I can probably glue together and use, butsome of the more load bearing structures I’ll glue together to make a formand then reproduce the part.

For what it’s worth, the left side of the front fuselage got compressedand exploded into bits. The right side of the forward fuselage is"reasonably" intact. This would indicate that the aircraft had some rightlateral motion when it impacted the ground. That is the direction the tailswung around after impact and it was the right wing that ripped off.

After staring at the pieces for a few minutes today, I believe this Rascalcan be rebuilt and will fly again, but it will take some effort. It won’tbe a completely trivial rebuild.

September 26, 2005.

Until further notice, Rascal #1 is offline. We are transfering all ourinstrumentation and cameras over toRascal #2.Follow that link to the most current interesting info.

September 21, 2005.

Today we flew 3 very nice flights testing out a new patch antennafor our video system. The new antenna seemed to yield much better results thanwe were getting before. Plus we had determined that the ground transceiverfor our radio modem link had also been interfering, so we put some goodseperation between the radio modem transceiver and the wireless videoreceiver and that all worked much better.

The video was working well so the next thing we wanted to try was havingme fly by video only (using a buddy box system and a safety pilot.)Take offs and landings would be done visually as per standard R/C procedures. The fly by video would only happen during a short segmentof the flight.

Shortly after take off (with maybe 75′ altitude) the engine sputteredand died. I thought I had plenty of altitude to turn back to the fieldso I initiated a turn. By my recollection I stayed off the elevator toavoid any chance of stalling, so the nose dropped substantially duringthe turn. However, once I got pointed down wind and tried to roll out ofthe turn (still with 20-30′ of altitude) the plane was unresponsive anddove straight in at a pretty sharp angle. As you can see there wassubstantial structural damage.





img_2936Case of dumb thumbs? Did Iride full elevator all the way into the ground? I didn’t think so at thetime, but the consensus of the audience was that I stalled it in. Buthere is my thinking: 1. TheRascal is nearly impossible to stall, 2. I am aware of this issue and I*thought* I was intentionally staying off the elevator specifically toavoid this mistake, and 3. the plane seemed completely unresponsive inthe final one or two seconds.

But I also don’t trust my recollection and I know my mind can play trickswith me. I am hoping we have good MIDG data from this fateful flight.I am hoping that I can compare the planes directional vector with it’sorientation to get an estimate of velocity and alpha. I don’t think Istalled it in, but I’m hoping the data can shed some light on what reallyhappened. We don’t have a way to record control inputs or indicatedairspeed, so we may never know for sure what happened. Just so I don’tforget, wind estimate for the time of the crash was 5 mph out of the south.The MIDG will give me speed relative to the earth, not speed relative tothe local air mass.

Update (Sep 23, 2005):

  • For some unexplained reason (and this has never happened to us before) our MIDG didn’t have a gps solution for the final flight. This means we had no position or velocity data, only attitude data.
  • The attitude data clearly shows the take off, climb out, and turn back to the field.
  • Our engine died during the climb out before the turn. But during the 180 turn back to the field, the nose immediately drops to between 10-15 degrees pitch down. This supports my intention to lay off the elevator during the entire turn so that gravity would keep the aircraft above a safe airspeed and eliminate the risk of stalling.
  • Because of data buffering and the fact that when the main gear departed, it sheared off our radio modem antenna, I believe we lost the last second or two of data. Our wonderful video capture software automatically deleted the video for us because it detected too much snow (after the crash.)


Note that I am speaking unofficially here, and from the perspective ofthe pilot in command with an ego to defend. Whatever the evidence,the conclusion will be that it was not my fault. πŸ˜›

I believe I properly executed my plan to turn back to the field withzero elevator input. The resulting natural dive during the turnshould have kept the airplane at safe flying speed since it naturallyseeks an equilibrium. This aircraft is *very* difficult to stall andin all previous stall tests, stalls were slow, required a tremendousamount of forced up elevator, they were gentle not sharp, and somelimited control authority was always preserved even during the stall.This makes it hard for me to believe that I could have been in a stallregime, and even if I was, I would have expected different behaviorfrom the aircraft. I believe I had sufficient and safe airspeed.However, when I tried to roll out of the turn and pull out of the diveI had nothing. The plane gave no response and continued to divestraight into the ground.

My conclusion then is that given my recollection of the control inputsand my intentions (supported by the attitude data) combined with myunderstanding of aerodynamics and my specific knowledge of theparticular flight characteristics of this aircraft, I believe theaircraft maintained safe airspeed throughout the 180 turn backmanuever, and very likely I over compensated and gained more airspeedthan needed through the turn/dive. Based on my understanding of thespecific characteristics of this plane, I find it highly unlikely thatI was any where close to the stall regime. The more likely scenariois the relative orientation of the plane’s R/C receiver antenna to theground transmitter, combined with the interference patterns of the twoon-board transmitters (1 for video and 1 for data) put us in atemporary "dead" zone. Unfortunately our close proximity to theground when this occured meant that we were unable to fly through thedead zone and recover … we hit the ground first.

I think I can rule out pilot error in the direct operation of theaircraft, however there are still higher level issues we have controlover that likely contributed to the crash. Specifically engine tuningprior to the flight. We did run up the engine on the ground beforetake off and it sounded perfect, but perhaps we missed something.Also we were using a buddy box system for the first time on thisflight. Did that contribute in any way? Crashes seem to always be along sequence of events where the initial problem leads to, but is notthe source of the final crash. What else could we have done prior tothe flight, with the setup of the airplane, the setup of the buddy boxsystem, the setup of our instrumentation, our flight plan, etc. tohave prevented this crash? Are there things we can do to ensure morereliable engine operation?

This big Rascal can be rebuilt and will fly again.

Sig Four Star 40

Sig Four Star 40

Kit built, purchased Spring, 2005. Sold to a fellow club member (I forget the date, but maybe Summer of 2006-ish?) Β Yes, it is pink! Β That is what I get for buying off of ebay. πŸ™‚




November 11, 2005

Today we had unseasonably warm weather (high of 61F!) so I shifted around my work schedule so i could fly in the afternoon. I replaced my aging/ailing transmitter battery and needed to test the new one.

The 4* is a lot of fun to fly … quick, nimble, easy inverted flight, tracks really well through loops, does outside loops with ease, does nice rolls. It makes the pilot look a lot better than he really is. πŸ™‚

For the first time in my life, I took off, climbed a bit, rolled inverted before the first turn and flew for a while inverted. Usually I wait until I’m really up high to try that scary stuff, but the 4* does such a good job it softly beckons to me … “come on, fly inverted, do it lower, how about a roll 20 feet off the deck, you can probably do it …”

Hangar 9 Piper Cub

Hangar 9 Piper Cub Ultra Series (ARF) w/ Floats

Purchased from ebay, March 19, 2006.



This turned out to be a deal I literally could not refuse. It was listed as ‘local pickup only’ on ebay and I ended up being the only bidder. After church on sunday, I burned rubber down to Madison to pick it up. There was a major winter storm bearing down on us and I wanted to get back before things got too bad. The last hour or two of the drive home saw a mix of precipitation, ice, snow, rain, but the roads stayed good all the way home. We ended up getting 8-10 inches of wet, heavy snow by noon the next day.


Here is the history of the airplane as best as I know.

Originally this aircraft was assembled by an older gentlemen. He bought the Carl Goldberg Super Floats to go along with it and really did a nice job of assembling everything, and added a few nice touches along the way. Unfortunately he passed away before he had a chance to fly it.

This gentleman’s son worked with a guy who did R/C so he sold off his father’s fleet to him. This person flew it once (off water with the floats.) However, it turned out to not be his cup of tea and needed to clear some space in his shop, so he put it up for sale on ebay.

As far as I know, the aircraft and engine have only one flight on them. The covering has a few wrinkles in places that are typical for ARF’s and typical for the plastic type covering. I need to see if they will shrink out. Other than that, the airplane is in pristine and brand new condition.

December 31, 2006

I did a few maintenance tasks. 1. I replaced the wing servos. Something is drawing way more current than it should and this is my first stab at figureing that out. 2. I added some lead to the tips of the floats to help balance the aircraft with the floats on. 3. I still need to move the rear float mount to lower the tail relative to the rear of the floats.

November 25, 2006



I finally got organized enough to get my Cub up to my parent’s lake. There is a small thin sheet of ice forming at the middle of the lake so this is most likely my last chance to fly off water this year. Β Check out how sweet the cub looks flying off water:

Piper Cub on floats photo shoot!

September 9, 2006

Finished float installation — needed another control horn on opposite side of rudder to drive the water rudders. I am ready for some water flying!

May 20, 2006: Battery update

I cycled my battery after the chirper went off yesterday. I still had 2 hours of time at the accelerated discharge rate, so the battery was good. I plugged in a voltwatch unit and that indicates full charge even after the chirper kicks in. So I’m confident I have a bad chirper, not a bad battery or an accelerated battery drain problem.

It might be time to rig up the old floats for this bird.

May 19, 2006: B-day flight

Weather: middle 70’s, almost no wind, mostly clear sky with some high cirrus clouds. Perfect, perfect, perfect day for flying.

I had planned a long late afternoon and evening of relaxing flying. Unfortunately my onboard battery minder started chirping after the first 1/4 tank on the first flight. πŸ™ Needless to say I packed it up and called it a day.

I have no idea. It’s a brand new battery, it’s been cycled a couple times with an accucycle and showed solid numbers. It performed well the first time I went out to fly, but was fading fast today after a good solid charge. I don’t know if I should debug the problem or get rid of this older radio equipment and just buy a new flight pack.

April 1, 2006: My Maiden

Weather: middle 40’s, light winds ranging from E to S, overcast. I had a bit of trouble getting the engine tuned up, and had to richen the idle mixture a bit, but having done that, the engine ran quite well. I had several succesful flights and started to get the hang of cub flying by the end of the day. One thing is for certain, this is no R/C trainer.

It is pretty easy to get too slow and with a bit too much up elevator you stall and immediately enter a snap roll. I did this once on the back side of a loop. I got too slow over the top and due to my low altitude, I tried to tighten up the backside on the way down by feeding in some additional elevator. But she snapped hard on me. I released the elevator and got some speed and then pulled back again to avoid the ground and she started to snap again. But I somehow managed to find some sort of middle ground with the elevator to keep pulling out of the dive while maintaining just enough aileron authority to somehow save it. Both wing tips were literally inches from the ground at various points in the manuever and I was still flying right on the ragged edge of the stall. I was one tremble short of another full snap roll. The spectators claimed that ground effect saved me. πŸ™‚ Somehow in the end I was back flying with no vegetation in the gear or wing tips. WHEW!

Lesson of the day: A cub needs it’s respect, it needs finess. You don’t go horsing it around the sky at any speed. One mistake can burn you.

But the good news is that with my new found respect, the cub is a great and gentle flyer. You just need to manage the rudder and the elevator and the throttle with finess and don’t do anything stupid.

ο»Ώο»ΏPiper Cub on floats wheels shoot!

Thunder Tiger Tiger Bipe 40

Thunder Tiger Tiger Bipe 40

Purchased: May 23, 2004 (from ebay)

This is a partially assembled ARF I bought in a moment of weakness. Much of the assembly work was already done so it only took me an evening or two to of work to get her ready to fly. She flies like a dream – tons of fun. She is very aerobatic; quick, nimble, and light to the touch, but has pretty long moments so is also stable. All in all a very nice flier.

October 3, 2005

Sold to a nice guy in Georgia who will provide her a nice home. πŸ™‚ Here are a couple picts I took as I was packing it up.




July 5, 2005

After flying this airplane once this year I became totally fed up with it’s tendency to nose over on landing. I had the day off today, so I replaced the wire gear with an aluminum gear and moved the wheels an inch foward. This should help the ground handling quite a bit and I think everything looks nicer without that spindly wire gear.


June 16, 2004

Posing with cowl and wheel pants and windshield.




May 28, 2004

I was on a roll so I stayed up until about 1am last night to get this mostly polished off. The muffler that came with the engine was goofy (someone attemted to turn it into a tuned pipe) and one of the screws was hopelessly bent so I think I will chuck it. Turns out the muffler mount is exactly the same dimensions as an OS 40 FP down to the screws so I grabbed a muffler from a spare engine I had laying around and that worked perfectly. Whew I didn’t want to have to wait around a couple weeks ordering something new.

I haven’t put on the cowl the wheel pants, or the windscreen yet, those are the only remaining things to do.

Here are some pictures at the field before the maiden flight:






I gassed her up, adjusted the engine to be pretty rich since the engine is relatively new and I wasn’t sure if it was fully broken in yet.

She flies really nice. Very nimble, kind of quick, but not overly fast. It has a very light touch and the engine has more than enough power. Half throttle loops are a breeze. It’s lighter construction than some of the other planes I have, so I backed off on the throttle on the down directions so I wouldn’t overload the airframe (but all indications so far is that the airframe will hold up to whatever I throw at it.) When you do cut the throttle and she eventually slows down, she can be really gentle on the landings. That’s something where I need a bit of practice. πŸ™‚ I always tend too high and too fast. But it will be possible to do really nice three point landings with this aircraft.

May 27, 2004

Posing in my living room …





May 23, 2004

I bought this aircraft brand new from Ebay. We were in Chicago for the weekend so we did the pickup on the way back and fortunately it all fit in the trunk since the car was full and we had picked up an extra passenger on the way back. Much of the assembly work was already done and the craftmanship was excellent. Here is a picture of the box:

80_3 I was a bit surprised that the wings were so small, but I guess there are two of them so they need to be smaller than the wing of a similar monoplane.

Aerobird Challenger

Hobbyzone Aerobird Challenger

Purchased: October 13, 2003 (RTF)

August 24, 2005

Sold to the highest bidder … πŸ™‚

August 17, 2005

For Sale: Click here for my ebay add.

November, 2003

This little beauty comes ready to fly. I’ve been having a blast with it. I can fly it in the field behind my house. It’s a great plane for flying on a whim.




Sig Rascal 110 #1 Flying

Sig Rascal 110 #1 – UMN UAV Project


Project started March, 2005.

I am involved with the University of Minnesota Aero Dept. on a UAV project. My part of the project involves assembling the airframe as well as being the chief test pilot.

June 7, 2005.

Today we flew the Rascal 110 on it’s maiden flight! Winds were about 10-ish out of the SE, gusting to 15+. It was a bit on the windy side and the gusty cross wind was tricky, but we managed.

Posing at the start of the day …


img_2547 Curt at the controls …



img_2551 Turning final …

img_2550 Landing …

img_2552 Ready for another flight …

img_2553 Greg at the controls …






img_2560 Still in one piece at the end of the day … πŸ™‚

img_2561 The Rascal is a big beautiful flying airplane. It’s a tremendous floater. Even at 1/4 throttle, the tail comes up quickly on the take off roll, and it’s airborn soon after. We powered the Rascal with an OS 1.60 FX 2-stroke. That is plenty of power and she can sure fly with a lot less engine, but the airplane is big enough to handle all that extra power just fine. It will go unlimited vertical, but just barely. It was a bit tricky to handle in the gusty cross-wind, really wanting to weathervane into the wind, but I’m sure with some practice and more flight time I will get a better feel for how it handles on approach. It’s a great flying aircraft and should be able to carry quite a load.

June 16, 2005.

Today I made two very short flights with the Rascal. Both ended early with the engine quiting. I safely dead sticked both times, but I wasn’t in the mood to practice dead sticking today. I couldn’t get the engine to run reliably, even after a fresh glow plug so I gave up for the day. I’m going to rip the cowl off and play with it at home to see if I can figure out what’s going on. No clouds, barely any wind, temp in the mid-70’s, other than engine proplems, it was a great day for flying. πŸ™

The prop got damaged on the trailing edge midway between the center and the tip during the maiden flight, so today I was flying with a new prop. I went with an 18×8 (instead of the original 18×10) to try to get more “braking” action on landings to counteract it’s tendency to float forever. I’ll have to wait to get the engine running reliably again before I know how much this will help.

June 18, 2005.

Today I put in 3 really good flights. I yanked the cowl at home and ran a tank through in my front yard which I think cleared out the cobwebs. I think it was still a little tight from being so new and I was a bit off on my needle valve adjustment last Thursday. But today I had the engine running great. It pulls the Rascal through the air authoritatively and allows you to do *big* beautiful maneuvers. I probably ran 60+ oz of fuel through the engine today.

July 2, 2005.

Today we tested a simple telemetry system consisting of a Garmin Etrex GPS and an AeroComm radio modem. The aircraft flew great. The telemetry worked great. The GPS worked great and we got WAAS correction. Everything went pretty much as good or better than expected. From the data collected the max speed we hit with the Rascal 110 was 88.9 kts and I suspect that was with the wind which was running 5-10 kts at the surface. The Rascal can cruise comfortably at 25 kts and can lollygag and putter around at maybe 15-ish or even a little slower. But fire up the throttle and she get’s up and goes.

Last minute tweaks and engine tuning before a flight.


img_2658 Slow fly by and final approach.


img_2660 I also hacked together a system to load in the gps track, interpolate/smooth the 0.5hz data to 60hz and fake roll/pitch, then blast the result to FlightGear via UDP packets. The result is a virtual replay of our flight and it turned out pretty reasonable for a linear interpolation. FlightGear provides a working virtual instrument panel (AI, ASI, Alt, DG, and VSI) as well as a working HUD and a 3D sythetic world view.

These are virtual views from the flight playback. Notice the working instruments in the virtual cockpit view. Oh, and it’s flight gear so I tuned in a nearby VOR station. πŸ™‚ If we recorded control inputs we could animate yoke, pedals, and control surfaces in FlightGear as well.

Virtual-UAV-01 We can also do external chase views and include a HUD if we like.



Virtual-UAV-04 Here is a plot of a portion of one of our flights.


August 5, 2005.

We had to scrub today’s tests due to radio interference problems (eventually traced back to the receiver.) Our intention was to test the newly installed wireless video system with two cameras. One pointed straight down and one pointed forward 45 degrees.




August 24, 2005.

Today we did 3 really nice flights to test our MIDG II IMU and our 2 camera, 2 channel wireless video system. We think we got excellent looking data back from the MIDG and it appeared to work *very* well. Unfortunately, our wireless video was really bad. We are going to have to do a lot of work on the video system to get it up and running satisfactorily.

We bought a second Rascal (RTF). This one is powered by a Zenoah G26 2-stroke gas engine.

Update: I worked over the weekend on parsing the MIDG binary data and feeding it into FlightGear. The result is a really nice animation of the 3 flights. The 50hz data rate on the MIDG captures a lot of the subtle nuances of the flight, dutch roles, wind gusts, twitchy thumbs, and even does a good job capturing aerobatic maneuvers–loops, rolls, wing overs, etc.

Sig Rascal 110 #1 Construction

Sig Rascal 110 #1 – UMN UAV Project


Project started March, 2005.

I am involved with the University of Minnesota Aero Dept. on a UAV project. My part of the project involves assembling the airframe as well as being the chief test pilot.

November 3, 2004.

It appears that our small UAV project got funded here at the U of MN. Hooray! I get to be paid (for a short time) to build and fly R/C airplanes. We plan to purchase our first hardware in early February ’05 and immediately work on assembling and test flying the airframe .

February 24, 2005.

U of MN UAV project update: We have done the initial airframe, engine, and R/C gear order. A couple items were backordered so we don’t have any fun toys to play with quite yet. The airframe will be a Sig Rascal 110 running an OS 1.6 2-stroke engine. Initially we will hand fly it (perhaps using an onboard camera rather than direct line of sight?) but eventually we will develop autonomous capabilities as well.

April 4, 2005.

Installed ailerons, aileron servos, linkages, and routed servo leads. The wings are essentially complete. Here are some pictures of the different pieces:





April 6, 2005.

Here are a few pictures of some of the toys hanging around the Aero work shop:




May 2, 2005.

Installed OS 1.60 engine into the Rascal with special ordered beefier engine mount.

May 4, 2005.

U of MN UAV project update: I cut, fit, and installed the cowl today. I found an 18×10 prop (in the recommended range) floating around the lab and slapped it on temporarily. Yikes … it is big! I will have to make one more opening for the mixture adjustment. It looks like we will need to special order a spinner for this beast. I also took a heat gun to the wings and fuselage and shrunk out most of the wrinkles.







May 6, 2005.

Today I bought a larger tank (24oz) than stock and fit it. I haven’t locked it in place yet, but that’s [hopefully] a quick thing. I also glued in the fairings which provide a bit of extra support for the horizontal stabalizer where it attaches to the fuselage. Next up is installing the elevator and rudder servos in the tail. Here are a couple pictures from inside the cabin.




May 9, 2005.

Today I installed the rudder and elevator servos in the tail of the Rascal. This minimizes the length of the linkage used (thus reducing slop and the risk of flutter.) I then attached the horizontal and vertical stabalizers and the additional two fairings on the top side of the horizontal stab. Then I attached the elevator, tail wheel, and finally attached the rudder. Next up is the rudder and elevator linkages.





May 10, 2005.

Today I fabricated and installed the rudder and elevator linkages. I also installed the springs that attach the rudder to the steerable tail wheel. After that I turned my attention to the inside of the aircraft and installed the onboard radio on/off switch and the throttle servo and linkage.



img_2529 Then I assembled and installed the main gear. The Rascal wheel pants come completely finished, even with blind nuts already installed. It’s about a 10 minute job to assemble and attach the main gear, wheels, and wheel pants, including taking them out of the baggies.



img_2530 With the main gear installed, the Rascal can now stand on her own, so it was time to pose for some pictures.


img_2519 Now I add the wing.




img_2523 I almost forgot about the cowl.


img_2525 And I might as well put on a prop while I’m at it.






May 11, 2005.

Items completed today:
Installed the side windows.
Installed a new prop (appropriately drilled out for our shaft diameter.)
Secured fuel tank.
Installed an extension to the receiver on/off switch.
Initial balance tests indicate that we might come out pretty close with no added weight.

May 12, 2005.

Items completed today:
Pad and secure battery and receiver.
Route the receiver antenna.
Touch up and shrink covering in a few areas.

May 13, 2005.

Today I checked the control surface throws to verify they matched the manufacturer’s recomendations. I also moved the battery as far forward as possible to put the aircraft in balance. I think we are now balanced with no need to add additional dead weight. With the exception of final checks, this plane is ready to fly.

May 19, 2005.

Today we fired up the brand new OS 1.60 FX 2-stroke engine and ran 24oz of fuel through it. The engine behaved well and pulls *very* strong. The next big step is the maiden flight. I will be gone most of next week so we will likely shoot for a day the week after next weather permitting.

May 30, 2005.

Fit and installed new spinner. We still need to get all the right tools so I can properly tighten everything up. Right now a couple pieces are only finger tight, but they look good.

June 6, 2005.

New pictures … all ready for her maiden flight tomorrow (weather permitting.)