AIRCRAFT OPERATING
ENVIRONMENT
• Forecasts
• The forecasts of MET conditions pertinent to the accident
should be documented. Dependent upon the nature of the
• occurrence, some or all of the following types of forecasts
may require review:
• a) aerodrome forecasts (TAFs and amended TAFs),
• b) forecasts of area QNH (if applicable),
• c) marine forecasts,
• d) forecasts of upper-air pressure, temperature and wind,
• e) forecasts of MET conditions at surface /Gradient Wind
Streamline (if applicable),
• f) meteorological warnings (including civil/public),
• g) SIGWX forecasts
• h) Volcanic Ash and Tropical Cyclone Advisory information,
• i) forecasts of thickness vorticity and vertical
velocity;
• j) forecasts of stability indices
• k) forecasts of icing,
• l) forecasts of turbulence, .
• m) AIRMET,
• n) SIGMET,
• o) GAMET,
• p) Aerodrome and wind shear warnings
Three people on board a small plane escaped serious injury
when the aircraft crash landed approaching a small Alberta
runway
• At around 9:15 on29 January,2013, Tuesday morning, a small plane from La
Crete, Alberta with three people aboard tried to make landing in inclement
weather at Three Hills Airport(Three Hills Airport, (TC LID: CEN3), is
located 2 NM (3.7 km; 2.3 mi) east southeast of Three Hills, Alberta,
Canada.
• (The Prairie School of Mission Aviation (PSMA), an affiliate of Prairie Bible
College, utilizes this airport as its training base. PSMA offers a 2 year
Associate of Arts in Mission Aviation degree to successful graduates of the
program.)
• . It landed short of the runway, sending one person to hospital. RCMP say
the single-engine Piper Meridian ended up on the runway with a damaged
left wing and landing gear.
• Three Hills RCMP, Fire and EMS were called to the scene to provide
assistance.
• One passenger was transferred to a hospital after complaining of pain to his
chest area. The pilot and another passenger were not hurt.
• Police say the Transportation Safety Board is to investigate the cause of the
crash.
• Local authorities are dealing with a fuel leak from the plane which will have
to be cleaned up to prevent any contamination.
• Three people on board a small plane escaped serious injury
when the aircraft crash-landed while approaching a small
Alberta runway, as biting temperatures and howling winds
blasted the province.
• The plane crashed in inclement weather on Tuesday morning,
as it approached the airport at Three Hills in southern
Alberta, Mounties said. Aircraft was a Piper PA-46-500TP
Malibu Meridian - registration C-GMHP registered to 1649808
Alberta Ltd., based at La Crete Airport, Alberta
• "The plane landed short of the runway coming to rest on the
runway, damaging the landing gear and left wing of the
aircraft," said Three Hills RCMP Const. Seth Adair. "A
passenger on board received minor injuries and the pilot, and
another passenger, were not injured."
• The injured passenger was taken to Three Hills suffering from
chest pains and the Transportation Safety Board of Canada is
investigating the crash.
• Briefing and Flight Documentation
• A copy of any MET and aeronautical documentation
covering the flight should be obtained for study.
Particular attention should be paid to the currency
and accuracy of all such operational information
that was requested by and/or provided to the flight
crew in the preflight preparation and during the
flight.
• Statements should be obtained from personnel who
supplied any operational information to the crew
both prior to departure and while en-route.
Emphasis should be placed upon determining
whether the crew was adequately informed
regarding hazardous MET conditions.
• Post Flight Analysis
• An assessment should he obtained from a qualified (and noninvolved) meteorologist of the MET conditions throughout
the flight resulting from an analysis of all the MET information
brought to light in the investigation. Careful consideration
• should be given to the possibility that hazardous phenomena
may have been present which were not readily apparent
• from the forecasts and observations available at the relevant
time, particularly in the case of en-route occurrences
• involving structural failure. Such phenomena might include
mountain wave effects, tropical cyclones, severe turbulence,
• freezing rain, volcanic ash, etc. Where the weather is
considered to be a contributing factor, specialist plotting of a
cross sectional flight profile should be obtained.
• RADAR CROSS-SECTION FLIGHT PROFILE GENERATION
AND EXECUTION
• To predict aircraft flightpaths for conducting
ground-to-air RCS measurements, flight profiles are
developed at ATR and then taken to the Manned Flight
Simulator (MFS) at the Air Combat Environment Test &
Evaluation Facility (ACETEF). These maneuvers are then
flown in the aircraft cockpit of interest. The MFS is
equipped to compute and display presented aspects
resulting from each of the maneuvers in real-time.
Flight cards are generated from this data, which provide
the required location and flight parameters to precisely
fly each of the validated maneuvers.
• Adequacy of service
• Emphasis should be placed upon determining whether
the crew was adequately informed regarding hazardous
MET conditions. The observing, forecasting and briefing
facilities involved and the services provided should be
examined with a view to determining whether:
• a) pertinent regulations and procedures were
satisfactory, available, and adhered to
• b) disparities existed between workload and staffing,
• c) forecasts and briefings were accurate and made
effective use of all known and relevant information,and
• d) communication of information to the relevant
aeronautical personnel was accomplished without
delay and in accordance with prescribed procedures.
• Adequacy of flight documentation and messages
• In particular, localised, frequently observed MET phenomena
at an aerodrome may be listed in flight supplements as a
warning to aircraft. These flight supplements are often used
for flight in Visual Meteorological Conditions (VMC).
• However, these same warnings may not be included in
documents relating to flight in Instrument Meteorological
Conditions (IMC) for the same aerodrome. Therefore,
comparison of such documents should be made so as to
highlight possible disparities. As an example, a flight
supplement for an aerodrome surrounded by rough terrain
with frequently strong winds, may warn of possible
mechanical turbulence. However, this warning may not be in
approach plates used in IMC. In addition, investigators must
also consider the possibility that frequent use of these
particular aerodromes, may breed complacency and thus the
exclusion of such information.
• Adequacy of flight documentation and messages
• Aside from flight documentation, consideration to
messages in flight must also be given. For instance,
most pilots receive SIGMETs via radio and thus lack
a hard copy for thorough analysis. Such data should
be examined for clarity and brevity and whether
they facilitated understanding and use of messages
given conditions of flight. In addition, there are
possible limitations of reports (e.g.., IREPs/PIREPspilot weather Reports). These limitations are
particularly relevant to reports of icing and
turbulence given their interpretation is subjective
• Operating norms and policy
• Norms, whether organisational, group or individual may
significantly influence behaviour and operations. In relation to
• MET conditions, an investigator should analyse the various
organisations, groups and norms of the aircrew (if possible).
• Particular attention should be paid to norms and policies relating
to the dissemination of information, and analysis of data. For
instance, a possible norm of pilots failing to read dispatch reports
in their entirety due to their considerable length. This norm of
seeking only certain data may have restricted the
comprehensiveness of weather briefings provided.
• Regulatory body’s and operator’s operational policies regarding
flight in hazardous weather conditions and the operational reality
should be analysed for disparity. Such analysis may also be applied
to industry norms (e.g., penetration of thunderstorms in terminal
areas).
• The forecast and observed MET conditions should be compared to
any limitations on aircraft or aircrew, including regulatory and
company policies.
• Availability of data
• Each investigation will differ in relation to the
availability of data. This may be a result of scarce
reports in remote areas and inadequate data
collection networks. There may also be limitations
of technology used to collect, display and
disseminate data. In such cases an investigator may
be forced to utilise considerable innovation in
analysis techniques and tools. In such situations, it
may be useful to consult various colleagues, experts
and researchers in these areas. It is also advisable
to look for information and advice from the various
existing and available sources of MET information
• (WAFCs, VAACs, TCACs, MWOs, etc).
• Collection of occurrence particulars
• Important data must be collected (e.g., time of occurrences, route)
to facilitate or complement collection of MET information. For
instance, it is obvious that the data and time of an occurrence be
known to gather correct data. Primary sources of such data shall
be obtained from flight plans, Air Traffic Services (ATS) radar data,
navigation and topographical charts. Data collected should
include:
• a) occurrence date (UTC and LMT),
• b) occurrence time (UTC and LMT),
• c) occurrence location,
– i. general location
– ii. grid reference
– iii. elevation and topography
• d) departure point,
• e) cruising altitude or flight level,
• f) destination and intermediate stops (with ETAs/ATAs and
ETDs/ATDs), and
• g) RADAR tracks.
• Collection of technical data
• Collection of technical data may include the
breakdown and testing of MET instrumentation,
and collaboration with other
• Groups to gather data on aircraft instruments (e.g.,
altimeter). Data should also be collected with
regards to the State’s,
• operator’s, and ATS’ tools, (e.g., RADAR technology,
high-resolution satellite imagery, numerical weather
prediction (NWP) models)
• Collection of human factors data
• Human factors data, from a MET standpoint, should be
collected to not only gain insight into aircrew decision making
but also organisational oversight and omissions that may have
contributed to the occurrence.
• Copies of any MET documentation covering the flight should
be obtained for study. Particular attention should be paid to
• all MET information that was requested by and/or provided to
the flight crew in the pre-flight preparation and during the
• flight. In addition, statements from personnel who supplied
MET information to the crew both prior to departure, whilst
• en-route, and at the destination (if applicable) should be
obtained with emphasis in the acknowledgement by the crew
of the existence of forecast of hazardous MET conditions.
• Statements of personnel and documentation
relating to the coordination and dissemination of
MET data should be collected. Such data, both intra
and inter-organisational, should be collected from
organisations such as the appropriate ATS agency,
the State’s weather service, and the aircraft
operator (e.g., airline, flight school). In addition,
data relating to staffing levels and personnel’s
workload, for all organisations, should also be
collected if applicable.
• Analysis of data
• An analysis of all data collected should be made by a
qualified (and non—involved) person with specialised
meteorology training, and with, in some instances,
other Groups (e.g., Human Factors/Human
Performance).
• Careful consideration should be given to the possibility
that hazardous phenomena may have been present
which were not readily apparent from forecasts and
observations available at the relevant time. Such
phenomena might include tornadoes, severe
turbulence, freezing rain, low level wind shear and
volcanic ash. Analysis should also examine technical
equipment and human factors data for possible
influences.
• Analysis of occurrence particulars
• It is imperative that an analysis of the accident particulars
precedes the analysis of MET conditions. For instance,
information regarding the elevation will be required for the
calculation of Pressure Altitude, and knowledge of location
and terrain will aid in the analysis of possible local weather
effects. Data on natural light conditions combined with the
• occurrence date and time will aid the possible identification
of local winds (e.g., land/sea breeze, katabatic winds).
• Further, comparing flight plan data against RADAR tracks may
provide clues to conditions faced aircrews. The Meteorology
Group may benefit from collaboration with the Performance
Group on aspects such as aircraft speeds, which again may
point to conditions faced by aircrews. For instance, a low
aircraft Ground Speed (GS) despite a tailwind component may
point to the crew slowing to the Turbulent Penetration Speed
(VB) providing a possible indication of significantly turbulent
flight conditions.
• A Katabatic wind, from the Greek word katabatikos
meaning "going downhill", is the technical name for
a drainage wind, a wind that carries high density air
from a higher elevation down a slope under the
force of gravity. Such winds are sometimes also
called fall winds. Katabatic winds can rush down
elevated slopes at hurricane speeds, but most are
not that intense and many are on the order of 10
knots (18 km/h) or less.
• Not all downslope winds are katabatic
• Analysis per phase of flight
• Following the analysis of all the data collected
understanding of the atmosphere must be related
to each phase of flight, namely:
• a) taxi, takeoff to top of climb,
• b) enroute data, and
• c) top of descent, approach, landing, and taxi.This
method, in large measure, should provide the
investigator with considerable physical
understanding of the atmospheric conditions during
different phases of the flight.
• Analysis of technical data
• There are many items which may have restricted the accuracy and
comprehensiveness of meteorological data provided to aircrews,
State weather agencies, ATS units, and operators.
• If the accuracy of MET information is suspect, investigators may
breakdown and test MET instrumentation.
• In winter, consideration should also be given to the possibility of
ice accretion on MET instrumentation. For instance, during periods
of freezing precipitation ice accretion may reduce the efficiency or
cause complete failure of anemometers, thus restricting the
validity of wind data. These same considerations may be applied to
aircraft instrumentation. In such cases, weather investigators may
benefit from collaboration with other Groups.
• Technology for gathering and displaying MET information may vary
from State to State, and thus examination of the capabilities and
limitations of such tools (e.g., RADAR technology, high-resolution
zoom satellite imagery) should be analysed. Consideration must
also be given to possible limitations of technology as a result of
atmospheric phenomena.
• For instance, aircrews flying into thunderstorms,
and areas of hail, as a result of false RADAR returns
caused by RADAR attenuation due to absorption.
• Weather forecasting has seen a general
improvement aided largely by greater NWP model
accuracy and by the availability World Area Forecast
System (WAFs) forecasts globally. Despite this
improvement model limitations possibly restricting
the accuracy of forecasts must be considered.
• Analysis of human factors data
• Comparison of forecast conditions, aircrew actions, and
the investigator’s identification of possible hazards may
suggest possible issues with aircrew judgement.
However, simply stating that the pilots flew into
adverse MET conditions does little to explain why. The
investigator, together with the Human
Factors/Performance Group, must endeavour to
identify
• why the aircrew’s decisions made sense to them at the
time. There are a number of human factors barriers to
effective aircrew weather decision making. Such
barriers may include lack of knowledge due to
inadequate training or poor provision of MET
information, and operating norms.
• The overall process of occurrence investigation
within the human factors field is similar across
many methodologies.
• However, differences arise in their particular
emphasis of the techniques. Whilst some focus on
management and organisational oversights and
omissions, others consider human
performance/error problems (on the frontline) in
more depth. Both levels must be examined to
permit a comprehensive analysis.