The Operations Manual and the MEL - ATPL 070 — Operational Procedures

The operations manual's rules

The operator shall establish an operations manual whose content reflects the applicable annexes and, crucially, shall not contravene the operations specifications attached to the AOC: the book may never promise what the certificate forbids. It may be issued in separate parts and in any form, electronic included, so long as accessibility, usability and reliability are assured; the acceptable means wants every part consistent, readily amendable, and its amendment status controlled and clearly indicated, with the manual describing its own amendment process. All operations personnel get easy access to the portions relevant to their duties, the manual is kept up to date with personnel made aware of relevant changes, and each crew member is provided a personal copy of the relevant sections, each holder being responsible for keeping that copy current with the operator's amendments. The whole book is written in a language its users understand, presented so it can be used without difficulty, observing human factors principles.

Amendments run on three speeds. Ordinary notifiable amendments are supplied to the competent authority in advance of their effective date; amendments to procedures tied to prior-approval items need the approval before they take effect; and when safety demands an immediate change, it may be published and applied at once, provided any required approval has been applied for. The operator incorporates every amendment the authority requires, and data taken from approved documents must be correctly reflected, though nothing stops the operator publishing more conservative data and procedures of its own. Material may be borrowed, from the flight manual, a manufacturer's operating manual or a specialist route guide, copied in or referenced, but borrowing never absolves the operator of verifying that the material is applicable and suitable.

Four parts, one manual

For commercial air transport the manual's main structure is fixed in four parts. Part A, General/Basic, holds all non-type-related operational policies, instructions and procedures. Part B, aircraft operating matters, holds all type-related instructions and procedures, taking account of differences between types, variants or even individual aircraft. Part C carries the route, role or area and aerodrome or operating-site instructions and information, and Part D carries all training instructions for the personnel a safe operation requires. Only the simplest operations escape the structure: single-engined propeller-driven aeroplanes or single-engined non-complex helicopters of five seats or fewer, taking off and landing at the same place under VFR by day, which may run on a single condensed manual with a shorter contents list.

The exam asks which named items live where, and Part A's list is the longer: the ground de-icing and anti-icing policy, adverse and potentially hazardous atmospheric conditions, wake turbulence, the incapacitation of crew members, the use of the MEL and configuration deviation lists, security, the handling of accidents and occurrences, altitude alerting system procedures, ground proximity warning system procedures, and the policy and procedures for TCAS/ACAS. Part B answers with the type-bound set: the abnormal and emergency procedures, the configuration deviation list itself, the minimum equipment list itself, and the emergency evacuation procedures. The trap sits in that split: the policy for using MEL and CDL is non-type-related and lives in Part A, while the lists themselves are type-related documents of Part B. The CDL, for completeness, is the configuration deviation list: the airworthiness-side catalogue of missing external parts, panels and fairings an aircraft may fly without, cousin to the MEL's equipment relief.

The journey log and the flight's paperwork

Particulars of the aircraft, its crew and each journey shall be retained for every flight, or series of flights, in the form of a journey log, or equivalent. The acceptable means lists a dozen entries, where applicable: nationality and registration, the date, crew names and their duty assignments, places and times of departure and arrival, hours of flight, the nature of the flight, scheduled or non-scheduled, any incidents and observations, and the signature of the person in charge. Equivalent means the information may live in other documents, the operational flight plan or the aircraft technical log, and paper is not required. A series of flights earns a single set of documentation when consecutive flights begin and end within 24 hours, at the same aerodrome or operating site or within a local area the manual specifies, and under the same pilot-in-command. The operational flight plan itself was built in the flight-preparation lesson, route, levels, fuel line and alternates; here it earns its second life as a record: a document that can stand in for the journey log and that the operator must keep after the flight is flown.

How long the papers live

The retention clocks are pure recall material. The information used for the preparation and execution of a flight is stored for 3 months: the operational flight plan, route-specific NOTAM and AIS briefing documentation if the operator edited it, the mass and balance documentation, notifications of special loads including the written dangerous-goods information to the commander, the journey log or its equivalent, and flight reports. The operator's management-system records and the like live for at least 5 years. Personnel records run on their own clocks: the licence or attestation record for as long as the crew member exercises its privileges for that operator, training, checking and qualification records for 3 years, recent experience for 15 months, route and aerodrome or task and area competence for 3 years, dangerous-goods training for 3 years, and for other personnel with a required training programme, the last two training records. The operator maintains each crew member's training records, shows them to the crew member on request, preserves them even after ceasing to be that person's operator and passes them to the next operator when the crew member moves, both duties running within the prescribed retention periods. One clock from another lesson deliberately does not appear here: the fatigue lesson's flight and duty records run on their own 24-month rule.

The MEL and its master

The minimum equipment list is a list of equipment that may be temporarily inoperative, subject to conditions, at the commencement of flight, and its vocabulary is examinable word by word. Commencement of flight is the point when the aircraft begins to move under its own power for the purpose of preparing for take-off. Inoperative means the item does not accomplish its intended purpose or is not consistently functioning within its approved operating limits or tolerances. A rectification interval is a limitation on the duration of operations with inoperative equipment, and the categories ladder is classic: category A takes the interval the MMEL itself states, category B gives 3 calendar days, C gives 10, D gives 120, all excluding the day of discovery, with category D reserved for items whose absence raises no workload and on which crew habit and training do not rely.

The relation to the master list is a one-way ratchet. The MMEL is the master minimum equipment list established in the aircraft's operational suitability data; the operator builds its own MEL based on it, tailored to its configuration, routes and the geography of its spares and maintenance, and the MEL, its rectification intervals included, shall be no less restrictive than the MMEL. When the MMEL changes in an applicable way, a shortened interval or a more restrictive item, the operator amends the MEL within acceptable timescales, 90 days in the acceptable means. The extent of the MEL has a sharp edge the exam probes: the list governs dispatch at the commencement of flight; for a failure occurring between commencement and the start of take-off, the decision to continue is subject to pilot judgement and good airmanship, and the commander may refer to the MEL before deciding. And the guidance states the philosophy: the MEL is an alleviating document, its purpose is not to encourage flying with inoperative equipment, and operation in that condition should be minimised.

Who owes what under the MEL

The operator establishes the MEL with its preamble, revision statuses and scope, sets the rectification intervals, runs an effective rectification programme, and provides the operational and maintenance procedures the list references. The competent authority approves the MEL and every amendment, and holds two escape valves: it may approve a procedure for the one-time extension of category B, C and D intervals, at most the same duration again, only for events beyond the operator's control and never as a routine, with each use notified, within 1 month in the acceptable means; and it may approve, case by case, operating outside the MEL but within the constraints of the MMEL, under the same beyond-the-operator's-control discipline.

The crew's share is procedural, and the acceptable means and guidance spell it out. Items needing an operational procedure are marked (O), normally accomplished by the flight crew, completed when planning for or operating with the listed item inoperative; items marked (M) need a maintenance procedure completed before operating with the item inoperative, normally by maintenance personnel. Inoperative items are placarded so the crew knows the equipment's condition, anything airworthiness-related that is not listed is automatically required to be operative, and an inoperative item may not be removed from the aircraft unless a maintenance procedure permits it. The commander's authority frames the whole system: the flight-preparation lesson already taught that the flight is not commenced until the commander is satisfied, and the MEL is the instrument of that satisfaction for broken equipment at dispatch, while after commencement of flight the judgement, with the MEL as counsel, is the commander's own.