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
Missed obstacles
Approach obstacles
Fly edges of approach area
Fly approach all the way at minimums

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.

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

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
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.

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.


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.
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.

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.

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)


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
he 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.


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.


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.