User Guide

Flight Instruction
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Flight Instruction
244
Similarly, if the EFIS system goes out completely, (and it has
so many reversionary modes that’s highly unlikely), there is a
standby artificial horizon: just above the standby airspeed and
altimeter, with built-in ILS cross-pointers linked to the #1 NAV
receiver.
Just to the right of the standby instruments is what appears
to be a radar; in fact, it is, among other things, but it can be much
more. This is the Multifunction Display Unit (MDU). In addition
to displaying radar data (controlled by the knobs just below the
MDU), it can serve as a backup for any failed EFIS indicator or dis-
play navigation data. Below the MDU are fuel gauges for the left
and right wing systems, and a simple “FULL/EMPTY” indicator for
an extra fuel tank in the aft fuselage. Flanking them on either side
are the integrated radio tuning units (RTUs). Each of these nor-
mally controls the comm, nav, ADF, and transponder on its side of
the airplane. The two large panels, with keyboards and CRT dis-
plays, control the dual Flight Management Systems (FMSs) These
are computers which tie together the airplane’s various navigation
systems (including a remoted-mounted GPS), and can generate
and store multi-leg flight plans. In FLY!, flight plan and fuel load-
ing information will automatically be transferred into the simula-
tion from the flight planning screens.
Just right of center are the two vertical rows of engine instru-
ments. In turbofan engines, the primary power setting instrument
at lower altitudes is fan speed in per cent, labeled N1. Each N1
indicator has an orange reference “bug” which can be set accu-
rately, using digits displayed in the indicator, by the knob to the
right of the digits. . Below this is interstage turbine temperature
(ITT), which is a limiting instrument at low altitude and a power
setting instrument in high-altitude cruise. Finally, at the bottom of
the stack we find N2, indicating (in per cent) the speed of the core
engine; this is primarily a limiting rather than power setting
instrument. Very small oil pressure and temperature indicators are
at the bottom of the center panel.
Let’s start with the glare shield, and we’ll work outward sym-
metrically from the center. At the top center of the glare shield is
the Autopilot Control Panel. Flanking it to either side are display
selectors for the captain’s and copilot’s electronic flight instrument
systems (EFIS), which we’ll cover at length a bit later. These also
incorporate the course arrow and heading bug adjusting knob for
the captain’s and copilot’s electronic HSI, allowing either
crewmember to adjust either the own unit or the other crewmem-
ber’s without having to lean across in front of them. Just outboard
of these, on each side, are the red MASTER WARNING flashers,
which will illuminate any time a red warning light appears on the
main annunciator panel. Pressing either of them will extinguish
both of them, but the annunciator on the panel will remain lit.
Now the glare shield jogs downward a step, and both the
captain and copilot have a mode selector for their (separate) flight
directors. The autopilot can follow the commands of either flight
director (and is normally switched to the captain’s side). The slant-
ing area of each side of the glareshield contains selector switches
for that side’s EFIS symbology and dimmer knobs for various areas
of panel lighting.
On to the main panel itself! As usual, flight instruments are
arranged in the “sacred six” in front of each crewmember. Unless
you’ve already powered up the avionics, you’ll notice that the
Attitude Director Indicator (ADI) and Horizontal Situation
Indicator (HSI) are blank. Rather than electromechanical instru-
ments, these are the screens of the Electronic Flight Instrument
System (EFIS).
The “conventional” instruments, such as the altimeter, VSI,
etc. - aren’t as conventional as meets the eye, either. Because of
the wide range of speeds and altitudes at which a jet operates,
they’d have very serious errors if they used only pitot and static air
pressure inputs. Instead, they’re operated by an Air Data
Computer (ADC) which ensures that their readings are accurate
and consistent throughout their entire operating range. What if the
ADC quits? Use the copilot’s. What if it quits? Use the little stand-
by airspeed indicator and altimeter just to the right of the captain’s
combined altimeter and VSI - they’ll have errors, but they’re cer-
tainly good enough to get you through an instrument approach
and onto an airport.