Introduction

RCRCM, a Chinese manufacturer, is a newcomer on the composite glider market. RCRCM offers a range of original products, designed by their "house" engineer, Dr James Hammond, an Englishman living in Taiwan for years. The product range is pretty wide, going from the 60-inches to the F3B/F3J, and from the F3F glider to aerobatic gliders. I propose you now the review of the Typhoon, a 2m allrounder, cross and all moving tail, suitable for all slope pilots looking for a compact but performant sport flying sailplane.

Specifications

• Wingspan: 2.00 m
• Lenght: 1.20 m
• Weight: 1620 g (Ballast 700g)
• Wing Airfoil JH8 8% vers 7.5%, puis 7%
• Tail section: SD8020
• Manufacturer: RCRCM
• RCRCM Distributor for France : wittnaircomposite

The overall impression is excellent, the quality is pretty good, and the kit comes complete with clevises, servos frames, etc .... In option you can buy the servos lead extensions including green MPX style connectors, and the wing/fuselage bags. I like very much the new color scheme, it couldn't be better. Everything fits together perfectly. I just had to paper sand a little bit the joiner on one side to make it more free and not force in the joiner box. The surface finish of the wing is to the highest standard. There is an huge 20 mm ballast tube in the fuselage already in place and accessible by the bottom of the fuselage. The space for radio installation is not that big but with the servos, battery and receiver I have, it should be fine.

A quick look at the root airfoil, the JH8 series, also developed by James Hammond: 8% at the root, 7% at the tip, and with a max thickness very forward, which make me think to the famous S7003. We should expect a good behavior under high wing load.

The Weight per element is the following:

• Left Wing: 347 gr
• Right Wing: 341gr
• Left Tailplane: 25 gr
• Right Tailplane: 25 gr
• Fuselage: 293 gr
• Joiner: 41gr

The fuselage, very cute, comes with the ballast tube installed, the elevator and rudder linkages installed. The mould line is clean without reaching the prefection of some production from Eastern Europe. My Typhoon is a carbon version, but 2.4 friendly, which means that the nose and the nose cone are in fiber glass.

Assembly

I started with the fuselage. The work consists in cutting the servo tray and install the rudder and elevator servos. I decided to try a new servos brand, Power-HD. They are very tiny and provide an high torque for their size.

Elevator servo: Power HD-2213MG Voltage: 4.5v~6v

• Speed: .16sec
• Torque: 2.7kg/cm
• Bearings: 1BB
• Gears: Metal
• Weight: 16g
• Size: 23x12x24mm

Rudder servo: Power HD-1581HB

• Voltage: 4.5v~6v
• Speed: .16sec
• Torque: 1.9kg/cm
• Bearings: 1BB
• Gears: Nylon
• Weight: 12g
• Size: 23x12x20mm

The place for the battery and the receiver is limited. I have seen different layout on RC forums. On my side I initially choose to install the battery (4x Eneloop 2000 mAh) on the side, and the receiver too. Then I changed the layout and put the battery under the receiver, and I suppressed the switch and use JST plugs instead. The objective is to clear the maximum of space for the nose lead. The receiver is finally an Assan 2.4 Ghz. It is installed on a piece of white hard foam that allow to maintain it far enough from the battery, and insert the 2 small antennas in the foam to optimize their position and optimize the reception.

I continued with the installation the wing plugs. I don't know why, but the servos extension leads arrives with the male connector on the wing and the female connector on the fuselage. I personnaly think that this is not good because the connector on the fuselage is not integrated into the fuselage and not protected from shocks. So I reversed them in order to have the male connector fully integrated in the fuselage. It gives a little more work but the result is much nicer and reliable, from my point of view. I do like this for ages without any problem. The risk of short cut is higly unprobable.

On the wing side, I started to use the servos frames provided in the kit. I first modified them to the size of the wing servos. Then I discovered that the way they are designed hinds the optimum cinematic of the the control rods. So I decided to build my own servo mounts with some 4mm plywood. I glued them in place with rapid epoxy. The servos is the new BMS 555 from blue bird (not the digital one). Il has the following specifications:

• Weight: 23g / 0.82oz
• Dimensions: 30.00 x 10.00 x 34.00mm / 1.18" x 0.39" x 1.33"
• Torque At 4.8V: 4.2kg/cm , 57 oz/in
• Torque At 6.0V: 4.7kg/cm , 181 oz/in
• Speed At 4.8V: 0.15 sec / 60° at no load
• Speed At 6.0V: 0.13 sec / 60° at no load

Despite their thickness (only 10 mm) the ailerons servos exceed the max thickness of the servo bay. The assembly tooks a little more time than usual because of some surprises: Both the aileron and the flap horns made from epoxy plate and that come already installed are not at the correct height. The consequence is that a metal clevis cannot move freely, even after some sanding. I decided first to reposition the horns,but finally I swapped them with brass horns I had in stock. Apparently, according to the UK forum, I’m not the only typhoon owner having this issue. Of course this is not a big deal because it takes few minutes to fix it, but it’s still frustrating. The flap servo covers are perfect. But for the ailerons, they are not usable with the servos I choosed. I used caches servos boss from another glider (Strega).

Balancing and settings

As expected, I needed lots of lead (about 200g) to get a CG at 87 mm. The lead has been molded to the correct shape of the nose of the glider by taking the nose cone as template and and making a mould with a foil of aluminium, everything being placed in sand to prevent warping. The lead is then poured in the aluminum foil. Once cooled down, you just have to remove the aluminium foil. The settings provided in the building instructions are a good start. The only point on which we must apply it to obtain the maximum deflection down to the butterfly function for effective braking and easier landing. The final flying weight is 1620 gr.

Let's go to the slope !!!

The very snowy winter in our part of the country (French Alps) didn't allow me to try the glider end of 2009 despite it was ready to take the air. This is only with the return of spring and the sun that the Typhoon could take the air but it was worth the wait!

After few seconds the Typhoon gives an impression of stability that is usualy the one of larger gliders. This behaviour can be felt in all phases of the flight. The ailerons are accurate and efficient. The elevator and rudder are homogeneous and well decoupled. The flight line is tight and the Typhoon flies through the turbulences without being shaken. The cruise speed is rather fast, which allow to cover wider area and make the "thermal hunting" very interresting. With some flaps, it slows down and is more demonstrative when entering a thermal. Usually I fly with the snap-flaps always active. In thermal conditions, the snap-flaps allow a better climb, while circling. The Typhoon is no exception: It is happy both in the light air when you need to fly as horizontal as possible or while searching for a strong thermal, requiring more aggressive piloting.

As soon as the wind wakes up, the typhoon shows a good speed and penetration capability. It accelerates quickly when sollicited and you feel tempted to do some aerobatics: In this domain, the glider is a great surprise. Without reaching the perfection of gliders specifically designed for aerobatics, the Typhoon is much better than average showing a good inertia and a accuracy on the roll axis. You can do 3 consecutive rolls without losing speed and without side effects, with little or no differential on the ailerons. The 4 steps roll is excellent, the glider perfectly "marks" each step and giving the sensation to obey to the finger and the eye. Inverted flight requires only slight pressure on the elevator stick. The combinations of horizontal and vertical manoeuvres is no problem: vertical eight, cuban eights, double reversal, the glider does not disappoint!

Typhoon RCRCM from Pierre Rondel on Vimeo.

In F3F or pylon racing, turns at high speed shows a very good energy retention, meaning that the glider does not dissipate its energy during the turn. It exits at least as fast as it entered the turn. The different types of turn are possible: normal turn, flip turn, energy management turns. The only drawback for F3F will be its small size that will prevent the Typhoon to be as competitive as a "true" 3m F3F glider. This is not very serious because it is not designed for that. In windy conditions, the ballast tube can carry between 600 and 800g depending on the density of material (lead, brass, tungsten), which is more than enough for a 2m glider, it will fly rarely "full ballast" unless there is a storm. Although ballast, the wings begin to fold a bit because of the thickness of the section. On another hand, the glider becomes a real ballistic missile, which is exhilarating!

Another pleasant surprise that I like is when we will fly on the dark side of the slope (Dynamic Soaring). I consider it as an excellent indicator of the performance of an airfoil and overall design of the glider. If the glider has trouble accelerating (ie, a visible increase in speed at every circle), the section does not work well at high number of Reynolds. The Typhoon is just the opposite: it accelerate from the first circle and above all, it flies with an impressive stability compared to other DS gliders of the same size. At the point it made me to revise my opinion that the ideal DS glider should be about 2.5m but not 2m. Now, stay cautious because the frame is not designed for hard DS. the good news is that a rumor says that a DS glider on the basis of the Typhoon would be in preparation ... Yum yum ...!

During the landing phase, butterfly are very efficient and the plane still controlable allowing to land almost everywhere you want, even if a small area. In brief, You will understand from this report, that the Typhoon is very versatile, sometimes being a mini F3B Glider, sometimes F3F, or aerobatics or DS. In short, we are very close to the "5 feet" sheep.

Conclusion:

RCRCM designed a very good, if not the perfect allrounder, with a good moulding quality and great flying perfomances.  If you are fade up with taking several planes with you to go to the slope to cover different type of flying conditions, then the Typhoon is the solution. it is compact enough to be placed "discretly" in your car while leaving for holidays, and it will offer you flying capabilities without compromise. Certainly a good choice! Good flying to all.