曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
had been involved in the inspection, including the owner/student who had installed a headliner. The mechanic with the
Inspection Authorization (IA) who signed off the annual was supervising several annuals, so most of the maintenance was
performed by other mechanics.
After the inspection, the engine had been run-up according to the usual post-inspection procedures. The student and instructor
had flown the airplane for a half-hour familiarization flight. The next day’s engine start resulted in a runaway engine with
the apparent cause due to the lack of the throttle rod-end hardware being safetied.
Risk Management
Chapter 9
9-2
Figure 9-1. Types of risk.
Types of Risk
The sum of identified and unidentified
risks.
Risk which has been determined
through various analysis techniques.
The first task of system safety is to
identify, within practical limitations, all
possible risks.
Risk not yet identified. Some
unidentified risks are subsequently
identified when a mishap occurs.
Some risk is never known.
Risk which cannot be tolerated by the
managing activity. It is a subset of
identified risk that must be eliminated
or controlled.
Acceptable risk is the part of identified
risk that is allowed to persist without
further engineering or management
action. Making this decision is a
difficult yet necessary responsibility of
the managing activity. This decision is
made with full knowledge that it is the
user who is exposed to this risk.
Residual risk is the risk left over after
system safety efforts have been fully
employed. It is not necessarily the
same as acceptable risk. Residual
risk is the sum of acceptable risk and
unidentified risk. This is the total risk
passed on to the user.
Total Risk
Identified Risk
Unidentified Risk
Unacceptable Risk
Acceptable Risk
Residual Risk
Three deficient areas in this annual inspection were identified
by a round-table discussion group of aircraft and powerplant
(A&P) mechanics and the student. These areas were:
• Lack of responsibility
• Checklist misuse
• Complacency
Lack of responsibility—no one took responsibility for the
entire inspection. The chances of something being overlooked
increase with an increase in the number of mechanics
involved in an inspection. The responsible person is removed
from the actual procedure. The student remembers hearing
the IA ask one of the engine mechanics about the throttle.
However, the question was vague, the answer was vague,
and the rod-end was not safetied.
Checklist misuse—all checklists have a line item regarding
inspection of the engine controls for rigging and safety.
Perhaps the throttle rod-end had been disconnected for
maintenance after the IA had signed off the control
inspection. In that case, a discrepancy should have been
entered onto the discrepancy sheet stating “reconnect and
safety throttle rod-end.”
Complacency—an insidious and hard-to-identify attitude.
Each of the mechanics involved in the incident thought
someone else had inspected the throttle rod-end. The IA
signed off the annual inspection because he had either asked
the mechanics about the items on the checklist or in his
frequent visits to the airplane had inspected the various items
himself and decided that was good enough. Complacency
crippled the mechanics’ quality of work by removing any
thoughts of double-checking each other’s work.
While a definite answer to the question of what happened
remains a matter of speculation, professional mechanics
should heed warning signs of potential problems. The
combination of a lengthy inspection, numerous technicians,
an overworked supervisor, a poor checklist, and vague
communication should raise a red flag of caution. Although
the ultimate responsibility for the safety of any flight rests
with the pilot in command (PIC), it is not unreasonable for the
PIC to assume that mechanics also take their responsibilities
seriously.
This scenario underscores the need for safety risk management
at all levels of aviation. Safety risk management, a formal
system of hazard identification and analysis, is essential
in keeping risk at acceptable levels. Part of this process is
selecting the appropriate controls to mitigate the risk of the
identified hazard. The primary objective of risk management
is accident prevention, which is achieved by proactively
identifying, assessing, and eliminating or controlling safetyrelated hazards to acceptable levels.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Aviation Instructor's Handbook航空教员手册(147)
