BY ORDER OF THE AIR FORCE PAMPHLET 91-215 SECRETARY ...

A2.A.4. THE PRELIMINARY HAZARD ANALYSIS
A2.A.4.1. FORMAL NAME. Preliminary Hazard Analysis
A2.A.4.2. ALTERNATIVE NAMES. The PHA, Preliminary Hazard List, the PHL
A2.A.4.3. PURPOSE. The PHA provides an initial overview of the hazards present in the overall flow of
the operation. It provides a hazard assessment that is broad, but usually not deep. The key idea of the
PHA is to at least briefly consider risk in every aspect of an operation. The PHA helps overcome the
strong tendency in traditional, intuitive risk management to focus immediately on risk in one aspect of an
operation. This often leads to overlooking more serious issues hidden in other aspects of the operation.
The PHA will often serve as the total hazard ID process when risk is low or routine. In higher risk
operations, it serves to focus and prioritize follow-on hazard analyses by displaying the full range of risk
issues.
A2.A.4.4. APPLICATION. The PHA is used in virtually all risk management applications except the
most time critical. Its broad scope is an excellent guide to the identification of issues that may require
more detailed hazard ID tools.
A2.A.4.5. METHOD. The PHA/PHL is usually based on the operations analysis or flow diagram. The
analyst or group takes each event in turn from the operations analysis. They apply their experience and
intuition, use reference publications and standards of various kinds, and consult with personnel who may
have useful input. The extent of the effort is dictated by resource and time limitations and by the estimate
of the degree of overall hazard inherent in the operation. Hazards that are detected are often listed directly
on a copy of the operations analysis as shown at Figure A2.5. Alternatively, a more formal PHA format
such as the one at Figure A2.6 can be used. The output of the PHA/PHL is either hazards noted on the
operations analysis or the more formal completed PHA worksheet listing all of the hazards of each phase of
the operation. The completed PHA is used to identify hazards requiring more in-depth hazard
identification or it may lead directly to the remaining five steps of the ORM process if hazard levels are
judged to be low. A key to an effective PHA/PHL is to assure that all events of the operation are covered.
Figure A2.5. Building The Pha Directly From The Operations Analysis Flow Diagram.
Operational Phase Hazards
List the operational phases vertically
down the page. Be sure to leave plenty
of space on the worksheet between each
phase to allow several hazards to be noted
for each phase.
A2.A.4.6. RESOURCES. The two key resources for the PHA are the expertise of personnel actually
experienced in the operation and the body of regulations, standards, technical orders (TOs) and operations
instructions (OIs) that may be available. The PHA can be accomplished in small groups to broaden the
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List the hazards noted for each operational
phase here. Strive for detail within the
limits imposed by the time you have set
aside for this tool.