Bentonville Municipal Airport · 1.5 miles west-southwest of campus · field elevation ~1,298 ft MSL
Fetching the latest observation…
Your call, before anything else
A flight from campus in the next hour, under the BHS Training Multirotor Profile. Commit now. It isn’t graded: you’ll check it against the limits at the end of the day, and a wrong first call is where the lessons start.
FAA 3 SM visibility · 500 ft below any cloud · 400 ft AGL ATC 100 ft AGL at this field in Class E hours Program 15 kt sustained · 20 kt gust · no precipitation
ATC BHS is inside the Bentonville (KVBT) Class E surface area from 5:30 AM to 11:00 PM: a flight from campus then needs ATC authorization (§ 107.41) and stays at or below the altitude it approves, 100 ft AGL on the program’s authorizations. Overnight it’s Class G, and the 400 ft cap applies.
From the sky group and remarks aboveHeights to scale, AGL at KVBT, not over campus. The limit holds only if that layer is over your site. Vertical distances only: the 2,000 ft horizontal distance from a cloud’s sides isn’t in any report, so it gets settled at the site.
What this report can’t tell you
The flight visibility you can see from your control station
Where the clouds actually are relative to your aircraft
Whether any cloud, low scud and ragged bases included, will be within 2,000 ft horizontally of where you fly
Whether the reported layer is over your operating area at all
Whether the ATC authorization this field needs is in hand, and the altitude it approves
Terrain and elevation differences between the airport and your site
How old this observation is by the time you fly
Whether conditions have changed since it was issued
Those are yours to check, and so is the call.
Bellringer
Turn in today’s bellringer
Download the PDF, filled in from your answers with your name and record ID, then upload it to today’s Google Classroom assignment. Your name is only on the PDF; on a shared computer, delete it afterward.
Anatomy of a METAR
Lesson 1 of 10 · Read it · ~10 min
By the end of this lesson you can name every group in a METAR, in order, and say which ones a drone pilot acts on.
Worked example
Adapted from the example in the FAA’s Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25), which prints OVC012CB: an AUTO report can’t type a cloud, so the CB is dropped here
Two right in a row, on two different reports, completes this lesson.
One thing to get straight now
A METAR is evidence, not the legal standard. § 107.51 is written around the flight visibility you observe from your control station, not a sensor’s prevailing visibility at an airport miles away. Cloud heights are AGL at the reporting field.
Read the METAR, then confirm it with your own eyes.
Then read the remarks
Everything after RMK. Times are minutes past the hour when they fall in the report’s own hour.
Read it
All the remarks to know
AO1 / AO2
Automated station without / with a rain-snow sensor
AO1 can’t tell rain from snow.
PK WND 28045/15
Peak wind 45 kt from 280°, at :15
A gust stronger than the report body shows.
WSHFT 30 FROPA
Wind shift at :30, with a front passing
The weather just changed.
RAB05E30
Rain began at :05, ended at :30
It was raining this hour.
TSB25 TS SE MOV NE
Thunderstorm began at :25, southeast, moving northeast
Where the storm is, and where it’s going.
LTG DSNT W
Lightning in the distance to the west (beyond 10 miles)
A storm you can’t see yet.
VIS 1/2V2
Visibility varying from 1/2 to 2 SM
Plan with the low end.
CIG 005V010
Ceiling varying from 500 to 1,000 ft
Plan with the lowest.
PRESFR / PRESRR
Pressure falling / rising rapidly
Falling fast often comes ahead of a front.
SLP132
Sea-level pressure 1013.2 mb
Context, not a limit.
TSNO · PWINO · $
Thunderstorm sensor out · weather sensor out · station needs maintenance
The report can’t see everything it normally would.
On the test From the FAA’s sample Remote Pilot questions (testing supplement, Figure 12)
SPECI KMDW 121856Z 32005KT 1 1/2SM RA OVC007 17/16 A2980 RMK RAB35
What are the current conditions for Chicago Midway Airport (KMDW)?
Sky 700 feet overcast, visibility 1-1/2SM, rain.
Sky 7,000 feet overcast, visibility 1-1/2SM, heavy rain.
Sky 700 feet overcast, visibility 11, occasionally 2SM, with rain.
Answer
A. OVC007 is 700 ft (hundreds of feet), RA without a sign is moderate rain, and 1 1/2SM is one group: a whole number and a fraction.
Put It in Order
Lesson 2 of 10 · Read it · ~5 min
A METAR always follows the same field sequence. Get it into muscle memory and you’ll notice instantly when something is missing. By the end you can put any report’s groups in order without the colors to help.
1Report typeMETAR or SPECI
2StationKVBT
3Date/time011753Z
4ModifierAUTO, COR · may be absent
5Wind20010G22KT
6Visibility10SM · RVR after it, if any
7Weather-RA BR · may be absent
8SkyFEW080 OVC095
9Temp/dew22/19
10AltimeterA2992
11RemarksRMK AO2 … · may be absent
Groups marked “may be absent” are optional: a report can leave them out. The others are routine, though one can drop out when a sensor isn’t reporting. Field groups follow this standard sequence, although international formats differ in some details.
Arrange these fields
Pieces
Your answer, left to right
What’s missing?
Why the order matters
Groups have no labels. You know 10SM is visibility partly because of how it’s written, and partly because of where it sits: right after the wind. When a group is missing, the order is how you notice.
Read left to right, every time.
On the test Adapted from an FAA sample question
SPECI KJFK 121853Z 18004KT 1/2SM R04R/2200FT FG OVC005 20/18 A3006
The wind direction and velocity at KJFK is from
180° true at 4 knots.
180° magnetic at 4 knots.
040° true at 18 knots.
Answer
A. The wind group sits right after the time: 18004KT. C is what you get reading numbers out of the wrong groups. METAR wind is true, not magnetic.
Zulu Time
Lesson 3 of 10 · Read it · ~10 min
METAR and TAF timestamps are UTC, spoken as “Zulu.” Nobody converts it for you, and the exam won’t either. By the end you can convert both ways, across midnight, and say how old a report is.
Two clocks, one moment
Swipe the ruler sideways for all 24 hours.
Select any hour to pair it. Watch the date row: the first few Zulu hours of a day are still the day before in Arkansas.
UTC − 5Central Daylight Time (CDT), from 2 a.m. on the second Sunday in March to 2 a.m. on the first Sunday in November
UTC − 6Central Standard Time (CST), the rest of the year
Getting the season wrong is the single most common way to blow this conversion. Zulu to local: subtract. Local to Zulu: add.
Convert it
Answer in 24-hour time, four digits. Uses today’s real offset.
Five right in a row completes this lesson. Skipping one with New resets the streak.Streak 0 · Best 0
Quick check
A METAR is stamped 081453Z. It’s 0920 local time in Arkansas, during Central Standard Time (UTC − 6). How old is this observation?
Why reports land in the :50s
Most timestamps fall between :53 and :56, and that isn’t chance. FAA Order JO 7900.5E ¶ 3.5f(3) tells observers to “prepare and code METAR reports for transmission between H+55 and H+00,” and the observation is taken shortly before that.
Not every station works that way. An AWOS generates a METAR every 20 minutes and sends no SPECI, so its stamps don’t cluster in the :50s.
A report stamped 241853Z describes the sky at 18:53 Zulu, not 19:00.
On the test Test-style
SPECI KMDW 121856Z 32005KT 1 1/2SM RA OVC007 17/16 A2980 RMK RAB35
The remarks section for KMDW has RAB35 listed. This entry means
rain began at 1835Z.
rain began at 1935Z.
rain will begin in 35 minutes.
Answer
A. Remark times are minutes past the report’s own hour: the report is 1856Z, so :35 is 1835Z.
Cloud Clearance Drill
Lesson 4 of 10 · Work it · ~10 min
The single most-missed piece of Part 107 weather arithmetic. The rule isn’t about the ceiling. It’s about any cloud. Drill it daily, like Zulu time, until you know the answer instead of working it out.
500 ftFAA§ 107.51(d) below any cloud
2,000 ftFAA§ 107.51(d) horizontally from any cloud
400 ft AGLFAA§ 107.51(b) maximum altitude, in any airspace class
100 ft AGL at the BHS fieldATC§ 107.41 BHS is inside the Bentonville (KVBT) Class E surface area from 5:30 AM to 11:00 PM. A flight from campus then needs ATC authorization and stays at or below the altitude it approves: 100 ft on the program’s authorizations. Overnight it’s Class G.
1lowest cloud of any coverage − 500 ft2then take the lower of that and 400 ft3at the BHS field in Class E hours: the lower of that and your authorized altitude
Work it out
Assume the reported layers are over your operating area and you’re away from any structure. If there’s no room under the cloud, type 0. A report tagged “At the BHS field” is a flight from campus, so step 3 applies.
Three right in a row, on three different questions, completes this lesson.Streak 0 · Best 0
Why it works, and the traps
Under a layer, the 500 ft is the number you plan with. 900 − 500 = 400 ft, and § 107.51(b) caps you at 400 ft AGL anyway, so 400 ft is the planning limit either way, if that layer is over your site. This is the half of the rule a reported cloud height can speak to; the 2,000 ft horizontal distance, next, is the half it can’t.The 2,000 ft measures out from the cloud’s sides. Two aircraft at the same height: the only difference between them is how far each is from the cloud’s side. This figure doesn’t say whether either one is allowed to be there; it only shows which way the 2,000 ft is measured. That distance isn’t in the observation: a METAR reports coverage at the airport, not where the nearest cloud is over your site.
Heights to scale, distances not. Two minimum distances, measured in two different directions, and only the vertical one can be read off a report.
Trap 1: “It’s not a ceiling”
A FEW or SCT layer isn’t a ceiling, but it still counts. The rule says cloud, not ceiling.
Trap 2: “The two make one test”
Under a layer, plan with the 500 ft. The 2,000 ft measures out from a cloud’s sides, and no report can tell you where the nearest cloud is, so that gets settled at the site. The FAA has published no single test combining the two.
Trap 3: “Near a structure”
The § 107.51(b) structure exception lets you go above 400 ft near a structure, but it never lets you into a cloud. The 500 ft still applies.
Trap 4: “400 ft is always the number”
400 ft is the most § 107.51(b) ever allows, in any airspace. In controlled airspace the altitude your ATC authorization approves can be lower, and it governs. At the BHS field in Class E hours it has been 100 ft.
On the test Test-style
Under 14 CFR part 107, what is the minimum distance a small unmanned aircraft must remain below a cloud?
500 feet.
1,000 feet.
2,000 feet.
Answer
A. § 107.51(d) sets 500 ft below a cloud and 2,000 ft horizontally from it. 1,000 ft is how far a manned aircraft stays above a cloud under § 91.155, not a Part 107 number.
Guided Walkthroughs
Lesson 5 of 10 · Work it · ~15 min
Five reports, and the help fades as you go. The first is worked for you, group by group. Then you say what each group means before it’s shown, then the colors go, and the last one you read cold, which is what a real preflight looks like.
A. The ceiling is the lowest broken or overcast layer: BKN070. SCT008 is lower, but scattered isn’t a ceiling. It still counts for cloud clearance.
What Changed?
Lesson 6 of 10 · Work it · ~15 min
A call made an hour ago can expire. Two reports from the same station, an hour or two apart. Find the change that takes the later report past a limit, then decide whether your call changes with it.
Program The calls assume the BHS Training Multirotor Profile: 15 kt sustained, 20 kt gust, no flight in precipitation, and a shorter flight at or above 35 °C.
On the test Test-style
A SPECI is
an unscheduled report taken when significant changes in the weather occur.
a routine report issued every hour.
an amended forecast for the next six hours.
Answer
A. A SPECI goes out between the routine hourly METARs because something changed enough to report early.
Decoder and Builder
Lesson 7 of 10 · Work it · ~15 min
One decoder, three ways in. Decode any report, build one yourself and watch what a real station would never send, or pull a live observation from anywhere. The lesson is the Build challenges: five reports made to order.
US format only: international groups such as CAVOK aren’t supported.
Today’s KVBT report is on the Today view. Reports update about once an hour.
The sky is obscured, with vertical visibility of 100 feet.
Visibility varies by 1 mile.
There is one cloud layer at 1,000 feet.
Answer
A. VV is vertical visibility into an obscuration, in hundreds of feet. It counts as a ceiling.
METAR vs. TAF
Lesson 8 of 10 · Call it · ~15 min
A METAR tells you what the sky is doing; a TAF tells you what a forecaster expects it to do. By the end you can lay your flight window on a TAF and say what’s forecast for it, before you drive to the field.
Your window on today’s TAF
Loading today’s KROG forecast…
TAFKROG…
Your task on today’s TAF
…
A forecast isn’t an observation, and it’s for the airport, not your field. Check the newest METAR and the sky where you stand before you launch.
Worked example: two launches, one forecast
A training report built for this example, not a real observation
METARwhat it is, 1453ZMETAR KROG 141453Z AUTO 18008KT 10SM CLR 28/14 A3008 RMK AO2
The METAR right now looks perfect: 10 SM, light wind, and no cloud detected at or below 12,000 ft (that’s what CLR means on an automated report).
But the TAF forecasts thunderstorms, gusts to 25 kt and 3 SM from 1800Z. A 45-minute flight launched at 1500Z lands before the change. One launched at 1730Z lands at 1815Z, 15 minutes after the thunderstorms are forecast to arrive. The METAR can’t tell you this; only the TAF can.
Reading a TAF line by line
§ 107.49 requires the remote PIC to assess local weather conditions; METARs and TAFs are important tools for doing so. A sound preflight combines current observations with forecasts.
A TAF uses the same wind, visibility, weather and sky codes as a METAR, so what you’ve learned here carries over. What’s new is its first line and its change groups: FM, TEMPO, PROB30, and the BECMG and PROB40 that appear on the knowledge test’s Figure 15.
AC 107-2A points remote pilots to two free sources before every flight:
1800wxbrief.com: a Flight Service briefing, free with an account. Flight Service’s phone line is intended for manned aircraft pilots.
aviationweather.gov: the Aviation Weather Center’s METARs and TAFs, free with no registration. Check tfr.faa.gov for flight restrictions while you’re there.
Then look at the sky where you stand.
On the test Adapted from the testing supplement’s TAF figure (Figure 15)
BECMG 1306/1308 02008KT BKN012
In a TAF, this group means
a gradual change to these conditions between 0600Z and 0800Z on the 13th.
a temporary fluctuation lasting less than an hour.
a 40% chance of these conditions.
Answer
A. BECMG is becoming: a gradual change during the period. TEMPO is temporary, and PROB40 is a 40% chance. NWS TAFs don’t use BECMG or PROB40, but the test’s figure does.
Go / No-Go Trainer
Lesson 9 of 10 · Call it · ~20 min
Three questions, in order: do the reported numbers meet the minimums, would you fly the mission, and how sure are you? The number to watch is confident and wrong.
BHS Training Multirotor Profile
In force for every scenarioProgramclassroom limits 15 kt sustained · 20 kt gust · no flight in precipitation · at or above 35 °C, a shorter flight · haze, mist or smoke, a smaller radiusDetails
Max sustained wind
15 ktProgram
Max gust
20 ktProgram
Precipitation
Flight not permittedProgram
At or above 35 °C
Shorter flight, larger battery reserveProgram
Haze, mist or smoke
Smaller operating radius; keep the aircraft closer than on a clear dayProgram
Program limits are the instructor’s: a classroom training limit, not a universal manufacturer specification.
On the test Test-style
Before flight, 14 CFR 107.49 requires the remote pilot in command to assess the operating environment, including
local weather conditions.
the TAF for the nearest towered airport.
a METAR no more than one hour old.
Answer
A. § 107.49 names local weather conditions. METARs and TAFs are important tools for assessing them, but the rule doesn’t name either one.
Exam Mode
Lesson 10 of 10 · Call it · ~15 min
Ten questions, three choices each, like the real test. No colors and no hints. In Practice and Test, four are built fresh from a random report every run, so they can’t be memorized, and the next run leans toward the topics you missed. Test figures asks about the two weather figures printed in the test’s own supplement.
Cheat sheet
Reference · print it for your binder
Every code in one place. The same facts the lessons teach, on one sheet. Print it and only the sheet comes out, colors included.
Part 107 weather minimums
Flight visibility
3 statute miles, judged from your control station
Below any cloud
500 ft
Horizontally from any cloud
2,000 ft
Maximum altitude
400 ft AGL (unless within a 400 ft radius of a structure and no higher than 400 ft above its uppermost limit, § 107.51(b))
At the BHS field
Class E surface area 5:30 AM to 11:00 PM: ATC authorization required (§ 107.41), and no higher than it approves (100 ft AGL on the program’s authorizations). Class G overnight: 400 ft AGL
Maximum groundspeed
87 knots
METAR times
UTC (Zulu)
Cloud clearance applies to every cloud, FEW and SCT included. § 107.51(d) sets 500 ft as the minimum distance below a cloud and 2,000 ft as the minimum distance horizontally from one. Under a layer the 500 ft is what you plan with; where the nearest cloud actually is isn’t something a report can tell you.
Mist (visibility 5/8 to 6 SM), fog (below 5/8 SM), haze, smoke, dust, sand, volcanic ash
VC
In the vicinity: 5 to 10 miles away, not at the station
Sky coverage
SKC / CLR
SKC: sky clear, from an observer. CLR: no cloud detected at or below 12,000 ft by an automated station
FEW
Few: 1–2 eighths
SCT
Scattered: 3–4 eighths
BKN
Broken: 5–7 eighths
OVC
Overcast: 8 eighths
VVnnn
Vertical visibility: the sky is obscured, e.g. VV003 = vertical visibility 300 ft AGL (an indefinite ceiling)
CB / TCU
Cumulonimbus / towering cumulus, appended to a layer, e.g. BKN040CB
NSC
No significant cloud (ICAO). The US uses SKC or CLR
A ceiling is the lowest BKN, OVC or VV layer. Cloud clearance applies to the lowest layer of any coverage.
Wind codes
00000KT
Calm: no measurable wind
VRB03KT
Variable direction: usually light wind, 6 kt or less, whose direction keeps shifting
21015G25KT
Gust: sustained 15 kt gusting to 25 kt, from 210°
18010KT 150V210
Variable range: from 180°, varying between 150° and 210°
METAR wind is from true north. Tower and ATIS give magnetic. 360° means from the north; 000° appears only in calm (00000KT).
Visibility codes
10SM
Ten statute miles or more, at an automated station: its sensor reports nothing higher
M1/4SM
Less than 1/4 statute mile (M = minus)
1 1/2SM
One and a half statute miles (a space separates whole and fraction)
R28L/2600FT
Runway visual range on runway 28 Left: 2,600 ft
P6SM is a TAF value, not a METAR one. An automated station reports ten miles or more as 10SM. A human observer can report more, as in the 15SM and 30SM of the knowledge test’s Figure 12: read them as that many statute miles.
Report modifiers
AUTO
Fully automated observation: no human observer on duty
COR
Corrected report: replaces the previous observation for this hour
AO1
Automated station without a precipitation discriminator (can’t tell rain from snow)
AO2
Automated station with a precipitation discriminator (most ASOS sites)
Common remark codes
RAB05E30
Rain began at :05, ended at :30 (minutes past the report’s hour)
TSB25 TS SE MOV NE
Thunderstorm began at :25, southeast, moving northeast
LTG DSNT W
Lightning in the distance to the west (beyond 10 miles)
VIS 1/2V2 · CIG 005V010
Visibility / ceiling varying: plan with the low end
SLPnnn
Sea-level pressure in millibars (e.g. SLP132 = 1013.2 mb)
PK WND dddff/(hh)mm
Peak wind: direction and speed / time it happened (e.g. PK WND 28045/15)
WSHFT (hh)mm FROPA
Wind shift and when it began; FROPA if a front passed
PRESFR / PRESRR
Pressure falling / rising rapidly
$
Station needs maintenance: data may be degraded
TSNO
Thunderstorm information not available
PWINO
Present weather identifier not operating
PNO
Precipitation amount not available
FZRANO
Freezing rain information not available
RVRNO
Runway visual range not available
ASOS and AWOS
ASOS
The primary network (NWS, FAA, DoD): a METAR every hour, plus a SPECI when conditions change
AWOS
FAA or non-federal: a METAR every 20 minutes and no SPECI; often fewer elements than ASOS
By radio or phone
Both broadcast observations updated every minute
Where to get the weather
1800wxbrief.com
Flight Service briefing, free with an account (AC 107-2A App. B.3). Its phone line is for manned pilots
aviationweather.gov
Aviation Weather Center: METARs and TAFs, free, no registration
tfr.faa.gov
Temporary flight restrictions: check them too
METAR vs. TAF
METAR
What the weather is: an observation at one field, usually hourly
SPECI
An unscheduled observation, sent when conditions change significantly between hours
TAF
What the weather is expected to be: a forecast for 5 statute miles around the field, issued four times a day
FM ddhhmm
From: conditions change at the given time
BECMG ddhh/ddhh
Becoming: a gradual change during the period
TEMPO ddhh/ddhh
Temporary, and expected: more likely than not. An hour or less each time, together less than half the period
PROB30 ddhh/ddhh
Probability: a 30% chance of the conditions during the period. Not likely, and not nothing. PROB40 (40%) appears in military and international TAFs and on the knowledge test
NOSIG
Not a TAF group: an international METAR trend for "no significant change in the next 2 hours". US METARs don’t use it
§ 107.49 requires the remote PIC to assess local weather conditions; METARs and TAFs are important tools for doing so.
Density altitude
Hot, humid, high, or low-pressure air is thin air: less lift per propeller revolution, so the aircraft works harder for the same hover.
Temperature ↑
Density altitude ↑
Humidity ↑ (small temp/dew spread)
Density altitude ↑
Altimeter setting ↓
Density altitude ↑
Field elevation ↑
Density altitude ↑
What it costs: shorter flight time, slower climb, less hover authority, less margin in an emergency.
Three different questions
1. Reported minimums
Do the numbers in this airport observation meet § 107.51? MET or NOT MET.
2. Site verification
The flight visibility you observe, where the clouds actually are, whether any will be within 2,000 ft horizontally of where you fly, whether the layer is over your area, terrain, observation age, changes since.
3. Operational call
Given the aircraft, the program limits and the hazards: Operational GO, GO with restrictions, or Operational NO-GO.
Reported minimums MET isn’t a clearance for your site. Answer all three, in order.
Program operating limits
Traps to watch for
SM, not NM
Visibility is statute miles.
AGL, not MSL
Cloud heights are above the ground at that field.
True, not magnetic
METAR wind is true north. Tower and ATIS give magnetic.
SCT still counts
Cloud clearance isn’t just about the ceiling.
AUTO isn’t “unreliable”
It means no human observer, not bad data.
Small spread = fog risk
Temperature and dew point within 2 °C (4 °F).
That airport isn’t your field
Conditions and ground elevation both differ.
Wind isn’t a Part 107 number
No maximum wind speed in the rule. Limits come from the aircraft and local policy.
Thunderstorms are a hazard
Not an enumerated numerical prohibition, but § 107.49 and § 107.19 still apply.
Turn in your progress
Everything this browser has saved
Your record, on one PDF. Every lesson, today’s work, and how the drills and the exam went. Download it and upload it where your instructor asks.
Download your progress report
The PDF carries your name and record ID. Your name is only on the PDF; on a shared computer, delete it afterward.
Check today’s call
Last step · ~5 min
There’s no answer key for today, and that’s the point. Here’s every reading from today’s report next to the rule or limit it’s held against. Hold your call up to it.
FAAa Part 107 rule, cited by sectionProgramthe instructor’s classroom training limit
Your flight orders. Two Letter pages: today’s brief on the front, aircraft checkout on the back. Print them, take them to checkout, and turn them in when the drone is back.
