In the 1950’s, before the advent of spy satellites the only reliable way to assess the capabilities and intentions of your enemy was to fly over and take pictures. Since not many hostile countries were in a hurry to give the USAF permission to operate reconnaissance aircraft over their military facilities the Air Force required an aircraft that could operate outside the envelope of intercept fighters and surface to air missiles of the day. Designer Kelly Johnson and the Lockheed Martin Advanced Development Projects division (aka “Skunkworks”) submitted a design proposal based on the existing F-104 Star Fighter. The design was rejected by the military but a large contract was awarded from the CIA and the U-2 Dragon Lady was born.
With an operational ceiling over 70,000 feet, the U-2 over flew the Soviet Union with impunity and public secrecy until May 1st 1960 when Francis Gary Powers was shot down over while flying a mission over the Soviet Union.
U-2’s were also staged in Orlando, Florida during the Cuban Missile Crisis of 1962 and provided vital intelligence while the United States and Soviet Union approached the brink of nuclear war.
The unique design of the aircraft provided several operational challenges to pilots. At altitude the U-2 only had about a 10 mph window, too slow and it would stall and loose precious altitude, too fast and the aircraft would exceed it’s maximum speed and airframe failure would result. The U-2 was also a handful to fly at low altitudes and to land as the unassisted flight control system was designed to operate at very high altitudes.
- Looks awesome!
- Includes radio and power system, battery, and charger.
- No glue needed to assemble.
- Easy battery access via magnetic canopy hatch.
- Had surface damage out of the box.
- Wing pegs didn’t align to holes in the fuselage.
Kit Name: Phase 3 U-2 Spy plane EDF RTF
Price: MSRP $239.99
Wing Span: 66.5″ (1690mm)
Fuselage Length: 40.5″ (1030mm)
Flying Weight: 21.2 to 22.9oz (600 – 650g)
Motor/Fan Used: Included
Battery Used: Included 3S 1650mah LiPo
Radio Equipment: Includes 2.4Ghz Hobby People Aerosport 5 channel radio system, Airtronics receiver, and servos.
Skill level: Low
Time to complete: less than 1hr
Frustration Level: No problem
4 AA batteries
I have always been a fan of the U-2 and the work done at Lockheed’s Skunkworks so I was excited that someone was finally coming out with an R/C model of one. I was even more excited to find out that I would be reviewing the Phase-3 U-2 EDF Ready To Fly. The U-2 is available in 3 versions from Hobby People. The fully equipped version that we are reviewing, a version that comes with everything but the transmitter that’s ready to bind to your existing Airtronics 2.4ghz radio, and an unpainted kit version that comes with just the motor and fan. Given the number of U-2 variants that were produced, the kit would make a great project to recreate one of the later U-2s or even the blue and white ones used by NASA for high altitude research.
I unpacked the U-2 and sat down for a few minutes to study the included 8 page instruction booklet. I’m a stickler for instructions and the Phase 3 manual that accompanies the U-2 includes everything that I think a good manual should. Specifications for the installed components, a complete kit inventory, safety warnings, and a replacement parts listing were all there. The manual contained easy to read instructions and lots of photographs, so it would be hard to make a mistake based on the manual.
The RTF version that we received for review includes everything you need to get the U-2 in to the air in about the time that it takes you to balance charge the included battery with the included battery charger. In addition to the battery and charger, the Airtronics receiver, servos, 40 amp esc, motor, and fan are all installed and ready to go. The transmitter uses for AA size batteries and that is the only thing you need to track down to get started.
After reviewing the charging instructions in the manual I hooked up the 1650 Mah 3S LiPo battery to the included charger and set it aside to charge while I assembled the airframe. I would also recommend covering any areas that the foam parts are sitting with a towel to protect the finish.
The empennage is attached without glue using factory applied double sided tape. I was a little dubious about double sided tape holding the tail feathers on an EDF jet but reviews are built according to the instructions unless there’s a really glaring error. Everything seemed to hold up just fine during flight testing but I’m sure if anything happens, a little foam safe CA will fix things right up. The tail is self aligning and when we peeled away the tape and stuck everything together, the elevator and vertical fin were perfectly straight. Connecting the elevator control rod completes assembly of the tail.
Installing the wings was the only real frustration that we encountered while assembling the U-2. There are 3 carbon rods in each wing that get inserted in to corresponding tubes glued into the fuselage. The right wing on the review aircraft went in fairly easily. There is no double sided tape and in fact the only thing holding the wing in place is the aileron extensions, and the pressure of the rods against the tubes. Again, I was a bit skeptical but it’s held up well enough so far. I considered covering the gap with black electrical tape but have thus far not found the need.
On our aircraft, the pins on the left wing were not lined up nearly as well as the right wing and I had to put so much sideways pressure on one of the rods to get things to line up and slide in place that I was afraid I was going to break it. I eventually managed to get the wing panel in place but I’m glad I can transport my U-2 without trying to take the wings off as the left wing would probably be a bit of a chore. The good news is, the fit is so tight that I’m sure I wont have any problem with this wing slipping on the pins in flight.
That’s all that is required to get the U-2 ready to fly. I spent a few minutes researching some pictures of the full scale U-2 and used them to place some of the decals that were included with the kit. They are a nice touch and a very realistic subdued red. The decals are quite delicate so take your time and ensure that the backing is soaked thoroughly so that it slides away from the surface without pulling on the decal.
When the decals dried and the battery was charged, I decided to run some tests on the power system. The first thing I discovered was that the receiver was not bound to the included transmitter. The transmitter has it’s own instruction book and I had the transmitter bound up to the included Airtronics receiver in just a few moments.
The battery has to be pretty far back to get the U-2 to balance at the recommended 70-75mm from the leading edge at the wing root. Mark the battery and install some velcro so it doesn’t slip. Since the aileron servos were pre-installed, and the instructions specified which hole to install the pushrod I only glanced at the throws and they appeared to be what was specified in the instruction manual.
I ran a few tests with my watt meter/data logger and attached the output graph. This accomplished two things (three if you count disturbing my neighbors). It allowed me to get a few cycles on the LiPo battery before heading to the field, and it let me make sure everything was operating within safe parameters.
As you can see from the chart the ESC peaked at 34 amps. The 40 amp speed controller should have enough over head for the peak full throttle loads. The C rating of the included battery may be another matter. I couldn’t locate the exact battery included with the U-2 (the part number in the manual came back to a decal set) but most of the similar ones I found were 20C. That would put the estimated capacity of the included battery at 33 amps continuous so I will be keeping an eye on the battery temperature.
The system produced 380 watts at full power so at a pound and a half, the U-2 EDF should have respectable flight performance. The only thing left was to head to the flying field and try out the U-2.
Sitting on the bench, the unique look of the U-2 drew a crowd of onlookers as soon as I took it out for pictures. Given the large military population of the Jacksonville area, any military aircraft model generally draws war stories. The first comment about the U-2 though was from a youngster that said he just learned about the U-2 while studying the Cuban missile crisis.
I dragged a helper along for the first flight just because I always like to be on the sticks for any surprises. I contemplated giving it a gliding toss or two but I was confident in the power system, the CG was right in the recommended range, and the control throws looked good. As I powered up to full throttle and my helper Frank gave the plane a throw straight and level into the wind. The U-2 flew straight out and started climbing but I found out that even with full down trim I needed forward stick to keep it straight and level. I brought it around and landed in the grass to see what was going on suspecting the CG was too far back. I moved the battery forward and tried it again to much better results. After the first two test flights the U-2 was successfully launched by the pilot without any issues. It’s not going to rocket out of your hand, but you don’t require the arm of an NFL quarterback to safely launch it either.
The marketing materials claim that the U-2 EDF flies in a scale manner. Having seen the real thing in person an number of times rotate and climb at a 45 or 50 degree angle straight out of sight I would have to disagree with that assessment. The plane does fly very well though, and full power gives a good positive climb rate. I thought that the wing design might give a tendency to tip stall like high performance sailplanes but was pleasantly surprised by it’s docile handling even at fairly low airspeeds.
A U-2 certainly isn’t designed to perform aerobatics and lacking a rudder the models repertoire is somewhat limited in that regard. It will perform loops and, owing the large ailerons, a respectable roll despite the glider like wing. Loops do require a little nose down to build up some speed to make the maneuver look like a loop and not merely a flop over.
If you’re throwing the coals to the fire the whole time, keep your flights in the 4 minute range to be safe. With a bit of throttle management however, 6 and 7 minute flights are within safe battery usage limits. In the two days of flight testing for this review we probably put a total of 10 flights on the supplied LiPo battery and it showed no signs of any problems. ESC and battery temperatures were not an issue, and the Aerosport 2.4ghz radio performed flawlessly.
I would not recommend this model for a beginner but anyone that has some time flying sport models with ailerons shouldn’t have any problems.
Landings are easy but if you don’t have any wind make sure you have plenty of room to line up because the U-2 will float a pretty good distance even with the power cut. Flying higher and floating around is a real pleasure with the U-2. It’s not going to win any races, nor any thermal duration contests, but it does pretty well in between.
The mission of the full scale U-2 required it to remain covert and its design and flat black color helped achieve that. While that may be a desirable quality in a real aircraft, when flying a model it has certain…uh…drawbacks. Be careful how far you stray and against what background you choose to fly or you might find your U-2 EDF rather hard to see.
The Phase-3 U-2 RTF EDF is an excellent value when you consider it includes everything needed to get into the air with the exception of 4 AA batteries. The fan, receiver, ESC and servos are preinstalled and wired from the factory. The battery, which comes with its own balancing charger, uses a standard Deans connector and doesn’t require any soldering. I thought the included transmitter may be a hindrance with it’s lack of dual rates or mixing but the U-2 simply didn’t need anything. The only thing I missed when compared with a computerized transmitter was a flight timer.
Assembling the U-2 and applying the decals takes about as long as charging up the battery. The only minor annoyance was the fit of the wing pins and that was pretty easy to over come. Battery access via the magnetically attached canopy is convenient.
As I said in the flight testing section, this isn’t a plane for a beginner. Any pilot with some aileron experience shouldn’t have any troubles adjusting to flying the U-2 though. Hand launches are no problem even if you don’t have a helper, just make sure you have some room to build up speed to climb. If you have the mentality that anything that doesn’t disappear straight up in 5 seconds is underpowered then you may well find the U-2 a bit underpowered. Aside from the climb rate however, the flight envelope of the U-2 is quite realistic (indeed its a lot easier to land than the real one!).
If you’re looking for something different, the U-2 is a great looking plane that’s a solid performer.
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