Scope - HIL | leonwiki

Overview

The HIL (Handling Instructions Letter) scope covers maintenance deferrals and aircraft technical discrepancies recorded against an aircraft. Each HIL record tracks a defect or limitation that has been deferred in accordance with the Minimum Equipment List (MEL) or similar approved document — including the associated MEL item reference, applicable flight limitations, due dates for correction, and current status.

Operators use this scope to monitor open HIL items across their fleet, track upcoming due dates and extension deadlines, report on deferred defects by aircraft or status, and support airworthiness and compliance oversight.

What reports can you build with this scope?

Examples of typical reports operators build with this scope:

Open HIL items by aircraft — list all currently open deferrals for each aircraft in the fleet
Upcoming due dates — identify HIL items approaching their correction deadline or extension limit
HIL items with flight limitations — report on all active deferrals that impose restrictions on flight operations
MEL category breakdown — analyse deferred items by MEL category (A, B, C, D) to prioritise rectification
Corrected items history — audit trail of HIL items that have been cleared, including date corrected

Available columns

Columns are the data fields that can appear in your report. When building a report, select the columns most relevant to your analysis.

Item identification

Column	Column key	Description
HIL item no.	`hil_item_no`	The unique identifier assigned to this HIL entry
MEL item no.	`hil_mel_item_no`	The reference number of the associated MEL item
Cat	`hil_mel_cat`	The MEL category of the deferred item (e.g. A, B, C, D), which determines the maximum deferral period

Aircraft

Column	Column key	Description
Registration	`hil_aircraft_registration`	The registration of the aircraft to which the HIL item is assigned

Dates

Column	Column key	Description
Date	`hil_date_start`	The date the HIL item was raised / defect was recorded
Limit	`hil_date_due`	The original due date by which the item must be corrected
Extension Due Date	`hil_date_ext_due`	The revised due date if an extension has been granted
Date C/W	`hil_date_corrected`	The date the discrepancy was carried out (corrected / cleared)

Discrepancy details

Column	Column key	Description
Discrepancy Description	`hil_description`	A description of the defect or discrepancy that has been deferred
Flight limitations	`hil_flight_limitations`	Any operational flight limitations imposed by this deferred item
Limitations Note	`hil_how_affects`	Additional notes describing how the deferral affects the aircraft or operations

Technical limits

Column	Column key	Description
TAH limit	`hil_due_tah`	The Total Airframe Hours (TAH) limit at which the item must be corrected
TAC limit	`hil_due_tac`	The Total Airframe Cycles (TAC) limit at which the item must be corrected

Status and attachments

Column	Column key	Description
Status	`hil_status`	The current status of the HIL item (e.g. open, closed, extended)
Files links	`hil_files_links`	Links to any files or documents attached to the HIL item

Available filters

Filters let you narrow down the data to the specific subset you need — by aircraft, item number, status, and more.

Filter	Description
Operator	Filter by the operator the HIL records belong to
Aircraft	Filter by one or more specific aircraft in the fleet
HIL item number (wildcard)	Filter by HIL item number, supporting wildcard (partial) matching
List of HIL item numbers	Filter by a specific list of HIL item numbers
MEL item number (wildcard)	Filter by MEL item number, supporting wildcard (partial) matching
List of MEL item numbers	Filter by a specific list of MEL item numbers
Flight limitations	Filter to show only items that have flight limitations applied
Status	Filter by the current status of the HIL item (e.g. open, closed)