IFR clearances

Know what the clearance authorizes

An ATC clearance authorizes flight under specified traffic conditions. It can assign a limit, route, altitude and restrictions different from the filed proposal. It does not establish that the aircraft is airworthy, that its climb performance is adequate, or that hazardous weather has become safe. The PIC remains responsible for the aircraft operation.

Section 91.123 requires compliance with the obtained clearance unless an amended clearance is obtained, an emergency exists, or the deviation responds to a TCAS resolution advisory. An uncertain clearance requires an immediate clarification request. Do not treat silence or a filed preference as an amendment.

An IFR route clearance, a departure release, and a takeoff clearance at an operating tower answer different questions. A route clearance with “hold for release” does not permit departure under that clearance. “Line up and wait” positions the aircraft on a runway but does not authorize takeoff. At a nontowered airport a release does not control local runway traffic; use the appropriate airport procedures and collision avoidance.

§91.123(a)–(e): compliance, clarification, deviations and aircraft identity · §91.3: PIC responsibility and emergency authority · AIM 4-4-1: purpose and limits of an ATC clearance · AIM 5-2-5 and 5-2-7: LUAW and departure release restrictions

Copy the complete instruction, then read its meaning

CRAFT—clearance limit, route, altitude, frequency and transponder—can organize notes, but it is a memory aid, not the complete list of possible restrictions. Record departure procedure/version/transition, initial heading, crossing restrictions, speed, release/void time and any holding or further-clearance information. Distinguish an airport from a same-name aid or fix.

Study clearance: N742FD is cleared to Pine Airport via GROVE direct, maintain 3,000, expect 7,000 ten minutes after departure; departure frequency 124.6; squawk 4621. Pine and GROVE are fictional teaching locations. The limit is Pine Airport; GROVE is part of the route. The immediate assigned altitude is 3,000. The 7,000-foot instruction is an expectation for a later clearance, not permission to climb there automatically after ten minutes while communications work.

“As filed” abbreviates the accepted route, not every requested flight-plan value. The filed cruise altitude is not automatically authorized. If the route/destination was amended before requesting clearance, tell ATC and request the appropriate full route clearance. Verify the cleared procedure and transition against the current chart and database.

“Maintain” an altitude differs from “climb via SID” or “descend via STAR”; the latter instructions require understanding the published path and constraints. A clearance to the destination airport is not by itself an approach clearance or permission to leave the assigned altitude. “Cruise” is a distinct clearance authorizing a block from minimum IFR altitude through the stated altitude; after reporting descent from an altitude in that block, return requires further clearance. Request clarification when an unfamiliar term changes your intended action.

AIM 4-4-3: clearance limit, route, altitude, cruise and holding instructions · AIM 5-2-6: as-filed scope and changed flight plans · IFH 10-4: clearance examples and cruise clearance

Close the communication loop

Make a written record for IFR and compare it with the filed plan. Read back critical altitude assignments/restrictions, headings/vectors and runway assignments in the sequence given, using the aircraft identification. For an initial departure clearance, include the issued route and important restrictions so any difference can be corrected before takeoff. AIM readback guidance is a mutual-verification practice; do not invent a universal regulation that every word of every clearance must be repeated.

Use standard phraseology and phonetics, stating heading as three digits and UTC time unambiguously. If a frequency, fix, restriction or number was missed, request the specific item again. “Roger” acknowledges receipt; it cannot establish that an unclear clearance was understood. Ask before programming or maneuvering on an assumption.

With similar call signs, use full identification and tell the controller about the confusion. N742FD must not act on a clearance to N724FD merely because the altitude sounds appropriate. Include identity in acknowledgments, listen for controller correction and verify that the response is for your aircraft. After a frequency change, check in with the correct agency and assigned/current altitude information.

A readback error corrected by ATC changes your understanding, not the already-written original into a valid alternative. Mark the corrected value clearly, reverify it, and update the relevant selected altitude, heading, source or radio under the aircraft procedure.

AIM 4-4-7: written record and readback practices · AIM 4-2-3/4/7–12: contact, full call signs, phonetics, numbers and UTC · §91.123(a), (e): clarification and instructions for another aircraft

Separate the departure window from the notification deadline

Hold for release prohibits departure using that IFR clearance until ATC issues a release time or further instructions. A release time is the earliest departure time. A void time requires being airborne before that time. Coordinate when actually ready so aircraft preparation and local traffic do not force a rushed departure.

Study instruction: released at 1840Z, void if not off by 1845Z; if not off, advise ATC not later than 1850Z. The departure window starts at 1840Z and ends before1845Z. The 1850Z communication deadline does not extend the window. If the aircraft will not depart, advise ATC as soon as possible and obtain a new acknowledged release before IFR departure.

Expiration withdraws authority to depart IFR; it does not automatically cancel the departure clearance or the IFR flight plan. The normally assigned notification period cannot exceed 30 minutes, and failure to contact ATC within 30 minutes after the void time initiates overdue/search-and-rescue procedures. Other IFR traffic may be blocked while ATC determines whether you departed. Treat prompt notification as operationally important.

An EDCT used in traffic management is a different restriction; AIM expects departure no earlier than five minutes before and no later than five minutes after it. Read the actual restriction rather than treating EDCT and void time as synonyms. A VFR departure is a separate lawful decision with appropriate cancellation/code coordination; it does not promise an airborne IFR clearance or a safe climb through clouds.

AIM 5-2-7: hold for release, release/void times, notification and EDCT · §91.173: appropriate clearance before controlled-airspace IFR

Say unable while there is still room to solve the problem

Compare the clearance with actual performance, navigation approval, current publications and weather. A required climb gradient may exceed the aircraft's available climb at loaded weight and temperature. An RNAV procedure may require a capability or sensor unavailable in the installation. A runway or navigation aid may be closed, and a reroute may consume the fuel needed for a suitable alternate. Tell ATC the actual limitation and request a workable amendment.

For example: “N742FD unable that departure gradient; request another runway or departure.” Or: “N742FD unable RNAV one; request conventional routing.” Use the true installation limits; this lesson does not supply an avionics approval or an aircraft performance figure. Do not accept first and hope to solve an impossible restriction after takeoff.

When an amendment arrives, determine what it changes and what remains in force. Recheck route, terrain, fuel and any affected procedure constraints; record and read back the critical revised parts. If the amended instruction conflicts with another restriction, immediately clarify. A vector or direct clearance that leaves a SID/STAR can change which published constraints apply; the departure/arrival lessons teach those specific cases.

Workload is also a limitation to manage. Ask for a repeat, a simpler clearance or time when needed. Use appropriate automation only when familiar with its modes and indications. Fly and monitor while programming; a passenger can assist with an agreed simple task, but the pilot retains responsibility for verifying the instruction.

AIM 4-4-1/4/7: safe acceptance, amendment and responsibility · AIM 5-2-9: departure capability and changed SID/ODP instructions · AIM 5-5-1: pilot/controller responsibilities · ACS III.A.R1–R4: understanding, clearance validity, capability and identity risk

Preserve the clearance and reports without radar

Radar contact changes some reporting duties; it does not eliminate the assigned route/altitude. In a nonradar environment, ATC relies on accurate position reports, estimates and clearances to separate aircraft. Maintain the appropriate frequency and report designated/requested points as applicable, unforecast weather and other safety information. Report navigation/approach/communications failures and their practical effect as soon as practical.

If cleared to a fix other than the destination and delay is expected, obtain the holding instructions and EFC. Use the assigned charted pattern when appropriate; if no pattern/instructions are available, ask before the fix. With communications operating, an EFC is an expectation, not permission to leave the limit or descend. Report arrival time/altitude at the clearance limit and leaving it, and obtain clearance beyond it. The holding lesson develops entry and fuel decisions.

If two-way communications fail, §91.185 supplies a different decision framework. If VFR conditions exist or are encountered, continue under VFR and land as soon as practicable. Otherwise use the assigned route; if vectored, proceed directly to the fix/route/airway specified in that vector clearance; then, when no assigned route exists, use ATC's expected route, and finally the filed route if neither exists. Fly the highest applicable assigned, minimum IFR or ATC-expected altitude for each segment.

Leaving a limit depends on whether it is a fix from which an approach begins. At such a fix, begin descent/approach as close as possible to EFC, or if none, ETA calculated from filed/amended estimated time en route. If it is not such a fix, leave at EFC or, without EFC, upon arrival; proceed to an approach-start fix and begin descent/approach as close as possible to that ETA. These are introductory legal distinctions. Lost communications develops diagnosis, timing and application; memorized initials alone do not resolve every case.

§91.183: continuous frequency watch and reports · §91.187: malfunction reports · §91.185(b)–(c): VFR, route, altitude and clearance-limit framework · AIM 5-3-2/3/8: position, additional and holding reports

Use PIC authority when immediate safety requires it

Under §91.3, the PIC is the final operational authority; in an in-flight emergency requiring immediate action, the pilot may deviate from Part 91 to the extent required to meet the emergency. Protect control and immediate safety rather than waiting for permission to take necessary emergency action.

Declare the problem clearly when able, describe the needed assistance and notify ATC as soon as possible of a clearance deviation. A malfunction may need an amendment without being an immediate emergency; a rapidly worsening situation can require emergency action. Do not let fear of using the word “emergency” delay assistance when priority or prompt action is necessary.

Section 91.3 requires a written deviation report to the Administrator if requested. Section 91.123 has separate notification/report provisions, including a detailed report within 48 hours to the ATC facility manager, if requested, for emergency priority under paragraph(d). Do not invent a universal requirement to file a report for every emergency declaration. Discuss the actual event and applicable requests with appropriate qualified support afterward.

§91.3(b)–(c): emergency deviation and requested report · §91.123(c)–(d): deviation notification and requested emergency-priority report

Rehearse the instruction and the resulting cockpit setup

On the ground with an instructor, copy and read back a fictional full clearance, an amendment and a release/void restriction. Interpret the limit, route and altitude, then compare them with current charts, NOTAMs, aircraft navigation approval and performance. Resolve a similar-call-sign case and an unclear altitude without guessing.

Using the actual cockpit or a suitable training setup, identify required radios, frequency changes, navigation sources/identification, course/radial/bearing selections and transponder code. Verify the route and source against the clearance; use the normal checklist for the relevant phase. Rehearse how you will intercept/track the cleared course while monitoring flightpath and automation, without assuming one universal button sequence.

Discuss the ACS III.A.S5 flight standards: applicable airspeed within ± 10 knots, heading within ± 10°, altitude within ± 100 feet and selected course/radial/bearing within ¾-scale CDI deflection. Identify the indications and cross-check that will support them in instructor-led practice. These are practical-test performance standards, not navigation-approval tolerances or an online completion claim.

Assign workload before practice: retain aircraft control and monitoring, use a written record, keep essential publications accessible, and call for clarification when attention or understanding is inadequate. This is ground preparation for III.A.S1–S7; actual timely compliance, interception and instrument performance must be developed and assessed in flight or appropriate supervised training.

ACS III.A.S1–S7: clearance, setup, publications, intercept, performance, SRM and checklist preparation · AIM 4-4-7: clearance record and mutual verification

FLIGHT SCENARIO

What would change your plan?