The “PTS” in this airplane’s name stands for “Progressive Trainer System”. Hangar 9 first introduced this concept several years ago in their P-51 Mustang PTS Basic Trainer. Read the Sport Aviator review on this excellent concept and airplane by clicking the blue text. The PTS concept was, and is, to convert a scale airplane into a gentle, basic trainer while still allowing its performance to grow as its pilot’s skills advanced.

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The P-51 Mustang PTS excelled as a basic trainer while looking like a fighter. It was powered by an Evolution 45 and was equipped with drooped leading edges, a 3-bladed propeller, speed brakes and flaps. The Droop leading edges converted the Mustang’s symmetrical airfoil into a flat-bottomed airfoil outboard of the flaps. This slowed the airplane’s response to aileron input while increasing lift. The Speed Brakes added drag for better airspeed control while the flaps lowered in-flight and approach speeds; making the airplane a gentle performer for the newest pilot.

The fixed, or optional servo controlled, flaps also increased lift for the wing area inboard of the ailerons. The 3-bladed propeller reduced the airplane’s top speed. The combination resulted in an airplane that performed as an excellent basic trainer without having to look like the box it came in. Once the pilot had gained sufficient flying skills, the speed brakes could be removed and then the flaps could be raised. This resulted in a slightly faster, slightly less forgiving airplane but one that was still on the gentle side. In fact, with the brakes removed and the flaps raised, the Mustang PTS performed much like an Advanced Trainer.

Once the pilot had mastered the Advanced Trainer version of the Mustang PTS, the last steps were to remove the drooped wing tips and to install a 2-bladed propeller. Now, the Mustang PTS not only looked like a P-51, it flew like one as well. Level top speed reached well above 100 mph. Tighten a steeply banked turn by pulling too much “up” elevator and the airplane could snap roll on the unwary, and greatly surprised, pilot. Landing, approach and stall speeds reached “scale” levels.

But the unencumbered P-51 was far more maneuverable than its trainer version. Vertical performance improved once the extra drag and weight were removed. While the airplane was more forgiving than most Mustang versions now available, a “first airplane” it was not. Hangar 9 featured the Mustang PTS as “two airplanes in one”. Actually it has proven to be three airplanes in one. It is a great Basic Trainer at the start. Remove the speed brakes and raise the flaps and it becomes a great second airplane. Remove the drooped leading edges and it transforms into a high-performance scale airplane. Too bad it didn’t have retractable landing gear. Hmmm, now there is an idea. Maybe it can be converted to one. We will have to look into that possibility!

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But,getting back to the PTS concept. Since the Mustang PTS was so successful, Hangar 9 introduced another PTS fighter, the F-22 Raptor. Designed to appeal to the “Post WW II” oriented pilot, the Raptor featured flaps, wing extensions and the now famous drooped leading edges (also wing span extensions here). Instead of speed brakes mounted on the main landing gear, the Raptor featured a fuselage made very wide by including large “air inlet” ducts on each side. Unlike the Mustang’s gear mounted speed brakes, these air ducts can not be removed later.

With all the drag and lift devices attached, the Raptor proved a gentle, forgiving Basic Trainer. Its appearance was very “jet-like” but, as originally equipped, its 3-bladed propeller slowed the airplane’s speed and rate of climb a little too much. Changing to a 2-blade 11 x 5 in. propeller fixed that as detailed in the Sport Aviator F-22 Raptor Update Article. With this one minor change, the Raptor PTS became the excellent Basic Trainer it is today. (Note: the Raptor RTF now arrives equipped with a 2-blade propeller.

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Both the Mustang and Raptor PTS airplanes are powered by the very successful Evolution 45 glow engines. These engines are very user-friendly for the new pilot. They even have mixture limiters that prevent abuse while keeping the powerful engine reliable and trustworthy. But they are glow engines and electric power has become more popular recently. That brings us to the subject of this review: The E-flite T-34 Mentor 25 PTS.

Do not confuse the E-flite T-34 RTF with the nearly identical appearing T-34 ARF. The ARF is really a glow-powered airplane with an optional electric power conversion. The ARF does not have flaps or drooped leading edges and can be converted to retractable landing gear.

This T-34 has flaps, fixed gear and is powered by the powerful E-flight 25 outrunner electric motor using a 3-cell Lithium Polymer battery. The E-flite uses the same Progressive Training System found on the glow powered PTS airplanes. The leading edges, outboard of the flaps, are “drooped” to transform that section of the wing into a flat-bottomed airfoil. The inboard wing section relies on the flaps for extra lift and drag.

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There are no speed brakes like those on the Mustang. Instead, the T-34 uses a large cowl to add the drag required to keep the airplane’s airspeed in the training range. Like the other PTS aircraft, the T-34 is a Ready-To-Fly (RTF) Basic Trainer that will grow with the pilot’s abilities. There are few parts in the “kit” as expected with an RTF. The wings and tail surfaces just bolt in place. The power and radio systems are factory installed and connected. Assembly requires about 45 minutes.

Equipment

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Unlike many other electric powered RTF trainers, the T-34 arrives fully flight ready, including a 3-cell, 11.4 Volt Lithium Polymer battery and charger. The battery is the popular E-flight 3200 mAh 15C (EFLB1040). “15C” means that the battery’s maximum continuous discharge rate is 15 times the 3.2 Amp capacity (hence “C”) or 48 Amps. The Electronic Speed Controller (ESC) is rated for 40-Amp discharge and has a Battery Eliminator Circuit (BEC) which means the motor battery also powers the on-board radio system.

The included E-flite charger is a balanced charger for 2 or 3 cell packs. Input voltage is 12 Volts and the charger has a socket plug for use in a car or other voltage source such as an auxiliary auto “jump starter”. The charger’s output is adjustable from 0.5 to 3 Amps.

Most importantly, this is a “balanced” unit meaning that the charger first senses each cell’s voltage, matches all the voltages and then keeps all cells at identical voltages until full charge is reached. Charging is through the battery’s balancing plug. Balance charging not only extends battery life while providing additional safety, but also insures that the highest capacity possible is stored in the battery for longer flight times and maximum performance.

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The included transmitter is the new Spektrum DX 6i 2.4 Ghz, 6-Channel transmitter. The DX 6i is a true computer transmitter that is user friendly, even for beginners. The programs are complete, factory set and easy to understand and program.

Speaking of programming, a few T-34s have come through with the exponential settings, a programming means of allowing full control surface movement without making the airplane too sensitive around the neutral positions, set incorrectly. The Exponentials were set at negative numbers thereby making the airplane too sensitive around the neutral, center positions and less sensitive at full deflections. This is easy to fix. Just follow the transmitter directions on how to enter the Exponential Function and change the numbers from negative to positive. Keep the same numerical values, just make them positive. See the table at the end of this article for all the proper settings.

The Spektrum AR 6200 is a special, lightweight 2.4 Ghz receiver based on DSM2 technology. It is a full range unit so it can be used in any aircraft and flown within visual range. As do all Spektrum receivers, it features Dual Lock®. This means that the receiver locks on to two unused frequencies of the available 80 and then uses a digital code so the receiver listens only to its own transmitter. This eliminates the need for frequency control and makes the T-34 nearly impossible to “shoot down”.

The transmitter / receiver system also features Model Match®. Even though the transmitter stores trim settings for ten different aircraft, only the aircraft named on the transmitter screen will respond to the transmitter commands. It is impossible to fly the “wrong” airplane, preventing possible damage if different airplanes use different trim settings such as reversed ailerons or throttle.

The included servos are E-flite’s standard size servo, the EFLR 7120. While specs for this servo are not published, they have proven to be more than adequate for the T-34 and have functioned without problems. In fact, they seem almost as precise as sport digital servos. The 7120’s work very well. The fifth servo, added for the flaps, is an “ancient” JR 505 standard servo. More than 10 years old and having served in 5 airplanes totaling about 500 hours airtime, the 505 has proven to be an exceptional sport servo. Except for being converted to ball bearing, this servo has remained untouched for its entire service life.

The motor is the very popular E-flite 25 outrunner motor. This motor pulls the T-34 through all the basic aerobatic maneuvers while providing flight times in the 12 minute range. However, with the supplied 12 x 8 in. propeller and 15C Li-poly battery, the motor and the onboard radio system (servos at idle) draw 37.1 Amps at full power. This is perilously close to the Electronic Speed Control’s (ESC) 40 Amp maximum current draw. Since the servos will be drawing extra current while moving in flight, the actual current draw must be close to 38 Amps, maybe a little higher. There is little reserve left in this system.

Assembling the T-34 Mentor

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As a true RTF airplane, there is not much to putting this aircraft together. Photo 12 shows, there is not much hardware needed to get the Mentor flying. That means there is not much work needed. The wing is a safe, easy first assembly step so start there.

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Insert the aluminum anti-rotation pin in the rear hole near the wing’s trailing edge. This pin prevents the wing halves from rotating during flight. If fixed flaps are to be used, insert the flap linkage post in the wing slot. This post is not a very tight fit. If you really are going to use fixed flaps, then put a few thick CAA drops into the slot, after the wing is assembled, to hold the post in place.

A better idea is to install retractable flaps as this provides more control flexibility. Since this is basically a $15 option (for the extra standard duty servo) that requires 10 minutes to do (the operable flap control rod is already included), why wait? However, the choice is yours.

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Insert the black aluminum spar (note photo 12) into the socket in one wing half. Pick the same half that has the installed anti-rotation pin. Make sure that both aileron servo wires exit their respective holes in the top of each wing half. Then, slide the two halves together over the spar. The anti-rotation pin should be fully inserted into the corresponding hole and the halves joined tightly.

Lock the assembly together using one of the landing gear nylon straps as shown in photo 15. The holes are already drilled for the two screws. If you want operable flaps, cut the covering over the flap servo mount, install the extra servo and screw in place as shown. The control rod is included. Insert one end into the servo arm and the twin end to the two flap control linkages as shown. Use the included “Y” cord to connect the aileron servo to a single receiver port.

The DX6Ei has “flaperon” capability which would allow individual servo receiver connections. With this system, the ailerons may be individually adjusted to eliminate adverse yaw at very slow airspeeds (the T-34 is capable of flying at some very slow speeds) and the ailerons could be lowered as additional flaps during landing. This has not yet been tried as it is part of the future article about the “clean” T-34 with a few upgrades. But it will be!

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