IFR systems
ATC at
Work
The VFR conditions responsibility to
see and avoid rests with you, the pilot. ATC’s responsibility, authority and
accountability for separation exists only under IFR conditions for IFR vs. IFR
flights. A controller who ‘violates’ minimum separation standards is under zero-
tolerance standards of performance. All other ATC services are subordinate to
IFR vs. IFR separation. Because of this responsibility and accountability the
controller has the authority to assign IFR aircraft altitudes, headings, routes,
and clearances. Under the same VFR circumstances the controller can ignore VFR
flights but he cannot order or command. For VFR aircraft the controller is
limited to advisories and suggestions. As a VFR PIC you can reject any ATC
advisories or suggestions.
A computer detected non-collision bust of 500' or less will be addressed by
administrative action. (Warning letter) A loss of separation reported by the
computer can require re-certification of the controller. Reading back ATC
clearances as you have heard them is a good practice in the event of ATC's
failure to correct the read-back. If you are directed to call a particular
number by ATC reply "Roger" but you do not "have" to make the call. Instead fill
out the NASA form to protect your behind.
If an approach has "radar required" as a note, the approach cannot be flown
except under a radar watch. On any approach it is good procedure for you to
request a "call" for any fix even though you may be able to determine the fix
with your equipment. Some radar fixes do not appear on the charts. You can
request that ATC call the FAF for you if you wish.
On an approach the radar vector approach gate is normally a mile outside the
marker or the FAF. Radar normally tries to vector you well outside the gate but
can on request give you a close in or far out vector. Don't let ATC vector you
in so close to the marker that you don't have time to stabilize the approach.
Don't accept vectors to the marker.
You are asked to maintain a speed to match that of the following jet. ATC has
three techniques to place you into this situation: the tight vector to the FAF,
the high speed final, and the slam dunk. All of these are contrary to what you
would use in training. I have, on occasion, requested a vector 360 so as not to
be pressed by following traffic. ATC may request that you maintain speed up to a
certain point, even the threshold. If ATC asks for a higher approach speed than
you can handle...just say "unable". You are PIC. Ask for another option. If ATC
gives you a too steep/fast arrival from above the glide slope, miss the approach
and ask for another vector. It is important that both ATC and you have an
understanding as to when you will slow down.
The next problem is being held well above approach altitude. Years ago at Las
Vegas I heard an airliner being so held and then told to descend for the
approach. The pilot complained throughout the descent and finally had to execute
a missed. I later found out over coffee and doughnuts with a neighbour that he
had been the Captain involved. Getting down for the small aircraft involves
getting the aircraft as dirty as possible and keeping the engine warm. You could
try to do this after a high speed descent but you risk engine damage. It is wise
to pre-plan your procedure selection before it happens and advise ATC of your
intentions. Don't promise ATC anything you can't deliver. Call upon controllers
for help during emergency situations, but as PIC you must make and stand behind
your decisions.
Who's In Charge?
ATC exists to ensure enough safe separation between IFR traffic in
controlled airspace. Additionally ATC will provide control tower airport
services, route control for IFR aircraft, and weather/traffic information. The
advent of radar dramatically changes many of the ATC functions giving ATC the
ability, but not the responsibility, to control and navigate aircraft. ATC is
not primarily responsible for obstacle clearance as written and diagrammed in
approach plates and charts. The pilot who expects ATC to take over these latter
responsibility is not using a full deck of FARs. However, anytime ATC issues an
off-airway clearance or vector, ATC is responsible for terrain clearance. It is
up to the pilot to know if an ATC vector or other instruction is correct or
incorrect. If doubt exists, the pilot should get a clarification. If safety is
not a problem do as ATC directs, but if something seems wrong and cannot be
adjusted to your satisfaction, declare an emergency and take the safest option.
Using the System
Knowing what to expect is when the
pilot holds the winning hand. Then the pilot is prepared to question any change
of direction or altitude. He is also prepared to follow any ATC directive
because it is within expectations.
ATC is regulated by rules not
readily available to the pilot. The antenna system available and in use may
limit ATC to requiring aircraft to fly the full procedure instead of getting
vectors. With vectors there will be no procedure turns. A ceiling 500' above
minimum vectoring altitude or minimum instrument altitude allows the controller
to vector for a visual approach so long as visibility is three miles. Once the
airport is in sight and reported so to ATC you can get a visual approach
clearance. At larger airports you must report a specific runway before being
able to get your clearance. An alternative to this procedure is for you to
identify and acknowledge that you see a specific aircraft to follow as specified
by ATC. By doing so you relieve ATC of any avoidance accountability. A visual
approach is not an IFR procedure even when on an IFR flight plan.
Each radar screen station usually has two specialists: a radar controller and a
flight data controller.
There must be an instrument
approach procedure before you can get a visual approach. A contact approach does
not require that there be an instrument approach procedure.
When weather is variable about
vectoring minimums the controller may bring you in for a look. This means he
will bring you into the final approach course in the hopes that conditions will
break for a visual approach. This vector will take you into the vector 'gate'.
The 'gate' is a point that radar uses one mile before the FAF. The vector
clearance includes your distance from the marker, altitude to maintain until
established and the "cleared for the (type & runway) approach". Any vector
inside the 'gate' must be approved and accepted by the pilot since there will be
little time to make adjustments.
When on an approach, momentary 'radio problems' may make you miss the tower
giving you RVR minimums that preclude you from making the approach. Should the
radio problems persist until you have passed the FAF, you can shoot the
approach.
There are several ways to get an
IFR clearance. The easiest is at a controlled airport and entering the Tower En
route program. The second easiest is where the Tower En route clearance may not
be available. You just ask for a Tower En route to an approved destination and
as soon as you get into the system ask for an amendment.
Pre-filing is always an
adventure since it is very unlikely you will get what you filed for unless you
use the AF/D and get a 'preferred route'. Even with the preferred route filed
and given as a clearance, you will probably be vectored across the corners.
Telling ATC that you have LORAN or GPS capability makes cutting corners all the
more likely. It does little good to ask for short-cuts from an approach or
departure control. Wait until you get handed off to the next facility and begin
negotiating there.
The most interesting of system
entries is from an uncontrolled airport when you use a phone to get a void time
clearance. Most of the AIM references to this system entry has not been changed
since the advent of the cellular phone. My recommendation would be to get all
loaded and ready to go and then phone the FSS for your clearance. If you tell
them that you are ready, they can get a very short 'time off' for you. ATC likes
this since it does not tie up so much airspace. A ten-minute time/altitude block
on an airway or radar sector can cause quite a traffic back-up.
The 'pop-up' entry is the
easiest if you can set yourself up properly. This means that you can position
yourself over a 'known' location or intersection, have the correct contact
frequency, and say what you need to say to get into the system. You should have
the proper charts and plates available and perhaps even studied.
The 'pop-up' can be a bit dicey
if you make radio contact but are below an altitude where ATC cannot issue a
clearance until they have radar contact. I faced this situation on a May, 2000
light between Salina KS, and Kansas City, MO. I had no charts or plates, but
with the help of ATC was able to complete the flight safely. ATC has two major
levels of operation. Flying and working by the book until no one is watching
that then doing whatever works is good-to-go.
Flight Check of IFR Navaids by FAA
Specific intervals
Fix accuracy
Centreline
Missed obstacles
Approach obstacles
Fly edges of approach area
Fly approach all the way at minimums
Letters-of-Agreement
An LOA puts in writing the extent to
which ATC can pass information from sector to sector and airspace to airspace by
Standard Operating Practice (SOP). These LOA/SOPs cover parachute jumping,
military operations, airspace delegation, SVFR procedures, emergency
responsibility, and IFR procedures.
The 20 centres of the U.S. subdivide authority and responsibility to other
facilities through LOAs. The LOA set airspace dimensions, procedures,
responsibility, authority, time periods, sectors. LOAs can exist between two
airport Class D airspaces. Pre-set LOA reduces the communications and procedure
stress by working according to a plan.
Different divisions of ATC have
developed methods of moving traffic via a system that is relatively unknown and
unknowable to pilots. Towers can launch traffic into TRACON air space as part of
a departure clearance including a transponder code that tells TRACON about the
aircraft.
TRACONs work on a system of
1000' vertical separation and three mile lateral separation. LOL aircraft will
depart along a route with an altitude restriction so that the departure allows
multiple aircraft to get in the air and on their way. This is a pre-coordinated
procedure developed in-house by ATC to make a system work where otherwise it
wouldn't.
APREQ is a variation of the LOL
in which individual controllers make an 'Approval Request'. A controller from
one position are moved to other conditions to help maintain a wider awareness of
the entire system. A pilot request may require that a controller make an APREQ
to allow a selected aircraft to intrude into another controllers airspace to
facilitate its movement. As a pilot, knowing that APREQ exists makes it possible
for me to take airway shortcuts that avoid extensive en route excursions.
Major ATC Pilot Problems
Entering ARSA/TCA without authorization
Runway incursions
Altitude deviations.
ATC Separation
ATC separation is done in three dimensions, vertical, lateral, and
longitudinal.
Vertical separation is based on
altitude. The amount of altitude separation is different for IFR from IFR and
IFR from VFR and VFR from VFR. The hemispheric rule usually applies but is often
evaded when aircraft are being sequenced for approach, separation will be
maintained. Obstacle clearance is 1000'. Every altitude assigned must be above
the minimum vectoring altitude. (MVA) VFR aircraft can be cleared to fly below
the MVA.
Once cleared for IFR you are
separated in all airspace except Class G. An IFR pilot can fly in Class G
without dealing with ATC but without ATC being at all responsible. ATC will
separate only IFR from IFR in Class E airspace. The tower of Class D will do its
best with or without radar to provide separation but VFR separation is not
guaranteed. Class C ATC separates all IFR from IFR as well as VFR inside the 10
mile ring. In the 20-mile outer ring of Class C IFR from IFR is provided but not
from VFR. This is because VFRs are not required to accept ATC control between
the 10 and 20-mile arcs.
TRSAs which surround some Class
D airspace separate IFR from IFR but not from VFR since VFR is not required to
participate. Class B provides total separations of everybody from everybody
else. Class A gives total separation. 18,000 to 29,000' IFR from IFR is 1000';
above 29000' its 2000' vertical.
Lateral separation from
displayed obstacles is 3 miles. Visual separation is not allowed by IFR aircraft
from obstacles, even if in sight. Radar separation remains in effect. ATC radar
is used to maintain airspace separations such as special use airspace (SUA) and
jump zones.
Longitudinal separation is
normally 3-miles in trail. The aircraft in front cannot be heavier than the
plane behind and the tower must be able to see the runway's turnoffs. Where wake
turbulence is a factor four-mile separation is required by small aircraft behind
large aircraft and five miles behind the 757. Small aircraft must be six miles
behind very large aircraft. Small aircraft are all that weigh less than 41,000
lbs. Once a pilot accepts responsibility for separation by saying that he has a
'point-out' in sight then what happens is totally his responsibility until he
says he has lost sight again. Best option is to request vectors for greater
spacing.
When you ask ATC for a change in altitude, you must realize that what happens
TOTALLY depends on the amount of separation such a change would allow. Those of
you who fly slick airplanes realize that failure to descend means that you will
have difficulty slowing down when you get closer in. The turbo does not enjoy
being shock-cooled.
Final Approach
On final you should realized that at the outer marker you are five miles out
and 1500’ above the runway. Within the lateral limits of the CDI the slope or
steps of the approach will keep us above any obstacles. As we descend to 200’
above decision height the lateral limits become so constrained that full CDI
deflection occurs at the end of the runway in only 500’. Properly flown you have
guaranteed obstacle clearance. The new TERPS criteria obstacle clearance above
obstructions at five miles is 755’ and at DH the new criteria provide 122’.
Non-precision approaches provide 250’ obstruction clearance throughout the
approach. The lights that have reference value for an approach and landing are
the runway lights, the end identifiers, approach and VASI.
Block Altitudes
There will be times when IFR flight
conditions make it difficult to impossible to maintain an altitude. Actually
almost any time you can request a block altitude. The block gives you a practice
playground between two altitudes that are above the minimum instrument altitude
of FAR 91.177 or minimum vectoring altitude. This way you can legally fly so as
to be actual by picking up clouds a few hundred feet higher or lower inside your
block. Cloud scooping it is called.
ATC RADAR Sectors
Controllers live by rules in
7110.65. A radar controller separates aircraft as they move through "his"
airspace. ARTCC or Air Route Traffic Control Center cover all the wide open
spaces between Terminal facilities. Terminals funnel aircraft to and from their
airports. Airspace is transferred from ARTCC to Terminals and thence to airports
by Letter of Agreement (LOA)s. "Letters of Agreement", often unpublished and
unknown to pilots, exist between ATC facilities. These letters allow special
flight routes, altitudes and procedures.
"Radar contact" does not guarantee terrain clearance any time you are below MOCA
or MEA altitudes. ATC radar airspace is different than a pilot's airspace. A
tower may by LOA (letter of agreement) lose control of a part of its space under
certain weather conditions or because of the needs of an adjacent airport
approach. It helps the pilot to know the ATC preferred direction of traffic and
airspace alignment.
Some sectors and frequencies are
more "quiet" than others. On weekends sectors may be combined so the frequency
you normally select will be only monitored so as to assign the active frequency.
One sector will feed into another sector by means of a "handoff" Several such
sectors may feed to a final controller. If too many aircraft are loading up the
final sector some of the outlying sectors may be required to "spin" (hold)
aircraft to lessen the final controller's load. The "spin" may consist of a
completely different routing.
The handing off of an aircraft
from one sector to another requires coordination. This means asking approval via
phone/computer of the adjoining sector's controller if the will accept another
aircraft. Controllers are not allowed to violate adjoining sectors. Your vector
may be simply to avoid an adjacent sector. Every favour one pilot receives,
delays another. The controllers can't make all the phone calls in time to meet
requests in complex environments. Computerized handoffs are rapidly replacing
the phone.
Aircraft on the controllers
screen have a data tag that gives call sign, type, groundspeed, altitude readout
and may include destination, type of flight and a controller letter of
identification. The new automated handoff has some problems since the airspace
sectors is often subdivided several times. When a controller notes that an
aircraft is leaving his airspace he tells the computer. The computer then
decided who gets the aircraft. The originating controller may not know who gets
it. If the aircraft fails to make the proper radio contact we have a loose
cannon in the system. When the Mode S transponders get used every aircraft will
have a permanent code.
A "point out" is similar to a
handoff but allows an aircraft to nip through a corner of a controllers airspace
without changing frequency or making radio contact. ATC can do this without the
pilots knowledge.
Separation Standards
Some ATC calls are courtesy calls,
some are ‘point outs’, some are advisories, and some are mandatory advisories.
The pilot must learn to listen to the tonal variations of the controller to
separate one from the other since there is no other obvious distinction.
ATC contract..."provide
separation". If standards are violated a "deal" occurs which causes economic and
training problems for controller. To protect themselves from the minimums
controllers maintain greater than minimum required separation. Separation can be
both horizontal or vertical and need not be both. a ‘snitch patch’ in the
computer tells if separation is less than standard. Makes a ‘deal’ for the
controller
Standard separation is
determined by aircraft type, altitude, type of ATC facility, stage of flight
(departure, cruise, approach) weather, and antenna distance. If visual
separation exists by pilots or by ATC the separation may be much closer than 5
miles. If aircraft are separated by altitude the separation may be as little as
2.5 miles.
A limiting separation factor is
the distance of the aircraft from the antenna, class of airspace and size of
aircraft (heavy). Minimum is miles within 40 nm of antenna; 5 miles beyond 40
nm. Centre (ARTCC) uses 5 nm standard separation and 1000’ below FL290
regardless. Terminal areas most likely 3 nm and 1000’ with visual separation
allowed. Vertical rules are same everywhere. There are no standards of
separation for VFR aircraft. Only in Classed B and C is IFR separation
mandatory. Class B separation of IFR/VFR is 500’ and 1500’. Class C separation
is 500’ and ‘green between. In Class C there are no mandatory advisories. VFR
advisories are given as load allows.
IFR aircraft fly in a cylinder
10 nm (ARTCC) to 6 nm (terminal) diameter. The cylinder extends 1000' above and
below the aircraft, ATC normally allows much more space.
Your encoding altimeter must be
within 300' because the "snitch patch" of centre's radar is set to alarm if
altitudes encroach on 700' separation. An encoder off by 300' could set off the
alarm. If you should wander more than 300' off IFR assigned altitude and ATC
questions, delay your response until altitude is within 300'. Better yet, advise
"unreadable" while making the correction. "Snitch" is found (1993) only in ARTCC
radars.
A radar target may not be in ATC
contact so the altitude is only ‘indicated’ not confirmed. Traffic advisories
are a part of flight following which includes weather advisories, terrain,
obstruction, and low altitude alerts. asking for flight following and being
given flight following leaves out the rest of radar flight services. You can
even request that traffic advisories be omitted from flight following.
An IFR flight with visual
contact on VFR aircraft is allowed to manoeuvre to avoid without regard to an ATC
clearance. The radar controller is required to advise you if your target merges
with another on the screen. The advisory may just to indicate how far above or
below you the altimeter reading indicates. Giving ATC your indication of visual
contact relieves them of responsibility. ‘Mode-C intruders’ are aircraft that
have encoders but are not in communication contact with ATC. Many radars can
give you two-three minute warnings if such an aircraft is in conflict with your
route.
Centre Facilities
Radar is a multifaceted term. The
antenna of a centre is known as a sensor. Several sensors have their radar
returns made into a mosaic the presents a single picture via digital computers
for each controller’s sector.
Each antenna either an ARSR-3 or -4 has two parts, the search antenna and the
transponder interrogator. Some -3s cannot get primary targets at all.
Centre antenna turn slowly and
search in slightly over 10-degree arcs at a time. At a distance the 10-degree
arc covers so much distance that a target blip can be a mile long at the
100-mile range setting. At five turns a minute the antenna a target can move
several hundred feet between return updates.
Updates are processed to allow
the best antenna data to the controller. This data can be used to forecast
future positions and to give direct route vectors with a couple of clicks.
Projections allow conflict alerts and Minimum Safe altitude Warnings (MSAW)
warnings. None of these work within 25 miles of your destination. Carry a
sectional.
Centre can help with weather
because of the multiple antenna used. One antenna can show the front of a
weather condition while another antenna will show the back side. Light
precipitation is shown as slashes. Where two antenna (sensors) have overlapping
slashes there will be areas of Hs. Pilots should be told by ATC to avoid areas
of such Hs.
Radar Help
Centre radar is not good enough to safely call step down fixes. TRACON
can call fixes that are on their screens. There is no way to know extent of
radar coverage to secondary airports unless you get some idea of the minimum
vectoring altitude from the SVFR clearances given. SVFR clearances usually give
an altitude that in poor conditions indicates the letter-of-agreement separation
altitude of a Class D and TRACON. You might just ask ATC what it is.
All radar facilities have
differing capabilities. Centre antenna rotate slower than TRACONs and has a more
limited vectoring precision. Centre is a mosaic of a number of long range radars
and a given controller has a limited sector scan for working aircraft in a
specific area. Within 40 miles of the antenna separation is 3-miles; beyond that
it is 5-miles.
Radar
Altitudes
Radar contact means nothing relating to
altitude safety.
Minimum Vector Altitude (MVA) TRACON chart may take you lower than you like.
Query
Minimum Instrument Altitude (MIA) used by ATC Centre
Minimum Safe Altitude (MSAW) Warns ATC without regard to other terrain.
Minimum En route Altitude (MEA) is arc around navaid.
Emergency Safe Altitude (ESA) is used by military.
Minimum Off-Route Altitude (MORA) by Jeppesen grids.
Off-Route Obstacle Clearance Altitude (OROCA) Government charts.
IFR Separation from IFR
VFR-on-Top
and visual climb/descents responsibility: A VFR on top clearance is all right
below a cloud deck or between layers as long as you can remain VFR and meet
cloud clearance-criteria. ARTCC 5 miles/1000' Relieves ATC only during altitude change. Class B 3 miles/1000' Other aircraft need not be visible.
Class C 3 miles/1000' Use when possible.
IFR Separation from VFR
ARTCC nothing When IFR pilot agrees to keep visual separation, ATC is
relieved of responsibility. Class B 1.5 miles/500' Class C conflict/500' Pilot may climb, descend or get closer than ATC minimums. TRSA 1.5 miles/500'
VFR Separation from VFR
ARTCC nothing
Class B 1,5 miles No requirement but you may get traffic advisories and safety
alerts.
Class C nothing Be careful in Class C.
TRSA 1.5 miles
Visual Separation
ARTCC limited Must report aircraft in sight to ARTCC
Class B allowed then must report passing clear. Seldom used.
Class C allowed ATC controller uses his visual contact of allowed aircraft
involved to expedite
TRSA When a pilot acknowledges visual contact he relieves ATC of responsibility
for
separation.
Note: There is no time duration limit on this exchange of separation
responsibility. A pilot can hand back this responsibility to ATC by advising
that visual contact cannot be maintained or is lost.
Diverging Course
ARTCC no
Class B allowed This means IFR aircraft at same altitude may be allowed to break
minimums if their
Class C allowed courses are divergent.
TRSA allowed
Radar Surface Movement
Guidance and control system (SMGCS); Special low visibility, RVR less
than 1200', taxi routes with lighting and surface markings. Green taxiway
centreline lights, 2 red lights on each side of the taxiway serve as stop bars,
these are ATC controlled. At no time shall a pilot cross an illuminated red stop
bar. Flashing yellow lights are across taxiway in runup area as taxi-holding
position lights. Position markings are pink circular numbered marking along
taxiway. 3 amber lights across centre of taxiway are holding bar indicators.
See the AIM for latest on
airport markings...a MUST
When ATC Screws-Up
The ATC system requires that the pilot maintain the situational awareness
required to know when something is missing from a clearance, a route, frequency
change, or a procedure. Be prepared to question ATC instead of waiting for them
to recognize a problem. Be prepared to protect yourself by knowing what is
supposed to happen.
Radar Failure
If approach facilities do not have radar...no traffic can be seen. When
radar fails at a radar facility two backups exist: DARC is used by Centre.
CENRAP is used by Approach
When ARTS computer fails all aircraft are given the same discrete code, slashes
appear instead of numbers. When a complete radar and computer failure occurs we
have a reversion to CENRAP which will use a radar signal from one of centres
antennae. Separation becomes 5 miles instead of 3. Mode C is unusable so all
altitudes must be reported. No altitude or conflict alerts can be given.
Aircraft are put into lines at different altitudes and processed to the approach
and landing in order. Pilots should expect requests for position and altitude.
IFR Without Radar
An approach is called "single threaded" if only one IFR operation at time is
allowed due to lack of radar coverage.
Plan to execute the full approach procedure in non-radar conditions.
Know and obey the altitude restrictions.
You must make the required position reports.
Leaving an altitude
Procedure turn inbound
Final approach fix
ARTCC Weather Radar
ARTCC radar has three keys WX 1-2 and 3. which will give rain return
information on a digitized circuit. It takes 4000 feet of clouds to make rain.
If its wet where you are, figure to climb at least 4000' to top the clouds. This
information must be requested by the pilot. Digitized Hs on his screen indicates
weather to be avoided. The controller is obligated to give you the worst
possible interpretation of any weather return.
1995 NEXRAD radar coverage is 100% east of North Dakota line to the Gulf. WSR-88
display precipitation and wind if particulates are present in the air. Data will
go to Center Weather Service Units and Flight Service Stations. 175 antennas
will give circular coverage out to 285 miles up to 10,000'. Most will be away
from major airports about 10 miles. It can sector scan over airport and down
main weather runway. In the future these displays will be in the cockpit.
Radar Service Terminated
Becoming overly dependent on radar can cause problems. You should be
prepared to operate in a non-radar environment. This means defining your own
fixes, required reporting points, and altitudes. Without radar to help, your are
responsible that your position and altitude will provide terrain clearance. Your
preflight preparation made you aware of terrain and obstacles that intruded into
your approach route. Review the chart to make sure that the correct frequencies
are set. abandon the approach if you feel that something isn't right.
Radar service terminated means that the pilot will become totally responsible
for the altitudes, headings, terrain, and aircraft on his flight route. Some
radar services are automatically terminated in IFR conditions as:
1. Cancellation of IFR flight plan except where basic radar service is always
provided as in Airspace Classes, B, C, and TRSAs.
2. When on an instrument approach ATC advises to change to the CTAF or tower
frequency.
3. On completion of a radar approach.
4. VFR aircraft told to change frequency, or squawk VFR.
5. There is no flight difficulty that can’t be made more complex by technology.
Protect yourself at all times was good advice when I was fighting golden gloves,
still good advice for pilots.
LORAN
If you have non IFR LORAN or GPS
they can be used as advisory. LORAN like GPS can fly you into terrain unless it
has the correct data base. The mutual use of Loran or GPS by two aircraft in the
vicinity of a given intersection or navaid greatly increases the likelihood of a
mid-air. The accuracy of these makes such an accident probable where with the
use of VORs it was unlikely but possible.
Global Positioning System (GPS)
Paper charts will still be required in addition to a local GPS
transmitter that may or may not be capable of avoiding any military induced GPS
errors. A faulty navigation signal is flagged within 30 seconds.
For Receiver Autonomous Integrity Monitoring (RAIM) six signals are only
required so many areas and approaches will have RAIM "holes'. GPS overlays will
be added to current approaches primarily to improve course guidance. FAR
91.205(d)(2) says that for IFR navigation equipment appropriate to the ground
facilities to be used must be operational and on the aircraft. The greatest
problem to be resolved is the IFR approved GPS which allows DME and ADF
substitutions on a published overlay.
GPS can confirm the information on the HI, altimeter, airspeed indicator, VOR,
ADF and correct the DME. GPS can be used to point toward the airport. (See GPS
material under VFR cross-country) The military accuracy will be available to all
as of April 1996. If flying with a hand-held or panel mounted GPS not certified
as IFR, just file ‘GPS equipped’ under remarks
There are 4600 GPS overlay approaches. Fixes have been converted to GPS
waypoints. There is no vertical information at the waypoints. All GPS navigation
is TO a waypoint. Some synthetic fixes have been created to allow outbound
headings and for increased GPS sensitivity on final approach. Timing is losing
its importance for determining the missed approach point.
Waypoint type
ADRIW is what is called a "sensor
FAF". A Sensor FAF is a final approach waypoint created and added to the
database sequence of waypoints to support GPS navigation of a published, no FAF,
non-precision approach.
The other useful thing to know about the fixes with their names in ()'s is that
ATC doesn't know about them. So, on the approach in question, if the controller
were to ask you for a position report, and you were to say, "We're just crossing
ADRIW outbound", he wouldn't know where ADRIW was.
There are GPS Phase II and III
overlay procedure charts. On NOS charts there is no way to tell the phase.
Jeppesen provides a list. Phase II requires that navaids be available but you
are not required to use them.
Phase III charts have GPS or ... this form of GPS is a stand alone procedure. On
airways you can use GPS if you also have standard navaid devices.
GPS provides an opportunity to seamlessly bring arriving and departing aircraft
in and out of airports including taxiing. The WAAS system will allow due near
the end of the year 2000 will allow 3000 non-precision runways to be used for
precision GPS approaches with an system error of 21 feet. WAAS will allow
accurate altimeter settings and reduce the 90% of CFIT accidents that occur
within 15 miles of an airport. WAAS has precisely surveyed station locations
that correct standard GPS system errors.
Uncontrolled Airspace
Uncontrolled airspace is just that.
Any current instrument pilot can fly IFR in uncontrolled airspace wherever it's
IFR. Airspace below 700/1200 AGL is uncontrolled. You don't need an IFR flight
plan or clearance to operate there, regardless of weather. You do need to follow
91.177 and 91.179 regarding minimums, however. Can't be done? ATC says the pilot
is on his own until reaching controlled airspace.
The ultimate IFR question is whether what you did was the right thing to do. Any
arrival or departure from an uncontrolled airport will involve IFR flight in
Class G airspace. This means at least some small portion of the flight does not
have the services of ATC for IFR separation. The purposes of the 1200 and 700
foot transitions areas is meant to maintain IFR separation services on the
approach corridor for as long and as low as possible.
There are a few Class E airports and a number of Class D airports that have
Class E extensions activated by below VFR minimums. These Class E airspaces
touch the ground and have ATC IFR separation services. The Jepp charts show such
airports with a small E but NOS charts show nothing. The sectional is the best
place to look. Look where an FSS airport used to exist or where an official
weather observer was once available or has been replaced with ASOS/AWOS. The
type of approach has nothing to do with the type of airspace. VFR flights will
require a SVFR clearance.
The FAA can cite you for a violation when flying IFR in uncontrolled airspace
even though FAR 91.173 says you don't need a flight plan or a clearance. FAR
91.155 allows you to fly IFR in uncontrolled airspace. Once you get above 700’
AGL you IMMEDIATELY must comply with the required VFR cloud clearance. Better to
stay low and find some 1200’ transition airspace before looking for an area
where you can climb with required cloud clearance. The FAA will catch you on FAR
91.13 for careless and reckless flight if you don’t have the cloud clearance.
ATC
Weather
Within limits wind determines the runway ATC will select. When wind is less
than 5 knots ATC may select a noise-abatement runway or even a downwind runway.
Visibility determines the right to do an approach, land, or takeoff. ATC is a
source of advice but the action is up to the PIC.
Ceiling requires a decision on an alternate, if the destination weather is
forecasts or reported not to give a ceiling of 2000' one hour before or after
plus three miles of visibility at ETA. Precision alternates must have 600 and 2,
non-precision 800 and 2. Ceilings from any source are legal for Part 91.
Runways
Precision This is the safe bet with DH 200’ HAT, lights and 1/2 visibility
Precision with obstacles inside DH DH 250 or higher, 1 mile visibility, may have lights. Over 250 DH means
obstacles inside DH. Non-precision Could have 1/2 mile visibility, clear approach path on
centreline. VASI and/or VDP, usually the ILS runway Non-precision with obstacles below the MDA VASI say no obstacles on final from four miles out. If you are unfamiliar you
may or may not have obstacles.
Runway Departure Safety Zones
An ATC clearance does not assure obstacle avoidance during departure.
Obstacle clearance occurs only when ATC radar provides navigational direction
such as radar vectors. Until such assistance is obtained it is the
responsibility of the pilot use visual charts to avoid hitting anything. DPs
allow departure planning and reduce communications. Use an area chart or
sectional to confirm terrain and location of obstacles. Advise departure of your
need for a specific departure or DP due to limited climb performance. ATC will
accommodate your request.
Instrument Departure's Three Zones of Obstacle
Clearance
The first zone is from the departure end, 500' to each side and 35' high
in a 15-degree fan to each side for a distance of two miles in a 40:1 slope or
152 ft/nm.
Zone 2 extends from a point on the
centreline of the runway and 2000' from the
approach end. This zone extends in a semicircle arc toward the departure end at
a 40:1 slope until reaching minimum enroute altitude (MEA).
Zone 3 extends from the same point in a 40:1 slope toward the approach end of
the runway until reaching the MEA.
VASI
If you have visual contact with the runway the FAA recommends flying the
VASI if it is available. If there is a visual descent point (VDP) you can
descend below the MDA if you have visual reference as required by FAR
91.175(c)(3). You cannot descend below the MDA before the VDP.
According to FAR 91.129 (d)(3) a flight into a VASI at a controlled airport with
the tower open must remain at or above the glide path until lower is required
for landing. The rule applies only to a VASI and not to other glide slope light
system. The rule applies only if the tower is operating.
VASI extends to 4 n.m. and PAPI to 4 s.m. unless installed since
July 2004. All PAPIs must be resurveyed by local authorities (Not FAA) Any PAPIs
installed since mid-2004 are, or should be, 4 n.m
The three-bar VASIs has two glide paths. The far two bars are for large
aircraft; the two near bars are for small planes. Normal glide path is 3 degrees
and upper glide path is 1/4 degree higher. Some locations have 4.5 degree glide
path to give obstacle clearance. VASI is not part of instrument landing system.
An inoperative VASI does not affect IFR minimums. Obstacle clearance up to 4
miles or less and 10 degrees to each side.
Tri-colour VASI
Green is on glide path, white is
above and amber/red when below.
PAPI
Four lights to left of runway. 4 white for high 2 with/two red for just
right, four red for low.
VASI extends to 4 n.m. and PAPI to 4 s.m. unless installed since
July 2004. All PAPIs must be resurveyed by local authorities (Not FAA) Any PAPIs
installed since mid-2004 are, or should be, 4 n.m
AWOS Weather
AWOS-3 is official weather.
Airport may qualify as alternate airport with AWOS-3.
AWOS-3 gives altimeter, ceiling, visibility, wind, temperature, dew point, and
density altitude above 1000'
At controlled airports AWOS-3 is available only when ATIS is not.
Some AWOS have a phone number listed in A/F Directory.
Reading Charts
The geographic coordinates are at
the airport reference point (ARP) shown as a circle with a +. The letter K now
prefaces every three-letter airport designator. Airport elevation is the highest
useable runway surface. Frequencies are listed as used for arrival. Airport
diagram is drawn to scale with magnetic bearing below runway number at end of
runway. Takeoff minimums, visual reference and climb gradient is given by
aircraft categories. Departure procedures may be either for IFR or Obstacles.
53,000 changes in Jepp charts
every week;.
Lower left corner is "Changes" Of the three options will be 'reissue", 'see
other side', 'Chart re-indexed', or a specification as to the change.
All chart changes are recorded and the last change is printed on the lower left
margin vertically.
The plan view is the largest area displayed below the briefing strip. The scale
of the view is along the left side. This scale is normally one inch to five
miles but may be 7.5. The symbols are the same as as on the en route charts. The
inbound course is a bold line. Approach plate frequencies are on the briefing
strip as well as ovals on the plan view. Dark lines can be used as transitions
while light lines cannot. A dark holding patter indicates it is a part of the
procedure.
Profile not to scale
Markers showed as shaded areas
Markers have altitudes for the approach
Compare altritude at marker to TCH on chart
Marker altitudes are minimums unless designated by mandatory, maximum, or
recommended
Final approach is from Maltese cross except in the ILS which is from
intercept
Precision FAF is where glide slope intercept altitude meets glide slope.
Touchdown elevation is highest point of first 2300 feet of runway
Profile distances can be confusing. FAA leaning toward all DME rather than
time.
If takeoff minimums are specified as ceiling and visibility both must be
reported to be valid.
STD (standard) on plates means 5000RVR or one mile visibility
Any restrictions in the far right box of takeoff/obstacle applies to all
categories.
Read the fine print on the plate.
Follow the procedure precisely as charted
Know the minimums
Airports with capital letters have IFR approaches.(Jepp)
Airports in lower case letters do not have IFR approaches. (Jepp)
IFR
RNAV Chart
No more charts with GPS in title. RNAV used instead.
Extreme cold conditions cause inaccurate altimeter. See Chart warning on
briefing strip.
TAA (Terminal Arrival Area) allow arrival from any direction without course
reversal.
UNAYY system chart has minimum safe altitudes in several quadrants.
…GLS is the GNSS or global navigation landing system using WAAS with 200' and
half-mile minimums.
LNAV/VNAV (lateral and vertical) uses special altimeter
GPS charts are now named RNAV
because the FAA standard will put all forms of RNAV on one chart. the minimums
for different systems will be different. LNAV minimums apply to IFR certified
GPS. Approach plates are designed to allow pilot nav operations. This makes the
load on ATC lighter.
Existing
GPS procedures will be updated but new GPS procedures will be called RNAV.
Terminal Arrival Areas (TAA) will now give altitude and course information from
any direction for an approach.
lfThe purpose of the TAA program is to eliminate any need for a course reversal
of any kind.
TAA altitudes can be used instead of the previous MSAs. The TAAs can be flown
as approach altitudes whereas MSAs were emergency altitudes only.
The WAAS system will give 200' minimums with 1/2 mile visibility
Using ATC in Emergencies
Complete aircraft engine failures is
relatively rare because of simplicity, duality and strength. Of all aircraft
components the pilot is most likely to initiate a flight failure. The cheapest
engine failure insurance you can get is the best possible maintenance. Even so,
engines can be expected to give some warning. All flying accidents could be
reduced by 80% were pilots to use common sense and a conservative approach to
flying. It has been recently disclosed that there is a 'risk-gene' that drives
certain personalities to take chances. Fuel, altitude and the 180 add reserve to
the so-called critical margin of safety.
The airport that is five
nautical miles distant may be reachable in a failed-motor aircraft but it is
likely that the reaching may not provide enough margin to make a landing. It is
far better to use your 2-miles per 1000 feet to select a closer landing place
that will allow a more normal positioning for landing. A normal landing attitude
at the lowest possible airspeed at ground contact is the most survivable
accident you can ever have.
In an emergency it is far better
to tell ATC about your circumstances and what you are going to
do. Only if you lack local area knowledge should you ask for directional help.
The entrance of weather into the
equation requires the pilot to start reading in-between the lines of what is
happening over the radio. Night and a non-precision approach compounds the
hazards of weather.
Some situations are such that
very vital information is casually passed that have significance not brought to
the attention of the pilot. ATC may change runways, turn up lights, remark on
missed approaches and approve holding without equating these as red-flag
warnings to a particular aircraft or pilot. With ATC emphasis a pilot may ask
for an alternate missed, a vector for holding, or an update on existing
visibility conditions. This visibility is important because if a visibility
change has occurred since the pilot has passed the FAF he might wish to abort
the approach. The failure to pass on information related to rapidly changing
weather is hazardous to flight safety.
Letters for Words
MNPA Minimum navigation performance
airspace
RVSM Reduced vertical separation minimums airspace
AMASS Airport Movement and Safety System
MEA assures obstacle clearance and radio reception.
MOCA Obstruction clearance off airway but radio reception 22 miles. (Jeppesen
has a T)
MORA - Jepp only minimum off-route obstacle clearance within 1- miles.
MCA - Minimum crossing altitude with associated Minimum Enroute Altitude change
to follow.
MRA - Minimum reception altitude capable of identifying an intersection or
allowing navigation.
MAA - Maximum authorized altitude because of amount of traffic on airway.
MSA - Minimum sector altitude is pie chart depiction of safe obstacle clearing
altitudes.
Transition Level
The
transition level is the lowest flight level above the transition altitude. The
transition level is only used when descending, and must be picked up from ATIS
or Tower before landing. The transition level is where the altimeter setting is
changed from STD to QNH. The layer between the transition altitude and the
transition level is called transition layer. It is somewhere between 0 and 500'
thick, and no level flight is allowed there. Reason is that both QNH and STD
references are used here.
Terminator Legs on Charts
An obstacle clearance rate of
climb is based on crossing the threshold at 35 feet, maintaining runway heading
to 400 feet. Before turning and maintaining a minimum climb rate of 200 feet per
minute or as specified thereafter.
A 'VA leg" is a vector on a heading to a specific altitude.
An 'FD leg' departure can terminate on a DME arc at a specific altitude as a
'fly-over fix'.
A fix may be a 'fly-by fix' or a fly-over fix.
A VI leg is a vector to an interception
Letter x on a DP (Departure procedure) chart is a turn point.
A TF 'track to fix' the x 'turning point' is a fly-by
Computer based, the above will lead the intercepts while not allowed in hand
flying.
In a two pilot cockpit, one pilot should stay with ground based navaids as
insurance.
Over reliance on automation in high-workload situations precipitates
accidents.
Proficiency in computer flying requires considerable experience.
Complacency is the greatest danger to experienced pilots.
Changing a pre-planned decision is one of the most difficult things to do as a
pilot.
Computer flight planning can cause a lack of situational awareness.
The challenge of computerized flying is knowing when to say when.
New Way IFR
Basic problem of IFR is to know where you are and how to get where you
are going.
GPS makes the distinction between precision and non-precision invalid.
GPS is a navigator using an array of fixes.
By selecting a desired track to a fix, you are effectively flying a radial.
There is no need to find the identifier for the fix
The FMS (flight management system) must know where you are by using raw data
from available sources.
The pilot must know where he is going and by what route while keeping the
needle centred.
Pilots and Instructors must be more accepting of the potential of the present.
Navigational Databases
Some procedures as radar vectors
cannot be programmed into data bases.
Procedures may not be stored because of inadequate storage.
Step-down fixes between FAF and MAP are not in the databases.
The database vertical angle may not be displayed by the system.
Route legs must be geographic point to geographic point to be displayed.
All legs of a procedure must be flown as shown on paper, regardless of RNAV
display.
All procedures are not in all databases. You must have the paper.
Fly IFR procedures as charted
Data base may not have departure procedure, STAR or approach
Data base may not have all leg or segment of procedure
Confirm waypoint or navaid retrieved is the one you want.
GPS, FMS or lmap displays do not take the place of paper charts.
FAA requires that you use no hand-entered fixes.
You are required to have on 'paper' any route or fix used with GPS.
The database is information; software lets you find and use the information.
GPS database is at three levels:
1. The highest level is the inclusion of all data needed for the whole flight
planned route. 2. The next level is all the route structure such as DPs, STARs and
approaches. 3. The last level is all the navaids and fixes expressed in longitude and
latitude on the surface.
STARS
STandard Arrival RouteS are STARS
A STAR is a method of providing tracking and IFR separation for arrival
aircraft
A STAR allows arrivals not to affect enroute or departing IFR traffic
A STAR reduces required radio time
A STAR may affect spacing, speed, diversions or congestion. It does not always
work well.
A glitch in the STAR can cause the system to effectively fail
Getting the airport ATIS early will help you know what STAR to expect.
STARS often have a series of crossing altitudes that vary with your aircraft
capability
STARS often have a series of fixes, headings, and vectors that are going away
from your destination
STAR charts are not drawn to scale
Read all STAR notes carefully
Don't go into a busy airport without your STAR chart
You can file a plan with "No DPs No STARs in remarks of your plan.
Fixes:
The VOR can have up to fifteen
different identifying elements that are constant in the database.
An airway fix has at least five identifying elements in the database.
Every geographic location, worldwide, has a unique five-letter identification
code.
Airways have eight identifying elements the identifier, altitudes, courses,
distances, revision date and a sequence listing on the route.
Airway numbers go from south to north and from west to east.
Altitude
Database
Most systems do not have airway altitudes.
Not in database
Minimum descent altitude (MDA)
Decision altitude
Minimum obstruction clearance
Minimum reception
Minimum safe
Minimum sector
Minimum crossing
ATC's Variables
Ceilings and Visibilities
Coupled approaches have interception two miles outside (approach gate) which
is one mile outside OM.
Interception of glide slope is from below.
Localizer intercept at 20-degrees inside of two miles of OM and at 30-degrees
outside two miles of OM
Ceilings below 800' and visibility less than 2 miles means ATC Tower must keep
ILS critical area clear.
Ceiling 300' above MVA/MIA and 3 mile visibility means ATC may vector for
visual approach.
Advise ATC when you are making a coupled approach
Be Ready for IFR Changes
Overall IFR procedures are 90-percent canned and always the same. Not
necessarily so in busy corridors. ATC may want to move you out of the way of the
big boys.
Anticipatory planning can shortstop many distractions. Biggest item is to have
quickly available instrument covers. You will never appreciate how necessary
they are until you have a serious need for them. The preflight is the best place
to take care of common distractions such as zero airspeed because the pitot heat
was not confirmed prior to takeoff. Keep all the charts for the departure and
arrival airport approaches together and arranged according to anticipated use.
Use your passengers as much as necessary such as keeping the most flight
experienced next to you.
Base your approach selection on the one that offers the most direct route. Get
your IFR approaches over with before dark. A proper preflight has prepared for
the least likely equipment failure.
What is
IFR?
Begins with "Cleared to…"
Forms of clearance limits, ground limits, clearance delivery route limits,
takeoff limits, radio failure limits, vector limits, initial approach fix
limits, airport ETA limits.
FAA facilities think and act differently. Flex as required.
IFR
after 9/11
Being IFR is no longer the
violation proof system of yesteryear.
Your weather briefing is no longer more important than protecting yourself
from ATC mistakes.
You are more likely to be guided into a TFR/FRZ/TFR by ATC than by any other
means.
The FAR emergency procedures of yesteryear are no longer overriding.
The clearances no longer are no longer to be relied upon to keep you
inviolate.
As the PIC you are more likely to be held accountable than the controller.
You are best off to refuse any clearance, vector, or directive that will fly
you into restricted airspace.
Notams are not as reliable or accurate as they should be.
The system no longer works as well as the FAA wants it to.
Get a full briefing from the FSS so the recording will serve as a protective
cover for you flight.
Make last minute check to FSS prior to departure from every leg of a flight.
Be in radio contact with ATC at all times.
Make sure your GPS has a current database
Have current charts, plates, and frequencies.
Past reliance on ATC for traffic avoidance is no longer recommended.
|