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By following this guide, you will create MEL deferrals for inoperative instruments and equipment, assign the correct MEL category (A—D), track rectification intervals, monitor expiration dates, manage operational limitations, and close deferrals when the item is repaired.
Who should read this: Directors of maintenance, maintenance controllers, dispatchers, and pilots in command responsible for determining whether an aircraft may be operated with inoperative equipment under MEL provisions.Required permission: maintenance_ops — read to view, update to create and manage deferrals. MEL certificate authority may be required for initial deferral creation depending on your organization’s MEL procedures.Regulatory basis: 14 CFR 91.213 governs the operation of aircraft with inoperative instruments and equipment. 14 CFR 135.179 establishes MEL requirements specific to Part 135 operations. Your operator-specific MEL, approved by the FAA as part of your OpSpecs, defines which items may be deferred and under what conditions.

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MEL Category Reference

MEL items are classified into four categories that determine the maximum time allowed for repair:
CategoryRectification IntervalDescription
AAs specified in the MELTime interval stated in the MEL entry itself
B3 consecutive calendar daysExcluding the day of discovery
C10 consecutive calendar daysExcluding the day of discovery
D120 consecutive calendar daysExcluding the day of discovery
Calendar day intervals exclude the day the malfunction was recorded. “3 consecutive calendar days” means the item must be repaired by the end of the third calendar day after the day of discovery. Extensions beyond these intervals require specific FAA authorization and must be documented.

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The MEL Deferrals List

Navigate to Maintenance > MEL Deferrals to see all active and historical deferrals. The list shows:
ColumnDescription
MEL ReferenceMEL item reference (e.g., “32-1-1”)
AircraftRegistration of the affected aircraft
CategoryMEL category A, B, C, or D
DescriptionWhat equipment is inoperative
Deferred DateWhen the deferral was created
ExpiresRectification deadline based on category
StatusOpen, Extended, Closed
ExtensionsNumber of times the deferral has been extended
Items nearing expiration show an amber badge; expired items show a red badge.

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Create a MEL Deferral

1
Open the new deferral form
2
From the MEL Deferrals page, click New Deferral. You can also create a deferral directly from a discrepancy detail page by clicking Defer Under MEL.
3
Select the aircraft and MEL reference
4
  • Aircraft — Select the aircraft registration
  • MEL Reference — Enter the MEL item number from your approved MEL (e.g., “32-1-1”)
  • CDL Reference — If deferring under the Configuration Deviation List, enter the CDL item
    • 5
    Set the MEL category
    6
    Select Category A, B, C, or D. PlaneConnection automatically calculates the rectification deadline based on the selected category and the deferral date:
    7
  • Category A: Uses the interval specified in the MEL entry
  • Category B: Deferred date + 3 calendar days
  • Category C: Deferred date + 10 calendar days
  • Category D: Deferred date + 120 calendar days
    • 8
    For Category A items, manually enter the specific rectification due date, hours, or cycles as defined in the MEL.
    9
    Enter deferral details
    10
  • Description — What is inoperative and the MEL provisions being applied
  • Deferred Date — Date the deferral takes effect (typically the date of discovery)
  • Certificate Number — Certificate number of the person authorizing the deferral
    • 11
    Document operational limitations
    12
  • Operational Limitations — List any operational restrictions that apply while the item is deferred (e.g., “Day VFR only”, “No flight into known icing”)
  • Placards Required — List any placards that must be installed per the MEL procedures (e.g., “INOP placard on affected instrument”)
    • 13
    Always refer to your FAA-approved MEL for the specific operational procedures (O) and maintenance procedures (M) required for each deferred item. The MEL entry defines what must be done before each flight while the item is deferred.
    14
    Configure rectification tracking
    15
    For deferrals tracked by flight hours or cycles in addition to calendar time:
    16
  • Rectification Interval — Days, Flight Hours, or Cycles
  • Rectification Due Date — Calendar deadline
  • Rectification Due Hours — Flight hour limit
  • Rectification Due Cycles — Cycle limit
    • 17
    Create the deferral
    18
    Click Create. The system records the deferral, links it to the discrepancy (if created from one), and begins tracking the rectification deadline.

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    Monitor Deferral Expiration

    The MEL Deferrals list highlights items approaching their rectification deadline:
    • Items within 24 hours of expiration show an amber badge
    • Expired items show a red badge and an Overdue status
    • The compliance dashboard includes a fleet-wide MEL deferral count
    Operating an aircraft with an expired MEL deferral may constitute a violation of 14 CFR 91.213 and 14 CFR 135.179. Expired deferrals must be resolved before further flight or extended with proper authorization.

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    Extend a Deferral

    If authorized by your MEL procedures and the FAA, deferrals can be extended:
    1. Open the deferral detail page
    2. Click Extend
    3. Enter the new expiration date and the authorization reference
    4. The extension count increments and the event is audit-logged

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    Close a Deferral

    1
    Open the deferral
    2
    Navigate to the deferral detail page.
    3
    Record the repair
    4
    Click Close Deferral and document:
    5
  • Resolution — What corrective action was taken
  • Work Order — Link to the work order that performed the repair
  • Closed By — Name and certificate number of the person who verified the repair
    • 6
    Confirm closure
    7
    Click Close. The system marks the deferral as closed, updates the linked discrepancy status to Resolved, and removes any operational limitations from the aircraft record.

    Manage Discrepancies

    Create and track the underlying defects that lead to MEL deferrals.

    Compliance Dashboard

    Monitor fleet-wide MEL deferral status at a glance.

    Manage Work Orders

    Create work orders to resolve deferred items before expiration.

    AD/SB Compliance

    Track Airworthiness Directive compliance alongside MEL deferrals.
    Last modified on April 5, 2026