(In) Flight Monitoring

A flight dispatcher plays a crucial role in ensuring the safe and efficient operation of flights. Flight monitoring is one of the key responsibilities of a dispatcher and involves several subtasks.

The main activities of a flight dispatcher can be divided in 3 core tasks:

1.?????? Pre-flight planning

2.?????? Inflight monitoring

3.?????? Post-flight activities including logging

This article, as the name suggests, focuses on the inflight monitoring part, but I think it’s worth mentioning the other activities for context on what we are exactly monitoring when performing inflight monitoring. Another consideration to make is that during a shift a dispatcher will both plan and monitor flights simultaneously (as there are multiple flights in various stages of progress when the dispatcher starts his shift, or which still need to be planned either from scratch or with pre-defined company routes), which in essence means constantly re-prioritizing which tasks need to be handled first.

Inflight monitoring is essentially how the flight is progressing in actuality versus how it was planned, to take appropriate measures if circumstances so dictate. One tangible example can be when ATC keeps our flight unexpectedly at a flight level below our filed/planned flight level, which is in the large majority of the cases the optimum flight level for the prevailing atmospheric conditions. This of course impacts our fuel burn, which will be significantly higher than planned and could mean an en-route refueling stop. The same would count if ATC mandates an unexpected reroute due to weather conditions.

The additional fuel burn might become so great that an intermediate refueling stop becomes necessary in order to safely continue the flight. In order to timely start taking measures( e.g. reducing cruising speed to save fuel on board) and discuss possibilities with all relevant parties to reach the best decision in the actual circumstances we will need to identify the anomaly as soon as possible and formulate a decision point, where, if the situation does not improve we will need to initiate all the ground related activities the refueling stop and inform the relevant parties if they have not been informed yet.

And the relationship between post-flight activities, which is mainly to report any relevant particularities via the prescribed method of the operator, and /or discuss them for feedback on a particular flight with the Flight Crew after arrival of the aircraft, or the colleague who planned the flight and/or with the relevant departments.

Pre-flight Planning:

Before a flight takes off, the dispatcher creates a detailed operational flight plan which, when it’s ready, is shared with the pilot in command with whom he/she and airline operations control team will collaborate? to update, where necessary, this flight plan to the most actual and appropriate circumstances.

There are many causes for an adjustment of the flight plan, just to name a few:

1. Delay due to aircraft handling: (Cleaning, Catering, Servicing, Technical, Fueling, Movement (e.g. from the hangar) or Passenger Handling, Loading. Crew Rotation etc.
2. Unforeseen technical issues which have a performance/fuel burn implication or both.
3. Higher or lower payload.
4. Aircraft change.
5. Developing weather at the departure, en-route or destination/ alternates.
6. Closure of alternate airports, especially in case of delayed short haul flights in Europe in the evening time.
7. Last but not least: CTOT ( colloquially called “ slot”, to regulate traffic flow between airports etc.)

Escape routes from these so-called slots help avoid delays from air traffic control (ATC) when departing. While they can help to safeguard on-time performance of the flight, they invariably make the flying time longer and therefore cost more fuel, which could mean carrying less cargo if the flight is performance limited already and once filed, no possibility to reduce the flying time anymore unless ATC grants pilots a more direct route when inflight. SLOT delays, depending on the cause and its progression often improve as the departure time gets closer. Rerouting obviously only applies to en-route restrictions, if the restriction is due to reduced capacity at the departure airport or destination airport (which is also possible) rerouting would not make any sense.

As general “ballpark rules” to identify if flights affected by a slot are eligible for rerouting, we apply the following: It is recommended to consider a slot escape route if:

1. The optimum track (plus slot delay) will result in an arrival later than STA.
2. If the departure delay is more than 15 minutes.
3. If extra flying time by using slot escape route is less than half of the delay caused by slot on optimum route.

Luckily nowadays we can see in the latest version of the Network Operations Portal from Eurocontrol pretty clearly if alternative routing is free of slots, or have better slots, but for flight specific info operator-granted logins are needed. As an example, I will add below 2 screenshots of the (alternative) routing and flight level restrictions we can have.

The initial draft Operational flight plan release typically happens a few hours before departure, but this is operator specific, depending on, among others if it’s a domestic, international, or intercontinental operation. Parameters include taxi times (think about winter operations with taxying to and away from the de-icing stand, extended work in progress at the aerodrome etc.) ?flight times, routing, the calculated time elapsed per waypoint and corresponding fuel on board ( FOB), winds aloft, alternate airports, fuel requirements ( legal) and allocations, weights, NOTAMS ( NOTifications to AirMen). Next to this the dispatcher will file, update or cancel where necessary an ATC flightplan, which is a less detailed version of the operational flight plan, containing only information relevant to Air Traffic Control. It states details about the aircraft (type, registration, communication and navigation equipment, color, number of persons on board) and details about the planned flight (speed and altitude of the aircraft, departure airport, arrival airport, alternate airport(s), flight time and endurance). This ATC flightplan is sent to all relevant FIR’s and UIR’s along the intended route so the local ATC is aware of the traffic which is planned to fly through their airspace. Just for reference I will add a fictional flight generated by a flight simulator flight planning application, SIMBRIEF, for an EZY flight between Amsterdam and Ljubljana which is realistic enough for the purpose of this article.

The ATC Flight Plan ( page 7) is very condensed as depicted below:

(FPL-EZY1221-IS?-A319/M-SDE3FGHIRWY/LB1?-EHAM1030?-N0455F370 RENDI2S EDUPO Z739 MISGO DCT TIVUN DCT TESGA DCT DINKU DCT BESNI DCT LATLO DCT OBEDI DCT LUMUS LUMUS4L?-LJLJ0127 EDDM?-PBN/A1B1C1D1O1S1 DOF/230923 REG/GEZAX EET/EDVV0011 EDGG0012 EDUU0022 LOVV0101 LJLA0116 OPR/EZY PER/C RVR/075 RMK/TCAS)

While the whole Operational Flight Plan (OFP) is as extensive as this PDF document attached.

Inflight Monitoring

Introduction:

This link and embedded short video gives a nice ?general overview from what airlines require for a flight tracking application while? Collins endorses their product.

Weather and traffic Monitoring: Dispatchers continuously monitor weather conditions along the planned route and at the destination airport. They use various sources and tools to obtain up-to-date weather information, including radar data? (USA), satellite weather reports (USA) , PIREPS, for example on this site.

Most network carriers opt for an integrated solution for their own network because especially with the amount of flights in the responsibility scope of the dispatcher and all the different countries to be overflown it is much safer and more effective to have this integrated in one solution.

Volcanic Ash Advisory Center ( VAAC) forecasts of active volcanoes. A good explanation on how to interpret a volcanic ash advisory is found on this link, and here you can find a detailed article of how damaging volcanic ash can be to jet engines.

To monitor aerodrome traffic, which can also be a pretty important factor on whether an aircraft can land on the planned destination with the legal amount of remaining fuel or not. Also here, the sooner we know we can expect “ trouble” the better.

?We use FlightAware, casper and Flight Radar24, but we can also use operator-approved country specific sources for planning purposes ( as FlightAware and Flight Radar 24 show only the actual traffic situation).

In the USA and Canada, we have, for instance:

https://www.fly.faa.gov/aadc/ for the expected demand vs capacity per major aerodrome in time.

https://nasstatus.faa.gov/map which gives a visual overview of the status of the aerodromes.

https://aviationweather.gov/trafficflowmgmt/gate for weather related info in so-called arrival gates in 1 hr. time brackets which can affect the traffic flow and the explanation of the setup of the page in question.

Flight Progress and Fuel Monitoring:

Once the flight is airborne, the dispatcher tracks its progress using various tools and communication systems. They receive regular updates from the aircraft systems and other remote systems, which include the aircraft's position, altitude, and fuel status and also weather along the route, which changes continuously as the flight progresses which can worsen or improve the performance. This implies that, for instance optimum flight levels might vary especially with longer flights as the atmospheric conditions change. Both pilots and light dispatchers continuously monitor the aircraft's fuel consumption to ensure that it has enough fuel to reach its destination and any alternate airports if needed.

The ETOPS check is another example of inflight monitoring, which is an additional check, after each ETOPS flight enters the ETOPS segment of the flight (which is the segment of the route where the aircraft is further than one hour from a diversion airport at the one-engine-inoperative cruise speed, over water or remote lands) The check entails ensuring that before entering that segment all the planned ETOPS alternate airports are still useable for diversion when needed. This additional check is because the quantity of useable airports in remote areas (Atlantic Ocean) is very limited.

Emergency Response and Decision-Making:

In the event of adverse weather, technical issues, or other emergencies, the dispatcher works closely with the flight crew to assess the situation and make necessary adjustments. These decisions are made in consideration of safety and operational factors.

This can involve rerouting the aircraft to avoid severe weather (enroute) or finding and agreeing on the best weather permissible alternate airports, in case the ones in the plan become unusable for whichever reason. Depending on the specific emergency ‘the best’ enroute alternate might vary. (think of, e.g. a medical emergency of a passenger vs an engine failure. A well- equipped aerodrome might still be a poorer choice in case of an engine failure if there is a mountain range to cross to be able to reach it.) Yet another aerodrome might have better and nearer medical facilities than the airport with better infrastructure.

Communication:

Dispatchers maintain constant communication with the flight crew, providing them with important updates and information. They also coordinate with air traffic control and other relevant agencies to ensure the flight's safe progression and set up conference calls in case the aircraft is fit with satellite phone communication to facilitate the communication decision making process especially in case of complex and urgent situations.

Regulatory Compliance:

Dispatchers must ensure that the flight operates within the regulations and guidelines set by aviation authorities, including adhering to maximum duty and flight time limits for the flight crew.

Continuous Monitoring:

Flight monitoring is ongoing throughout the flight until the aircraft safely lands at its destination. Even after landing, the dispatcher may be involved in coordinating ground services and any necessary follow-up actions. Overall, in- flight monitoring by a dispatcher involves real-time tracking, decision-making, and communication to ensure that flights operate safely and efficiently, even when faced with unforeseen challenges.

Shift / Workload Changeover

While not necessarily an inflight monitoring activity, as during a shift changeover flights in various stages are handed over to the next dispatcher I would still like to mention this important task which ensures the continuity and safety of the operation.

At the moment of the shift change Flight Dispatcher shall brief the arriving Flight Dispatcher, using the ‘ALARM’ acronym for instance as a checklist for guidance; only irregular items should be mentioned.

Aircraft: Highlight all relevant aircraft (technical and schedule) deviations.

Load: Highlight all relevant load issues (connecting passengers, NOTOC items, special passengers, fuel planning etc.)

Airport: Highlight all relevant airport issues (WX (e.g., Aircraft Induced Lightning), NOTAMS, staff issues, field conditions (e.g., SNOWTAMS), slots etc.)

Route: Highlight all relevant route issues (Slots, level capping, delay recovery, Airway closures, activity in restricted areas etc.)

Miscellaneous: Highlight all relevant issues not discussed under the above (Schedule deviations, incidents etc.)

Post-flight activities including logging.

Documentation: Detailed records are kept throughout the flight, documenting all decisions, communications, and updates. This documentation is essential for post-flight analysis and regulatory compliance.

Note: I would?like to thank my co-writer Terry Mitchell for his contribution to the design of the article and for ensuring readability also for people outside the aviation industry.