Norman,
Do you have any reports on taxi testing progress?
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Norman,
Do you have any reports on taxi testing progress?
Grant
Last week the first trip to the lake was fruitless at the last start up before taxing out on the lake the pull starter rope stayed pulled all the way out and had to shut down and go home
Today Sat at the lake 5:00am trying to beet the boaters to the launch. We had better luck. The first taxi took place with mixed results.
There is a steering system that didn't work at all (water ruder). After locking it out.the air ruder provided enough control to taxi. low speed taxi was fine . the plane moves through the water level and with minimal correction.
Adding throttle it bow planes,not to severe. I didn't take a lot of notes this time so I don't have the fine details.Somewhere near half throttle it quickly gets up on hull plane and builds speed, but here The problems begin . there are control problems that turn the plan resulting in sponsons dipping and and throwing water into the prop. I limited my test to taking the video and took the plane home to ponder the resolve.
It may be a while before I attempt more testing but should be this flying season.
The control problem has been found .After talking with Grant I went to inspect my prop for water strike damage and looked again at my cable mapping.After all this time its been reversed.I was stepping on my right ruder thinking I was just not getting a response I was it was left turn . I will make the changes and return to the lake next weekend.(weather permitting)
A photo bucket video of the water taxi test run.
video deleted addware the video early design V tail never flew
After thinking about the upload of the video I tried it works pretty good . the explanation above and this video tells the story.
Starting my first reply with bad info . please all take note of that I edited and applied the reason for the control problem.
The sponsons are a problem as well and the arch and style of the rear floats will be redone soon.Taxi testing will resume with a flip side reversing of the sponsons putting them tail first will make some difference in there behavior and may allow me to skim and make hops.
I have little to add, but moral support, but if you need an extra pair of hands, I'd love to see the project. I live in Portsmouth, and have Family in Northwood (near Bow Lake and the Strafford line). Are you doing your taxi tests on Northwood Lake? Harvey? Bow?
WBNH
I will extend my hand and welcome any help.It has been difficult arranging to have a safety for the days I can fly.My son was operating the boat,and shot the video.
I had the last week of July off and couldn't get a day on the water with anyone. Help is scarce to say the least. people work and on the week end the launch is busy with other boaters.If you would like to attend I expect to do more testing Saturday first light to avoid the boater traffic. wind and weather permitting I test only in the morning.
The lake is Northwood lake. The launch is across the street from True Value Hardware . My #603 -942-6213
I would like to add this is only the beginning .
I sincerely hope your test program moves along perfectly. I'll miss Saturday, however, as a lot of family is gathering at my place for B-fast and to avoid the traffic congestion and carpooling to the airshow at Pease. Front row, box 12. After B-fast, gates open at 8...I'll be there at 7:30 waiting...
...Thunderbirds just arrived...saw one over the area a half hour ago...just flying in circles. Drumming up business?
2nd taxi test Saturday 8-11-11 the video shows still having no control after hull plane and medium speeds [less than flying speed]
video deleted add ware
I am thinking its all due to a high angle of attack resulting in pushing the bow down and making it squirrel y and appearing as adverse yaw. Boats do not behave any better with there bow over loaded (down)
I will make the change and try again half what it is. presently at 10 degrees incidence to the hull.
Anyone wish to make a suggestion on this? I am listening.
The third taxi test Sunday 8-21-11
there are still multiple problems . the major difference is the angle of incidence to the hull plane.This is much improved .now a 6 degrees I will make this a permanent change . This video shows a lot of turning and most of it was uncontrolled. only at low throttle and large turn radius was it at my will.
One major adverse effect was the rotation around the vertical axis. not having enough ruder influence to counter this .The plane would flat spin or slip around being effected greatly by engine throttle more throttle more right spin.
I tried using the aileron to counter and this did have some effect right roll resulted in left turn slight as it was the down aileron acting as a brake. This proved dangerous because it produced an adverse roll to the turn. A tricycle tip over.
The video does not show anything that you can determine what kind of control I was applying. During the tight turns almost always trying to counter . None of these were intended.
When the plane was being put back in the hanger the sponson arch broke through . Until the rework is finished there will obviously be no more test runs
Here is the new video link .My son made one long video it a long one.
In -spite I was having intense fun !!!
Expand it to full screen if you can.
I made an error stating longitudinal axis for the slip turn. it is the vertical axis. If anyone still understood what I was trying to say about the behavior OK , I just felt this needed to be corrected.
video deleted addware
the videos early design V tail never flew
Norman,
Could you please post a photo of your current configuration? It is a bit hard to see from the video. It would be easier for people to evaluate it here, rather than having to try to find it on the old message board.
I looked for a picture that represents the plane .best I have is what was tested on the first run. the sponsons have since been turned around and the angle of incidenceAttachment 328Attachment 329 was changed to 6 degree with a spacer on this last run.
The angle I refer to is the hull plane verses the wing
At a glance (hard to tell from these pictures), I suspect you may have inadequate vertical tail area. Also it looks like the tail is outside the prop wash, further limiting control at low airspeed.
Is there a water rudder?
Dana
There is not a typical water rudder. There is an experimental system there as built ,that steers the plane at low speed. I lock it straight during any high speed taxi attempt. It is the sponson float system they pivot with the controls can lock in or lock out.
The v-tail was always an unknown especially to me with no experience. I expect you are right on there .
I plan to replace the tail with the standard vertical and horizontal. The only consideration is a middle or high stabilator. Raising the horizontal will resolve my wet tail concerns. (that being when the pilot is absent the tail rides low enough to be in the water] the main reason for the odd sponson floats is support for the engine weight if the pilot exits with the plane in deep water. The V-tail takes on water if I let it go on to long.
The bottom line is I now believe the V-tail is a bad Idea for this short arm pusher. There is obviously insufficient area and the arm is to short. If this was a tractor engine things may be different.
A new float support system and new floats are being made .They should resolve much of the in water behavior.
The air frame will be modified slightly to accommodate the more reasonable angle of incidence of 5 or 6 degrees hull to wing. Lastly the new Tail.. there maybe another test run before the tail is replaced .But I am sure it is the reason for lack of ruder control and the right turn slip. That I believe is P factor ( more throttle = more severe right turn slip) this plane has a 68 inch prop . I know when I was up on plane I was slipping sideways over the water and turning to the right.
I thought it was odd since I didn't think I was flying But I was skipping sideways on the water the wing must have achieved G E flying speed. Every time I took the plane up to this speed there was virtually no ruder. I was able to keep it straight a bit longer using reverse aileron. But this proved dangerious when the plane rolls to the opposite of the turn. And added power made the effort feeble with immediate turn response.
Sorry I ramble on so.
Norm
Nice looking little amphibian there. Too bad the V tail isn't working out, they always look nice.
If I might be so bold as to suggest looking at existing seaplanes for workable ideas. The SeaHawker design uses sponsons on both sides of the hull to provide lateral support when in the water and to help keep spray out of the prop. Perhaps a small float at the far aft end of the tail boom would keep the new tail out of the water when the pilot is not aboard and provide a location for a water rudder. It appears that (1) much more (air) rudder area is needed, (2) in the prop wash for low speed control and (3) elevators in the prop wash to allow low speed pitch attitude control. It looked in the video like the primary pitch control was power rather than the elevators. Take to look at the Lake Amphibian. It has a cruciform tail (horizontal stab in the prop wash) and the elevators are split to provide really huge trim surfaces at each end of the horizontal stab that are controlled separately from the normal elevators. Sort of secondary elevators controlled by the pitch trim control in the cockpit. Best wishes and good luck !
Tom thank you
A new float system has been fabricated. No trials were performed yet. As the season ended and the changes were worked out. The transport trailer needed a revision to accommodate the new configuration of the dolly that conveys the plane to the water.All those watching my progress will have to wait for early summer maybe in May.
I want to make a note to all there is something maybe significant in the works. That make up wings and control surfaces typically for use in Ultralights.
I need to put my new tail together before I toot this horn
For now here is a picture of the new float system. It was finished for testing but not for looks should they need alterations.They were created VIA suggestion of My mentor here in the forums. I do pay attention and ponder all suggestions. If I deem it practical to deviate and rework I will. Being an Ultralight I have the weight factor to consider.
My current portion of the project is the new tail. The V-tail weighed 6# and that was before covering and the root area connection plus control hardware. I would guess finishing at or near 8# I will confirm this sometime after I tare it all of and add the new tail. This new tail A mid tail stabilator . I have found a new way of using my channel to create structural rather than just airfoil members making the whole tail only about 10# vertical and horizontal. I am anxious to say the least and this is premature. Next week I will have my stabilator partially assembled and something to show. The picture was before sanding fiberglass was applied
Attachment 1182
Regards to all
Hi Norm,
Just wanted to encourage you to keep up the good work. It excites me to see other real "EXPERIMENTERS", that are willing to show/share what they are working on. I've been following your threads with keen interest; even though I am not much of a float guy -just happy to learn from what you have learned and shared. -Zach
I promised some pictures of what I was working on. A completely new way of making U/L ribs. I believe at least not done this way before.
I have been slow because of the extensive tooling.
What I have here is a stabilator and the vertical fin plus the ruder foam cores. Still yet to fab its rib channels.[special bender required] I also have no leading edge material its on order.
Laid out on the floor just to express the general idea.
The stabilator is a lift generating airfoil with a center bearing it is actually 2 pieces . Will be mounted mid way up the fin
The fin ribs will have porting done to allow for the control rod .
Looking at this you will assume its all heavy. you are deceiving yourselves if you think so the largest of the ribs having a 36 inch chord weighs 4 oz.the spar tubes are .035 1.75" and the fin is .035 X 2" ruder spar is .035 X 1.75
What you see is foam encapsulated by a full perimeter .035 channel splayed then compressed over the foam. each rib becomes complimented by combined materials character . The rib becomes like a stress skin panel in the vertical. Light and more structural than the usual U/L . I use them to reduce structure and end up light typically a single spar tube ,LE an TE.
I have very pleasing numbers so far.The V-tail when weighed all components was every bit of 10# I expect to be very near the same. with far more control surface.Attachment 1217Attachment 1218Attachment 1219
Ok I guess I need to start begging for feed back. I really need to know what you all think of this process .
Has anyone seen any thing like this?. do you need more info?
I'm not the teacher here I am a student . So I can make stuff help me know its worth doing.
I have only a very few real people to talk with and show it to, that even have a clue about airplanes. They like it but that is only 4 people
Regards to all Norm
If you need to e-mail Me at pjlucky@metrocast.net
Norm, others have done foam ribs with aluminum cap strips... I'm planning something similar for the ultralight biplane design I'm working on. Some of this has been discussed over on homebuiltairplanes.com.
Finally the new tail is partially complete . Enough to show anyway. I still need to turn some hardware . After that I can cover. It will be ready for the spring.
Some may wounder why the inverted stabilator . I can only tell you I have had discussions with good authority,I am not qualified to debate it.
Generally you are seeing a fin, ruder and stabilator with lift generation airfoil in the lift down configuration. It will be reversible if need be.
The weight I wish was better but I am not displeased entirely. I expect 15# after covering.That includes all hardware and controls. brake down is like this each stabilator Half Attachment 1427Attachment 1428Attachment 1429is 3#4oz. the ruder is 2# and the fin with interface hardware and control horn 5#4oz. That is as you see it.
Norm, Haven't been on the forum in a long time. Life gets in the way at times.
In the videos I noted a lot of spray coming from the prop/engine area. The sound of the engine changed during those spray moments. Is the prop picking up water? It will cause some problems with prop tip erosion.
I give you great credit for keeping going on this project.
Jim there are three video's .The first run was the worst and the prop was being hit with spray produced by the rear float system. In each test something was changing the middle test the sponson system was turned around and did produce less spray. In the last runs the arch support was failing from over the road damage.As a result One sponson was dragging more than the other.It did produce some spray .The control problems are what made the tests stop and the V-tail is being changed out .
A couple of pictures of the new tail configuration
I just finished rigging the controls so now its time to detail things and get to covering
A look down the air frame gives some Idea of the prop wash over the new tail the center of the prop is about 10 inches above the top of the frame. Ignore the object in the wing mount area its the pivot jack for the wing. looking only down the outer tube you will get the alignment described.
In the old archives there was notations about wet tail the V-tail was so low it was in the water when no pilots weight was applied.Causing many undesirables. This tail will be dry even if the boom rests low, That will quickly drain away when pilot is aboard. This new tail features a stabilator and it is cantilevered.Also its in the negative lift configuration, being an none symmetrical airfoil. It is however easily reversed if necessary. I am expecting much better control this time.
Attachment 1679Attachment 1680
I like the idea of the new tail much better than the old V design. This one is up and in the prop wash, which should help immensely with low speed control. In looking at some of your old videos, I was also concerned about the (previous) low tail airflow getting blanked by the wings in a stall. That would make it more difficult to recover from a stall. This design should be better in that instance, also.
I can't say for sure that any of this will actually work, since I have only looked at the pictures you provided here, and I am not an aeronautical engineer. My thoughts are only observations from comparing your design to common airplane designs. Cessna and Piper put a lot of testing and engineering in their designs, so just by observing you can get the benefit of someone else's work. :)
Winter is over and I am on track for spring trials .I am expecting first or second week end in May.First runs are just straight taxi runs working on and gathering facts . dont be expecting to see it fly for a while .I will post the results and videos as they evolve.Attachment 1825Attachment 1826Attachment 1827Attachment 1828Attachment 1829
Looking good Norm! Keep us posted. My project is slow getting started again this spring; just about to pay the house off, and had lightening strike the house -caused quite a bit of damage. That's put the plane on the back burner for a couple months :( It's encouraging to see others still moving forward! -Zach
Norm,
Do you think you have the clearance on the sponsons to rotate for take offf? Please let me respond before you do any attempt at high speed taxi, rotation or lift off. This could be a clasic case of an airplane that is difficult to rotate but once rotated it jumps off the ground/water climbs steeply and stalls at about 30 to 50 feet. Several have done that with fatal results. Mark Staul for the latest well known example. The airplane will fly at a slower speed than you will imagine once rotated.
Yes Jedi I do think there is enough for rotation.I will take another photo of the front view and try to show the elevations. If you can zoom in on the frontal shot and note that the side shot show a bit of an angle of attack on the hull bottom.I think now with the wing at a 6 to 8 degree angle for rotation there should be no contact from the ruder portion of the sponson. A higher angle of rotation may spike in about 3 inches or so. Do you see that as being enough resistance to create issues.
I have no intent to try flying yet, only straight taxi. The sponsons do not sport finish paint because they may need adjustment.
Looking again. I see some potential contact. It all depend how deep the hull sets at rotation. the tunnel hull effect developed by the chine flare . Is something I have not been able to verify. from any of my previous video . Here is a new side shot, It still can not be seen how far down the hulls V is only the chine.Attachment 1836
You really don't want to rotate for takeoff anyway. Let the aircraft build speed on the water and it should fly itself off.
Attachment 1936 Took the plane on its first road trip this year to work where the floor space permitted some weights and balance check. My boss like me LOL.
The best news I can tell you IT QUALIFIES!!! weighing in at 287 # The rest isn't so good I have some work fixing the CG.
I get right on that though .
Regards ALL
Tail heavy I presume. Where is current CG as a percent of MAC? For your weight ______ and for 140 pound 200 pound pilot?
The current CG was calculated with myself in the pilots seat I weigh in at 160# position was 39.7 % of a 68 inch MAC this is using the ailerons as part of the MAC. The wing plus the flaperons .Using the formula in the book Flight testing Home Built Aircraft. the point loads were taken with me on board.
My coworker tried calculating the point by a vector analysis. that didn't. verify but, a actually lifting the plane with the fork truck with me on board put it exactly where the calculation said it was. About 7 inches to the rear. of the 30% point
I have reconfigured the hang cage to accommodate an a adjustment . of about 6 inches to the rear wing and engine while lengthening the moment of pilot and hull and shortening the moment of the tail. This should be enough to bring it back into spec. I have had to argue this move already please don't
Those who don't see why its the best option. Here is why. I can move three of the 4 major inputs to the balance but that's the best I can do.My people couldn't see that they just think move the pilot but why that's only one of 4 and requires greater distance and much rework. The wing and engine are in a typical pusher moment arraignment. The new tail and the fact that I moved the hang cage forward last fall are the real reasons for the falling out of spec. Pivoting the hang cage to remove the steep angle of attack resulted in the 6 inch wing forward
CG corrected
Moving the hang cage . Has done the trick. All with no significant weight change.The Cg is corrected to 30% MAC for a 160# pilot and 25% MAC for a 200# pilot. calculations have been done for a MAC of 68 inches. I plan on adding my canopy it will help with 4# forward or I may have to eat more. My ruder pedals are a bit cheesy I have something much better on my computer I made . They would add about 2# far forward.
I am contemplating taking the plane to the lake tomorrow afternoon. It depends on getting some final things done and the weather . Since its Mothers day. That may also interfere and postpone til next week end ,weather permitting.
Hey Norm, this is a really handy site for calculating your static margin of safety
http://www.geistware.com/rcmodeling/cg_super_calc.htm
Attachment 1980 Saturday morning back on the lake taxi tests. Unfortunately my camera operator couldn't figure the camera was on stills and not in video mode. This is one of the best shots.
All I can give you is a report for today. The plane did well the sponsons dint give any adversity but they didnt help where I need it . This is due to the recent balance changes moving the wing back with the engine put much more weight on the sponsons than they can support in static mode without a pilot they do nothing for me and it takes two people to launch and extract. On the water they behave reasonably no spray into the prop, they come up on plane and out of the water near the lift of speed. I have a lot of practicing to do . For me its a bit tense at higher speeds the little breeze was very adverse. Left ruder is very responsive while right ruder is mushy and becomes more effective with full ruder . The stabilator is also very effective ,I didn't put much atention there to day, since all I was interested in was ruder control. I did notice when I pulled back on the stick I had a rush of speed and the plane gained rapidly I did only three fast taxi runs and noticed the more sensitive ruder and the uncertainty of the trim I should have there left being better than right. Also I topped one run off at 23mph but didn't dare to hold very long I need more time on the stick first. I felt the great change it wasn't far from going into ground effect.
I must be patient.
Regards all
Sounds great! Be careful, and keep us advised. -Zach
During the last 6 months or so, those of us in the Shelton Washington area have sighted what is obviously the top part of a weight shift trike attached to a Zodiac inflatible boat. It looks like it flies well. Nobody Ive talked to seems to knows who this is or where it lands, (lots of hidey holes around here). Colapsable seaplane? food for thought!
It's called a Flying Inflatable Boat, and there are quite a few of them around.
Most likely it is a Polaris FIB (Flying Inflatable Boat). These were manufactured in Italy over the past 30 years or more and have been successfully sold worldwide. There were a few companies that copied the design but were not as successful as considerable development work was required to get the right combination into a practical machine that would work.
Doy, the developer and US supporter, died about 4 to 5 years ago but his son still manufacturers them, I believe. In the US market they are a casualty of the Light Sport legislation. There is not a SLSA version and it cannot be registered as a homebuilt experimental.
I believe there a still a few places to get a somewhat simlar craft or there are resale units available.
North Wing out of Wenatchee makes wings for trikes on floats and they may have a FIB model as they have had a few water projects.
There are two WSC Sea pilots in the Gig Harbor area and I believe they both fly from a smaller harbor directly west of town on the opposite shore of the peninsula. The harbor opens to the north and has a small island a mile or so further to the north. I do not recall the name of the harbor nor do I have convenient access to a map.
Dave Sherifinski is one of the pilots.
Most of the Polaris FIB are boat only but there is a conversion to wheels and an amphibious version. Contact me if you want more information.
Watch for the SEA ERA operating in the area out of Lake Samamish. It is a lifting body flying boat with more or less conventional configuration otherwise. It is a really cool, one off, singe seat ELSA of foam and composite construction powered by the 80 hp Jabiru. It will hopefully be making the trip to Mason Lake several times this summer and has been on display at the Arlington Airshow for the last 2 years.
If there is more interest in either of these projects, please start a new thread with comments or questions.