indicator shall display "0" on both the digital and bar
The Fuel Flow Indicators are protected by 0.5-
ampere circuit breakers, placarded FUEL FLOW #1
and #2, located on the overhead circuit breaker panel.
2-40. ENGINE TREND MONITOR.
a. General Description. The Engine Trend
Monitor (ETM) is a monitoring system that monitors
and records data on engine and airframe parameters,
e.g., fuel used, cycle counts, total hours, and engine
and airframe exceedences. It provides automatic
cycle and engine start counting and automatic data
collection. The ETM provides maintenance personnel
with a complete, accurate, and detailed record of the
engine and airframe use. At the time of first
installation of the ETM in the aircraft, the data in the
ETM is revised with the current pertinent statistical
data concerning the airframe and engines. The ETM
can also serve as a log that will contain detailed
records of each event in a flight from power on, engine
starts to engine stops, and power off.
When the ETM system is inoperative, pilots
are responsible for manually recording
engine trend data.
b. System and Related Components.
(1) The ETM Processor. The processor
contains the main computer, and is the collection point
for data received from the various engine transducers.
(2) The Airdata Computer. The Airdata
computer provides airdata calculations and is the
interface to the KLN 90B GPS receiver.
(3) The Display & Key Recorder. The
Display and Key Recorder is a cabin mounted display
that houses both the key recorder equipment and
(4) Indicator Light. An indicator light, labeled
ETMS, is located on the right side of the instrument
panel below the stormscope. The ETMS indicator light
illuminates when the ETM is recording data and for
10 seconds after the master switch is turned on.
c. Normal Operations. When the master
switch is turned on, power is applied to the ETM
causing the ETMS indicator light to illuminate and the
ETM to perform a self-test. It is vital that the pilot
follows certain procedures when starting up and
shutting down the aircraft.
(1) When starting the aircraft, wait a full
10 seconds before starting the engines after turning on
the master switch to allow the ETM to complete its
(2) If the engines are started before the ETM
has completed its startup sequence, the system will
not record any engine starts. This will result in
inaccurate cycle counts, engine start counting, and
(3) When shutting down the engines, wait
until the gas generator speeds of both engines drop
below 10% prior to turning off the master switch.
monitors and records data on the engine and airframe
parameters and notifies maintenance personnel when
the established limits of those parameters are
exceeded. This data is, in turn, used for later trend
analysis. The ETM has a secure feature that prevents
unauthorized changes to the retained statistical data
Section IV. FUEL SYSTEMS
2-41. FUEL SUPPLY SYSTEM.
The engine fuel supply system, Figure 2-18,
consists of two separate, identical systems, connected
by a valve-controlled line, that share a common fuel
management panel. Each fuel system consists of five
interconnected wing tanks, a nacelle tank, an engine
driven boost pump mounted on each engine, a
standby fuel pump located within the nacelle tank, a
fuel heater (engine oil-to-fuel heat exchange unit), a
tank vent system, a tank vent heating system and
interconnecting wiring and plumbing. The aircraft are
equipped with auxiliary (inboard wing) fuel tanks with a
fuel transfer pump located within each tank.