If you’ve crashed your MASH helicopter and need new rotor blades, grips, or even a new flybar then you’re grounded until new parts arrive. Enter the crash kit – a carefully chosen assortment of the most commonly needed replacement parts, all in one convenient and discounted package. If you keep one of these on hand, you won’t have to stop flying and wait for new parts in the mail again. The MASH helicopter was designed to be user-serviceable just like larger fuel and electric helis. If you’ve got a broken part, then it’s almost certain that it can be replaced without anything more complicated then a screwdriver. This guide will walk you through replacing the most common parts:

Replacing Main Rotor Blades

The main rotor blades can become cracked in a severe crash and pieces can break off. While it’s completely possible to fix small cracks and dings with some medium CA glue and accelerator, this can negatively affect blade balance and make the helicopter vibrate. It’s easier and faster to replace the old blade so here’s how to do it:

1. Get a small Phillips head screwdriver and unscrew the single aluminum screw at the root of the damaged blade. The blade will now be free, and you can remove and dispose of it. Damaged blades can be sharp, so be careful not to cut yourself.
2. All the top rotor blades come with a white warning label on their upper surface. Choose from the upper and lower rotor blades as needed so that the rotors look like this when viewed from the front. As viewed from the front, the right top rotor blade should curve upwards and the bottom right rotor blade should curve downwards. This picture shows the correct blade orientation.
3. Install the replacement blade and tighten the screw just enough so that the blade swings freely when you tilt the helicopter, but is secure enough that it won’t fly off. This has to be done by feel – it’s not critical that the screw is perfectly adjusted, but the blade should feel secure and move freely.
4. Repeat this for any other rotor blades that need replaced. It’s helpful to install them one at a time to keep track of the orientation.

Replacing the Blade Grips

The blade grips / holders are black clevis like objects which clamp down on the root of each blade and hold it to the main shaft. If one of these becomes damaged, use this procedure to replace it:

1. Remove the both of the rotor blades that the blade grips are holding by following the instructions above.
2. Lay the helicopter on its side and observe the two screws that hold the blade grips together and on the main shaft. This picture shows one screw removed, viewed from the bottom of the helicopter.
3. Unscrew the blade grips and keep the screws in a safe place where they can’t roll away.
4. Replace the broken blade grip and install the screws.

Replacing Ball Linkages:

Ball linkages connect the RC helicopter’s servos to the swashplate and flybar. It’s fairly unlikely that these will get broken in a crash, but if they do, here’s how to replace them:

1. Snap off the damaged ball link using your fingers or a screwdriver.
2. Find the replacement link that matches the one you took off and press it on to the spherical plastic nubs where the broken link connected. This picture shows a partially disconnected ball linkage on the flybar:

What makes the MASH helicopter unique is its ability to be completely disassembled and user serviceable. You don’t usually find this on helicopters in the 100 to 200 dollar price range, which are usually meant to be flown and then discarded when they break. Want to learn more about the MASH helicopter, or get one to fly around your living room? RCtoys sells them at a great price. If you just want the crashkit, RCtoys.com has that as well.

The swashplate isn’t included in the crashkit, because it rarely breaks.  If you need a replacement swashplate, you can get one online for a low cost.

The helicopter became a prominent military asset during the Korean conflict of the early 1950s. The United States Army started using helicopters for medical evacuation in order to increase the survival rate of critically wounded soldiers. Helicopters were used in conjunction with forward mobile army surgical hospitals (MASH units).

When many people think of helicopters being used for medical evacuation in Korea the Bell H13 Sioux (designated the Bell-47 by the US Army) is the one that most comes to mind. Most people know this helicopter as the MASH helicopter because of its important role in the TV series MASH. EF has come out with an amazing flying replica of this famous MASH helicopter.

Included with the EF MASH Rescue Chopper

The EF MASH Rescue Chopper includes everything you need to fly, right out of the box. This is what is included:

• 2.4 GHz 4 Channel Transmitter
• RTF MASH Rescue Chopper
• 7.4v 800 mAh LiPo Battery for the Helicopter
• Two 7.6 gram Micro Servos
• 3 in 1 2.4GHz receiver

Main Features of the EF MASH Rescue Chopper Indoor RTF RC Electric Helicopter

The EF MASH Rescue Chopper is easy and fun to fly while still maintaining the stand off scale looks of the helicopters used in the TV series MASH. The dual rotors (co-axial) make this micro electric helicopter easy to fly and perfect for the beginner RC helicopter pilot. Experienced helicopter pilots can work on there skills to make the flight look as realistic as possible.

It is very quick to get the EF MASH Rescue Chopper ready to fly. All you will need is a screw driver and 8 AA batteries. The MASH Rescue Chopper Indoor RC electric helicopter does require a small amount of assembly. Before you begin the assembly start charging the LiPo battery. This way you will be flying the helicopter in no time.

This mini indoor electric helicopter has a coaxial rotor design which provides great stability, and eliminates the need for a separate tail rotor to control torque induced yaw (rotation around the main rotor axis). Coaxial RC electric helicopters are great for flying indoors, because they are both stable and offer precision control.

A 3.7 volt LiPo battery powers the EF MASH Rescue Chopper for a flight time of eight to ten minutes. The battery is charged in the controlled and takes about 30 minutes to charge. To get maximum enjoyment out of your helicopter it is a good idea to buy a spare battery for it. This way you can be charging a battery while flying and cut down your down time.

If you do happen to have a mishap and crash the MASH Rescue Chopper you will be amazed at how incredibly resilient it is. However things do and can break, but not to worry as a full line of inexpensive replacement parts are also offered for this helicopter.

In summary if you want to try some basic scale electric RC Helicopter flying you should look into buying the EF MASH Rescue Helicopter.

Included with the EVO Flight Mini Stinger

The EVO Flight Mini Stinger includes everything you need to fly, right out of the box. Here’s what is included:

• The EVO Flight Mini Stinger Micro RC Helicopter
• A 2.4 GHz, DSM-2 Spread Spectrum Transmitter (requires 4AA Batteries)
• A Portable Lipo Charger built into the transmitter
• 1 cell 3.7V 110mAh Li-Po Battery

The Evo Flight Mini Stinger is great for beginner and experienced pilots, because you do not have to buy any additional parts. You can use this helicopter to get experience and practice your orientation indoors when you cannot fly outdoors because of the weather.

Main Features of the Evo Flight Mini Stinger Indoor RTF RC Electric Helicopter

Like the Blade MCX the Evo Flight Mini Stinger has a proportional four channel radio. Four channel control means that pilots can fly the helicopter with four dimensions of freedom. The Evo Flight Mini Stinger can fly up/down, rotate left/right, pitch forwards/backwards, and bank left/right. With a four channel radio you can precisely control the Evo Flight Mini Stingers’ movement through all three dimensions. With a rotor size of 188mm (7.4”) and a length of 213mm (8.4”) this helicopter can easily fit in the palm of your hand.

The coaxial rotor design of the EVO Flight Mini Stinger provides this helicopter with great stability, and eliminates the need for a separate tail rotor to control yaw (rotation about the main rotor axis). The main rotors spin in opposite directions, canceling out rotor torque caused by their rotation. Coaxial RC helicopter are great for flying indoors, because of their stability and the precision control provided.

The Evo Flight Mini Stinger uses a tiny 1 cell lithium polymer battery for power. Unlike most micro RC helicopters, the battery is removable and interchangeable. Each cell provides 3.7 volts of power with a capacity of 110 mAh (Milli ampere hours). You charge the battery using the included transmitter, which runs off four “AA” alkaline batteries. A typical charge takes about 30 minutes and provides an average flight time of 6 to 8 minutes. Because the battery is interchangeable, we recommend that you purchase an extra so that you can use one while the other is charging.

Weighing only 1 ounce, the Evo Flight Mini Stinger is virtually crash proof. A sudden drop from a few feet above the ground won’t damage it, and in most cases minor collisions with walls are not a problem. Although it is not indestructible, the Evo Flights durability makes it an ideal present for anyone over 12 years of age.
If you want to get into the exciting world of RC helicopters, the Evo Flight Mini Stinger makes a great starting place. It will show you all the basics of RC helicopter flight, and can be used as a starting place to more advanced models. If you’re already an experienced RC helicopter pilot, you’ll like the Mini Stingers control and stability. Watch our site for tutorials on the Mini Stinger, including a how to for installing replacement parts.

The Megatech Micro Flyer includes a charger that is built right into the transmitter. This lets you charge the RC helicopter on the field, maximizing flying time.

A simple to use transmitter operates on the radio band, not the line of sight infra red frequency that is often used with micro helicopters. The transmitter also uses buttons instead of sticks, requiring less skill to operate precisely.

The Megatech Micro Flyer uses a coaxial design, giving it good flight stability. A separate tail rotor is used to control yaw.

The Megatech Micro Flyer is a great, easy to fly electric RC helicopter for beginners. You can read more about it on it’s website

There are different ways that coaxial RC helicopters can be designed.

Coaxial Helicopters – How Do They Work

Besides using the tail rotor to control the yaw, two main rotors can be mounted on the helicopter, and spun at different rates. The difference in thrust causes the helicopters nose to turn. This duel rotor design is used in several full scale helicopters. The CH-47 Chinook is a good example of this duel rotor design, and is frequently used as a military transport helicopter because of its large lifting capacity. RC Helis use the same principle, but most of the time each rotor is mounted on the same axial, hence the term “coaxial”.

Twin rotors that spin in opposite directions

The rotors of a coaxial helicopter need to spin in opposite directions to cancel out the gyroscopic force. On some helicopters, both rotors are mounted on top of each other The main axial of a coaxial helicopter is actually two separate axils. One axial is mounted inside the other. Each sub axial is connected to a gear at the base of the main shaft, and each gear is connected to an electric motor. These two motors operate independently of each other, so the speed of each rotor can be changed.

Since the rotors need to spin in different directions, the top and bottom rotor blades are curved in different directions. This is because each rotor needs to be traveling into the air flow in order to work. The bottom rotor spins in a clockwise direction, and the top rotor spins in a counterclockwise direction.

Two Channel Coaxial RC Helis

It is possible to build a coaxial helicopter so that it only needs two main rotors, and eliminate the tail rotor entirely. Tilting the main rotors forward slightly, results in a constant forward movement. These helicopters are great for beginners due to their simple controls.

Three Channel Coaxial RC Helis

In some coaxial helicopters, a tail rotor is still added. The tail rotor is oriented in the same direction as the main rotors. The forward and reverse rate of the helicopter can be changed, because this system allows pitch control. You can fly forwards, backwards and also hover with this kind of helicopter.

Four Channel Coaxial RC Helis

Even though the coaxial design is most frequently used in small, fixed pitch RC helicopters, it can also be used for models with cyclic collective pitch. The only difference between these models and the conventional designs is their lack of a tail rotor. As with the models above, yaw is controlled by changing the rate at which each rotor spins, but the rotors can change their pitch. This allows the helicopter all four degrees of freedom: pitch, bank, throttle, and yaw. The Esky Lama V4 is good example of the four channel coaxial design.

How The Coaxial Design Benefits RC Helicopters

• Yaw can be controlled by changing the speed of the main rotors, so the pitch can be controlled with the tail rotor.
• The main rotors spin in opposite directions, which gives the helicopter stability.
• Coaxial RC helicopters are a good way to learn how to fly, because they are very stable.

One possible contra-rotating layout has one rotor blade mounted at each end of a long fuselage, as it is for the full scale Boeing CH-47 Chinook, and is known as a tandem rotor. This concept is explained well by the Tandem Rotor article on Wikipedia. Alternatively, both contra-rotating rotors can be placed on the same shaft, resulting in a coaxial design (sharing the same axis). Another good Wikipedia article on Coaxial Rotors explains the theory behind this.

Coaxial rc helicopters are very stable and easy to fly. The Bladerunner series of indoor rc helicopters made by Interactive Toy Concepts, and the ESky Lama V3 and Lama II V4 electric RC helicopters are examples of designs using co-axial rotor blades.