Pat Tritle 84" span P-3 Orion - RC Groups
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Jan 12, 2013, 09:42 PM
Veni Vidi Volavi
Brian Allen's Avatar
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Pat Tritle 84" span P-3 Orion

Greetings all.

Well I have a number of Pat's designs in the close to cover stage so of course it is time to start another. I am always looking for somewhat obscure or rare aircraft to model and with the advent of reliable E power systems and batteries multi motor planes are now a snap. A few years back I built one of Pats' DC-6 designs done up as an Air Force C-118A Liftmaster. Not a complicated build and the final result flies great and looks fabulous in the air. Another modeler here on the EZone took Pat's DC-6 and enlarged it to an 80" span model with retracts and I have gone over that thread and ordered the cowls he made for it so I can do that one also. While discussing the design, it was noted that Pat had designed an 84" P-3 Orion a number of years back and had not built it. This peaked my interest and I contacted Pat, ordered a set of his preliminary drawings and ordered the short kit of parts that Charlie at Manzano Laser had available. I have had the items for 5 to 6 months now and have finally gotten started.

The plans that Pat has drawn up were done in 2008. The design is very similar in many respects to the DC-6 design only larger. I would recommend that anyone who is interested in this design review Pat's DC-6 design thread here in the scale forum. The plans are mostly completed, except Pat had not come up with a firm design for the nacelles, so I am on my own here!!! I have a few ideas I am fooling around with for the nacelles so they don't need to be done up right away.

The design as I noted is very similar in construction to the DC-6 only larger. The fuselage on this beast is about 92" long with the MAD Boom attached!!!! The fuselage is also fully sheeted unlike the DC-6 which was covered with film. Pat had not specified any power system and we have emailed about that. The current plan is to frame it up, get an estimated completed weight and then figure something out. My initial guess is a flying weight of 8 to 10 lbs so four 300 watt or so outrunners should work, most likely on 3S or 4S depending on Kv, prop etc. So power system TBD.

The design calls out some Robart pneumatic retracts but I am thinking of E flite electric retracts or maybe something from Hobby King. I need to look around and see what is available and affordable.

I have looked at a number of books on the P-3 and there are a lot of interesting schemes available. Depending on my level of motivation I am leaning towards doing one of the AEW&C birds with the rotodome on top that the Customs guys fly. If I don't do that I have a couple of other standard and interesting schemes for the basic P-3.

There are at present a couple of other gents who are either building one of these P-3's or who have purchased the plans and/or short kit from Pat and Charlie. So welcome aboard!!!

I started construction this past Tuesday and have the basic fuselage box completed and have started adding the formers to round out the shape. Did I mention this thing is long?? I have taken a number of photos and will post them in the next day or so as the construction proceeds.

So I hope all who like the P-3 will join in and watch and comment. I would welcome any suggestions from anyone to help with the nacelle design so if you have anything that might be of help please comment.

Thanks to Pat for coming up with an interesting design and to Charlie and Vicki for providing the cut parts.

Brian Allen

Veni Vidi Volavi

I came I saw I flew
Last edited by Brian Allen; May 05, 2013 at 08:36 PM.
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Jan 12, 2013, 10:30 PM
It's a fine fiddly business.
Robert R's Avatar
Very, very cool build. Must have pictures we cried. I see the pics are promised.
Best (We) Robert
Jan 12, 2013, 11:03 PM
P3_AOC_MAGGIE's Avatar

I'm here

Subscribed Brian!!!
Jan 12, 2013, 11:15 PM
Registered User
I'll be watching.
Jan 12, 2013, 11:35 PM
a.k.a Maltone
Pat Lynch's Avatar
Should be an interesting build Brian - not at all what I have come to think of as 'Tritle' I'm also gratified that you too have many almost completed builds - makes me feel almost normal

Jan 12, 2013, 11:51 PM
payne9999's Avatar

I almost bought the plans and laser parts last year. I too built Pat's DC-6 as a C-118 and then built a sized up 80" C-118 which I still fly today. My 80" C-118 is only 5 lbs AUW and uses four 450 size motors and one 3S 3800. I also have Pat's plans for a 75" B-17.

I do want to build the Orion though. I was thinking of developing a set of plugs to make some vac formed or possibly fiberglass parts. The nacelles look just like several other heavy lifting military planes (T-56 nacelle). Sparky has several sizes of these but I think the size you need is not one of them.

At 8-10 lbs I would guess you need about 1Kw. Maybe four .10 size electrics. I used the E-Flite retracts in my big DC-6 and they have been perfect.

Looking forward to watching this one go together.

Jan 13, 2013, 09:01 AM
Registered User
portablevcb's Avatar
No, it is not a traditional Tritle design. But, Pat will design anything you want for a price. And if you send him a bit more he'll even build it for you.

Jan 13, 2013, 01:54 PM
Visitor from Reality
Good build. The P3 and its variants did a lot of work in the day when there were lots of submarines crawling around under the waters of the world. Not exactly exciting paint jobs, though the USN anti-sub squadrons had classy tailfin badges to echo their squadron nicknames.

Never even got a ride in a P3, though went on a few on the ground. The Canadian Aurora version had much nicer internal layout and a very good galley!

Thankfully, the odd tales I have of P3 activity aren't exactly what this site goes in for One of few is when we were patrolling in our Nimrod four jet off Oman and came across a USN P3 doing who knows what. It was ambling around with one outer prop stopped and feathered - anti-sub aircraft were always flying around on less than four engines - and we chatted awhile as we cruised along in loose parallel track formation. The P3 captain then announced she had someplace to go, wound up her three running engines and left us standing.

Our pilot compensated by smartly turning off in another direction so it didn't look too embarrassing, but it was somewhat not discussed that a P3 on three turboprops could easily outrun a Nimrod four jet...

Good luck with the build Brian. Have to see if I can figure out a visit to the DC sprawl and get to see you fly her one day.

Jan 13, 2013, 08:24 PM
Official Boat Bum
Eddie P's Avatar
This will be fun to watch, I can imagine several others will take notice too. The P-3 is a great flyer in RC format and it's a natural for electric power (as all 4 engine aircraft are). Bigger flies better so the size seems about right for today's electric power and equipment that is available.
Jan 14, 2013, 04:17 PM
Veni Vidi Volavi
Brian Allen's Avatar
Greetings All

Well as promised I have downloaded some pictures from the camera. I spent some additional time today (after my nap of course!!) working on the fuselage. I have added the side formers on both sides so all that is left former wise id to add the bottom ones and then the couple that form the tail area for the MAD Boom. I may leave the bottom formers off for a while as it makes it much easier to place on the bench with the flat bottom versus having to place it on some form of support cradle to keep from breaking the formers off. Next step would be to start stringering the fuselage up and then work on the front retract mount installation, as soon as I decide on retracts. Am leaning towards the E Flite 60-120 size at this point but nothing is set in stone yet.

The formers all went on OK. Had to make a few minor adjustments in order for the sides and top ones to line up properly. Had to add some shims in a few places, most likely due to some variances in the size/dimensions of the basic fuselage box. Just wanted to make sure that the edges of all the formers matched up correctly. Charlies laser work as usual is top notch as are Pat's plans.

After I get the fuselage basically framed up and the front retract setup I will probably start on the tail pieces and save the wing for last. Still need time to figure out the nacelles and the associated retract setup.

Basic fuselage construction is a box with formers on all four sides. The fuselage longerons and some of the verticals are 3/16" sq and the remaining uprights and diagonals are 3/32" x 3/16" balsa. The wing saddles are laminated from a 1/8" piece and a 1/16" pieces as these are the only cut parts that are 3/16" thick. This prevents Pat from makes a small piece of 3/16" balsa needed in the short kit. The basic cut parts are all 1/16", 3/32" and 1/8" sheet balsa.

Pin the saddle down and start adding the sticks. I used basswood for the longerons, a scarf joint is required in the top one due to its length. I also used bass for the uprights in the wing saddle area. As I did not have any 3/32" x 3/16" balsa handy and not a great supply of 1/8" x 3/16" either, I made all the remaining vertical pieces 3/16" sq balsa and used my remaining stock of 1/8" x 3/16" for the diagonals. Pat's design as drawn is fine, I did this based on materials on hand. Did not want to have to wait while I ordered the sizes I did not have.

As the length of the fuselage side was longer than my building board I framed up the side to about former 14, unpinned everything, slid the plans down the board, repinned everything again and completed the side. Worked out fine. The second side was framed up directly over the first to insure that they were as close to identical as possible.

I then sanded both sides and placed the top view on the board. One side was pinned upside down to the board using builders squares, the second done in the same manner and all the cross pieces top and bottom and diagonals were added. Care must be taken here to insure good joints on the diagonals but not to force them as it can distort the frame. Again I had to unpin and slide to complete the frame. I then popped it off the board, added the front cockpit cheeks and roof and started on the top and side formers.

As the frame stands now it is about 11 oz.

More to come.

Brian Allen

Veni Vidi Volavi

I came I saw I flew
Last edited by Brian Allen; Oct 13, 2014 at 02:52 PM.
Jan 15, 2013, 12:10 PM
It's a fine fiddly business.
Robert R's Avatar
Your build is a joy to look at. I really love the truss box with small exterior formers. That design leaves lots of uncluttered interior space for equipment installation. In that respect is is very superior to keel and half-shell designs. I wish I could figure out how to design truss boxes to fit just inside the edges of the fuselage cross section the way Pat does.
Anyway nice work.
Jan 15, 2013, 08:44 PM
P3_AOC_MAGGIE's Avatar

Looking great so far.....

Thanks so much for the photos Brian.... This is looking great so far..... I need to get back to work on mine.... I just can't seem to find the time right now.

Jim L.
Jan 16, 2013, 11:58 AM
Veni Vidi Volavi
Brian Allen's Avatar
Greetings All

Well yesterday and last night stringerfication of the fuselage got underway. Using a mix of basswood and balsa 3/32" sq stock for the stringers. Using bass in some of the more high stress areas and balsa towards the tail. I have gotten into the habit of using bass stringers in my Pat Tritle builds as I can break the balsa stringers Pat uses by just looking at them the wrong way. Usually I use bass in the areas where I know I will be handling the model and balsa elsewhere. Since this fuselage will be sheeted I did not use a lot of bass, most of it will be on the bottom where I will be picking it up.

There is one additional former on the tail end that has not yet been added (since I am convinced I will knock it off multiple times. It is the former the MAD Boom attached to so I will add that as I get some more stringers on so it can be supported properly.

As far as retracts I think I have decided to go with the E Flite 60-120 size electric retracts. The Robarts that Pat drew in on the plans are available but are a bit pricey (not that the E Flite ones aren't either!!) but the electric ones get you away from either mechanical linkages and servos or the air tank and plumbing. So we will see how they work out. As soon as they arrive I will be able to see how the nose mounts and whether I need to modify the mounting plate any. Once that is determines I can get the nose gear mounts installed and the front bottom formers and stringers in.

While I wait for the retracts I might start on the tail.

Brian Allen

Veni Vidi Volavi

I came I saw I flew
Last edited by Brian Allen; Oct 13, 2014 at 02:54 PM.
Jan 17, 2013, 12:02 PM
Veni Vidi Volavi
Brian Allen's Avatar
Greetings All

Back again. Did a few more items yesterday.

Got the wing bolt plate epoxied in the fuselage and then I also epoxied in Former 5C which is where the wing hold down dowels go.

I then started to add the bottom formers in place. I did not do the front three as they are put in along with the landing gear mount plate and I do not want to do that until I get the LG and see if any mods to the existing mounting pattern needs to be made. Always easier to do that with the plate out of the model instead of being glued in place.

I then added the bottom stringers from former 9 aft.

Next step is to get former 18 installed and when the E Flite electric retracts arrive I can get the nose LG setup and the LG mounts and front bottom formers installed.

Til next time!!

Brian Allen

Veni Vidi Volavi

I came I saw I flew
Last edited by Brian Allen; Jan 17, 2013 at 02:35 PM. Reason: Corrected Former number to 5C from 5D
Jan 19, 2013, 12:25 PM
Veni Vidi Volavi
Brian Allen's Avatar
Greetings All

Have been working on the P-3 a bit more that last few days. I ordered a set of Eflite 60-120 retracts and while waiting for them I continued to stringer the fuselage.

I added the last fuselage former #19. It is attached with a keel piece of 1/8" x 1/4" balsa that is glued to 17 and 18 and former 19 glues to the end. Once satisfied that all looked OK I glued it up and then proceeded to add the stringers from formers 17 to 19. I was quite surprised at how rigid the aft section of the fuselage here was. Having about 87 3/32" sq stringers helps I guess!!

I have also pretty much so added all the rest of the fuselage stringers except those around the nose gear area. I need to get the retract mounts in first before I can finish that. The retracts have arrived and I noted that the gear strut on the nose gear is not centered on the retract housing but is offset by about a 1/2" due to the shock coils wound into the gear strut. So in order for the gear strut to be centered on the fuselage centerline I will have to remake the mounting plate and move the cutout for the gear housing to one side by 1/2". Pat has the gear housing centered in the mounting plate. Since I have never fooled with retracts before I do not know if this is a standard setup or particular to the Eflite units. No big deal, just need to make a new plate from some 1/8" ply.

While waiting for the retracts I started on the vertical fin and rudder. The leading edge is made from two sections. The fin LE is laminated from 3 laser cut pieces which I glued up. The dorsal LE is made from 3 laminations of 1/16" x 3/8" balsa. As I usually do I stuck a bunch of pins along the outline and glued up the strips and pinned them in place. Too lazy to make bowing forms from cardboard or foamcore board!!

When all was dry I studied the design of the fin/rudder a bit more to familiarize myself with the construction. Pat has the fin and rudder designed to be built as a sorta one piece unit. The fin TE and rudder LE are made of 2 pieces each that were laminated together. The rudder LE was 3/16" too long at the bottom so I shortened it as needed. The whole assembly eggcrates together.

The way the ribs are laser cut made a bit of a problem. As the fin TE and rudder LE eggcrate into the ribs and the ribs have building standoffs on them, a section of the standoff on each rib needs to be removed to allow the TE/LE pieces to be installed. If you cut away this area the rudder section of the rib and building standoff will fall off. So I stripped some small pieces of 1/16" balsa and tack glued them to the top edge of the rib covering the area that needed to be removed. This provides enough support to remove the section in the standoff area and allow the fin/rudder to be assembled.

Once I figured this out the fin/rudder went together quickly. I installed the ribs on the fin TE and rudder LE spars, added the forward fin spar, pinned the ribs down and glued everything up. I then added the long fin base and the dorsal fin supports. The fin LE had a centerline drawn down it to match the small laser cut ticks in the rib LE's to provide a nice alignment visual and it was glued in place. The laminated dorsal LE was then added.

Once done the whole shebang gets sheeted with 1/16" balsa. This is still to be done.

Will probably make up the nose gear mount plate next and get the nose done. We shall see.

Brian Allen

Veni Vidi Volavi

I came I saw I flew
Last edited by Brian Allen; Jun 19, 2014 at 07:02 PM.

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