Jump to content

I'm excited....new design !!


Guest Maj Millard

Recommended Posts

  • Replies 54
  • Created
  • Last Reply

Top Posters In This Topic

Guest Maj Millard

Dazza, So does your Savage Cub, I wouldn't mind strapping one on sometime...my type of aircraft !.'

 

The thing I really like about the Lightwing that I currently fly (standard wing with flaps) is that I can cruise reasonbly efficiently, and comfortable for 3 hours at altitude at around 80 kts GS, arrive overhead at a small, short, station airstrip setup for a Slepcev Storch, and still have the energy to put the thing on, and get pulled up half way down the strip, in gusting 25kt winds, safely. Speed is easily achieved in an aircraft design, safe low-speed capability is not................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

Hi Major, yes the cub is nice to fly, i only have around six hours in her, it is current grounded, nothing major, just waiting for trim cable from italy.I am currently flying the eaglet again, until the trim cable arrives, (maybe Paul is getting the Ray Allen electric trim, for her, as it was a option from the factory). Paul Turner (a member of this site), owns her, i had a realy good conversation with him at boonah, a few weeks ago,he is a realy nice guy.It is a forgiving a/c as tail draggers go in landing, etc.I can only compare it to my experience in the drifter years ago and the hand full of hours i did with John Herd in the lightwing years ago.Guys like Paul and David Manson who both have heaps of hours in TW a/c, say that she is forgiving, but a little harder to land than the Drifter As soon as she is fixed, i will be concentrating on flying her.I realy like it.I like the tandem seating, being in the centre line.It is realy fun flying with the door open, (not above 60 knots, 60 knots is the limit with door open). I would realy like to fly the cubcrafters S2, as well to compare.Cubcrafters also has the carbon cub, with a CC340 engine (based on the lycoming 0-360), lightened, etc.It is rated at 180 hp, for five minutes, then 80 hp after that.I not sure why, i think it is because of the 120 knot limit, in the usa.Plus there maximum fuel capacity of 24 us gallons.Apparently there is no way to reduce the power (from 180 to 80,other than the pilot reducing the power via the throttle, after the five minutes.They climb solo at around 2500 fpm, at ISA.Both those a/c fit into the US LSA, regulations with a MTOW of 1320 Lbs.

 

PS- sorry for this getting long winded, but i got carried away lol.I love talking about TW aircraft. Anyway back to your thread. Your design looks wonderful, she is going to excellent when you finish Ross. Cheers

 

 

Link to comment
Share on other sites

Guest Maj Millard

Great stuff dazza, John Herd by the way has been up this way for some years now, and I have a 'Herdy sighting' occasionally around Ingham or Lucinda. They had bought land up around Mt Fox west of Ingham (North of Townsville) but I recently heard that he had put his fishing boat back in the water. John was a familiar visitor at the Late Bill Starkes 'acebase' west of Townsville in the 90s, which is now named 'Starke field' in his memory. John and Bill were great friends from Ballina Lightwing days. Bill was the main Lightwing dealer here in the North for many years, and I am happy to say he was the one who turned me on to them........Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

Hi Maj

 

Good to see you catching the bug again and getting the grey matter working.

 

As you know I have been working on a new design for over 3 years now.

 

You pod with a tail boom is not that different to what I started with. Although I was going a pusher with twin booms.

 

As you know my design has now taken a different approach but still not too far from your design criteria.

 

Anyway enough of what I am up to.

 

One area that you may like to have a close look at is the back of the pod. I looks like from your sketches that it is quite short from the back of the seats to the rear of the pod. I found this could be a big problem with a 2 (side by side) seater as it will create a lot of stale air and increased drag.

 

In your case I belive you are looking at an inverted v tail. Be very careful that with the high VNE you are looking for the vortexes and turbulence created by this stale air is not right on your V tail. You could find that even in normal flight your tail and elevator looses effect.

 

Remember the old > 1 to 3 streamline factor for good air flow and also allow for when the AC is side slipping.

 

With the lower VNE of the Lazair it is obviously not a problem.

 

Ross this is only my thoughts/theory and is not tested by myself in any way.

 

Ken

 

 

Link to comment
Share on other sites

Guest Maj Millard

Thanks Ken, all good food for thought. The rear of the cabin appears to be flat at present, but I am planning for it to be streamlined to nothing, to actually improve airflow onto the tail. After viewing the high standard of your Glass work, I may just have to consider you as a subcontract supplier !!

 

It is hard to highlight to others, the major in-flight advantages of the inverted V-tail. Unfortunatly unless you have actually flown one you don't really know how superior they can be. Most soaring birds-of-prey can't be wrong otherwise they would all have rudders.

 

I believe the main reason we don't have many around is because of the tailwheel/tail design problems.

 

The original Lazair had a little castor on the bottom of each tail surface. I personally never liked taxying out on a gravel strip, dragging my tail in the dirt knowing that I would need it shortly !!. I'm trying to solve that on my design.....................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

Guest Maj Millard

A training wheel Vs a tailwheel is worth in the order of 3-4kts at cruise, in my experience. Plus of course the potential damage done to the training wheel on rough or unprepared surfaces which usually ends in considerable aircraft and prop damage not to mention engine damage =costly repairs and extended time on the ground. And that's if it doesn't end up on it's back !!

 

As previously mentioned I am chasing at least the same capability with this design as the Lightwing, which can only be achieved by another taildragger.

 

I have already designed a tailwheel setup which should work well, and be rugged, and fits into the circular boom scenero well for this aircraft. As previously mentioned the main gear legs are to be slightly more foward than normal (ala Slepcev Storch). This allows for rapid application of brakes once the tail wheel is on the ground, allowing for a very short landing roll, and minimises the potential of nosing the aircraft over.

 

The distance between the mains and tailwheel will also be long, so I expect it won't be much drama on the ground, much like for instance your average Drifter.

 

I previously mentioned a retractable tailwheel, this has been abandoned now, and will be fixed on the prototype. Retractable mains and tailwheel could be a possibility down the road.

 

Ken, thanks for your offer on the glass, although I would like it to be an all metal aircraft, it is just going to make sense to use glass on the fuselage sourround (bolted to the c/moly frame), and for wingtips and engine cowls etc.

 

Goal in the next week or two is to concentrate on the wing and tail designs, plus take the tailboom to work for some minor repair work. Then a wood model of complete aircraft for hand-launched glide tests to vindicate wing /tail relationship, probabily done on the beach as there is always a steady breeze, and hopefully a soft landing !

 

.......................................................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

  • 4 weeks later...
Guest Maj Millard

New photos of the model, wing to be covered soon and struts attached. This model when completed will be statically balanced and used for hand launched glide testing. I am very happy with the wing, it is relativly shorter than the Lazair (lazair-36 Ft...Mine around 30 ft span) and looks like it should be capable of the targeted 100Kts +, but should also be suitable for short field operations with flaps.

 

It won't be one piece like in the model photos, but two separate wing panels attached to the center section similiar to the Lightwing. Side cockpit perspex may also be altered for a more streamlined look. Foward nose entry is just about right, and visability from the cockpit, particulary foward and out the sides will be unmatched, except in a Drifter. The eighth photo is my favorite, and shows the true style of the design....Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif All comments welcome !!

 

0706101547-00.jpg.911bde1cf6e192d2e513351033c2c69c.jpg

 

0706101548-00.jpg.a3d6b531ff39e1dc8b7de991d73e43cc.jpg

 

0710101924-00.jpg.d0e01acb82b55fa1eab2f0c121e8ba1a.jpg

 

0710101925-00.jpg.a8d940ba56ea611d5c3884b231cc27bf.jpg

 

0710101926-00.jpg.761ddaa2e06df591f49bb44375305a3d.jpg

 

0710101936-01.jpg.9629d7802356a1ff4ae75c508d7ad457.jpg

 

0710101940-01.jpg.a422055c076bc4c50b7b9e70062c7b06.jpg

 

0710101945-00.jpg.c3e7c8d5c90e288853194446000ddbfe.jpg

 

0710101945-01.jpg.a3f1a8988002476e7ea39f96ae120b69.jpg

 

0710101947-00.jpg.56943213d09f8c96ad2e5c9e0b0a6f33.jpg

 

0710101947-02.jpg.98966c342b87c54d230bf73f768568d2.jpg

 

0710101949-00.jpg.bd771fa795dea487ed9c2cd0eede4265.jpg

 

0710101950-00.jpg.ecdf93b2f2dbc394b8c005d2bdca5a92.jpg

 

0710101951-00.jpg.5073bf718f71de08eeed174c58c08764.jpg

 

0710101954-00.jpg.7bfa724167742e5b7bed8fdec0500082.jpg

 

0710101959-00.jpg.847cfa1a70633e8801e4b982567a081a.jpg

 

0710102000-00.jpg.c3e4efee5620de285a4b4db420fda42d.jpg

 

0710102000-01.jpg.d8bce291b8e6fbb84e3c18678aa205d8.jpg

 

0710101941-00.jpg.edeb9b64b80b96d08da51b47f073c02d.jpg

 

0710101957-00.jpg.b8a60ad3548bcd05bd64032a344ff3f9.jpg

 

 

Link to comment
Share on other sites

Maj,

 

I know the tailwheel is a problem

 

Have you thought about a retractable boom tailwheel extending from the rear of the pod.

 

The reverse of the Long EZ

 

A simple wind down mechanism or drop and latch would suffice with safety wheels on the tailfins

 

Just a thought

 

Cheers

 

Bryon

 

 

Link to comment
Share on other sites

Nice Maj,

 

It looks a little like a parasol in a couple of the photos.

 

I'm sorry but the tail feathers don't look right without a vertical fin:sad:

 

I do like the overall look though, especially the use of see through doors and other cockpit panels - very nice.

 

Pud

 

 

Link to comment
Share on other sites

Guest Maj Millard

Pud, Yes we are so accustomed to having some type of vertical fin surface. The inverted V does fly great, much better than the Upright V. There is plenty of vertical fin surface there, but it is not vertical...it's at around 45 deg. The air doesn't see angle, it just sees surface. When the wings are banked the tail surface becomes more banked and well more vertical. I firmly believe that we would have a lot more inverted V tailed aircraft if it wasn't for the tailwheel thing, which is a bit of a challange design-wise. A recent check on the Lazair website shows that many Lazair owners have done the conversion to a nose wheel. I did fly one of these once, and it was much easier to taxi on the ground with nosewheel steering etc...but no easier to land, in fact maybe a bit harder.

 

The Lazair Mk2 that Dale Kramer flew during his tour of California in 1982 was well capable of aerobatics as he demonstrated on occasions with smoke flares on his wingtips. I know he did loops and rolls but I don't recall anything more aggressive. He now owns and flys one on floats, and that video is posted on this forum somewhere.

 

When I flew Lazairs in the past the only difference I could feel was that the rudder pedal force was much lighter. The rudder still worked in the same manner, but the force was lighter. There was still plenty of authority. The inverted V didn't seem to 'hunt' like the upright V either. Anybody who has flown a Bonanza for instance will agree that they can waggle their tail quite noticably at times, especially at speed or in crosswinds.

 

I also feel that the inverted V just flys better in turns, and also reacts well in ground effect IE: lifts it's tail almost the instance power is applied, and seems to float down on landing which will make for a softer touchdown of the tail wheel. At real low speed on rollout for instance you might loose authority (bit like the Storch) but I do plan on having differental brakes on the main wheels which is the way to get around that.................Thanks for your input......................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

Guest Maj Millard

Cficare, It's been a while now since I flew a Lazair, but from memory the stalls were very benign and not a lot different from a 'normal' tail. Just a nod and you were back flying. We found out eventually that the easiest way to land one was to shut off both engines downwind, and just glide it on, which was one recommended method from the flight manual. With any power at all above idle (s!), they would just want to float right on down the runway with stick full back, until the fence came up, such is the capability of this wing.

 

Turbulance onto the tail from the wing is something I have also been thinking about. On the Lazair the tail is well above the wing line and it may be there for a reason. Even at low speed-high AOA, the air should still flow downwards off the TE of the wing. Use of flaps should increase this tendency even more. The lazair from memory tends to fly pretty flat, as opposed to needing a lot of high AOA, it takes off flat, and wants to land flat.

 

With the one I owned (Reg: 10AXA) we flew mostly at, or close to sea level. However

 

on one occasion a friend and I threw it in the trailer, and drove up to an airfield high in the Seirra Mountains to a small airstrip called Parker Carson, Elev 5500 Ft !!.(North of Minden and South of Reno) This airfield was owned by the son of the Parker Pen Dynisty, and is in the hills just to the east of Carson City, Nevada. We did several flights there with only minor engine adjustments required, and the aircraft seemed to perform no different at altitude than at sea level. I did several long flights to the East where there are several salt lakes. Most landings at Parker carson were with both engines off.

 

I'm feeling at this point that I really need to put some power on the model, with radio controlled flight controls to fully explore the designs flight capabilities, but I have no doubt the design will fly great, and I wish I were at the stage where I was flight testing it !...................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

As a footnote many aircraft using the classic tapered wing (often called the Lockheed wing) were classics, and noted for their speed and efficiency such as the P-38 Lightning, Super Constellation, Aerocommander and lockheed Loadstar to name a few.

 

739452460_P-38Renophotos.jpg.c89ab201d2c682264b2e4185a20a3958.jpg

 

 

Link to comment
Share on other sites

Guest Maj Millard

Yes funny that, I didn't invent the inverted V tail but I can guarantee you that it flys great.........................................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

  • 2 weeks later...
Guest Maj Millard

Gang, I have just been on the Mini Imp website . The Mini-imp is also an inverted V-tail aircraft and one of the successfull designs from the late Molt Taylor, who also designed the Aerocar and Coot amphibian.

 

Lots of great info available and good photos of Mini Imps, worth checking out the site by Googling mini imp. From Molts point of view there are some definite advantages with the inverted Vtail over other tails.

 

Also directs you to an Article on Vtails in the EAAs Sport Aviations magazine of Dec 88, which is also good reading......................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

  • 1 year later...
Guest Maj Millard

No mate, but thanks for asking. Like a lot of things in this world in these financially-strapped times, it's on hold. I look at the model often, and I will get back to it after I finish a Karatoo wing repair that I'm doing at the moment.

 

....................Cheers Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...