Generator Failure
Depending on aircraft being own, a generator failure is indicated in dierent ways. Some aircraft use an ammeter
that indicates the state of charge or discharge of the battery. A positive indication on the ammeter indicates a charge
condition; a negative indication reveals a discharge condition. Other aircraft use a load meter to indicate the load being
carried by the generator. If the generator fails, a zero load indication is shown on the load meter. Review the appropriate
aircraft operator’s manual for information on the type of systems installed in the aircraft.
Once a generator failure is detected, the pilot must reduce electrical load on the battery and land as soon as practical.
Depending on electrical load and condition of the battery, sucient power may be available for an hour or more of
ight or for only a matter of minutes. The pilot must be familiar with systems requiring electricity to run and which
continue to operate without power. In aircraft with multiple generators, care should be taken to reduce electrical load
to avoid overloading the operating generator(s). The pilot can attempt to troubleshoot generator failure by following
established procedures published in the appropriate aircraft operator’s manual. If the generator cannot be reset, inform
ATC of an impending electrical failure.
Instrument Failure
System or instrument failure is usually identied by a warning indicator or an inconsistency between indications on
the attitude indicator, supporting performance instruments, and instruments at the other pilot station, if so equipped.
Aircraft control must be maintained while the pilot identies the failed components and expedite cross-check including
all ight instruments. The problem may be individual instrument failure or a system failure aecting several instruments.
One method of identication involves an immediate comparison of the attitude indicator with rate-of-turn indicator
and vertical speed indicator (VSI). Along with providing pitch-and-bank information, this technique compares the static
system with the pressure system and electrical system. Identify the failed components and use remaining functional
instruments to maintain aircraft control. Attempt to restore inoperative components by checking the appropriate power
source, changing to a backup or alternate system, and resetting the instrument if possible. Covering failed instruments
may enhance the ability to maintain aircraft control and navigate the aircraft. ATC should be notied of the problem
and, if necessary, declare an emergency before the situation deteriorates beyond the ability to recover.
Pitot/Static System Failure
A pitot or static system failure can also cause erratic and unreliable instrument indications. When a static system
problem occurs, it aects the airspeed indicator, altimeter, and VSI. In the absence of an alternate static source in an
unpressurized aircraft, the pilot could break the glass on the VSI because it is not required for instrument ight. Breaking
the glass provides both the altimeter and airspeed indicator a source of static pressure, but pilots should be cautious
because breaking the glass can cause additional instrument errors. Before considering, pilots should be familiar with
their aircraft’s specic procedures for static problems.
Loss of Situational Awareness (SA)
SA is an overall assessment of environmental elements and how they aect ight. SA permits the pilot to make decisions
ahead of time and allows evaluation of several dierent options. Conversely, a pilot who is missing important information
about the ight is apt to make reactive decisions. Poor SA means that the pilot lacks vision regarding future events
that can force him or her to make decisions quickly often with limited options. During an IFR ight, pilots operate at
varying levels of SA. For example, a pilot may be en route to a destination with a high level of SA when ATC issues an
unexpected standard terminal arrival route (STAR). Because the STAR is unexpected and the pilot is unfamiliar with the
procedure, SA is reduced. However, after becoming familiar with the STAR and resuming normal navigation, the pilot
returns to a higher level of SA.
Factors reducing SA include distractions, unusual or unexpected events, complacency, high workload, unfamiliar
situations, and inoperative equipment. In some situations, a loss of SA may be beyond a pilot’s control. With an electrical
system failure and associated loss of an attitude indication, a pilot may nd the aircraft in an unusual attitude. In this
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