essary for helicopter performance information. This dif- fers from fixation in that you are using other instruments, but are giving too much attention to a particular one. During performance of a maneuver, you may sometimes fail to anticipate significant instrument indications fol- lowing attitude changes. For example, during leveloff from a climb or descent, you may concentrate on pitch control, while forgetting about heading or roll informa- tion. This error control of heading and bank. it necessary for you to constantly check the instruments and make appropriate changes in the helicopter’s atti- tude. The actual technique may vary depending on what instruments are installed and where they are installed, as well as your experience and proficiency level. For this discussion, we will concentrate on the six basic flight instruments discussed earlier. [Figure 12-10] At first, you may have a tendency to cross-check  rapidly, looking directly at the instruments without knowing exactly what information you are seeking. However, with familiarity and practice, the instrument cross-check reveals definite trends during specific flight conditions. These trends help you control the  helicopter as it makes a transition from one flight  condition to another.  In spite of these common errors, most pilots can adapt well to flight by instrument reference after instruction and practice. You may find that you can control the hel- icopter more easily and precisely by instruments.  The flight instruments together give a picture of what is going on. No one instrument is more important than the next; however, during certain maneuvers or condi- tions, those instruments that provide the most pertinent and useful information are termed primary instruments. Those which back up and supplement the primary instruments are termed supporting instruments. For example, since the attitude indicator is the only instru- ment that provides instant and direct aircraft attitude information, it should be considered primary during any change in pitch or bank attitude. After the new atti- tude is established, other instruments become primary, and the attitude indicator usually becomes the support- ing instrument. you will encounter a problem called “fixation.” This results from a natural human inclination to observe a specific instrument carefully and accurately, often to the exclusion of other instruments. Fixation on a single instrument usu- ally results in poor control. For example, while performing a turn, you may have a tendency to watch only the turn-and- slip indicator instead of including other instruments in your cross-check. This fixation on the turn-and-slip indicator often leads to a loss of altitude through poor pitch and bank control. You should look at each instrument only long enough to understand the information it presents, then con- tinue on to the next one. Similarly, you may find yourself placing too instead of relying on a combination of instruments nec- INSTRUMENT INTERPRETATION If you apply your full concentration to a single instrument, Figure 12-10. In most situations, the cross-check pattern includes the attitude indicator between the cross-check of each of the other instruments. A typical cross-check might progress as follows: attitude indicator, altimeter, attitude indicator, VSI, attitude indicator, heading indicator, attitude indicator, and so on. 12-6