BRT DIM 29.92" 0 FT Range View Aux OFF Bearing GPS2 Nav GPS1 Baro Set 29.92" VSI Bug 0 FPM Alt Bug 6500 FT Hdg Bug 300° Hdg Sync Range View OAT TAS GS 7°C - - - KTS 135 KTS 0Q5 BRG 270° 32.8 NM 00:14:34 20 10 10 20 20 10 10 20 270 ° BRT DIM 29.92" 0 FT FAST ERECT Hdg Sync Range View TAS GS 143 KTS 135 KTS 5100 5000 4900 50 40 20 00 160 150 140 130 14 4 3 2 20 10 5 0 -20 -10 -5 M a i n t a i n s t r a i g h t a n d l e v e l fl i g h t , t h e n e s s t h e “ F A S T E R E C T ” t t o n . R E F E R T O B A C K U P G A U G E S [ A T T I T U D E F A I L ] Figure 2-8. A PFD indicating a failed AHRS. Figure 2-7. A PFD indicating a failed air data computer. Awareness: Using Standby Instruments Essential Skills Chapter Summary PFD Failure The primary flight instruments can all be displayed  simultaneously on one reasonably easy‑to‑read video monitor  much like the flat panel displays in laptop computers. These  displays are called primary flight displays (PFDs). You must  still cross‑check around the panel and on the display, but more  The PFD itself can also fail. As a first line of defense, some  systems offer the reversion capability to display the PFD  data on the multi‑function display (MFD) in the event of a  PFD failure. The inoperative attitude indicator on the PFD in  Figure 2-8 indicates the failure of the AHRS. By understanding which  flight instruments are supported by which underlying systems  (e.g., ADC, attitude heading reference system (AHRS)), you  can quickly understand the source of a failure. It is important  to be thoroughly familiar with the operation of the systems  and the abnormal/emergency procedures in the pilot’s  operating handbook (POH), aircraft flight manual (AFM),  or avionics guides.  Every aircraft equipped with electronic flight instruments  must also contain a minimal set of backup/standby  instruments. Usually conventional “round dial instruments,”  they typically include an attitude indicator, an airspeed  indicator, and an altimeter. Pilots with previous experience in  conventional cockpits must maintain proficiency with these  instruments; those who have experience only in advanced  cockpits must be sure to acquire and maintain proficiency  with conventional instruments. Because any aircraft system can fail, your regular proficiency  flying should include practice in using the backup/standby  instrumentation in your aircraft. The backup/standby  instrument packages in technically advanced aircraft pro vide  considerably more information than the “needle, ball, and  airspeed” indications for partial panel work in aircraft with  conventional instrumentation. Even so, the loss of primary  instrumentation creates a distraction that can increase the  risk of the flight. As in the case of a vacuum failure, the wise  pilot treats the loss of PFD data as a reason to land as soon  as practicable. 1. Correctly interpret flight and navigation instrument  information displayed on the PFD. 2. Determine what “fail down” modes are installed and  available. Recognize and compensate appropriately  for failures of the PFD and supporting instrument  systems. 3. Accurately determine system options installed and  actions necessary for functions, data entry and  retrieval. 4. Know how to select essential presentation modes,  flight modes, communication and navigation modes,  and methods mode selection, as well as cancellation. 5. Be able to determine extent of failures and reliable  information remaining available, to include procedures  for restoring function(s) or moving displays to the  MFD or other display. 2-6