One
of the most important considerations a pilot must make is the assessment of the
weather conditions forecast for the flight. Weather at the departure airport,
en route, and at the destination airport are required pieces of information the
pilot must assess before embarking.
During
training, student pilots are required to learn about cloud types; determination
of what constitutes a ceiling; precipitation types; icing types, and conditions
conducive to icing; low and high level winds, and sources of weather
statistics. Weather data is perhaps the most critical piece of information the
pilot must gather to ensure the safe conduct of the flight.
The
Airplane Owners and Pilots Association Air Safety Foundation publishes
a yearly report analyzing the causes of aircraft crashes and categorizes them
statistically.
According
to the 2006 Nall Report, an annual review of the
prior year’s aviation safety record dedicated to the memory of Joseph T. Nall, an NTSB board member who died as a passenger in a
plane crash in Caracas, Venezuela, in 1989, pilot-related accidents account for
nearly three-quarters of all aircraft accidents.
Within
this category is included take-off and landing accidents, fuel exhaustion and
mismanagement, maneuvering, and weather-related accidents. Although
weather-related accidents account for only 4.6 percent of pilot-related
accidents, they account for 13.6 percent of fatal accidents within this
category.
Pilots
have several sources available to collect weather information.
Many
pilots pay particular attention to weather reports available on local
television, the weather channel, or newspapers.
These
sources allow monitoring of weather trends and forecasts of changes in the
weather conditions.
Additional
weather information is available to pilots through weather briefings from
sources under contract to the Federal Aviation Administration. These sources
are known as Direct User Access Terminal Service, and are administered by two
private companies: Computer Sciences Corporation and Data Transformation
Corporation. Both are accessible to pilots via the Internet or by telephone.
Services
in addition to weather briefings are the filing of flight plans and access to
Notices to Airmen that contain information critical to flight operations, such
as changes in frequencies for navigation or communication facilities or airport
and runway closures.
While
airborne, pilots also can obtain current weather conditions by radio from
flight service stations, Flight Watch, or from Air Route Traffic Control
Centers. Many center controllers have weather radar data available that provide
real time information on hazardous weather conditions, such as thunderstorms,
and can assist a pilot to avoid those areas.
Aircraft
also can be equipped with weather avoidance devices that include radar and “stormscopes,” electronic instruments that detect the
lightning and heavy precipitation present in thunderstorms.
Surprisingly,
it is not the heavy rain that is most dangerous to aircraft, but the extreme
turbulence of a thunderstorm that makes it a dangerous weather phenomenon.
Pilots
must obtain current weather for the time of the proposed flight and must
determine if weather conditions are forecast to be consistent with visual
flight rules or instrument flight rules. VFR conditions generally require
ceilings of 1,000 feet above the surface and flight visibility greater than
three miles.
IFR
conditions require that the aircraft must be equipped for flight in instrument
meteorological conditions, be cleared by Air Traffic Control to operate in
those conditions, and that the pilot be certified to operate the aircraft in
those situations.
For
information on conditions at an airport, a pilot may contact or monitor
automatic weather systems and receive that information by radio or telephone.
Automated Terminal Information Systems provide details at many airports and
provide listings of current weather conditions, runways in use, and additional
important operational reports.
Information
obtained from ATIS is referred to with a letter in the phonetic alphabet, and
the pilot tells the control tower that he has received the statistics.
Another
system in use is an Automated Weather Observation System.
This
is a system that makes use of specialized equipment to measure wind speed and
direction, air temperature, humidity, visibility, and ceilings.
These
measurements are then recorded and can be accessed by a pilot on radio or by
telephone. Santa Ynez Airport has an AWOS.
Santa
Ynez airport also has a webcam that is aimed at the fuel island.
This
webcam allows a pilot to view the weather conditions during daylight hours and
provides temperature and barometric pressure for the airport at that moment.
The webcam can be accessed by Internet at
www.santaynezairport.com and clicking on “webcam.”