File: 08HitecCorsair.ot1.doc
[Headline: Hitec Weekender F4U Corsair]
[Subhead: ]
[Author: Terry Dunn]
[Email: terrydunn74@gmail.com]
[Photos by Dr. Bryan McLarty]
[Sidebars included in text file]
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SPECIFICATIONS
Model type: Semi-scale park flyer ARF
Skill level: Intermediate pilot
Wingspan: 29 inches
Wing area: 157.5 square inches; 1.1 square feet
Length: 23.5 inches
Radio: Hitec Eclipse 7 Pro 2.4 GHz transmitter; Hitec Minima receiver; four Weekender WS-9 servos (included)
Components needed to complete: Four-channel or greater radio system; two-cell 1,000 mAh LiPo battery; charger
Minimal flying area: Soccer field
Flight duration: 6-7 minutes
Price: $185.95
TEST-MODEL DETAILS
Power system: Weekender DST-1300 brushless motor; 8.5-inch-diameter three-blade propeller; Weekender WBE-12A ESC; Thunder Power 2S 910 30C LiPo battery
Power with JST connectors: 10.8 amps; 77.2 watts; 82 watts per pound
Power with Deans Ultra Plug connectors: 15.3 amps; 116 watts; 123 watts per pound
Flying weight: 15 ounces, .9 pounds (13.2 ounces without landing gear or ordinance)
Flight duration: 5 minutes
Wing loading: 13.7 ounces per square foot
Wing cube loading: 13.1
PLUSES
• Impressive scale accuracy.
• Excellent fit and finish.
• Fun and nimble flight performance.
MINUSES
• JST battery plug limits power.
• Requires thrustline adjustment.
• Minor oversights in assembly manual.
The Corsair from Hitec’s Weekender line of warbird models is a prime example of how much foam models have improved over the last few years. As I removed the airplane from the box, I was impressed by the smooth surface of the foam parts and how cleanly the paint and decals had been applied at the factory. This model is nothing like the unpainted and flash-scarred foam airframes we dealt with in the past.
It is clear that Hitec put forth extra effort on the scale appearance of the Corsair. First of all, the scale outline is very accurate—better than many, much larger Corsair models that I’ve seen. What really set this model apart were the small touches such as the scale three-blade propeller, the rockets and fuel tanks, and even the strut covers for the main landing gear. All of this adds up to an RC model that could serve double duty as a desktop display piece.
Assembly
The Hitec Corsair arrived mostly assembled. A brushless motor with ESC and all servos were installed at the factory. A two-cell LiPo battery, four-channel receiver, and transmitter were all that I had to provide. I used the included glue, but the EPP airframe is CA friendly.
Hitec includes a black and white assembly manual that applies to all three warbirds currently in the Weekender series (the others are a P-51 Mustang and Hawker Hurricane). The manual states that the Corsair and its brothers are for novice pilots, but that just isn’t true. Intermediate-level modelers, however, should have no trouble completing or flying the Corsair.
The manual outlines eight steps to assemble the Corsair. Not including time for the glue to dry, I had everything completed in about an hour. All of the parts fit together very precisely and the resulting alignment of the wing and tail feathers was spot on. I was somewhat apprehensive about gluing painted surfaces, but the glue joints have not loosened at all.
The main landing gear can easily be attached or removed as desired. Each strut snaps into a plastic mount in the wing and is held in place with a single screw. A scale antenna mast is included in the kit, but not mentioned in the manual. I simply glued it into place behind the canopy.
A magnetic hatch is built into the fuselage just forward of the canopy. Beneath the hatch is a plywood tray intended for the battery and receiver. It seemed a bit too crowded, so I located my Hitec Minima 6E receiver below the tray. I had to cut away a little bit of foam in the fuselage wing saddle for the receiver to fit. I used a dab of glue to tack the receiver to the wing center section. This opened up a lot of room on the battery tray and kept the area clear of servo leads.
I removed additional wire clutter by omitting the included Y harness for the aileron servos and instead using the flaperon function on my Hitec Eclipse 7 Pro. There is no information in the manual regarding control throws or exponential. I set high rates at 100% throw and 35% exponential. Low rates are set to 70% throw with 30% exponential. I later moved the aileron pushrods to the next-to-last hole in the servo horn and increased exponential to 40%. This improved the roll rate considerably.
I chose a Thunder Power G8 Pro Lite 910 mAh two-cell LiPo battery for the Corsair. With the battery in position, it cannot be seen through the top hatch. I cut a wedge of foam from the kit’s packaging material to keep the battery secured. I put the battery in place and stuffed the wedge behind it. It does a good job of retaining the battery, but it is simple to remove. I fashioned a short tether from kite string to prevent the wedge from blowing away during battery swaps at the flying field.
Setup Tips
I logged numerous flights on the Corsair while zeroing in on an overall setup that fit my flying taste. You may want to implement some or all of these changes before your first flight.
I had to add 1.5 ounces of lead to get within the stated CG range of 1.5 inches to 1.75 inches behind the wing LE. I cut away a portion of the dummy radial engine and attached the weights just behind the forward lip of the cowl using the kit glue. During flight testing I removed the weights incrementally until there were none left. At that point, the CG was exactly 2 inches behind the wing LE (33% Mean Aerodynamic Chord) and I thought that the Corsair flew very well. The CG range in the manual is probably too conservative for many fliers.
Cutting away some of the dummy engine for nose weight had the added benefit of creating an inlet for cooling air into the fuselage. I also cut an exit hole on the underside of the fuselage behind the wing.
Initially, the Corsair required pitch and yaw trim changes at different throttle settings. I fixed this by angling the motor mount right and down a few degrees. I first removed the motor by loosening the Phillips-head set screw that is accessible through the hole in the top of the cowling. This allowed me to see the motor mount that is bolted to the firewall. I placed a single 1/16-inch thick washer between the motor mount and firewall at the top right screw location (when viewed from the front). This simple change made the Corsair much more predictable and relaxing to fly.
The kit’s included 12-amp ESC comes with a JST connector on the battery lead. I typically don’t like to use JST connectors on any system that draws more than 5 amps, and the Corsair reads more than double that value. The good news is that the stock connectors didn’t melt down during use, even on a 90° day. The better news is that I saw a 50% increase in measured power when I later replaced the JSTs with Deans Ultra Plugs. The Corsair’s flight performance was substantially improved. Never underestimate the importance of good connectors.
Flying
Once I had implemented the few simple tweaks outlined above, the Corsair became a very fun and manageable little warbird. The kit includes a steerable tail wheel, which provides good ground handling. Just like the full-scale Corsair, the big three-blade propeller necessitates a bit of rudder correction early in the takeoff roll. Once its tail lifts, the Corsair tracks straight ahead and accelerates to flying speed quickly.
Overall, the Corsair is mild mannered and easy to fly. It really excels at scale-like maneuvers. This is doubly fun thanks to the model’s accurate appearance. There is plenty of power and control authority for basic aerobatics. Loops can be nice and big if you want. Rolls are nearly axial in both directions. Inverted flight requires slight down-elevator pressure.
When you decide to push the edges of the Corsair’s flight envelope, it requires a bit more attention and experience. For instance, the rudder has strong authority, but it comes with roll coupling. Keep that in mind when setting up for a knife-edge pass or stall turn and be ready to correct it with aileron input. Also remember that yanking back on the elevator will cause a snap roll. It’s a great maneuver … as long as you’re doing it on purpose!
Stalls quickly develop into a spin that ceases as soon as you release elevator pressure. This behavior existed even when the CG was within the recommended range. When landing, just keep a little bit of speed until you are ready to flare. You should be rewarded with a no-bounce, three-point landing.
I have flown the Corsair with and without the dummy ordinance. Honestly, I can’t tell much difference in performance due to its lighter weight without the tanks and rockets (almost an ounce). It does however, seem to hold energy better without the drag of these embellishments. Mostly, I just prefer the cleaner look with the ordinance removed.
I have also removed the main landing gear for several flights. Shedding the landing gear lightens the load by nearly an ounce and further cleans up the profile. This gives a superb scale appearance for those full-throttle photo passes. Maybe that’s what makes this my favorite configuration to fly the Corsair. It just requires a firm underhand toss with full throttle to get going.
Conclusion
The Hitec Weekender Corsair is an impressive little foamie stuffed with many scale details that set it apart from other warbird models. With just a few minor adjustments, it is a great flying airplane that looks fabulous in the air. I think experienced modelers will enjoy it.[dingbat]
—Terry Dunn
terrydunn74@gmail.com
MANUFACTURER/DISTRIBUTOR
Hitec RCD
(858) 748-6948
www.hitecrcd.com
SOURCES:
Thunder Power RC
(702) 228-8883
www.thunderpowerrc.com
W.S. Deans Co.
(714) 828-6494
www.wsdeans.com