Transitional flight is easily explained as being the transition from a hover to forward flight or from forward flight to a hover. The purpose of learning how to properly transition from a hover is that it will allow you to effectively get your helicopter into forward flight in a nice, controlled manner. The proper transition from forward flight to a hover will ensure that your helicopter is correctly positioned for a safe and delicate touchdown. This is what each of us always tries to achieve. During this exercise, you will learn how to transition from a hover to a climb and forward flight, descend, and transition back into a hover.
Transition from a hover to forward flight.
We will start this exercise by starting off on the runway. Later, after you are proficient with the other lessons, you can start from the helipad and hover taxi to the runway. Now, with the engines properly started and have scanned your gauges to ensure everything is functional, look around so that you are aware of any obstacles and/or traffic that might cause a possible threat to you and your helicopter. Once you are clear, you will increase the collective and any anti-torque input that is needed to gently lift off the ground into a hover. Ensure that your helo is high enough off the ground so that if there is any directional movement, your skids will not touch the ground resulting in a possible roll over.
Now, we are going to gently increase the collective until we have a torque reading of about 75% and at the same time, apply forward cyclic until the attitude indicator reads at 4-5% below the horizon line. That would be just above the first line below the horizon line on the attitude indicator. This will give us a good rate of climb at about 500 ft. per min. Keep in mind that you will have to apply the proper amount of left or right anti-torque to stay in the same heading. Let me break things down a bit to explain what is happening. As you increase the collective, you will start to increase in altitude. To keep from just going straight up, we apply forward cyclic. This changes the angle of the rotor which in turn changes the direction of thrust down and aft. That is what will give us our forward movement. The more forward cyclic you apply the more your airspeed increases and the less altitude you gain. The less forward cyclic you apply, the less airspeed you will gain but the more altitude you will gain. Proper balance between the two will result in a good rate of climb.
Note: The settings mentioned above do not have to be exact, but do try. This will give you an understanding of the lesson at hand.
Look at the picture below. This will give you an idea of how the instruments should read. You will see that the main instruments to focus on are highlighted in green.
The next picture is just to give you an idea of how it looks from outside the helicopter. Notice that the nose is pointed toward the runway below. If one didn't know any better, one might think that the helicopter is flying toward the ground. That is not the case. I can assure you that it is gaining altitude. The two pictures shown are one in the same, just from different views. One from the instrument view and the other from the outside view.
Now that you are in the air and climbing, you must learn to land. In order to land you need to descend and transition into a hover. Being in a hover before you land will give you an opportunity to ensure that you are where you want to be before landing.
Transition from forward flight to a hover.
After climbing for about 15 seconds we are going to start descending so we can transition into a hover. Pull back on the cyclic gently until the nose of the helicopter is pointing about 5% above the horizon. As you pull back on the cyclic, your airspeed will decrease and you will notice that the helicopter wants to climb. That means that you have to lower the collective at the same time in order to descend instead of climbing. Lower the collective gently until you have a reading of about 45% torque. Just like any other time, when you increase or decrease torque you must apply the correct amount of left or right anti-torque to maintain the desired heading. Keep an eye on your airspeed, rate of climb, altitude, torque, and attitude indicators. Your goal is to slow the helicopter down while decreasing altitude gradually to transition into a hover. As the helicopter starts slowing down, it will gradually want to descend at a greater rate. So, in order to keep from plummeting to the ground, you need to increase collective. This is where scanning your gauges is a must! You don't want to descend all the way to the ground, so when you get about 40-30 ft. from the ground increase collective a little more until you are at level flight. That is when the rate of climb needle is on 0. Now, your airspeed should be decreasing and as it does, you will need to lower the helicopters nose gradually. The reason for this is because if you were to keep the nose pointing above the horizon when your airspeed reaches zero and then tried to level out, you would be in reverse flight. That would cause a lot more needless work for the pilot. As you lower the nose, increase the collective to maintain altitude. You may have to work your cyclic back and forth every now and then to come to a hover.
Look at the images below. The first one is just as I am levelling off and starting to descend. Notice the instrument readings as compared to when we were climbing?
The next one is during the middle of descent. The changes here are mainly the airspeed and rate of descent.
In this lesson I covered what transition flight is and explained to you how to perform a transition from a hover to forward flight and from forward flight to a hover. After you feel comfortable in performing these maneuvers on your own, you will be expected to demonstrate, in front of an instructor, a transition from a hover to forward flight and from forward flight to a hover. This will be done on the runway centerline.
Apply what you have learned in this lesson and PRACTICE, PRACTICE, PRACTICE!