IFR stands for instrument flight rules: the body of federal aviation regulation under which a pilot flies on a clearance from air traffic control, navigates by instruments and published procedures rather than by looking out of the window, and is separated from other aircraft by controllers rather than by seeing and avoiding them. It is a set of rules and a way of operating inside a system, not a description of the weather, which is why an IFR flight on a cloudless day is completely ordinary.
This page explains the system itself, in the order you meet it. If what you actually want is a comparison of the two rule sets side by side, with the visibility and cloud-clearance minimums for each class of airspace, read VFR versus IFR instead. If you are ready to train for the rating that lets you do this, start with the instrument rating in Los Angeles, which is the pillar page this one sits under.
IFR Is A Set Of Rules, Not A Weather Condition
The single most common confusion about IFR is that it means bad weather. It does not. The weather has its own vocabulary: visual meteorological conditions and instrument meteorological conditions, VMC and IMC, which describe what the sky is doing. Instrument flight rules describe what you are doing.
You can fly IFR in perfect visibility, and airline crews do it on every sector regardless of the forecast. You cannot legally fly VFR in instrument meteorological conditions at all. The two ideas overlap constantly but they are not the same thing, and pilots who keep them separate in their heads have a much easier time with everything that follows.
Under IFR you give up some freedom. You fly the route you were cleared for, at the altitude you were assigned, and you ask before you change either. In exchange you get three things that matter enormously: a controller whose job is to keep other airplanes away from you, a set of published procedures that take you from a runway at one end to a runway at the other without requiring you to see anything until the last few hundred feet, and the legal ability to fly through cloud.
The Four Things Every IFR Flight Has
Strip away the detail and an IFR flight is four elements. Every one of them has a regulation behind it.
A Flight Plan Filed With Air Traffic Control
14 CFR 91.173 is blunt: no person may operate an aircraft in controlled airspace under IFR unless that person has filed an IFR flight plan and received an appropriate ATC clearance. 14 CFR 91.169 sets out what the plan must contain, including the information required for a VFR flight plan plus, in most cases, an alternate airport. You file electronically, usually through an app or a flight-planning service, and the plan sits in the system waiting for you.
A Clearance You Read Back And Then Fly
A clearance is an authorization to proceed under specified conditions. It is not advice and it is not a suggestion. Once you accept it you are obliged to fly it, and if you cannot, because of weather, an equipment problem, or because it would put you somewhere you are not happy to be, the correct response is to say so and ask for something else, before you accept it rather than after.
Separation Provided By A Controller
Under VFR you are responsible for seeing and avoiding other aircraft. Under IFR in controlled airspace, a controller keeps a defined volume of empty sky around you, measured in miles laterally and in feet vertically. That is the deal, and it is why you do not get to wander off the cleared route to look at something.
Published Procedures From Runway To Runway
Instrument flying runs on paper, or more often on a tablet. Departure procedures, airways and routes, arrivals and instrument approach procedures are all published, charted and named, and they are designed so that following them keeps you clear of terrain and obstacles without needing to see either. Learning to read those charts quickly and correctly is a large part of what the instrument rating actually teaches.
How An IFR Flight Runs, Start To Finish
Before The Engine Starts
You check the weather at the departure airport, the destination, and any alternate. You decide whether the airplane is legal, which is a longer list under IFR than under VFR. You plan a route, work out fuel, and file. Under 14 CFR 91.167 you must carry enough fuel to fly to the first airport of intended landing, then to the alternate if one is required, and then for 45 minutes at normal cruising speed after that. That 45 minutes is not a comfort margin, it is a legal minimum, and it is the reason IFR flight planning takes longer than VFR flight planning.
The Clearance, And Why It Arrives In That Order
At a towered airport such as Van Nuys you request your clearance before taxi. It always comes in the same sequence, which pilots remember as clearance limit, route, altitude, frequency, transponder code. Knowing the order in advance is the whole trick to copying it: you are not listening for words, you are filling in five boxes you already drew.
A clearance out of Van Nuys typically includes a departure procedure, an initial altitude with an instruction about when to expect the final one, the departure controller's frequency and a squawk code. You read it back. If you misread it, the controller corrects you, and that exchange is a safety net rather than an embarrassment.
Departure
You fly the departure procedure as cleared. Instrument departure procedures exist for one reason: to guarantee obstacle clearance on a climb-out you may not be able to see. In Southern California that matters more than it does in flat country, because the terrain north and east of the Los Angeles basin rises quickly and the published procedures are built around it.
Enroute
You are handed from controller to controller along your route, holding the assigned altitude and the assigned track. 14 CFR 91.177 sets minimum altitudes for IFR operations, and the charted minimum enroute altitude for each segment is the number that keeps you above terrain and within navigation signal coverage. This is the calmest part of an IFR flight and, on a long leg, the part where a new instrument pilot learns how much of the workload is simply staying ahead of the airplane.
Arrival And The Approach
Approaching the destination you are cleared for an instrument approach procedure, or vectored onto one. From this point the flight becomes precise: specific altitudes at specific fixes, a final approach course to intercept, a descent flown to a published minimum, and a decision to make at the bottom.
The Missed Approach
Every instrument approach has a published missed approach procedure, and flying it is a normal outcome, not a failure. If you reach the minimum and the required visual references are not there, you climb, follow the published missed approach track, and go somewhere else or try again. Instrument students practice missed approaches until the response is automatic, because the one thing you must never do at minimums is improvise.
What An Instrument Approach Actually Is
An instrument approach procedure is a charted series of altitudes, headings and fixes that takes you from the enroute structure down to a point from which a landing can be made using visual reference, or from which a safe climb away can be made if it cannot.
Approaches divide into those that give you vertical guidance, a glidepath you fly down as on an ILS or an LPV approach, and those that do not, where you descend in steps to a minimum altitude and level off. The distinction changes the shape of the descent and the number at the bottom.
Reading The Minimums
Every approach chart publishes a minimum altitude and a visibility. On an approach with vertical guidance it is a decision altitude: you arrive at it on the glidepath and decide, at that moment, to land or to go around. On an approach without vertical guidance it is a minimum descent altitude: you may level off there and continue toward the missed approach point, but you may not go lower without the required visual reference.
Those numbers are not arbitrary. They are built from the obstacles in the approach area and from the accuracy of the navigation being used, which is why a precisely guided approach to a well-equipped runway has lower minimums than a circling approach to a small field.
What Lets You Descend Below The Minimum
14 CFR 91.175 answers the question every new instrument pilot asks: what exactly do I need to see. In short, the flight visibility must be at or above the visibility prescribed for the approach, the aircraft must be in a position from which a normal descent to landing can be made, and at least one of a specific list of visual references for the intended runway must be distinctly visible: the approach light system, the threshold, the threshold markings or lights, the runway end identifier lights, the visual glideslope indicator, the touchdown zone or its markings or lights, or the runway or runway markings or lights. Learning that list is not academic. It is the rule you apply, in real time, in a second and a half, at the bottom of a real approach.
The Airplane Has To Qualify Too
A pilot with an instrument rating cannot fly just any airplane under IFR. 14 CFR 91.205(d) adds a list of instruments and equipment to the VFR requirements: two-way radio communication and navigation equipment suitable for the route to be flown, a gyroscopic rate-of-turn indicator, a slip-skid indicator, a sensitive altimeter adjustable for barometric pressure, a clock displaying hours, minutes and seconds, a generator or alternator of adequate capacity, a gyroscopic pitch and bank indicator, and a gyroscopic direction indicator.
On top of that sit inspections with their own clocks. 14 CFR 91.411 requires the static pressure system, altimeter and automatic pressure altitude reporting system to have been tested and inspected within the preceding 24 calendar months before IFR flight in controlled airspace. 14 CFR 91.413 sets the same 24-calendar-month interval for the transponder. 14 CFR 91.171 covers the VOR equipment check required within the preceding 30 days for IFR operations using VOR navigation.
Two of our Piper Warriors, N3034Q and N6312C, are IFR-equipped and are the airplanes most of our instrument students train in. The Cirrus SR22 Turbo with its Perspective glass panel is the other common choice, and the whole fleet is listed on the airplanes you will fly.
Fuel, Alternates And The One-Two-Three Rule
IFR flight planning has a rule that catches everybody once. Under 14 CFR 91.169(b), an alternate airport must be listed on the flight plan unless the destination has a published instrument approach procedure and the forecast weather, for at least one hour before and one hour after the estimated time of arrival, shows a ceiling of at least 2,000 feet above airport elevation and visibility of at least 3 statute miles. Pilots call it the one-two-three rule: one hour either side, two thousand feet, three miles.
If an alternate is required, 14 CFR 91.169(c) sets what its forecast weather must be at your estimated time of arrival there: for an airport with a published precision approach, a ceiling of 600 feet and visibility of 2 statute miles; for one with a published non-precision approach, a ceiling of 800 feet and visibility of 2 statute miles; and if the airport has no published instrument approach procedure, the weather must allow descent from the minimum enroute altitude, approach and landing under basic VFR.
| Question | Rule | Numbers |
|---|---|---|
| Do I need to file an alternate? | 91.169(b) | No, if the destination has a published approach and the forecast is at least 2,000 ft ceiling and 3 SM visibility from 1 hour before to 1 hour after ETA |
| Can I use this airport as my alternate? | 91.169(c) | Precision approach: 600 ft and 2 SM. Non-precision approach: 800 ft and 2 SM |
| What if the alternate has no approach? | 91.169(c)(2) | Weather must permit descent from the MEA, approach and landing under basic VFR |
| How much fuel? | 91.167 | To the destination, then to the alternate if required, then 45 minutes at normal cruising speed |
Who Is Allowed To Fly IFR
14 CFR 61.3(e) is the gate: no person may act as pilot in command of a civil aircraft under IFR, or in weather conditions less than the minimums prescribed for VFR flight, unless that person holds the appropriate instrument rating or an airline transport pilot certificate with the appropriate category and class rating. The rating itself is earned under 14 CFR 61.65, and we set out every hour and endorsement it asks for on our page about instrument rating requirements.
Holding the rating is not the end of it. 14 CFR 61.57(c) requires that, within the six calendar months preceding the flight, you have performed and logged six instrument approaches, holding procedures and tasks, and intercepting and tracking courses through the use of navigational electronic systems, in order to act as pilot in command under IFR or in weather below VFR minimums. Let that lapse and there is a path back, explained on our page about IFR currency requirements.
What An Instrument Rating Does Not Give You
This is the part good instructors say early and often. The rating expands the weather you can legally and safely operate in. It does not make a light single-engine airplane an all-weather machine.
- Thunderstorms remain absolutely off limits. Convective weather can destroy an airliner, and an instrument rating does nothing to change that.
- Structural icing is a hard stop in an aircraft without approved ice protection, which describes almost every training airplane in the country.
- You cannot begin an approach below the published minimums in most operations, and you certainly cannot descend below them without the visual references in 91.175.
- Your own currency and recent experience matter more than the certificate. A pilot who flew six approaches last week and one who flew them five months ago hold the same rating and are not the same pilot.
What the rating genuinely buys is dispatch reliability in ordinary, unremarkable weather: a low overcast, a layer between you and a clear cruise altitude, a destination that is fine but reachable only by an approach. That is most of the weather that cancels flights, and it is precisely what IFR is for.
Why This Matters More In Los Angeles Than People Expect
Southern California has a reputation for perfect flying weather, and for most of the year it deserves it. Then there is the marine layer: a shallow deck of stratus that pushes in off the Pacific overnight and lies across the coastal basin in the morning, most often from late spring into midsummer. It is not violent weather. It is a low ceiling, a few hundred to a couple of thousand feet thick, that usually burns off by late morning.
For a VFR pilot it is a canceled flight or a long wait. For an instrument pilot it is a clearance, a climb through a thousand feet of gray, and a cruise on top in sunshine. That single difference is why so many pilots in this basin earn the rating and why we think the marine layer is the best training aid we have. Students here fly real approaches in real cloud, routinely, rather than spending the whole rating under a plastic hood.
The airspace helps too. Van Nuys is a Class D tower under the Los Angeles Class B shelf, surrounded by some of the busiest general aviation traffic anywhere, which means an instrument student here learns to work inside a genuinely complex system rather than an empty one. Our guide to Los Angeles airspace covers the geography, and airspace classes explained covers the letters.
What Learning To Fly IFR Is Actually Like
It is less about flying and more about managing. You already know how to make the airplane go where you want it. What changes is that you now do it while holding a picture of your position in your head, interpreting charts, talking to controllers, and staying about four minutes ahead of the aircraft the entire time.
Training usually runs in three phases: attitude instrument flying, where you learn to control the aircraft precisely on instruments alone; procedures and navigation, where holds, intercepts and approaches are built up until they are automatic; and IFR cross-country work leading into checkride preparation. A great deal of the early procedural work is done in a simulator, because a device can reposition you to the final approach fix in seconds and fail an instrument without any of the risk that would come with doing it for real. Our Redbird MCX full-motion simulator carries up to 20 of the 40 required instrument hours, which is the maximum the regulation allows.
Most students flying two or three times a week finish in two to four months. The course costs $11,700, and our instrument rating cost breakdown shows exactly where every dollar of that goes.
Related Reading
- VFR versus IFR — the two rule sets compared, with weather minimums by airspace class.
- Instrument rating in Los Angeles — the course, stage by stage.
- Instrument rating requirements under 14 CFR 61.65 — the hours, the tests and the endorsements.
- IFR currency requirements — six approaches, holding, intercepting and tracking.
- Instrument proficiency check — what to do when currency has lapsed.
- Flying in Los Angeles airspace — the Class B, the corridors and Van Nuys.
IFR Frequently Asked Questions
What Does IFR Mean In Aviation?
IFR means instrument flight rules: the regulations under which a pilot operates on an air traffic control clearance, navigates by instruments and published procedures, and is separated from other traffic by controllers. It describes how you are flying, not what the weather is doing.
What Is The Difference Between IFR And IMC?
IFR is a set of rules you choose to operate under. IMC, instrument meteorological conditions, is a description of the weather. You can fly IFR in clear air, and airline crews do it on every flight, but you may not fly VFR in IMC.
Do You Need An Instrument Rating To Fly IFR?
Yes. 14 CFR 61.3(e) requires an appropriate instrument rating, or an airline transport pilot certificate with the appropriate category and class rating, to act as pilot in command under IFR or in weather below VFR minimums. The rating is earned under 14 CFR 61.65.
What Is An IFR Clearance?
An authorization from air traffic control to proceed under specified conditions. It arrives in a fixed order: clearance limit, route, altitude, departure frequency and transponder code. You read it back, and once you accept it you are obliged to fly it unless you request and receive an amendment.
What Is An Instrument Approach?
A charted procedure that takes you from the enroute structure down to a point from which you can land using visual reference, or climb away safely if you cannot. Approaches with vertical guidance give you a glidepath and a decision altitude. Approaches without it give you step-down altitudes and a minimum descent altitude.
When Do You Need To File An Alternate Airport?
Under 14 CFR 91.169(b), an alternate is required unless the destination has a published instrument approach and the forecast shows a ceiling of at least 2,000 feet and visibility of at least 3 statute miles from one hour before to one hour after your estimated arrival. Pilots call it the one-two-three rule.
Can You Fly IFR In Any Weather?
No. Thunderstorms and structural icing remain off limits in a light training airplane regardless of your rating, and you may not descend below published approach minimums without the visual references listed in 14 CFR 91.175. An instrument rating buys reliability in ordinary weather, not immunity from serious weather.
How Much Fuel Does An IFR Flight Require?
Under 14 CFR 91.167, enough to fly to the first airport of intended landing, then to the alternate if one is required, and then for 45 minutes after that at normal cruising speed. It is a legal minimum rather than a comfort margin.
Why Is An Instrument Rating So Useful In Los Angeles?
The marine layer. A shallow deck of coastal stratus sits over the basin on many mornings from late spring into summer, canceling VFR flights that an instrument pilot completes with a clearance and a climb. It also means students here fly real approaches in real cloud rather than only under a hood.
See What Instrument Flying Looks Like From The Left Seat
If you are a private pilot weighing up the rating, book a free consultation and bring your logbook: the cross-country time already in it is what decides your timeline and your cost. If you are not a pilot yet and this page is where the idea started, a 60-minute discovery flight is $229, you fly it yourself from the left seat, and it logs as dual instruction toward any certificate you go on to earn. Call (818) 330-1318 any day from 9 AM to 9 PM, or find us at 7900 Balboa Blvd, Van Nuys, CA 91406, on Van Nuys Airport.