13 General Airline Knowledge

What is the difference between an AOC and an operating licence in the EU?

An AOC demonstrates the operator’s professional and organisational capability to conduct specified operations safely; an operating licence authorises the undertaking to provide commercial air services.

What do the operations specifications attached to an AOC define?

The operator’s authorised operations and specific privileges/approvals.

What is the difference between the State of the Operator and the State of Registry?

The State of the Operator has responsibilities related to oversight of the operator; the State of Registry has responsibilities associated with the aircraft’s registration and airworthiness framework.

What does operational control mean in airline operations?

The processes and responsibilities governing the initiation, continuation, diversion and termination of flights in the interest of safety.

What is the practical role of an Operations Control Centre (OCC)?

To maintain the operational picture and support safe, efficient flight execution through flight monitoring, disruption management, coordination and operational decision support.

Does operational control remove the commander’s authority and responsibility for the flight?

No. Operator-level control and support coexist with the commander’s authority and responsibilities for safe operation of the aircraft.

What is the difference between safety management and compliance monitoring?

Safety management identifies hazards and manages risk; compliance monitoring verifies that the organisation conforms to applicable rules, approvals and procedures.

What is the difference between a hazard and risk?

A hazard is a condition with the potential to cause harm; risk combines the likelihood and severity of the possible consequences.

What is the difference between an Operational Flight Plan and an ATS Flight Plan?

The OFP is the operator/crew’s operational plan including route, fuel, mass, performance and planning data; the ATS flight plan provides the information required by air traffic services.

How do AIP, AIP Supplement, AIC and NOTAM differ?

AIP - lasting aeronautical information; AIP SUP - temporary changes of longer duration or extensive content; AIC covers relevant information not appropriate for AIP/NOTAM; NOTAM - time-critical aeronautical information requiring rapid distribution.

Why should NOTAMs not become a substitute for permanent aeronautical information?

Long-term information belongs in the structured AIP system; excessive or obsolete NOTAMs make genuinely time-critical information harder to identify.

What is the operational purpose of the aircraft technical log?

To communicate aircraft technical status, defects and relevant operational/maintenance information between crews and maintenance.

What is good practice when recording a technical defect?

Describe the observed symptom accurately and objectively rather than inventing an unsupported diagnosis.

What is the purpose of a NOTOC?

To provide the commander with required information about dangerous goods carried as cargo and information needed to manage a related in-flight emergency.

Why are the exact location and quantity of dangerous goods important on a NOTOC?

They help the crew and emergency services assess the consequences of smoke, fire, leakage or other events in a particular cargo area.

What is the practical difference between ICAO and IATA airport codes?

ICAO uses four-letter location indicators primarily for operational/ATS purposes; IATA uses three-character location codes primarily for commercial passenger, baggage and scheduling systems.

What is the practical difference between ICAO and IATA airline designators?

ICAO assigns a three-letter operator designator and, where applicable, a telephony designator for operational/ATC use; IATA designators are primarily commercial identifiers used in schedules, reservations and ticketing.

What is the difference between a commercial flight number and an ATC callsign?

The flight number identifies the commercial service; the ATC callsign is the flight identification used in radiotelephony and may be modified to reduce callsign confusion.

Why is aircraft registration different from flight identification?

Registration identifies the individual aircraft; flight identification/callsign identifies the operation being conducted.

What is an ICAO aircraft type designator used for?

It identifies the aircraft type in ATS flight plans and ATM systems.

What is the difference between an airport slot and an ATFM slot?

An airport slot is permission to use constrained airport infrastructure at a scheduled date/time; an ATFM slot allocates a Calculated Take-Off Time to manage network traffic demand.

What is a CTOT?

The Calculated Take-Off Time allocated by the Network Manager to a regulated flight.

What is the standard EUROCONTROL CTOT Slot Tolerance Window?

From 5 minutes before to 10 minutes after the CTOT.

What is TOBT?

Target Off-Block Time — the time at which the aircraft operator or ground handler estimates the aircraft will be ready for immediate start-up/pushback.

What is TSAT?

Target Start-up Approval Time — the time at which ATC expects start-up/pushback can be approved, considering traffic, TOBT and constraints such as CTOT.

What is the practical difference between EOBT and TOBT?

EOBT is the flight-plan estimate of off-block time; TOBT is the current operational prediction of when the aircraft will actually be ready to leave the stand.

What is the purpose of Airport Collaborative Decision Making (A-CDM)?

To improve predictability and efficiency by sharing accurate turnaround and departure information between the airline, handler, airport, ATC and Network Manager.

Why is accurate TOBT important?

It drives departure sequencing and allows ATC/network systems to generate realistic start-up and take-off planning.

What is the critical path of a turnaround?

The sequence of dependent tasks whose completion determines the earliest achievable departure time; delaying a critical-path task delays the flight.

Why does completing one turnaround task early not necessarily enable an earlier departure?

Another dependent task on the critical path may still determine aircraft readiness.

What are the basic roles of the airline, ground handler, airport operator and ANSP?

The airline operates the flight; the handler performs contracted turnaround services; the airport operator manages airport infrastructure/operations; the ANSP provides air navigation services.

What is a code-share?

An arrangement in which one airline places its commercial designator on a flight operated by another airline.

What is the difference between the marketing carrier and operating carrier in a code-share?

The marketing carrier sells the flight under its code; the operating carrier actually operates the aircraft.

What is the practical difference between code-share and interline?

Code-share involves marketing the same operated flight under another carrier’s code; interline primarily allows passengers/baggage/tickets to connect across different carriers without necessarily sharing flight numbers.

What is the fundamental difference between wet lease and dry lease?

In a wet lease the aircraft operates under the lessor’s AOC; in a dry lease it operates under the lessee’s AOC.

What does ACMI normally mean?

Aircraft, Crew, Maintenance and Insurance — the core elements normally supplied by the lessor in a wet-lease arrangement.

What is the basic difference between hub-and-spoke and point-to-point networks?

Hub-and-spoke concentrates traffic through connecting hubs; point-to-point emphasises direct services between origin and destination.

What does Cost Index represent operationally?

The economic trade-off between time-related operating cost and fuel cost used by the FMS to determine an economical speed profile.

What happens broadly when Cost Index is increased or decreased?

Higher CI places greater value on time and generally produces faster speeds with more fuel burn; lower CI favours fuel efficiency over time.

Why is increasing Cost Index not automatically the best response to a delay?

Time recovery has a fuel cost and may be limited by route, winds, ATC, altitude and schedule circumstances; the economic optimum may involve only partial or no airborne recovery.