P-51 Mustang

Hanger 9 P-51 Mustang (.46)
Aircraft | Building | Flight Log
Aircraft

This ARF is made by Hanger 9. It's the .46-size PTS model, but in a new ARF configuration (without the pre-installed radio and engine). Built as an intermediate model from the beginning, none of the training aids were ever installed. It has operational flaps, and I also re-drilled the firewall and installed the motor at 90° (with a Pitts muffler and 2-blade propeller).

Quick Specs:
Wingspan:	58 inches (4 ft. - 10 in.)
Wing Area:	603 sq. inches
Length:	50 inches
Engine:	OS .46fx - 2 stroke BB
Servos:	Futaba (5) 3004, (1) 3003
Battery:	Futaba 4.8v 600mAh NiCd
Radio:	Futaba 6EXA and R127DF
Weight:	7 lbs.
Construct:	Balsa, Lite-ply, UltraCote
Prop:	11x6 MAS (Nylon)

8-12-2006	Acquired Hanger 9's P-51 Mustang 40 (PTS-ARF).
9-9-2006	Started building P-51 Mustang. Installing CA hinges for ailerons and flaps.
9-13-2006	Installing aileron servos, front landing gear and generally working towards finishing wing.
9-27-2006	Finished wing. Complete with operational flaps, all servos, and front landing gear.
10-9-2006	Re-drilled firewall and installed engine at a 90° angle.
10-14-2006	Started working on tail.
10-19-2006	Started installing radio, servos, and push-rods.
10-27-2006	Installing pilot and canopy. Balanced plane. Completed all final items and steps.
10-28-2006	Maiden flight.

Additional Components and Supplies

Engine: OS .46 FX (About 1.6 HP at 16,000 RPM max.)
Servos: (5) Futaba s3004, (1) s3003
Servo Extensions: (1) 24" Hobbico Pro. HD Y-adapter (HCAM2751), (3) 9" extensions
Misc: (1) Slimline Compact Pitts Muffler for OS .46 (# 3218)
         (1) Great Planes Easy Fueler valve (GPMQ4160)
         (1) Dubro In-Line Fuel Filter (# 2305)
         (1) Hanger 9 - 1/7 Scale US WWII Pilot (HAN8311)

Replaced (Substituted) Hardware

(1) Great Planes Med. Adj. Engine Mount (GPMG1061)
(4) Dubro 6-32 x 1" hex head cap screws & metal nuts with nylon insert
(4) Dubro 6-32 x 1" hex head cap screws & blind nuts
(1) Dubro Red 2-3/4" spinner
(1) 11x6 MAS 2-Blade Nylon Propeller
(2) Great Planes Nylon Wing Bolts 1/4-20x2" (GPMG4402) [Repair]

________________________________________________________________

Construction Details

I basically just followed the manual, so I'm only going into detail on items that were additional or contrary to it. Be sure to do everything detailed in manual in addition to these steps (unless otherwise noted).

Before installing CA hinges on flaps, be sure metal torque rod linkage moves freely. Test fit on flaps and make sure they can reach full up (off) and down (on) positions. If it's sticking keep moving it to loosen it up, or carefully remove a little bit of wood.

After gluing blocks to inside of cover, place servo all the way against cover before marking 4 holes for servo mounting. If you are using standard size servos, and leave a space (as suggested in manual) after you screw the cover down, the servo will protrude through the UltraCote on the other side of the wing. Possibly also due to the size of the s3004 servos, I had to enlarge the opening's sides slightly (just beside where the blocks go through) so the cover would fit down flat again. To reinforced the aileron servo mounting blocks, (in addition to epoxying) I drilled extra 1/16" holes (a little off-center as to not hit actual servo mounting screws), and screwed blocks to cover from outside with spare 1/2" servo mounting screws. Use 4 hole servo arms that rise high enough above cover (computer radio with EPA will be used to reduce arm throw to proper setting). Finally, do CA Hole Threads Procedure to install servo assembly in wing.

When mounting control horns to ailerons, be sure arm is perpendicular to aileron. Clevis holes in control horn should be centered above aileron/wing hinge (with aileron in neutral position).

I opted to epoxy wing halves together.

For flaps linkage, I just cut off the Z-bend (leave as much straight rod as possible). Then, used a Dubro E-Z connector in the second hole of the flaps servo control arm. The Tower Hobbies TS-53 is a Futaba s3003 clone. The manual never said what the throw rate of the flaps are, but I did have to dial-down the radios EPA quite a bit. I set flaps full throw at 5/8".

The rubber 3.5" wheels had to drilled out (with a 13/64" drill bit) to fit on large axles. Mounted wheels using Collar Mount Procedure.

Painted firewall and bare wood surfaces of fuselage (wing saddle and radiator scoop) with clear fuel-proof paint.

Temporarily install the engine in the supplied mount (at the 45° angle) at the distance described in the manual, to get your measurements of where the tip of the crankshaft ends up. I used 6-32x1" hardware to mount the motor-mount to the firewall. The 4 smaller holes are the 6-32 blind nuts epoxied in. The red lines point to the crankshaft center-line. The fuselage has 1 or 2 degrees of right-thrust built in, and works fine on a 90° mount.

6-32x1" hardware and nylon insert nuts attach the engine to the motor-mount. Now that the engine is at a 90° angle, the Slimline Pitts muffler can be used properly. The metal push-rod for the throttle didn't have to be re-drilled and moved, but I did have to put a large Z bend in it to move the clevis over a 1/4" or so (to line up with the engine's throttle arm). Cut cowl as described in the manual (using paper card templates).

Just follow the manual closely to get the tail control surfaces hinged properly. A tip here is to test fit the elevator halves and wire to the stabilizer and slightly bend the wire to adjust them even (as needed) BEFORE you glue on the halves. Note that the rudder control horn will end up on the pilot's right, and the elevator horn on the left (on the bottom of the left elevator).

I opted to epoxy glue the tail on. Assemble the tail pieces onto the tail of the aircraft all the way down (but don't install the washers and nuts yet). Everything should look perpendicular. Mark and open up the small hole for the fin dowel to key into the fuselage. Using a light colored, fine tipped, permanent marker, draw lines (on the tail pieces) where all the tail pieces come together (don't worry, the dried markings remove easy with some rubbing alcohol). Also make marks where the metal elevator rod goes across (so you know where NOT to apply glue).

Remove the tail pieces, and with a new blade, very carefully cut away the UltraCote 1/8" INSIDE the markings you made (do not cut into the wood). Transpose the metal elevator rod markings (onto the inside top and bottom) pieces of wood (... no glue on that 1/4" strip). Use a little alcohol on a rag to remove all other markings from the tail pieces and fuselage. It wouldn't hurt to snap it all back on again real quick and make some final notes about where epoxy is going to go and not go. In general, the pieces fit pretty tightly, so it doesn't take a lot of glue (Don't use so much it seeps out into a hinge or something). Using slow curing 30 minute epoxy (but work fast to get all the tail pieces glued on at one sitting), first glue the rounded fuselage fairing to the fin. Second, glue the stabilizer/elevator assembly to the fuselage (use a nail or toothpick to line up the holes). Try not to get any glue into the 2 bolt holes or onto the 2 bolts during this whole procedure. Lastly, apply glue to the bottom of the fin/rudder/fairing assembly, and insert into place and carefully press everything into it's final position. Following the manual now, install the washers and bolts and tighten (while the epoxy is still soft). Let dry 8 hours.

Here's a step I never found in the manual. Bevel the ends of the 2 wooden dowels slightly. Mark the middle of each. If they will fit in the wing's holes, dry-fit (no-glue) install them and make sure they fit in the fuselage holes and the nylon wing bolts, wing, radiator scoop, and fuselage all fit together. My dowels wouldn't fit the holes they get glued into, so I re-drilled the wing holes with a 5/16" drill bit. The hole centers should be about 2-3/8" apart (but check your own fuselage's pre-drill holes). Epoxy them half-way into the wing (up to the half-way marks) with 30 minute epoxy and let dry 8 hours.

It was either convert the tank to a 3 line system, or stick with the 2 line system and use an Easy Fueler. I made the Easy Fueler mount from the bottom of an old square nylon dental floss box, but you can also make one from plywood. After installing it, make a paper card template again to mark the hole it needs. Loosely install the cowl and use the template to mark the hole that needs to be cut in the cowl. Pictured here with a Dubro 2-3/4" spinner and MAS 11x6.

I cut about 3/4" off the bottom of the pilot, so he would fit properly and stuffed some more cotton in him. Made a base that will fit up inside and contact cement him on it. Being unpainted, he had to be completely hand painted. There was no cockpit floor, so I made one from lite ply and spray painted it black. 2 small screws hold the pilot to the new board, and then I screwed the whole assembly into the cockpit. 4 small screws hold the canopy on.

Here's the plane after it's maiden flight in October 2006.

________________________________________________________________

Balancing

For the plane to balance (upside-down) at the 4-1/2" mark, the battery was installed directly behind the fuel tank. Also, 2.0 oz. of weight was added to the firewall.

________________________________________________________________

Futaba	Low		High	D/R - Lo	D/R - Hi	EPA	Dir
1 - Ailerons	3/8"	3/8"		100%		60% : 60%	Rev
2 - Elevator	1/2"	1/2"		100%		80%	Norm
3 - Throttle						D 70 : U 82%	Norm
4 - Rudder	7/8"	7/8"		100%		100%	Norm
6 - Flaps	0"	5/8"		100%		65% : 30%	Norm
Expo	-20%		Unused	-20%	Unused

________________________________________________________________

Activity Log
Date	Field	Type	Equipment	Details
10/28/06 Saturday	ARCS AMA field	Flight	Futaba 6-Ch OS .46 FX 11x6 MAS Byron 15%	Maiden flight: Easy flying to get used to plane and trim it out. Did some loops, rolls, and made some low high-speed passes. Good runway landing. 2nd Flight: Performed the following maneuvers. - Low (full-throttle) high speed passes - Loops - Rolls - Stall turns - Snap rolls - 1 good runway landing from North
11/14/06 Tuesday	ARCS AMA field	Flight	Futaba 6-Ch OS .46 FX 11x6 MAS Byron 15%	*Total of 2 Flights:* Performed the following maneuvers. Practiced extra landings and made better use of flaps. - Inverted flight - Immelmans and 1/2 cuban eights - Split S - Low (full-throttle) high speed passes - Loops - Rolls - Stall turns - Snap rolls - 5 good runway landings from North
11/24/06 Friday	ARCS AMA field	Flight	Futaba 6-Ch OS .46 FX 11x6 MAS Byron 15%	*Total of 2 Flights:* Performed the following maneuvers. - Low (full-throttle) high speed passes - Loops - Rolls - Immelmans and 1/2 cuban eights - Split S - Stall turns - Snap rolls - Inverted flight - 3 good runway landings (1 extra) North Flaps: Takeoff=1/3 Landing=3/4
2/16/07 Friday	ARCS AMA field	Flight	Futaba 6-Ch OS .46 FX 11x6 MAS Byron 15%	*Total of 3 Flights:* Performed the following maneuvers. - Low (full-throttle) high speed passes - Loops - Rolls - Immelmans and 1/2 cuban eights - Split S - Stall turns - Snap rolls - Inverted flight - 4 good runway landings (1 extra) North Flaps: Takeoff=1/3 Landing=3/4
3/2/07 Friday		Repair		While assembling plane at field, noticed one nylon wing bolt would not tighten up completely. At first it looked ok (not cross-threaded and threads looked fine), but closer inspection revealed the threads had been very slightly worn down from just basic use. Replaced both nylon bolts with new spares (GPMG4402) from my toolbox.
3/2/07 Friday	ARCS AMA field	Flight	Futaba 6-Ch OS .46 FX 11x6 MAS Byron 15%	*Total of 2 Flights:* Performed the following maneuvers. - Low (full-throttle) high speed passes - Loops - Rolls - Immelmans and 1/2 cuban eights - Split S - Stall turns - Snap rolls - Inverted flight - 2 good (and 2 fair) runway landings (2 extra) North Flaps: Takeoff=1/3 Landing=3/4
3/23/07 Friday	ARCS AMA field	Flight	Futaba 6-Ch OS .46 FX 11x6 MAS Byron 15%	*Total of 2 Flights:* Performed the following maneuvers. - Low (full-throttle) high speed passes - Loops - Rolls - Immelmans and 1/2 cuban eights - Split S - Stall turns - Snap rolls - Inverted flight - 2 good (and 1 fair) runway landings (1 extra) North Flaps: Takeoff=1/3 Landing=3/4

Home