1. Introduction to user requirements
Finland (PT/LLF member in pilots role)
• The Finnish Aviation Association is the head of
total ~200 aviation clubs, founded 1937.
– +10 000 members
– Main activities are:
– Motorflying/normal category planes
– Soaring
– Parachuting
– Model flying
– Smaller groups:
» Ultralights (increasing), balloons
experimental and hang/paragliding
2. 09.03.10
09.03.10
2
User requirements generally, LL-IFR
• Inside GA and sport aviation the user needs
vary in wide range:
– For LL-IFR the rules of using weather information
for planning the flight are quite similar as for
heavier traffic, TAF´s playing the most important
role.
– Flight is conducted often ”inside” weather. This
points out the importance of relevant and detailed
route weather information starting from MOD
phenomena.
3. 09.03.10
User requirements generally VFR
• VFR is flown mostly on QNH settings or also on also low flight
levels.
• Because the cabins are normally unpressurized, this means
the use of max. height 12 000ft on en route. Higher
heights/levels can be used during short periods and with
oxygen masks vertical range increases.
• Turbocharged engines give extra capacity to penetrate
vertically the nasty weather.
• VFR is not so much regulated as IFR and it is the
responsibility of the pilot to maintain VMC. In VFR en route
and at least in IGA flights alternative route/destination AP´s
are however reasonable to take into account in planning.
4. 09.03.10
Views on IGA – flight planning
• Planning starts normally with longer term ”strategic”
planning and can be done by public weather data.
• In case, also alternative route may be planned in
advance.
• Preliminary calculations on wind/range are done.
• The fuel availibility, opening hours of the AP and
airspace restrictions etc may set limits to planning.
5. 09.03.10
Weather data used in IGA planning
• The general wx-situation is shown best on SW-charts.
• The flight time and range by W/T-charts.
• The more detailed picture by AREA FCST´s: GAMET,
GAFOR or Plain language.
• Most detailed information may be got via special
forecasts, if the route such requires.
• METAR´s and TAF´s on en route are used to check the
weather and its consistency with AREA FCST´s.
• For destination/alternative AP´s TAF´s and METAR´s are
used. If not available, the nearest is normally used.
6. 09.03.10
Weather data used in IGA planning
• SIGMET´s, AIRMET´s and Pilot Reports if
available any.
• WX- radar composite/short fcst+lighting data.
• Satellite imaginery
• ICING and TURB FCST´s if available.
7. 09.03.10
Difficulties experienced in IGA
flight planning
• The different lay out of AREA FCST´s may make them
difficult to interpret for the user.
• The main purpose of AREA FCST´s is to satisfy
domestic users, but for foreign pilots it may be difficult to
understand plain national language forecast.
• The availability of AREA FCST´s for whole route may not
realize allways in IGA.
• If the route crosses several states, there may be a
lenghty exercise to study all the AREA FCST´s having
several small subareas.
8. 09.03.10
Difficulties experienced in IGA
flight planning
• For the user it is time consuming to try locate
the long co-ordinate expressions for weather.
• For the unfamiliar foreign user it may not be
easy to try to locate reported detailed
geographical locations.
• In case of AP self briefing facilities malfunctions
it may not be easy to get assistance in wx-
briefing.
9. 09.03.10
Proposed ways to develope IGA
weather service
• To produce an english version of AREA FCST`s
if such not exists.
• To develope internet availability of AREA
FCST´s from EUR area.
• To harmonize the used lay out´s.
• To consider the use of graphical or other
interpretation forms easy for the user.
• To encourage the use of pilot reports.
10. 09.03.10
Typical operational values of GA - planes
• Most planes are not certified to known icing.
• Normal category is +3,8g - -1,5g. In practice there is
some extra design g - tolerance.
• Max. landing crosswind components are between
10-20kt.
• Most GA - planes have free aspirated engines and
have limited capability of climbing at or near MTOW
when approaching 10 000ft especially above
standard temperatures.
• Endurance is normally 3-6h and cruise spds 80-
250kt.
11. 09.03.10
VMC in controlled airspace/day
• Airspace
• class:
• A, B, C, D, E
VFR generally
at night: 3km in
landing circuit,
en route 8km
and no CLD
BLW 2000ft.
