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Uncontrolled airports
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Contents:
...Reference; ..Non-tower Overflights; ...Controlling the Uncontrolled Airport; ..Non-tower Operation; …Two kinds of unicom; ...The callup; ...Non-Tower Airport Arrival Procedures; ...Visual Indicators at Uncontrolled Airports ; …Wind sock; ...Uncontrolled Airport Traffic patterns; ....Traffic Indicators; ...What I dislike in this option is; ...Common Mistakes at Non-Tower Airports; ...Uncontrolled Airport Departures; Non-unicom Uncontrolled Airports
Reference
By sending a 9x11 envelope with 78 cents postage to
AOPA Air Safety Foundation
Nontowered Advisor
421 Aviation Way,
Frederick, Maryland 21701
or Downloading from ASF's pages on AOPA Online (www.aopa.org)
You can get a copy of material related to the safety considerations in operating at non-towered airports. The FAA has an advisory circular AC 91-66A available. Topics include pattern procedures, radio phraseology, right of way, etiquette, instrument procedures, and advice as to the relative merits of non-standard arrival and departure methods.
If you have occasion to cross in the vicinity of an uncontrolled airport, it is worth your while to monitor the CTAF frequency and even give sequential reports of your altitude and position in passing. Parachuting is becoming increasingly popular. Hang gliding, ultralights, and gliders can complete the mix of flying that make proximity hazardous. Recently flew near an airport used by parachutests well after dark. Seems they were having a party that night. They were parachuting at night as part of the festivities. You never know.
Before some of these activities take place the local radar facility is supposed to be advised. Making contact with this facility can warn you of what may be taking place. Jet aircraft and commuters are becoming more common. It is only through frequent communication that everyone flying can provide and maintain situational awareness. The radio call you make may save your life.
Controlling
the Uncontrolled Airport
Regulatory provisions relating to traffic patterns are found in
Parts 91, 93 and 97 of the FARs. ACs 90-42 and 90-66A are advisory
for safety and efficiency. See-and-avoid requirement fully applies.
All available information from AFD (Airport/Facilities Directory)
AIM and NOTAMs is required by FAR. Use of Visual indicators (segmented
circle, wind sock) must be used.
The straight-in approach to an uncontrolled airport is not, of itself, inherently dangerous. Straight in approaches, while not prohibited, must not be disruptive to normal pattern operations. Possible straight in approaches (as with instrument approaches) greatly increase see-and-be seen requirements. The straight-in eliminates the need to overfly and make a 45 entry. AC 90-66A advocates the 45 entry but indicates that the straight-in, IFR or VFR, should not require maneuvers that disrupt other traffic. FAR ,91.127(b) Says that all turns shall be to the left unless otherwise depicted. A straight-in requires no turns. NTSB Administrative Law Judges have found the straight in a violation of FAR 91.113.
Many uncontrolled airports may offer unicom service on the CTAF frequency given on the sectional. This means that there may be someone on the field to respond to a radio call during normal working hours.
Ideally aircraft operations at an uncontrolled airport are just as structured and organized as at controlled airports. Uncontrolled airport organization collapses when a pilot arrives who is not well versed in discerning airport procedures, decorum and communications. It only takes one confused pilot to create a chaotic airport.
Regardless of the Airspace class, if a tower is not operating it becomes an uncontrolled airport. The procedures at uncontrolled airports require that a pilot plan for and follow established procedures. Only by knowing the pattern altitude can you make an initial safe arrival. Even with radio communications without planning you will need to ask for the pattern altitude. With that, you can read the segmented circle, find traffic, use the radio and fly the pattern almost every time. Watch out at part time uncontrolled airports. Pattern directions are not always what you might expect. There are two airports in the Bay Area where right hand traffic patterns are flown when the tower is closed. (Napa and Livermore)
1. Plan your arrival. Read the A/FD, study the chart, monitor
the frequency and make your call-up well away at a known geographical
point. The precision of such a point removes most doubts as to
your direction of flight.
2. The call-up must include your intentions. The standard overfly
and 45-entry is recommended to the point that failure to do so
can be FAA interpreted as careless flying if accident results.
Still it is not contrary to the FARs to come in another way, just
not recommended. Few IFR arrivals to uncontrolled airports come
in on a 45.
3. Your first option for uncontrolled airport arrivals should always be the 45-degree entry.
4. The windsock sets the active runway.
5. Remember the segmented circle's arms are the base legs of the pattern.
6. Self announce your positions at the airport such as over
the field at 2300 on the left-45, downwind, base, and final etc.
Airport always the first and last words of all communications.
7. Never abuse your right of way privileges in a fit of righteousness.
8. Local agencies set patterns and pattern altitudes. Plan your
arrival accordingly
9. Maintain TPA until turning base.
10…Keep your pattern as small as your aircraft allows.
11. Make standard departure with adherence to noise abatement
notices.
12. Exercise your 'See and be seen' skills.
(See Airspace-low visibility operations)
Most midair collisions and near misses occur within a couple of
miles of non-tower airports. Operations at non-tower airports
are more dangerous than are tower-controlled airports. If you
habitually fly under ATC control and assistance then you must
step up a notch your see-and-be-seen skills when nearing non-tower
airports. There is no more dangerous place to fly than in the
vicinity of a non-tower airport.
Depart over the field on a reciprocal 45 degree to the 45 degree
entry. Lose half of altitude to pattern altitude. Execute a left/right
course reversal while descending to pattern altitude on 45 degree
entry. You should be at pattern altitude before reaching the pattern.
This greatly improves your see/be seen opportunities. Arriving
slightly high is better with high-wing and slightly low with low-wing
aircraft for better visibility. Watch the ground for shadows.
Non-radio-equipped aircraft are expected to determine pattern
in use. Since one in five General Aviation aircraft do not have
radios. Radio use is not required but good sense dictates monitoring
and use. One of the problem at uncontrolled airports is radio
complacency. You begin to believe that if no one is on the radio
that no one is there. Don't you believe it.
Two
kinds of unicom.
1.) Every tower airport has a unicom on frequency 122.95.
The callup gives, "Airport name unicom, aircraft identification
and request". Due to the personnel or physical constraints
several calls may be required to establish contact. Commonly used
to order fuel, services, or transportation. 122.95 is the universal
nationwide unicom frequency for TOWER fields. At such an airport
unicom is used for ordering fuel, taxis, making phone calls or
personal requests. It is frequently advantageous to contact the
unicom a few miles out so that transportation will be there when
you land. Some fields may have additional frequencies but 122.95
is standard. Only at the very largest airports will this frequency
operate on a 24-hour basis.
2) Many uncontrolled airports may offer unicom service on the CTAF frequency given on the sectional. This means that there may be someone on the field to respond to a radio call during normal working hours.
3) Giving position reports is an AIM recommended practice.
NORDO aircraft can't give or hear them. See and be seen is the
backup procedure.
Some of the CTAF frequencies are quite congested on weekends.
It is important that the NAME of the place/airport be the first
and last word of any CTAF communication. This alerts pilots in
your area and allows others to discount your presence. This change
is of relatively recent origin, about 10 years. You will still
hear many pilots failing to use this procedure because they were
not initially taught that way. Relearning is, perhaps, the most
difficult aspect of flying. Relearning is also one of the most
resisted phases of instruction. However, what was good enough
forty years ago or even five years ago is not good enough today.
"Name of field unicom, aircraft identification, location, altitude, request traffic advisories (or other request)and name of the field."
If there is a unicom response, it may be limited to suggesting
a runway and traffic direction. (The Good Samaritan situation
has created liability they may not wish to assume with additional
advice) If there is not unicom response all further transmissions
should be addressed to "traffic".
The addition of the name of the airport at the end of each radio
call is by an AD (Advisory Circular) June of 1985. When an omission
occurs you can be certain that the pilot has avoided additional
training since 1985.
The FAA oversight of non-tower operations is there and they're
watching you. I know a pilot who made a low pass over a runway
in Oregon and got a 90-day suspension for breaking the 500' FAR.
While some of the FARs are very specific regarding operations
much of the non-tower 'regulation' comes from the AIM or Advisory
Circulars 90-42 and 90-66A). The student before flight to a non-tower
airport should review FAR 91.127; 91.113 (g); 91.103 and 91.13.
The AIM recommends only the 45-degree entry to a non-tower airport
all others are not recommended and or considered as safe or acceptable.
Parts of the AIM to be reviewed include 4-53; 4-54; 4-8 and parts
of AIM Chapter 5, Section 4. AC 90-42F, 90-66A, and 90-48C are
for guidance of operations. Deviations of any parts of these at
a non-tower airport are those, which the FAA selects as coming
under FAR 91.13, the catchall. Byron airport has a mix of aircraft,
helicopters, gliders, ultralights and parachutes. This is a mix
best avoided by aircraft.
The courts, NTSB have agreed with the FAA's determination that the guidance provided by the FARs, AIM and ACs constitutes acceptable and safe operations. Everything else is relatively less safe. Airport owners and operators establish traffic patterns. Standard pattern is always to left barring noise or obstacle requirements. Arriving aircraft are expected to avoid the flow of traffic until established on the entry leg.
The entry leg on all FAA ACs appears as a 45-degree entry aimed at the runway landing threshold. The determination of the entry requires that wind, pattern, and traffic indications are confirmed prior to arrival at pattern altitude. Plan your descent to arrive at pattern altitude at the downwind turn. (AC 90-66A suggests that this turn occur at midfield. This works fine for 5000' runways but a good size pattern for a 2500' runway requires that the turn be abeam the departure end.) 1000' AGL is the new suggested pattern altitude. Some airports still publish and use the older 800' altitude.
The pattern altitude should be maintained at least until abeam the approach end of the runway. (CCR authorities require it until turning base.) Since there are local differences it is well to become familiar with the local requirements. Base turn is recommended at the 45 (key) point. Turn to final recommended at least 1/4 mile out
The selected runway for common use should be the one most aligned with the wind. A calm wind runway may be designated. If a secondary runway is used, flight must not interfere with preferred flow of traffic. Departing aircraft should not turn until beyond the departure end. Go arounds should not turn until well clear of any runway traffic and attempt to maintain visual contact. While in the pattern turns should not be initiated until within 300' of pattern. Such an altitude should assure the downwind turn being made at pattern altitude. Departing aircraft should not make their departure turn until reaching pattern altitude. (This is a slight change from what I have previously taught.)
FAR 91.1260-7 states that unless otherwise authorized all turns must be made to the left. Beyond this there is no 'regulation' that prohibits a base or straight-in entry. No turns are made in a straight-in approach. Some airports require only a straight-in (Ruth-northern most airport on the San Francisco Sectional.) A straight-in is only illegal if it interferes with other traffic. A straight-in with a two-mile final has been judged a violation of the FAR under this proviso.
Helicopter patterns are expected to be at 500' AGL and inside the aircraft pattern. Helicopter approaches will be steep. Glider operations may have a pattern inside the aircraft or with opposite turns. Ultralights usually have a 500' pattern inside aircraft and their own runway. Ultralights take off and land steeply.
Non-Tower Airport Arrival Procedures.
(SEE RADIO PROCEDURES)
1. PLANNING
Runways
Reporting points
45 degree arrivals only
Pattern altitude/direction
Frequency
Look for additional ways to determine runways in use, such as
arriving/departing aircraft, smoke/dust/waves. Nearby airports
are good indicators. Try to plan the most efficient arrival conducive
to safety. Avoid the pattern altitude until you are in it.
DON'T FLY INTO THE PATTERN ALTITUDE IN THE BLIND!!!!!
2. ARRIVAL
15 mile callup:
1. Podunk unicom Cessna 1234X KEY Intersection at 2000 request
traffic advisories Podunk (if no answer...
Podunk traffic Cessna 1234X KEY Intersection at 2000 planing to overfly at 2000 prior to landing Podunk
2. Podunk traffic Cessna 1234X over the field at planning landing
(runway) right/left traffic Podunk
Podunk traffic Cessna 34X on 45 for (runway number) Podunk
Podunk traffic Cessna 34X right/left downwind for (runway number) Podunk
Podunk traffic Cessna 34X right/left base for (runway number) Podunk
Podunk traffic Cessna 34X final for (runway number) Podunk
PRIORITIES:
-- Fly the plane
-- Maintain proper altitudes and headings
-- Keep eyes outside cockpit and watch for traffic
-- Communicate
122.9 Traffic only advisories at airports without frequency on
sectional
123.6 Uncontrolled field with FSS for arrival and departure only
About 1% of aircraft accidents are of the mid-air type. Of these
accidents 50% of those involved survive. Fatalities are 1.4 times
more likely than in other accidents. Midairs are most frequent
on final approach. The ratio of approach accidents is about 6
to 4 in favor of non-towered airports. Considering the relative
numbers of uncontrolled airports and towered airports it is just
possible that towered airports may pose the greater statistical
risk.
IFR flight into and out of uncontrolled airports are often determined
by the location of navigation facilities. Thus, the arrival and
departures often conflict with what are the recommended local
practices. Both IFR and VFR pilot must flex with the conflicting
requirements. Any time the IFR arrival can comply with the standard
traffic procedures the better. A phone call to the airport may
be the best way to resolve any conflicts or doubts before arrival.
Use of a current AFD is recommended.
Air carrier flight into nontowered airports that make straight-in
arrivals have resulted in some serious accidents. Along with communications
everyone must be on the same page (frequency) and giving advisories
as to position, altitude, and intentions.
1. Traffic flow altitude should be avoided until established on
the entry leg.
2. Entry should be on the 45 angle to the downwind leg.
3. Larger aircraft usually require a higher pattern altitude.
4. Base leg should be at least 1/4 mile from threshold.
5. Do not turn crosswind until past departure end of runway.
6. Time your crosswind turn so as to arrive on downwind at pattern
altitude.
7. Departures should be straight-out until reaching pattern altitude
with a 45 turn in pattern direction.
8. Instrument approaches should conform to normal flow of traffic.
Always include the runway number you plan to use. This provides
an additional alert if someone missed the place/airport name as
well as possible winds/ runways at nearby airports. Do not totally
rely on such runway calls for what you should use. Since the use
of the CTAF frequency nor the 45 degree entry is not REQUIRED
you must use see-and-be-seen vigilance in all directions. If you
have reason to believe density altitude over 1000' above AGL exists
it would be helpful to include your computation in your communications
with other aircraft.
Visual Indicators
at Uncontrolled Airports
(AIM 4-53)
DON'T MISREAD WINDSOCK, TETRAHEDRON, OR SEGMENTED CIRCLE!!!!
a. At those airports without an operating control tower,
a segmented circle visual indicator system, if installed, is designed
to provide traffic pattern information. The segmented circle system
consists of the following components:
1. The segmented circle--Located in a position affording maximum
visibility to pilots in the air and on the ground and providing
a centralized location for other elements of the system.
2. The wind direction indicator--A wind cone, windsock, or wind
tee installed near the operational runway to indicate wind direction.
The large end of the wind cone/wind sock points into the wind
as does the large end (cross bar) of the wind tee. In lieu of
a tetrahedron and where a windsock or wind cone is collocated
with a wind tee, the wind tee may be manually aligned with the
runway in use to indicate landing direction. These signaling devices
may be located in the center of the segmented circle and may be
lighted for night use. Pilots are cautioned against using a tetrahedron
to indicate wind direction.
Small windsocks have 15-knot limit for stiffening. Droop is only way to make lower estimates. Use 45-degree droop as 7-8 knots. For takeoff estimate crosswind heading correction as one degree for each knot of crosswind.
Headwind factor of sock 30 degrees off runway heading means that wind velocity is only 75% of a headwind. Up to 60 degrees off runway heading means the headwind velocity is only half as strong. Beyond 60 degrees wind is zero headwind.
Crosswind factor of sock 30 degrees off runway heading means that wind velocity is 50% directly into wind. Estimate a wind between 30 and 60 degrees as 75% of direct wind velocity. Give wind full value if beyond 60 degrees.
Tailwind off 30 degrees is estimated as full strength. Up to 60 degrees off tail is estimated at 75% base velocity. Over 60 degrees wind is estimated as 50% of base velocity.
Select a wind direction and draw in the appropriate diagrams
for the words.
Runway
segmented
circle
wind tee
wind sock
3. The landing direction indicator--A tetrahedron is installed
when conditions at the airport warrant its use. It may be used
to indicate the direction of landings and takeoffs. A Tetrahedron
may be located at the center of a segmented circle and may be
lighted for night operations. The small end of the tetrahedron
points in the direction of landing. Pilots are cautioned against
using the tetrahedron for any purpose other than as an indicator
of landing direction. Further, pilots should use extreme caution
when making runway selection by use of a tetrahedron in very light
or calm wind conditions as the tetrahedron may not be aligned
with the designated calm-wind runway. At airports with control
towers, the tetrahedron is lockable and should only be referenced
when the control tower is not in operation. Tower instructions
supersede tetrahedron indications. Make illustration showing positions
as though wind is from the west.
tetrahedron
4. Landing strip indicators--Installed in pairs...and used to
show the alignment of landing strips (runways)
Wind
sock
5. Traffic pattern indicators--Arranged in pairs in conjunction
with landing strip indicators and used to indicate the direction
of turns when there is a variation from the normal left traffic
pattern. (If there is not segmented circle installed at the airport,
traffic pattern indicators may be installed on or near the end
of the runway.)
Draw a segmented circle with runways going east and west. Draw
the base legs to the runways so that the 270 degree heading base
leg is for right traffic and 090 runway base leg is also right
traffic.
b. Preparatory to landing at an airport without a control
tower, or when the control tower is not in operation, the pilot
should concern himself with the indicator for the approach end
of the runway to be used. When approaching for landing, all turns
must be made to the left unless a traffic pattern indicator indicates
that turns should be made to the right. If the pilot will mentally
enlarge the indicator for the runway to be used, the base and
final approach legs of the traffic pattern to be flown immediately
become apparent. Similar treatment of the indicator at the departure
end of the runway will clearly indicate the direction of turn
after takeoff.
c. When two or more aircraft are approaching an airport
for the purpose of landing, the aircraft at the lower altitude
has the right of way, but it shall not take advantage of this
rule to cut in front of another which is on final approach to
land, or to overtake that aircraft (FAR 91.113(f)).
Uncontrolled
Airport Traffic Patterns
At most airports and military air bases, traffic pattern altitudes
for propeller-driven aircraft generally extend from 600 feet to
as high as 1,500 feet above the ground.... Therefore, pilots of
enroute aircraft should be constantly on the alert for other aircraft
in the traffic patterns and avoid these areas whenever possible.
Traffic pattern altitudes should be maintained unless otherwise
required by the applicable distance from cloud criteria (FAR 91.155)
A disproportionate number of near-midair collisions and actual
collisions occur at uncontrolled airports. Any pilot arriving
at such an airport should pre-plan his arrival and have the cockpit
so organized that maximum attention can be given outside the cockpit.
Seeing is harder in an unfamiliar situation that avoidance of
what you see. My using standard procedures you can better know
where to look and what to look for.
As a former schoolteacher I have memories of playing a visual
game with my classes on rainy days instead of going outside for
P.E. I would have one group of children put their heads down.
Another child would take a common object such as a key and place
it in an uncommon place such as on a shoe, head, door knob, or
projecting from a crack. On signal the selected group would raise
their head and walk around the room trying to see the object.
As the different children would find the key, they would return
to their seats without letting those still looking know that they
found the key. The quietest of the remaining groups would get
to put their heads down next. The children enjoyed the increasing
tension and the emotional control required not revealing they
had found the key. Neat game to tell any teachers you know.
The reason I tell the story of the game is that, always the same
children seemed to have the ability and skill to find the keys
first. There is a special skill in looking, seeing, and then recognizing
what you have seen. In my opinion, you have the required innate
ability/skill or not. Some of my students have consistently exceeded
my ability to spot aircraft. Physical conditions can be a negative/positive
factor. The size, glare, and clarity of the windshield, the existence
or non-existence of haze will make a difference. Knowing where
to look is an intellectual factor that any pilot can develop.
The most effective scan covers no more than 10 degrees of the
window and proceeds in successive 10-degree jumps. You cannot
see when your eyes are moving. The eyes must stop and focus for
a moment in order to see. A broad scan must be done by moving
the head and keeping the eyes stationary. Additionally the focus
distance (accommodations) must be varied from close to far. This
is most important when haze give an obscure view of distant objects.
Looking too long for distant objects in such conditions will cause
the eyes to re-focus at about 20 feet. Learn to react to things
in your peripheral vision even if it is a bug splatt. Any aircraft
that balloons in your vision without moving is going to hit you,
just like the runway.
--At night or any other time, an orange light is on top of
the windsock.
--The white traffic pattern indicators at right angles to the
landing strip indicators show that a right turn is required.
--Traffic pattern indicators may be installed on or near the end
of the runway.
While the 45-degree entry is recommended, the FAA has no suggestion
as to how to arrive at the initiating point when no advisory can
be obtained. You should first overfly at twice pattern altitude
to confirm wind direction and the pattern direction of the preferred
runway. There are two ways I have seen the initial 45 entry reached.
Every key point of each procedure should be identified for other
traffic.
1. At twice pattern altitude, cross over the runway at
a 90 degree angle toward the downwind leg, cross that leg and
fly on this heading at least another mile before turning 90 degrees
parallel to the runway toward the upwind end. At the 90-degree
turn descent to the pattern altitude should be initiated. Eyeball
for a 45-degree angle to the approach end and make your turn of
135 degrees. For left traffic this will combine two right turns,
the first of 90 degrees and the second of 135 degrees. Draw this
out around a diagram of an airport to see how it put you on a
45 entry.
What
I dislike in this option is
a) I have had an instructor use it without allowing for a strong
cross wind. His turn to parallel the downwind put us right into
the downwind traffic pattern.
b) The necessity for right turns restricts the see-and-be-seen
requirement.
2. From the approach end of the field depart on a heading
that will take you across the pattern side of the field on a 45-degree
angle toward the point of entry. You will be on this heading if
the runway # (number) is on the right front 45-degree mark of
your heading indicator. Proceed on this heading until clear of
the pattern and descend 500'. Initiate a course reversal (a required
private pilot procedure) first 90 degrees to the right which would
be away from the traffic and airport and then a 270 to the left
back to the entry position. On a correct 45 degree heading the
runway # number will be on your left rear 45 degree heading marker.
This inbound checking system works for all 45-degree entries left
and right..
Common Mistakes at Non-Tower Airports
1. Not calling up soon enough to get advisory
2. Not observing traffic pattern/windsock direction
3. Turning downwind too close to runway
4. Becoming distracted and not attending to airspeed and pattern
orientation
5. Trying to hit the end of the runway
6. Delaying addition of power if low
7. Delaying go around if a poor approach/flare
8. Not clearing runway immediately
9. Discourteous, rude and arrogant behavior
10. Flying a DC-8 pattern and not keeping your pattern square
and tight.
11. Make go-arounds to right side of runway
Uncontrolled Airport Departures
1. Full 360 degree clearing turn on ground in run-up pad prior
departure. Draw runway and run-up area with how
you might make such a departure: You must learn to taxi and talk
at the same time.
2. Advise traffic of departure and direction
3. Do not make a 45-degree departure until past the departure
end of the runway and at least half of pattern altitude. A premature
turn can put you into conflict with traffic inbound on the 45.
4. Make any downwind departures so that the downwind is closer
to the runway than would normally be used by landing aircraft.
This keeps you from crossing their 45-degree entry path.
Non-unicom Uncontrolled
Airports:
All callups are made to the airport "Location name, traffic,
aircraft identification, position, altitude, intentions and location
name" on 122.9. Any responses to your "blind" communications
would be from other aircraft.
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