Office of Aviation Safety
Weather Wise
Donald Eick & Paul Suffern
NTSB Meteorologists
2
Two Feet
of Snow
3
• Review Part 91 accident statisticsReview Part 91 accident statistics
– Main weather threat areasMain weather threat areas
– ThunderstormsThunderstorms
• Making weather wise decisionsMaking weather wise decisions
– Preflight weather briefingPreflight weather briefing
– Utilizing briefing sourcesUtilizing briefing sources
– UpdatesUpdates
– Weather in the cockpitWeather in the cockpit
Topics that will be discussed:Topics that will be discussed:
4
NTSB Accident Statistics
• 4,958 accidents
• 1,641 fatalities
• Weather was
cited as a cause
or factor in over
20% of these
accidents
5
NTSB Study 2007-2009
• > 60% Part 91 accidents involved
personal flights with fixed-wing aircraft
• Major CAST defining events:
– Loss of control in flight/ground (LOC)
– Abnormal runway contact
– Controlled flight into terrain
– Unintended flight into IMC
– Thunderstorms/Windshear
6
Part 91 Weather Related Accidents
2007-2009
7
Part 91 Weather Related Accidents
• Leading weather factors:
– Adverse winds
– Low ceilings & visibility
– High density altitude
– Aircraft icing; includes carburetor icing
– Turbulence
– Thunderstorms
– Windshear
– Precipitation; rain, snow, drizzle/mist, hail
8
ADVERSE WINDS
ACCOUNTS FOR ~52% OF WEATHERACCOUNTS FOR ~52% OF WEATHER
RELATED ACCIDENTS:RELATED ACCIDENTS:
• HIGH WINDHIGH WIND
• CROSSWINDCROSSWIND
• TAILWINDTAILWIND
• GUSTSGUSTS
• WIND SHIFTSWIND SHIFTS
• VARIABLE WINDVARIABLE WIND
9
Weather Related Accidents
Weather related accidents have one ofWeather related accidents have one of
the highest fatality rates!the highest fatality rates!
10
Unfavorable Winds & High Density Altitude
LAX07FA258
Quartering crosswind & tailwind
11
Fatal 2Fatal 2
Serious 2Serious 2
LAX07FA258
Cameron Park, CA
Aug 30, 2007
12
Before you launch, get a
preflight briefing!
13
Preflight Planning
NTSB study 41% of the weather relatedNTSB study 41% of the weather related
accidents the pilot did not obtain oraccidents the pilot did not obtain or
received an adequate weather briefingreceived an adequate weather briefing
14
“I looked at the destination forecast and it
indicated VFR conditions?”
Departure Destination
• What about the en route conditions?
• When was the forecast issued?
• Any adverse weather predicted?
• What’s in the surrounding area?
15
Say… what’s a mountain goat doingSay… what’s a mountain goat doing
way up here in a cloud bank?way up here in a cloud bank?
16
FOG
Not a violent or dynamic weather eventNot a violent or dynamic weather event!!
Most common cause of Part 91 weather relatedMost common cause of Part 91 weather related
fatalities - VFR into IMC conditions.fatalities - VFR into IMC conditions.
Number 1 cause of ATC delaysNumber 1 cause of ATC delays
Common factor in runway incursion incidents &Common factor in runway incursion incidents &
accidents.accidents.
Common factor in Part 135/121 CFIT accidentsCommon factor in Part 135/121 CFIT accidents
Flight crew not adhering to standard instrumentFlight crew not adhering to standard instrument
approach procedures.approach procedures.
Low Ceilings & Visibility
17
What was the worst aviation
accident in history?
18
Worst Aircraft Accident in History
KLM Flight 4805/Pan Am Flight 1736KLM Flight 4805/Pan Am Flight 1736
Los Rodeos Airport, TenerifeLos Rodeos Airport, Tenerife
March 27, 1977March 27, 1977
19
Tenerife, Canary Islands
Pan Am and KLM B747’s
March 22, 1977
583 fatalities
20
VFR into IMCVFR into IMC
21
ERA09LA392
RV7A, N774US
Sanderson, FL
July 8, 2009
• Non-instrument rated pilot
• Departed VFR cross country to pickup friend
and fly back to Sun City, FL
• No flight plan or preflight briefing
• Departure/destination - VFR
22
ERA09LA392 – Sanderson, FL
• Current conditions:
– Stationary front
– Convective activity
• Encountered area of
thunderstorms
• Low overcast ceilings,
rain and thunder
reported by witness
WX 240º 5KT 2 1/2SM TSRA BKN010 OVC020 23/22
A2990 RMK TSB14 OCNL LTGCG TS S MOV E
23
ERA09LA39 - Sanderson, FL
24
ERA09LA39 - Sanderson, FL
25
ERA09LA392 – Sanderson, FL
Fatal 1
26
FAR 91.103 – Preflight ActionFAR 91.103 – Preflight Action
27
Safety, better to think about itSafety, better to think about it
down here than worry about itdown here than worry about it
up there!up there!
28
• Automated Flight Service Station (AFSS)Automated Flight Service Station (AFSS)
1-800-WX-BRIEF*1-800-WX-BRIEF*
• Direct User Access Terminal ServiceDirect User Access Terminal Service
(DUATS)*(DUATS)*
• Internet sourcesInternet sources
• Private VenderPrivate Vender
• * Only recognized official sources* Only recognized official sources
Weather Briefing SourcesWeather Briefing Sources
29
• Adverse weatherAdverse weather
• SynopsisSynopsis
• Current conditionsCurrent conditions
• En route forecastEn route forecast
• Destination forecastDestination forecast
• Alternate planningAlternate planning
• Winds aloftWinds aloft
• Notice to AirmenNotice to Airmen
AFSS Standard Briefing
30
Internet Weather
A picture is
worth a
thousand
words!
31
Internet Sources
• Official NWS site
• Domestic &
International
products
• Text & graphical
products
http://aviationweather.gov/
Note chart – quick
indications of
IFR/MVFR/VFR areas,
turbulence, and icing
32
NWS Internet
33
Aviation Weather Services
AC 00-45GAC 00-45G
• Basic reference guide how to
read and interpret all NWS
weather products.
• Listed as required knowledge
in FAA Airmen test guides.
http://www.faa.gov/regulations_policies/
34
NWS Aviation Weather
http://aviationweather.gov/std_brief/
35
NWS Surface Analysis
36
Thunderstorms
Sun ‘n’ Fun March 31, 2011
Severe Thunderstorm winds of 65KT
40 aircraft damaged or destroyed
37
38
39
40
NWS Weather Radar
41
March 31, 2011
LCLLCL
42
Weather Watch (AWW)
WW 80 TORNADO FL CW 311000Z - 311700Z AXIS..75
STATUTE MILES EAST AND WEST OF LINE.. 20NE
OCF/OCALA FL/ - 55WSW PBI/WEST PALM BEACH FL/
..AVIATION COORDS.. 65NM E/W /46W OMN - 48NW MIA/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60
KNOTS. MAX TOPS TO 550. MEAN STORM MOTION
VECTOR 25040.
Discussion..an ongoing Quasi-Linear ComplexDiscussion..an ongoing Quasi-Linear Complex
of strong/severe TSTMS including embeddedof strong/severe TSTMS including embedded
supercells and bow echoes moving eastwardsupercells and bow echoes moving eastward
across central Florida. Conditions favorable foracross central Florida. Conditions favorable for
damaging winds and a few tornadoes.damaging winds and a few tornadoes.
43
44
45
Significant Weather Charts
• Pressure
centers
• Fronts
• Wind flow
• Precip type,
coverage
46
Satellite Imagery
47
Convection
48
Convective SIGMETs
49
NWS Convective Outlook Chart
• Convective Outlook (AC) – organized
areas of severe thunderstorms
50
Get the Big Picture
51
Convective SIGMETs
52
53
One final
thought on
preflight
planning!
54
• Forecasts are not always perfect!Forecasts are not always perfect!
• Weather conditions changeWeather conditions change – is there a– is there a
front expected in the vicinity, convectionfront expected in the vicinity, convection
expected, night or early morning arrival?expected, night or early morning arrival?
Get an update!Get an update!
• Flight WatchFlight Watch
• HIWAS & other weather broadcastsHIWAS & other weather broadcasts
In-flight Briefing
55
Weather Update
• NWS products are updated at
regular intervals
– TAFs updated 6-hr, AMD as necessary
– Convective SIGMETs – hourly 55
– AIRMETs – every 6-hr, AMD
– SIGMETs - unscheduled
– Weather Watches
• PIREPs
56
Hazardous Inflight Weather
Advisory Service (HIWAS)
• Selected VORs continuous broadcast
of inflight weather advisories within
150NM
57
En Route Flight Advisory Service
(EFAS)
• EFAS radio call “Flight Watch”
• Available 0600-2200 local
• Below FL180 on 122.0 MHz
• Discrete frequencies above FL180
58
Weather in the Cockpit
• Access to updated weather en route
• Increased situational awareness
• Caution with data lag (NEXRAD)
• Spatial resolution of data
59
60
 Conditions worst than expected?Conditions worst than expected?
 Make a command decision – divert,Make a command decision – divert,
alter plan, turn backalter plan, turn back
Wait it out & take a breakWait it out & take a break
 Consider: frontal position, prevailingConsider: frontal position, prevailing
wind, convection, time of daywind, convection, time of day
Don’t push a bad situation!
61
ThunderstormsThunderstorms
62
Why is the Thunderstorm the most
Dangerous Aviation Weather
Hazard?
The greatest number of aviationThe greatest number of aviation
weather hazards are bundled up in oneweather hazards are bundled up in one
single source, the thunderstorm.single source, the thunderstorm.
63
 Squall LineSquall Line
 TornadoesTornadoes
 TurbulenceTurbulence
 IcingIcing
 HailHail
 Low ceilings & visibilitiesLow ceilings & visibilities
 Altimeter errorsAltimeter errors
 LightningLightning
 Heavy rain, variable winds & runwayHeavy rain, variable winds & runway
contaminationcontamination
 Engine water ingestionEngine water ingestion
 Wind shear/Wind shear/MicroburstsMicrobursts
 Radar attenuationRadar attenuation
Thunderstorm Hazards AC 00-24BThunderstorm Hazards AC 00-24B
64
65
66
Gust Fronts Hazards
67
68
CEN09FA369
Cessna 182, N1826T
Dougherty, TX
June 18, 2009
• VFR cross country
• No weather briefing/flight
plan filed
• Witnesses reported
blowing dust & high
gusting winds at the time
• Loss of control in flight
after encountered
thunderstorm gust front
• Fatal 2
KLBB 26037G51KT 3/4SM BLDU SCT030 BKN070
24/14 A2990 RMK CB DSNT W-NW
69
Accident siteAccident site
70
71
72
Thunderstorms
• All thunderstorms imply severe and
greater turbulence
73
NWS VIP WSR-88D LVL
PRECIP MODE
dBZ
RAINFALL
0
 
0
1
2
<5
5  to 9
10 to 14
 
1 
VERY LIGHT
3
4
5
15 to 19
20 to 24
25 to 29
.02 /hr
 
2
LIGHT TO 
MODERATE
6
7
30 to 34
35 to 39
.09/hr
3
STRONG
8 40 to 44 .48/hr
4
VERY STRONG
9 45 to 49 2.50/hr
5
INTENSE
10 50 to 54 5.70/hr
6
EXTREME
11
12
13
14
15
55 to 59
60 to 64
65 to 69
70 to 74
     >  75
12.0/hr
 
 
 
VIP/DBZ Conversion Chart
Weather _
AC00-24B
• LGT-MOD Turb
and LTG possible
• SVR Turb and LTG
possible
• SVR Turb likely
With LTG
• SVR Turb, LTG and
GR likely, wind gusts
• SVR-EXTRM Turb,
LTG, large GR,
extensive wind gusts
74
30
40
45
50
55
60
60+
20
30
40
50
50+
20
Airborne
Radar
AC 25-11
NWS
VIP Levels
30
40
46
50
56
57+
18
Lvl 1
Lvl 2
Lvl 3
Lvl 4
Lvl 5
Lvl 6
>30
40
46
50
57
57+
Lvl 1
Lvl 2
Lvl 3
Lvl 4
Lvl 5
Lvl 6
ASR-9
Intensity
Light
Moderate
Heavy
Heavy
Extreme
Extreme
20
30
40
45
50
55
Unisys
DTN WSI
N
N N
10
15
20
25
30
35
40
45
50
55
60
65
70
75
NEXRAD
Cockpit
DO-267
10-30
>45-50
>50-55
>40
>30-40
>55
BoundariesFAA
Revised
Terms
Existing Systems and BoundariesAir Traffic Control
N = National Map
I = Individual Site
# = Radar Return in dBZ
4 levels
75
Weather And Radar Processor (WARP)Weather And Radar Processor (WARP)
76
NTSB Safety Alert
77
• IFR Part 135 flight from 
McKinney, TX (TKI) to 
Tampa, FL (TPA)
• Equipped with airborne 
weather radar, 
StormScope, XM satellite
• Weather briefing
• Anticipated deviating 
around weather
ERA09FA389
Cessna 421C, N4467D
Gulf of Mexico
July 8, 2009
78
79
Natures sign post in the sky!Natures sign post in the sky!
80
“Mr. Eick, may I be excused?
My brain is full”
81
Questions?Questions?
eickd@ntsb.goveickd@ntsb.gov
202-314-6384202-314-6384
Paul.Suffern@ntsb.govPaul.Suffern@ntsb.gov
202-314-6338202-314-6338
82
83
84
CEN11FA500
Piper Malibu PA-46, N46TW
Rantoul, IL
July 24, 2011
Encounter with severe weather at takeoff. Fatal 3.
85
Rantoul, IL
• Pilot obtained internet weather 
briefing and filed IFR flight plan
• Rantoul (KTIP) to Sarasota (KSRQ)
• In hurry to beat weather front 
moving through area
86
Surface Analysis
87
CEN11FA500 - Rantoul, IL
Photo’s taken by passenger on board accident airplane
88
CEN11FA500 - Rantoul, IL
89
CEN11FA500 - Rantoul, IL
1,163 lightning strikes within 30NM and 15-min of accident

NTSB presents: Weatherwise

  • 1.
    Office of AviationSafety Weather Wise Donald Eick & Paul Suffern NTSB Meteorologists
  • 2.
  • 3.
    3 • Review Part91 accident statisticsReview Part 91 accident statistics – Main weather threat areasMain weather threat areas – ThunderstormsThunderstorms • Making weather wise decisionsMaking weather wise decisions – Preflight weather briefingPreflight weather briefing – Utilizing briefing sourcesUtilizing briefing sources – UpdatesUpdates – Weather in the cockpitWeather in the cockpit Topics that will be discussed:Topics that will be discussed:
  • 4.
    4 NTSB Accident Statistics •4,958 accidents • 1,641 fatalities • Weather was cited as a cause or factor in over 20% of these accidents
  • 5.
    5 NTSB Study 2007-2009 •> 60% Part 91 accidents involved personal flights with fixed-wing aircraft • Major CAST defining events: – Loss of control in flight/ground (LOC) – Abnormal runway contact – Controlled flight into terrain – Unintended flight into IMC – Thunderstorms/Windshear
  • 6.
    6 Part 91 WeatherRelated Accidents 2007-2009
  • 7.
    7 Part 91 WeatherRelated Accidents • Leading weather factors: – Adverse winds – Low ceilings & visibility – High density altitude – Aircraft icing; includes carburetor icing – Turbulence – Thunderstorms – Windshear – Precipitation; rain, snow, drizzle/mist, hail
  • 8.
    8 ADVERSE WINDS ACCOUNTS FOR~52% OF WEATHERACCOUNTS FOR ~52% OF WEATHER RELATED ACCIDENTS:RELATED ACCIDENTS: • HIGH WINDHIGH WIND • CROSSWINDCROSSWIND • TAILWINDTAILWIND • GUSTSGUSTS • WIND SHIFTSWIND SHIFTS • VARIABLE WINDVARIABLE WIND
  • 9.
    9 Weather Related Accidents Weatherrelated accidents have one ofWeather related accidents have one of the highest fatality rates!the highest fatality rates!
  • 10.
    10 Unfavorable Winds &High Density Altitude LAX07FA258 Quartering crosswind & tailwind
  • 11.
    11 Fatal 2Fatal 2 Serious2Serious 2 LAX07FA258 Cameron Park, CA Aug 30, 2007
  • 12.
    12 Before you launch,get a preflight briefing!
  • 13.
    13 Preflight Planning NTSB study41% of the weather relatedNTSB study 41% of the weather related accidents the pilot did not obtain oraccidents the pilot did not obtain or received an adequate weather briefingreceived an adequate weather briefing
  • 14.
    14 “I looked atthe destination forecast and it indicated VFR conditions?” Departure Destination • What about the en route conditions? • When was the forecast issued? • Any adverse weather predicted? • What’s in the surrounding area?
  • 15.
    15 Say… what’s amountain goat doingSay… what’s a mountain goat doing way up here in a cloud bank?way up here in a cloud bank?
  • 16.
    16 FOG Not a violentor dynamic weather eventNot a violent or dynamic weather event!! Most common cause of Part 91 weather relatedMost common cause of Part 91 weather related fatalities - VFR into IMC conditions.fatalities - VFR into IMC conditions. Number 1 cause of ATC delaysNumber 1 cause of ATC delays Common factor in runway incursion incidents &Common factor in runway incursion incidents & accidents.accidents. Common factor in Part 135/121 CFIT accidentsCommon factor in Part 135/121 CFIT accidents Flight crew not adhering to standard instrumentFlight crew not adhering to standard instrument approach procedures.approach procedures. Low Ceilings & Visibility
  • 17.
    17 What was theworst aviation accident in history?
  • 18.
    18 Worst Aircraft Accidentin History KLM Flight 4805/Pan Am Flight 1736KLM Flight 4805/Pan Am Flight 1736 Los Rodeos Airport, TenerifeLos Rodeos Airport, Tenerife March 27, 1977March 27, 1977
  • 19.
    19 Tenerife, Canary Islands PanAm and KLM B747’s March 22, 1977 583 fatalities
  • 20.
  • 21.
    21 ERA09LA392 RV7A, N774US Sanderson, FL July8, 2009 • Non-instrument rated pilot • Departed VFR cross country to pickup friend and fly back to Sun City, FL • No flight plan or preflight briefing • Departure/destination - VFR
  • 22.
    22 ERA09LA392 – Sanderson,FL • Current conditions: – Stationary front – Convective activity • Encountered area of thunderstorms • Low overcast ceilings, rain and thunder reported by witness WX 240º 5KT 2 1/2SM TSRA BKN010 OVC020 23/22 A2990 RMK TSB14 OCNL LTGCG TS S MOV E
  • 23.
  • 24.
  • 25.
  • 26.
    26 FAR 91.103 –Preflight ActionFAR 91.103 – Preflight Action
  • 27.
    27 Safety, better tothink about itSafety, better to think about it down here than worry about itdown here than worry about it up there!up there!
  • 28.
    28 • Automated FlightService Station (AFSS)Automated Flight Service Station (AFSS) 1-800-WX-BRIEF*1-800-WX-BRIEF* • Direct User Access Terminal ServiceDirect User Access Terminal Service (DUATS)*(DUATS)* • Internet sourcesInternet sources • Private VenderPrivate Vender • * Only recognized official sources* Only recognized official sources Weather Briefing SourcesWeather Briefing Sources
  • 29.
    29 • Adverse weatherAdverseweather • SynopsisSynopsis • Current conditionsCurrent conditions • En route forecastEn route forecast • Destination forecastDestination forecast • Alternate planningAlternate planning • Winds aloftWinds aloft • Notice to AirmenNotice to Airmen AFSS Standard Briefing
  • 30.
    30 Internet Weather A pictureis worth a thousand words!
  • 31.
    31 Internet Sources • OfficialNWS site • Domestic & International products • Text & graphical products http://aviationweather.gov/ Note chart – quick indications of IFR/MVFR/VFR areas, turbulence, and icing
  • 32.
  • 33.
    33 Aviation Weather Services AC00-45GAC 00-45G • Basic reference guide how to read and interpret all NWS weather products. • Listed as required knowledge in FAA Airmen test guides. http://www.faa.gov/regulations_policies/
  • 34.
  • 35.
  • 36.
    36 Thunderstorms Sun ‘n’ FunMarch 31, 2011 Severe Thunderstorm winds of 65KT 40 aircraft damaged or destroyed
  • 37.
  • 38.
  • 39.
  • 40.
  • 41.
  • 42.
    42 Weather Watch (AWW) WW80 TORNADO FL CW 311000Z - 311700Z AXIS..75 STATUTE MILES EAST AND WEST OF LINE.. 20NE OCF/OCALA FL/ - 55WSW PBI/WEST PALM BEACH FL/ ..AVIATION COORDS.. 65NM E/W /46W OMN - 48NW MIA/ HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS. MAX TOPS TO 550. MEAN STORM MOTION VECTOR 25040. Discussion..an ongoing Quasi-Linear ComplexDiscussion..an ongoing Quasi-Linear Complex of strong/severe TSTMS including embeddedof strong/severe TSTMS including embedded supercells and bow echoes moving eastwardsupercells and bow echoes moving eastward across central Florida. Conditions favorable foracross central Florida. Conditions favorable for damaging winds and a few tornadoes.damaging winds and a few tornadoes.
  • 43.
  • 44.
  • 45.
    45 Significant Weather Charts •Pressure centers • Fronts • Wind flow • Precip type, coverage
  • 46.
  • 47.
  • 48.
  • 49.
    49 NWS Convective OutlookChart • Convective Outlook (AC) – organized areas of severe thunderstorms
  • 50.
  • 51.
  • 52.
  • 53.
  • 54.
    54 • Forecasts arenot always perfect!Forecasts are not always perfect! • Weather conditions changeWeather conditions change – is there a– is there a front expected in the vicinity, convectionfront expected in the vicinity, convection expected, night or early morning arrival?expected, night or early morning arrival? Get an update!Get an update! • Flight WatchFlight Watch • HIWAS & other weather broadcastsHIWAS & other weather broadcasts In-flight Briefing
  • 55.
    55 Weather Update • NWSproducts are updated at regular intervals – TAFs updated 6-hr, AMD as necessary – Convective SIGMETs – hourly 55 – AIRMETs – every 6-hr, AMD – SIGMETs - unscheduled – Weather Watches • PIREPs
  • 56.
    56 Hazardous Inflight Weather AdvisoryService (HIWAS) • Selected VORs continuous broadcast of inflight weather advisories within 150NM
  • 57.
    57 En Route FlightAdvisory Service (EFAS) • EFAS radio call “Flight Watch” • Available 0600-2200 local • Below FL180 on 122.0 MHz • Discrete frequencies above FL180
  • 58.
    58 Weather in theCockpit • Access to updated weather en route • Increased situational awareness • Caution with data lag (NEXRAD) • Spatial resolution of data
  • 59.
  • 60.
    60  Conditions worstthan expected?Conditions worst than expected?  Make a command decision – divert,Make a command decision – divert, alter plan, turn backalter plan, turn back Wait it out & take a breakWait it out & take a break  Consider: frontal position, prevailingConsider: frontal position, prevailing wind, convection, time of daywind, convection, time of day Don’t push a bad situation!
  • 61.
  • 62.
    62 Why is theThunderstorm the most Dangerous Aviation Weather Hazard? The greatest number of aviationThe greatest number of aviation weather hazards are bundled up in oneweather hazards are bundled up in one single source, the thunderstorm.single source, the thunderstorm.
  • 63.
    63  Squall LineSquallLine  TornadoesTornadoes  TurbulenceTurbulence  IcingIcing  HailHail  Low ceilings & visibilitiesLow ceilings & visibilities  Altimeter errorsAltimeter errors  LightningLightning  Heavy rain, variable winds & runwayHeavy rain, variable winds & runway contaminationcontamination  Engine water ingestionEngine water ingestion  Wind shear/Wind shear/MicroburstsMicrobursts  Radar attenuationRadar attenuation Thunderstorm Hazards AC 00-24BThunderstorm Hazards AC 00-24B
  • 64.
  • 65.
  • 66.
  • 67.
  • 68.
    68 CEN09FA369 Cessna 182, N1826T Dougherty,TX June 18, 2009 • VFR cross country • No weather briefing/flight plan filed • Witnesses reported blowing dust & high gusting winds at the time • Loss of control in flight after encountered thunderstorm gust front • Fatal 2 KLBB 26037G51KT 3/4SM BLDU SCT030 BKN070 24/14 A2990 RMK CB DSNT W-NW
  • 69.
  • 70.
  • 71.
  • 72.
    72 Thunderstorms • All thunderstormsimply severe and greater turbulence
  • 73.
    73 NWS VIP WSR-88DLVL PRECIP MODE dBZ RAINFALL 0   0 1 2 <5 5  to 9 10 to 14   1  VERY LIGHT 3 4 5 15 to 19 20 to 24 25 to 29 .02 /hr   2 LIGHT TO  MODERATE 6 7 30 to 34 35 to 39 .09/hr 3 STRONG 8 40 to 44 .48/hr 4 VERY STRONG 9 45 to 49 2.50/hr 5 INTENSE 10 50 to 54 5.70/hr 6 EXTREME 11 12 13 14 15 55 to 59 60 to 64 65 to 69 70 to 74      >  75 12.0/hr       VIP/DBZ Conversion Chart Weather _ AC00-24B • LGT-MOD Turb and LTG possible • SVR Turb and LTG possible • SVR Turb likely With LTG • SVR Turb, LTG and GR likely, wind gusts • SVR-EXTRM Turb, LTG, large GR, extensive wind gusts
  • 74.
    74 30 40 45 50 55 60 60+ 20 30 40 50 50+ 20 Airborne Radar AC 25-11 NWS VIP Levels 30 40 46 50 56 57+ 18 Lvl1 Lvl 2 Lvl 3 Lvl 4 Lvl 5 Lvl 6 >30 40 46 50 57 57+ Lvl 1 Lvl 2 Lvl 3 Lvl 4 Lvl 5 Lvl 6 ASR-9 Intensity Light Moderate Heavy Heavy Extreme Extreme 20 30 40 45 50 55 Unisys DTN WSI N N N 10 15 20 25 30 35 40 45 50 55 60 65 70 75 NEXRAD Cockpit DO-267 10-30 >45-50 >50-55 >40 >30-40 >55 BoundariesFAA Revised Terms Existing Systems and BoundariesAir Traffic Control N = National Map I = Individual Site # = Radar Return in dBZ 4 levels
  • 75.
    75 Weather And RadarProcessor (WARP)Weather And Radar Processor (WARP)
  • 76.
  • 77.
    77 • IFR Part 135 flight from  McKinney, TX (TKI) to  Tampa, FL (TPA) • Equipped with airborne  weather radar,  StormScope, XM satellite •Weather briefing • Anticipated deviating  around weather ERA09FA389 Cessna 421C, N4467D Gulf of Mexico July 8, 2009
  • 78.
  • 79.
  • 80.
    80 “Mr. Eick, mayI be excused? My brain is full”
  • 81.
  • 82.
  • 83.
  • 84.
    84 CEN11FA500 Piper Malibu PA-46,N46TW Rantoul, IL July 24, 2011 Encounter with severe weather at takeoff. Fatal 3.
  • 85.
    85 Rantoul, IL • Pilot obtained internet weather  briefing and filed IFR flight plan •Rantoul (KTIP) to Sarasota (KSRQ) • In hurry to beat weather front  moving through area
  • 86.
  • 87.
    87 CEN11FA500 - Rantoul,IL Photo’s taken by passenger on board accident airplane
  • 88.
  • 89.
    89 CEN11FA500 - Rantoul,IL 1,163 lightning strikes within 30NM and 15-min of accident

Editor's Notes

  • #6 Coding structure developed by the ICAO Commercial Aviation Safety Team (CAST) to describe the important circumstances of aviation accidents, rather than the probable cause.
  • #47 Update to match March 31, 2011 thunderstorm event at 1800Z for Sun ‘n’ Fun