In addition, the configuration of the power indicators installed  in each aircraft may vary to include the following types of  power indicators: tachometers, manifold pressure indicator,  engine pressure ratio indicator, fuel flow gauges, etc.  The control instruments do not indicate how fast the aircraft  is flying or at what altitude it is flying. In order to determine  these variables and others, a pilot needs to refer to the  performance instruments. The performance instruments directly reflect the performance  the aircraft is achieving. The speed of the aircraft can be  referenced on the airspeed indicator. The altitude can be  referenced on the altimeter. The aircraft’s climb performance  can be determined by referencing the vertical speed indicator  (VSI).  [Figure 6-26] Other performance instruments  available are the heading indicator, pitch attitude indicator,  and the slip/skid indicator. The performance instruments most directly reflect a change  in acceleration, which is defined as change in velocity  or direction. Therefore, these instruments indicate if the  aircraft is changing airspeed, altitude, or heading, which are  horizontal, vertical, or lateral vectors. The navigation instruments are comprised of global  positioning system (GPS) displays and indicators, very high  frequency omnidirectional range/nondirectional radio beacon  (VOR/NDB) indicators, moving map displays, localizer, and  glideslope (GS) indicators.  [Figure 6-27]  The instruments  indicate the position of the aircraft relative to a selected  navigation facility or fix. Navigation instruments allow  the pilot to maneuver the aircraft along a predetermined  path of ground-based or spaced-based navigation signals  without reference to any external visual cues. The navigation  instruments can support both lateral and visual inputs. In order to change the attitude of the aircraft, the pilot must  make the proper changes to the pitch, bank, or power settings  of the aircraft. Four steps (establish, trim, cross-check, and  adjust) have been developed in order to aid in the process.  Any time the attitude of the aircraft requires changing, the  pilot must adjust the pitch and/or bank in conjunction with  power to establish the desired performance. The changes  in pitch and bank require the pilot to reference the attitude  indicator in order to make precise changes. Power changes  should be verified on the tachometer, manifold pressure  gauge, etc. To ease the workload, the pilot should become  Navigation Instruments The Four-Step Process Used to Change Attitude Establish Performance Instruments XPDR 5537 IDNT LCL23:00:34 VOR 1 270 ° 2 1 1 2 4300 4200 4100 3900 3900 3800 4300 3600 3500 3400 3300 3200 3100 20 80 4000 4000 130 120 110 90 80 70 1 100 9 TAS 100KT OAT 7°C ALERTS NAV1 108.00 113.00 NAV2 108.00 110.60 134.000 118.000 COM1 123.800 118.000 COM2 $_{WPT }$_ _ _ _ _ _$_{ DIS }$_ _ ._ $_{NM}$ $_{DTK }$_ _ _$_{°}$ TRK 360° N-S E-W $_{5}$338 $_{1}$1652 200 46 13.7 2300 23.0 Airspeed indicator Vertical speed indicator Heading indicator Slip/skid indicator Pitch indicator Figure 6-26.  Performance instruments. 6-19