Chapter 3: Getting Acquainted with the Simulator

The X-Plane Helicopter interface shares many similarities with the rest of the X-Plane simulators on the iPhone and iPod Touch. A few differences arise, though, out of the unique way in which helicopters are flown.

Also, note that unfamiliar terms may be found in the glossary. A diagram of aircraft flight dynamics (that is, pitch, roll, and yaw) may be found here.

Basic Flight Controls

 * [[Image:Basic_controls_X-Plane_Helicopter.png]]

Found on the left side of every flight view is a sliding bar labeled COLL (number 1 in the image above). This controls the collective pitch of the main rotor's blades. By default, the blades' pitch is zero (thus generating almost zero lift) when the collective slider is at the top of the screen, though this can be inverted in the Set menu (see the Settings Menu section below). The default setup—with zero collective at the top of the screen—is ergonomically equivalent to the way that, in a real helicopter, the collective is at zero when it is pushed farthest away from the pilot; to increase the collective, the pilot pulls up on the collective handle. Note that a discussion of how helicopter flight works, as well as how the collective in particular works, can be found in Chapter 4.

The scrolling bar on the right side of the screen (number 2 in the image above) displays the throttle. When it is at the top of the screen, the helicopter is putting out full throttle, and when it is at the bottom of the screen, it is putting out zero throttle. Note that this is a visual display only—that is, the user cannot tap and drag this to control it. Throttle in helicopters is controlled automatically; for a discussion of why this is so, see Chapter 4.

The slider at the bottom of the screen (labeled 3 in the previous screenshot) commands the tail rotor. This slider is equivalent to the anti-torque pedals in a real helicopter. When in the center, this does not affect the torque of the craft at all. At full left, it spins the craft left, and at full right, it spins it right.

The button on the bottom left (number 4 in the previous screenshot) toggles the brakes on or off. When it is lit red, the brakes are on, and when it is dimmed, the brakes are off. Note that brakes are not available on all helicopters.

The button to the right of the brakes (number 5 in the image above) controls the gear. When this button is lit, the gear is down, and when it is unlit, the gear is up. Of course, this only applies to helicopters with a retractable landing gear.

To steer the aircraft left, tilt the device left. To steer it right, tilt right. This movement is referred to as roll. To pull the helicopter's nose up, tilt the device back toward you, and to push its nose down, tilt the device down away from you. This movement is called pitch. To move the helicopter's tail while keeping its nose stationary, use the tail rotor slider. This motion is referred to as yaw. See the Flight Dynamics section of the X-Plane Mobile manual for an image of this.

Note: When your aircraft crashes, go into the settings menu and select either a new airport to take off from or a random flight. This will reset the helicopter after the crash, giving you a brand new one to fly again.

Using the Menu and View Options
Tapping the center of the screen will cause the various menu icons to appear at the top. There are two rows of icons; the top row has six, and the bottom row has two, as shown in the image below.


 * [[Image:Menu_options_mobile.png]]

The menu option labeled 1 in the image above selects the default cockpit view, which is out the windshield with the head-up display (HUD). The HUD is described in detail in the HUD section, found below.

The menu option labeled 2 in the image on the above selects the external chase view. Hit that, then drag your finger around on the screen to adjust the viewing angle. To zoom out, put two fingers down far apart on the screen and drag them closer together. To zoom in, put two fingers on the screen close together and drag them apart. This is a nice way of controlling the view that is just not possible with a mouse pointer, since the simulator takes input from both fingers at once.

The next view option from the menu (labeled 3 in the previous screenshot) is the spot view. Selecting this will give the user a stationary view from which to watch as the helicopter flies by.

The fourth view in the top row of the menu (labeled 4 in the previous image) is the linear spot view, where the camera takes a constant-speed trajectory to match the airplane's flight path. This is like the view of a pilot with whom the user is flying formation if that pilot were to turn around and look at the user’s aircraft. This will look identical to the spot view until the user's craft changes either speed or direction—that is, until the user's craft changes velocity.

The menu option labeled 5 in the screenshot on the previous page opens the Settings menu, discussed in below.

The final menu option in the top row (labeled 6 in the screenshot above) is the pause button. When this is pressed, the replay buttons will appear, as highlighted in red in the image below:


 * [[Image:Replay buttons mobile.jpg]]

The center of these five buttons pauses the replay. The two buttons immediately to the left and right, respectively, rewind and fast-forward the replay at a slower-than-real-time rate. The two outer buttons rewind and fast-forward the replay much faster.

The first view option in the second row (labeled 7 in the first screenshot in this section) displays the aircraft’s instrument panel. This view is described in depth in Part B later in this section. Note that in this view, the only menu options available are the HUD view and the pause button. Thus, to access the settings menu or switch to an external view, the user must first return to the HUD view.

The second view option in the second row (labeled 8 in the first screenshot in this section) is the circle view. This is similar to the chase view, labeled 2 in the same figure. However, where the chase view re-orients the camera to track the aircraft, the circle view keeps a fixed heading and orientation as it follows the craft.

The final menu option (labeled 8 in the the first screenshot in this section) will cause X-Plane to display the aerodynamic forces acting on the helicopter. These are only visible when using an external view and are a visual representation of the forces that X-Plane is calculating for each piece of the aircraft. The green bars represent the lift being generated by each piece of the craft, while the red lines at the top of each green bar represent the drag from each piece. Additionally, in jets, an orange bar will be displayed to represent the thrust generated from the engine.

When in an external view, try maneuvering the helicopter around a good bit to see the little green bars move in real time. Just as in real life, it is these forces that act on the mass of the craft to accelerate it and move it through time and space—just as Newton predicted over three hundred years ago. Watch what happens as you add and decrease power or use the anti-torque controls.

The Head-Up Display in Depth
The head-up display, or HUD, allows the user to see a great deal of information regarding the aircraft's operation without sacrificing the view of the outside world.


 * [[Image:Hud_view_mobile.png]]

The ticking tape on the left side of the screen (numbered 1 in the image above) displays the aircraft’s speed in knots. Note that this is the aircraft's indicated airspeed, not necessarily its true airspeed. This measurement comes from the airspeed indicator (ASI), which, in its simplest form, it is nothing more than a spring which opposes the force of the air blowing in the front of a tube attached to the aircraft. The faster the airplane is moving the stronger the air pressure is that acts to oppose the spring and the larger the indicated speed. However, when there is little air available to "push" on that spring, the instrument will display a low number regardless of how fast the craft is moving. For instance, in the SR-71 Blackbird (found in X-Plane Extreme), the craft might be zipping along at Mach 1.5, but at an altitude of 70,000 feet, its ASI will show it moving at around 200 knots (around 0.3 Mach at sea level). Even better, in the Space Shuttle, the craft can be moving at around 17,000 miles per hour while its airspeed indicator shows zero (because, of course, there is no air at all in space).

In the bottom left of the screen is a fuel gauge, labeled 2 in the image above. When the triangle-shaped indicator is at the far right, as it is in the figure, the aircraft's fuel tanks are full. When it is at the far left, the fuel tanks are empty, and the aircraft’s engines will not be able to run.

Directly beneath the ticking airspeed indicator is the aircraft's speed relative to the speed of sound (numbered 3 in the image above). For instance, in the previous image, the craft was moving at 0.21 Mach.

The ticking tape on the right side (number 4 in the previous image) displays the craft’s altitude in feet above mean sea level. For instance, in the image above, the aircraft was at 4830 feet above mean sea level. The number directly below this (labeled 5 in the previous image) is the craft's climb rate in feet per minute. For example, in the image above, the craft was descending at a rate of 760 feet per minute, so the number displayed was -760.

In the center of the screen are two horizontal bars (labeled 6 in the image above), which indicates the helicopter’s attitude—that is, the combination of its pitch and roll.

Surrounding that bar are lines marking degrees of pitch. For instance, in the figure, the aircraft was pitched down at around 2 degrees (indicated by the V-shaped bar), and its wings were banked slightly to the left.

Finally, in the bottom center of the screen (marked with a 7 in the image above) is a directional gyro, indicating which direction the aircraft's nose is pointing.

The Panel View in Depth
In the panel view, the aircraft's instrument gauges and navigation radios are accessible. Flying from this view requires the use of the attitude indicator.

Note: In the panel view, the only menu options available are the HUD view and the pause button (both highlighted in red in the screenshots that follow). Thus, to access the settings menu or switch to an external view, the user must first return to the HUD view.


 * [[Image:Standard_six_with_HUD_and_pause_mobile.png]]

The first instrument in the top row (labeled 1 in the screenshot above) is the airspeed indicator. In its simplest form, it is nothing more than a spring which opposes the force of the air blowing in the front of a tube attached to the aircraft. The faster the helicopter is moving the stronger the air pressure is that acts to oppose the spring and the larger the deflection of the needle from which the pilot reads the craft’s speed. There are a number of ways that this reading can be thrown off (most obviously by flying at an altitude where there is little to no air), so bear in mind that this is the indicated airspeed, not necessarily the true airspeed.

The second instrument in the top row (labeled 2 in the image above) is the attitude indicator, which displays the aircraft's position in space relative to the horizon. This is accomplished by fixing the case of the instrument to the aircraft and measuring the displacement of the case with reference to a fixed gyroscope inside.

The third instrument in the top row (labeled 3 in the previous screenshot) is the altimeter. This displays the aircraft's altitude (in feet above mean sea level) by measuring the expansion or contraction of a fixed amount of air acting on a set of springs. As the airplane climbs or descends, the relative air pressure outside the aircraft changes and the altimeter reports the difference between the outside air pressure and a reference, contained in a set of airtight bellows.

The first instrument in the bottom row (labeled 4 in the previous image) is the turn coordinator. This measures the aircraft's rate of turn. The instrument is only accurate when the turn is coordinated—that is, when the helicopter is not skidding or slipping through the turn. A skid is the aeronautical equivalent to a car that is understeering, where the front wheels do not have enough traction to overcome the car's momentum and the front of the car is thus plowing through the turn. In a car, this results in a turn radius that is larger than that commanded by the driver. A slip is a bit more difficult to imagine unless one is a pilot already. It results from an aircraft that is banked too steeply for the rate of turn selected. To correct the slip, all the pilot has to do is increase back pressure on the yoke, pulling the helicopter "up" into a tighter turn, such that the turn rate is in equilibrium with the bank angle.

The second instrument in the second row (labeled 5 in the image on the previous page) is not the directional gyro of the "standard six." Instead, to facilitate instrument flight, the directional gyro has been replaced with an omni-bearing indicator (or OBI). More information on this instrument can be found in the "big" X-Plane Mobile manual.

The final instrument in the second row (labeled 6 in the screenshot above) is the vertical speed indicator, also called the vertical velocity indicator or variometer. This reports the aircraft’s climb or descent rate in feet per minute (fpm). Typically, non-pressurized airplanes will climb comfortably at about 700 fpm (if the plane is capable) and descend at about 500 fpm. Descent rates faster than this cause discomfort on the occupants which is felt in passengers’ ears. Pressurized airplanes can climb and descend much more rapidly and still maintain the cabin rate of change at about these levels, since the cabin altitude is not related to the ambient altitude unless the pressurization system fails.

Scrolling down in the panel (by dragging your finger up the screen) will show the navigation radios, as in the screenshot below.


 * [[Image:Prop_nav_radios_mobile.png]]

The BRAKES button here (labeled 1 in the image above) functions just like the one in the HUD view—when it is lit up red, the brakes are on, and when it is dimmed, the brakes are off. To the right of this button in the helicopters with retractable landing gear is the GEAR button. When it is lit, the gear is down, and when it is dimmed, the gear is up.

The NAV 1 radio (labeled 2 in the screenshot above) is used for navigation using a VOR. It is tuned using the two knobs on the instrument. The first knob (labeled 3 in the screenshot above) is used to tune the integer (or "counting number") portion of the frequency. The second knob (labeled 4 in the previous image) is used to tune the decimal portion of the frequency.

To turn a knob up, tap directly above it, and to turn it down, tap directly below it. For instance, if the frequency read 109.20 and the user clicked above the left knob, the frequency would increase to 110.20. If the user instead tapped above the right knob, the frequency would increase to 109.30.

To the right of the NAV 1 radio is the HSI source selection switch (labeled 5 in the previous screenshot). This selects between navigating using the frequency on the NAV 1 radio and that of the NAV 2 radio; tap the switch to change its position.

To the right of the HSI source selector is the NAV 2 radio (labeled 6 in the image above). This is functionally identical to the NAV 1 radio.

The Settings Menu
Selecting the fifth menu option from the left (marked in red in the following image) will open the Settings menu.


 * [[Image:Settings_highlighted_X-Plane_Helicopter.png]]

The Settings menu has nine tabs across the top, each of which shows a different set of options when selected. Tap one of the tabs to change the settings there, and tap the Fly button in the upper left to go back to the simulation.

Map
The options available on the Map screen are simple: Place the craft in a random location or on whole new random flight by pressing the respective buttons. The buttons in the lower half of the screen place the aircraft either on the runway for the indicated airport or on a final approach to that runway. The map can be dragged using a single finger or zoomed in or out of using two fingers, just like when using the external aircraft view. Additionally, placing two fingers on the screen and moving them in a circular motion (“swizzling” them) will rotate the map.

Tapping the Center button will center the map on your aircraft.

Zoom into the map near a navigational aid (NAVAID) or airport to view detailed information about it such as its ILS or VOR frequency.

The Map tab is also where you can reset a flight after a crash. Upon crashing, open the settings menu, which will come to the Map tab by default. Tap one of the location buttons (either for an airport or for a random flight) to “fix” your virtual aircraft and start a new flight.

Region
The Region menu allows the user to select which region to fly from. Tap a region to load it. The specific regions available are listed in Chapter 2.

Helo
The Helo tab lets the user pick one of the seven different helicopters included in the simulator. Tap an aircraft to load it (it will be placed on the default runway for the current region). The specific craft available in X-Plane Helicopter are discussed in Chapter 2.

Weight
The Weight menu is interesting. Here, the user can move the center of gravity forward to give the craft greater stability, or aft to make it more maneuverable. Additionally, the weight of the aircraft can be adjusted using the slider—just tap it and drag. Lighter helicopters will of course perform better than heavier ones.

Time
The Time tab of the Settings window allows the user to set one of four times of day, and thus four corresponding levels of daylight.

Sky
The Sky tab is used to set one of five cloud conditions, as well as to change the cloud base height and the visibility. To move a slider, simply tap and drag it.

Wxr
The Wxr ("weather") tab has four sliders (moved just like in the rest of the app) which are used to change the wind speed, turbulence, storm cell prevalence, and wave height. Additionally, the round button is used to set wind direction. To move this, tap near the edge of the circle and drag your finger. Wherever your finger releases is where the wind will come from.

Set
The Set menu allows the user to change the phone or iPod’s “control calibration.” Just hold the device at the desired angle and tap the SET CURRENT PHONE TILT AS CENTER button to make the current attitude of the phone or iPod the point for which input is zero. This lets users fly with the device in their lap when sitting or standing, or held vertical when lying down—kind of convenient!

Finally, at the bottom of this screen is the sound slider, set by default at 50%.

Multi
The Multi tab is used to set up multiplayer flights. When it is selected, X-Plane will search for other devices running the simulator. Both users need to tap the button labeled with the other user's device in order to play with that person. For example, if William and Mary want to fly together, William will need to go to the Multi tab and tap the Mary's iPod button, and Mary will need to go to the Multi tab and tap the William's iPhone button. Note that the button is selected when it turns a very light gray color. When both users have selected the other, click Done and X-Plane will set both users at the default runway.

Also, note that both users must be on the same wireless network in order to play together. This is configured in the iPhone/iPod's Wi-Fi setup (found in the device's Settings, as shown in the image below).


 * [[Image:Wifi_highlighted_mobile.png]]

In multiplayer mode, hitting the other aircraft will result in damage (sometimes fatal) just like hitting the ground in the simulator. If this occurs, simply open up the Settings menu and take off from an airport again. Note that both users must select the same airport if they are to fly together; otherwise, X-Plane assumes that the users want to start in different places and meet up somewhere.

Finally, when in multiplayer mode, a pointer will appear (in the shape of a little airplane) near the compass indicating the other user's location. Follow this pointer to join up with the other player in the event that you lose each other.

Updating the X-Plane Apps
The easiest way to update the mobile X-Plane applications is to go to the App Store (found on the device's "home page") and tap Updates down at the bottom of the screen. There, simply select Update All (as marked in the image below). The device will prompt for the username and password which were used to purchase the applications, then it will automatically download the updates.


 * [[Image:Update_small_mobile.png]]