IFR To VFR On Top
Changing weather conditions may allow pilots to transition from instrument flight to visual reference while remaining in controlled airspace. Understanding IFR to VFR-on-top operations helps pilots recognize how clearances, altitude selection, and continued compliance with instrument procedures support safe flight.
Introduction to IFR To VFR On Top
- Along the Pacific Coast, particularly in winter, there can be dense early morning fog with visibility less than a half-mile on the runway, but the fog layer tops out in bright sun only a thousand feet higher.
- Even the low coastal hills are above it all in clear air, as are all the inland airports.
- Closer to home, most, if not all, airports located at the bottom of a valley can experience the same thing, particularly after a nighttime temperature inversion.
- Instead of flying the whole flight on an IFR flight plan along assigned routes, you can file a flight plan for IFR to VFR-on-top.
- Instead of filing an IFR, you file your flight plan IFR to VFR-on-top.
- You still go through all the complete instrument procedures of getting a clearance before you take off, reading it back, flying an assigned route or assigned departure procedure, squawking an assigned code on your transponder, and contacting a controller.
- You depart on an instrument flight just like any other instrument flight.
- The difference is that the instructions in your instrument clearance read something like "...departure frequency [Frequency], climb as filed to VFR-on-top, if not VFR by [Altitude], maintain [Altitude] and advise...."
- Once you break out on top of the clouds, you can cancel IFR and fly VFR.
- Remember again that an IFR flight is an entirely controlled procedure, while a VFR flight outside the boundaries of an airport is uncontrolled.
- The same controller who was telling you what to do is now only advising you.
- You cannot casually lapse back and forth from one to the other.
- The controller is going to remind you of this after you cancel IFR by instructing you to "Maintain VFR".
- In fact, while Air Route Traffic Control Centers (called XYZ Center on the radio) handle the Instrument portion of the flight, the visual portion of the flight plan is on file with a Flight Service Station located somewhere else on a different frequency (called ABC Radio).
- In effect, you have two flight plans on file with two different groups of people, each of which needs to be activated and closed.
- The Instrument flight plan opens automatically when cleared for takeoff.
- It closes when you tell a controller, "Cancel IFR."
- The visual portion of the flight plan does not automatically activate.
- It activates when you call Flight Service and activate it, and closes when you call and close it.
- After you cancel IFR, you need to call a Flight Service radio - whose frequency is typically found on your sectional chart - and activate your VFR flight plan.
- Then you need to either close it by phone or radio when you land.
- If, for some reason, you don't break out of the clouds as expected, a second flight plan can assign routing to continue.
- Also, if you don't arrive at your destination, someone will come looking for you, and they will know where to look.
IFR Clearance for VFR-on-top
- A pilot on an IFR flight plan operating in VFR weather conditions may request VFR-on-top instead of an assigned altitude.
- Pilots are permitted to select an altitude or flight level of their choice (subject to any ATC restrictions).
- Pilots desiring to climb through a cloud, haze, smoke, or other meteorological formation and then either cancel their IFR flight plan or operate VFR-on-top may request a climb to VFR-on-top.
- The ATC authorization must contain either a top report or a statement that no top report is available, and a request to report reaching VFR-on-top.
- Additionally, the ATC authorization may contain a clearance limit, routing, and an alternative clearance if a specified altitude does not reach VFR-on-top.
- A pilot on an IFR flight plan, operating in VFR conditions, may request to climb/descend in VFR conditions.
- ATC may not authorize VFR-on-top/VFR conditions operations unless the pilot requests the VFR operation, or a clearance to operate in VFR conditions will result in noise abatement benefits where part of the IFR departure route does not conform to an FAA-approved noise abatement route or altitude.
- When operating in VFR conditions with an ATC authorization to "maintain VFR-on-top/maintain VFR conditions," pilots on IFR flight plans must:
- Fly at the appropriate VFR altitude as prescribed in 14 CFR Section 91.159.
- Comply with the VFR visibility and distance from cloud criteria in 14 CFR Section 91.155 (Basic VFR Weather Minimums).
- Comply with instrument flight rules that apply to this flight; i.e., minimum IFR altitudes, position reporting, radio communications, course flown, adherence to ATC clearance, etc.
- Note that pilots should advise ATC before any altitude change to ensure the exchange of accurate traffic information.
- ATC authorization to "maintain VFR-on-top" is not intended to restrict pilots so that they must operate only above an obscuring meteorological formation (layer).
- Instead, it permits operation above, below, between layers, or in areas where there is no meteorological obscuration.
- It is imperative, however, that pilots understand that clearance to operate "VFR-on-top/VFR conditions" does not imply cancellation of the IFR flight plan.
- Pilots operating VFR-on-top/VFR conditions may receive traffic information from ATC on other pertinent IFR or VFR aircraft.
- However, aircraft operating in Class B airspace/TRSAs must be separated as required by FAA Order JO 7110.65, Air Traffic Control.
- Note, when operating in VFR weather conditions, it is the pilot's responsibility to be vigilant to see-and-avoid other aircraft.
- ATC will not authorize VFR or VFR-on-top operations in Class A airspace.
IFR-to-VFR on Top Conclusion
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