Patent Description:
Embodiments of the subject matter described herein relate generally to datalink communication between a flight operation center (FOC) such as an air traffic control (ATC) center and flight crew in an aerial vehicle. More particularly, embodiments of the subject matter relate to systems and methods for enhancing datalink communication operation.

Controller Pilot Datalink Communication (CPDLC) is a method by which air traffic controllers can communicate with pilots over a datalink system. Communication with ATC via CPDLC is increasingly being encouraged by international Air Traffic Management authorities as it enhances safety and efficiency by reducing readback errors, reducing language barriers, reducing radio time, and providing more efficient routes (thus reducing fuel usage and flight times). Authorities are increasingly concerned with data communication performance, and many regions monitor communication performance. Transactions times for CPDLC exchanges are recorded for many aircraft. In some instances, aircraft that exhibit poor performance may have various approvals revoked.

Different airspaces require different levels of communication performance, for example, due to differing separation standards and differing densities of air traffic. The oceanic environment is different from the domestic environment. High altitude airspace is different from lower altitude airspace. An acceptable transaction time in one environment may be unacceptable in another. The complexity of a particular CPDLC uplink may require more cognitive workload from the flight crew (e.g., executing an altitude change is less complex than executing a route modification). Thus, authorities from different regions may define different expected pilot response times. Further, authorities within a region may define different expected response times for different CPDLC uplink elements.

Although flight crews are trained to respond to CPDLC uplinks as quickly as they can, they are likely unaware of the expected response time for the current uplink they are working on. Because the expected response may differ based on the airspace in which an aircraft flies, it is more likely that a flight crew may not know the expected response time for an uplink communication.

Document <CIT> discloses a flight deck system in an aircraft displaying a timer for counting down a time allowed for a reply to a CPDLC uplink.

Document <CIT> discloses an aircraft communication system configured to output a timeout alert if a set time limit to take pilot action is exceeded.

Hence, it is desirable to provide a system and method for alerting flight crew to the expected time for responding to a particular datalink communication in a particular airspace. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

In one embodiment, a flight deck system in an aircraft for enhancing controller pilot datalink communication (CPDLC) operation is disclosed. The flight deck system includes a controller configured to: receive a CPDLC message having a CPDLC message type from a flight operation center (FOC) having an FOC name; retrieve an expected response time for the CPDLC message from an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs; generate a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on the expected response time; signal the aircraft display device to display the timer; monitor communications from flight crew for a response to the CPDLC message; and signal the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message.

In another embodiment, a method in a flight deck system in an aircraft for enhancing controller pilot datalink communication (CPDLC) operation is disclosed. The method includes: receiving a CPDLC message having a CPDLC message type from a flight operation center (FOC) having an FOC name; retrieving an expected response time for the CPDLC message from an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs; generating a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on the expected response time; signaling the aircraft display device to display the timer; monitoring communications from flight crew for a response to the CPDLC message; and signaling the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message.

In another embodiment, a non-transitory computer readable medium encoded with programming instructions configurable to cause a controller in a flight deck system in an aircraft to perform a method for enhancing controller pilot datalink communication (CPDLC) operation is disclosed. The method includes: receiving a CPDLC message having a CPDLC message type from a flight operation center (FOC) having an FOC name; retrieving an expected response time for the CPDLC message from an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs; generating a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on the expected response time; signaling the aircraft display device to display the timer; monitoring communications from flight crew for a response to the CPDLC message; and signaling the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message.

Embodiments of the present disclosure may be described herein in terms of functional and/or logical components and various processing steps. It should be appreciated that such functional and/or logical components may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions.

Some regions of the world have mandated the use of CPDLC and restrict certain airspace to CPDLC equipped aircraft. For example, in January of <NUM>, the North Atlantic (NAT) region from FL290-FL410 mandated use of CPDLC (FANS). Non-compliant aircraft (with a few exceptions for certain military and state aircraft) must fly outside FL290-FL410 or must fly the far northerly 'Blue Spruce' routes. The ACARS network is used for FANS CPDLC (specified in ED-100A/DO-258A) in nearly all oceanic regions, and in extensive domestic airspace including Canada, US, Australia, India, Japan, China, Indonesia, and portions of South America and Africa.

Within the NAT oceanic airspace, certain routes are further restricted to aircraft that not only are FANS-equipped, but further have received PBCS (Performance Based Communication and Surveillance) approval from their regulatory authorities. Reduced Lateral Separation Minima (RLatSM) and Reduced longitudinal Separation Minima (RLongSM) via PBCS standards are defined in ICAO Doc <NUM> (PBCS Manual). Aircraft flying in the North Atlantic and Asia Pacific oceanic regions are eligible for reduced separation only if they file their flight plan with a code indicating their regulatory agency has approved them for PBCS operation. Aircraft flying in the NAT or APAC that do not file this code will be controlled via standard separation criteria. In the NAT region, certain highly efficient routes are designated as "PBCS Tracks" and are restricted to PBCS Approved aircraft only.

Authorities are increasingly concerned with data communication performance, and many regions monitor communication performance. Transactions times for CPDLC exchanges are recorded for many aircraft. In some instances, aircraft that exhibit poor performance may have its PBCS revoked.

The subject matter described herein discloses apparatus, systems, techniques, and articles for providing a separately loadable Expected Response Time database that can specify various expected response times for a datalink message (e.g., a CPDLC uplink). The disclosed apparatus, systems, techniques, and articles may specify various expected response times for a datalink message based on two inputs - flight operation center (FOC) names (e.g., KUSA (US domestic), EGGX (Shanwick oceanic), CZEG (Edmonton domestic)) and an uplink element numbers (e.g., UM19-CLIMB TO [altitude], UM79-CLEARED TO [position] VIA ROUTE CLEARANCE).

The subject matter described herein further discloses apparatus, systems, techniques, and articles for providing a cockpit timer display that provides a timer (e.g., countdown timer) specific to a current open datalink message. The disclosed apparatus, systems, techniques, and articles may retrieve an expected response time value for the timer from the Expected Response Time database, based on the current active FOC and the current uplink element number.

The disclosed apparatus, systems, techniques, and articles may locate a cockpit timer display in the form of a timer next to an existing forward display Alert that indicates an open CPDLC uplink exists. The disclosed apparatus, systems, techniques, and articles may provide a cockpit timer display in the form of a timer displayed on an existing ATC UPLINK page (e.g., on an MCDU or graphical page, depending on the platform). The cockpit timer display provided by the disclosed apparatus, systems, techniques, and articles may display a message such as text indicating 'Respond ASAP' when the previously displayed timer has expired and the flight crew had not yet responded to the uplink.

<FIG> is a block diagram depicting an example flight environment <NUM> such as one around a busy aerodrome. The example environment <NUM> includes a plurality of aerial vehicles (ownship aircraft <NUM> and traffic aircraft <NUM>, <NUM> in this example), but could include a variety of types of aerial vehicles such as helicopters, UAVs (unmanned aerial vehicles), and others. The example environment <NUM> also includes a plurality of flight operation centers (FOCs) (e.g., air traffic control towers <NUM>, <NUM>) containing control personnel such as air traffic controllers (ATC) for directing ground and air traffic in the vicinity of the aerodrome.

The example ownship aircraft <NUM> includes avionics equipment <NUM> that receives ongoing communications between the aerial vehicles (e.g., <NUM>, <NUM>, <NUM>) and ATC (e.g., via towers <NUM>, <NUM>) using communication equipment <NUM>. The avionics equipment <NUM> further includes a datalink system <NUM> that receives datalink communication, such as CPDLC communication, from the communication equipment <NUM>. The example datalink system <NUM>, for datalink communications directed to the ownship, decodes the datalink communications and retrieves message content including an instruction type from the messages and an FOC name. The example datalink system <NUM> accesses an Expected Response Time database that contains expected response times for a plurality of CPDLC message types for one or more air traffic control centers, generates a timer function that causes the display of a timer <NUM> (e.g., countdown timer) on an aircraft display device <NUM> that has a set duration based on the expected response time, and signals the aircraft display device <NUM> to display the countdown timer <NUM>. The example datalink system <NUM> further monitors communications from flight crew for a response to CPDLC messages and signals the aircraft display device <NUM> to end the display of the countdown timer <NUM> when a communication has been detected within the set duration that is responsive to the CPDLC message. The aircraft display device <NUM> may be one of many types of graphical display units onboard an aircraft such as a navigation display, a PFD (primary flight display), a PED (personal electronic device), an EFB (electronic flight bag), HUD (heads up display), HDD (heads down display), and others.

<FIG> is a block diagram depicting example avionics equipment <NUM>. The example avionics equipment <NUM> includes a datalink system <NUM>, and expected response time database <NUM>, an aircraft display device <NUM>. The example datalink system <NUM> includes an analysis module <NUM>, an output module <NUM>, and a communication monitoring module <NUM>.

Each of the datalink system <NUM>, the analysis module <NUM>, the output module <NUM>, and the communication monitoring module <NUM> is implemented by a processing component such as a controller (e.g., the same or separate controllers). The processing component includes at least one processor and a computer-readable storage device or media encoded with programming instructions for configuring the processing component. The processor may be any custom-made or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), an auxiliary processor among several processors associated with the processing component, a semiconductor-based microprocessor (in the form of a microchip or chip set), any combination thereof, or generally any device for executing instructions.

The computer readable storage device or media may include volatile and nonvolatile storage in read-only memory (ROM), random-access memory (RAM), and keep-alive memory (KAM), for example. KAM is a persistent or non-volatile memory that may be used to store various operating variables while the processor is powered down. The computer-readable storage device or media may be implemented using any of a number of known memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable programming instructions, used by the processing component.

The analysis module <NUM> is configured to receive an incoming datalink message <NUM>, such as CPDLC message, from ownship communication equipment, decode the datalink message <NUM>, determine an expected response time for the datalink message <NUM>, and set a time limit for responding to the datalink message <NUM>. The time limit may be equal to the expected response time or some time less than the expected response time. There may be circumstances wherein the time limit may be greater than the expected response time by some predetermined amount. In each case, the time limit is based on the expected response time.

Through decoding the datalink message <NUM>, the example analysis module <NUM> is configured to retrieve message content including an instruction type of the datalink message <NUM> and an FOC name for the datalink message <NUM>. The example analysis module <NUM> uses the retrieved message content to access (e.g., query) the Expected Response Time database <NUM>, which contains expected response times for a plurality of CPDLC message types for one or more FOCs, to obtain the expected response time for the flight crew to respond to the datalink message <NUM>. The example analysis module <NUM> can use the instruction type of the datalink message <NUM> and the FOC name associated with the datalink message <NUM> to identify the specific expected response time for the datalink message from the Expected Response Time database <NUM>.

The example analysis module <NUM> may include a keyword spotter and sentence segmentor for deriving segmented text from the datalink message <NUM> and a semantic/intent/data analyzer for analyzing the segmented text. The semantic/intent/data analyzer may be configured to analyze the segmented text to identify an instruction type for the datalink message <NUM> and an FOC name for the datalink message <NUM>.

To retrieve an expected response time for a datalink message, the example analysis module <NUM> may be configured to generate a query request for the expected response time database that includes the FOC name (e.g., for the FOC from which the CPDLC message originated or for the geographical area in which the aircraft is located) and an uplink element number that corresponds to the CPDLC message type of the CPDLC message. To retrieve the expected response time for a datalink message, the example analysis module <NUM> may be further configured to query the expected response time database <NUM>, using the query request, for an expected response time for the received CPDLC message, and retrieve a query result from the expected response time database <NUM> that includes the expected response for the CPDLC message.

The example output module <NUM> is configured to generate a timer function for a graphical display indicator (e.g., a countdown timer) for display on the aircraft display device <NUM> that indicates how much time the flight crew has left to respond to the datalink message <NUM>. The example output module <NUM> is configured to set a time limit for display in the graphical display indicator that is equal to the time limit determined by the example analysis module <NUM>.

The graphical indicator may take many different forms and may be displayed on different aircraft display devices or display device pages. <FIG> is a diagram of an example display page <NUM> on an aircraft display device (e.g., display device <NUM>). The example display page <NUM> displays information regarding a specific datalink message - 0410z ATC uplink. The example display page <NUM> also displays a graphical display indicator <NUM> that is specific to a current open uplink and that includes both text that indicates the time left to respond to the datalink message (0410z ATC uplink) and a numeric timer (e.g., countdown timer) that indicates how much of the time limit is left to respond to the datalink message.

<FIG> is a diagram of an example display page <NUM> on an aircraft display device (e.g., display device <NUM>). The example display page <NUM> displays aircraft status information <NUM> regarding aircraft systems during flight. Included in the aircraft status information <NUM> on the example display page <NUM> is a graphical display indicator <NUM> that is specific to a current open uplink and that includes text that indicates that the graphical display indicator <NUM> relates to the remaining response time for an ATC Message and a numeric timer (e.g., countdown timer) that indicates how much of the time limit is left to respond to the datalink message.

Referring back to <FIG>, the example output module <NUM> may be further configured to generate a Respond ASAP indication that indicates that a communication has not been detected within the set duration that is responsive to the datalink message. The example output module <NUM> may be further configured to signal the aircraft display device to display the Respond ASAP indication when a communication has not been detected within the set duration that is responsive to the datalink message. The example output module <NUM> may be further configured to signal the aircraft display device to end the display of the Respond ASAP indication when a communication has been detected that is responsive to the datalink message. The Respond ASAP indication may include the words "Respond ASAP" or may include other words, phrases, images, etc. that indicate to the flight crew that the timer has expired and that a response is still needed to the datalink message.

The example communication monitoring module <NUM> is configured to monitor onboard systems for communications from flight crew, determine when a communication is responsive to the datalink message <NUM>, and signal the output module <NUM> when the flight crew has responded to the datalink message <NUM>. When the example communication monitoring module <NUM> has detected that the flight crew has responded to the datalink message <NUM>, the output module <NUM> may terminate a corresponding graphical display indicator (e.g., graphical display indicator <NUM>, graphical display indicator <NUM>, or Respond ASAP indication) and signal the aircraft display device <NUM> to end the display of the corresponding graphical display indicator.

The example expected response time database <NUM> may be part of the datalink system <NUM>, located in other equipment onboard the ownship, or may be resident on a cloud-based system. The expected response time database <NUM> may be preloaded onto the aircraft before flight or downloaded onto the aircraft during flight. The example expected response time database <NUM> may be searchable via input of an FOC name and an uplink element number for retrieving an expected response time for a specific response time for a specific FOC.

The aircraft display device <NUM> may be one of many types of graphical display units onboard an aircraft such as a navigation display, a PFD (primary flight display), a PED (personal electronic device), an EFB (electronic flight bag), HUD (heads up display), HDD (heads down display), and others.

<FIG> is a process flow chart depicting an example process <NUM> in an example datalink system (e.g., datalink system <NUM>). The order of operation within the process <NUM> is not limited to the sequential execution as illustrated in the figure but may be performed in one or more varying orders as applicable and in accordance with the present disclosure.

The example process <NUM> includes receiving a datalink message (e.g., CPDLC) having a message type from a FOC (flight operation center such as an ATC center) having an FOC name (operation <NUM>) and retrieving an expected response time for the datalink message from an expected response time database containing expected response times for a plurality of datalink message types for one or more FOCs (operation <NUM>).

The expected response time database may be preloaded onto the aircraft before flight or downloaded onto the aircraft during flight. The expected response time database may be searchable via input of an FOC name and an uplink element number for retrieving an expected response time for a specific response time for a specific FOC.

Retrieving an expected response time for the datalink message from the expected response time database may include: generating a query request for the expected response time database that includes the FOC name for the FOC from which the datalink message originated and an uplink element number that corresponds to the datalink message type of the datalink message; querying the expected response time database, using the query request, for an expected response time for the received datalink message; and retrieving a query result from the expected response time database that includes the expected response for the datalink message.

The example process <NUM> includes, generating a timer function that causes the display of a timer on an aircraft display device that has a set duration based on the expected response time (operation <NUM>) and signaling the aircraft display device to display the timer (operation <NUM>). The set duration of the timer may be equal to the expected response time retrieved from the expected response time database or some predetermined offset (greater than or less than) the retrieved expected response time.

The example process <NUM> includes monitoring communications from flight crew for a response to the datalink message (operation <NUM>) and signaling the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the datalink message (operation <NUM>).

The example process <NUM> may further include signaling the aircraft display device to display a Respond ASAP indication when a communication has not been detected within the set duration that is responsive to the datalink message. The example process <NUM> may further include signaling the aircraft display device to end the display of the Respond ASAP indication when a communication has been detected that is responsive to the datalink message. The Respond ASAP indication may include the words "Respond ASAP" or may include other words, phrases, images, etc. that indicate to the flight crew that the timer has expired and that a response is still needed to the datalink message.

The subject matter described herein discloses apparatus, systems, techniques, and articles for advising flight crew in an aerial vehicle when to respond to a datalink message, such as a controller pilot datalink communication (CPDLC). In one embodiment, a flight deck system in an aircraft for enhancing controller pilot datalink communication (CPDLC) operation is provided. The flight deck system comprises a controller configured to: receive a CPDLC message having a CPDLC message type from a flight operation center (FOC) having an FOC name; retrieve an expected response time for the CPDLC message from an expected response time database containing expected response times for a plurality of CPDLC message types for one or more FOCs; generate a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on the expected response time; signal the aircraft display device to display the timer; monitor communications from flight crew for a response to the CPDLC message; and signal the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message.

These aspects and other embodiments may include one or more of the following features. The controller may be further configured to signal the aircraft display device to display a Respond ASAP indication when a communication has not been detected within the set duration that is responsive to the CPDLC message. The controller may be further configured to signal the aircraft display device to end the display of the Respond ASAP indication when a communication has been detected that is responsive to the CPDLC message. The expected response time database may be preloaded onto the aircraft before flight or downloaded onto the aircraft during flight. The expected response time database may be searchable via input of an FOC name and an uplink element number for retrieving an expected response time for a specific response time for a specific FOC. To retrieve an expected response time for the CPDLC message from the expected response time database, the controller may be further configured to: generate a query request for the expected response time database that includes the FOC name for the FOC from which the CPDLC message originated and an uplink element number that corresponds to the CPDLC message type of the CPDLC message; query the expected response time database, using the query request, for an expected response time for the received CPDLC message; and retrieve a query result from the expected response time database that includes the expected response for the CPDLC message. The set duration of the timer may be equal to the expected response time retrieved from the expected response time database.

In another embodiment, a method in a flight deck system in an aircraft for enhancing controller pilot datalink communication (CPDLC) operation is provided. The method comprises: receiving a CPDLC message having a CPDLC message type from a flight operation center (FOC) having an FOC name; retrieving an expected response time for the CPDLC message from an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs; generating a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on the expected response time; signaling the aircraft display device to display the timer; monitoring communications from flight crew for a response to the CPDLC message; and signaling the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message.

These aspects and other embodiments may include one or more of the following features. The method may further comprise signaling the aircraft display device to display a Respond ASAP indication when a communication has not been detected within the set duration that is responsive to the CPDLC message. The method may further comprise signaling the aircraft display device to end the display of the Respond ASAP indication when a communication has been detected that is responsive to the CPDLC message. The expected response time database may be preloaded onto the aircraft before flight or downloaded onto the aircraft during flight. The expected response time database may be searchable via input of an FOC name and an uplink element number for retrieving an expected response time for a specific response time for a specific FOC. Retrieving an expected response time for the CPDLC message from the expected response time database may comprise: generating a query request for the expected response time database that includes the FOC name for the FOC from which the CPDLC message originated and an uplink element number that corresponds to the CPDLC message type of the CPDLC message; querying the expected response time database, using the query request, for an expected response time for the received CPDLC message; and retrieving a query result from the expected response time database that includes the expected response for the CPDLC message. The set duration of the timer may be equal to the expected response time retrieved from the expected response time database.

In another embodiment, a non-transitory computer readable medium encoded with programming instructions configurable to cause a controller in a flight deck system in an aircraft to perform a method for enhancing controller pilot datalink communication (CPDLC) operation is provided. The method comprises: receiving a CPDLC message having a CPDLC message type from a flight operation center (FOC) having an FOC name; retrieving an expected response time for the CPDLC message from an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs; generating a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on the expected response time; signaling the aircraft display device to display the timer; monitoring communications from flight crew for a response to the CPDLC message; and signaling the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message.

These aspects and other embodiments may include one or more of the following features. The method may further comprise signaling the aircraft display device to display a Respond ASAP indication when a communication has not been detected within the set duration that is responsive to the CPDLC message. The method may further comprise signaling the aircraft display device to end the display of the Respond ASAP indication when a communication has been detected that is responsive to the CPDLC message. The expected response time database may be searchable via input of an FOC name and an uplink element number for retrieving an expected response time for a specific response time for a specific FOC. Retrieving an expected response time for the CPDLC message from the expected response time database may comprise: generating a query request for the expected response time database that includes the FOC name for the FOC from which the CPDLC message originated and an uplink element number that corresponds to the CPDLC message type of the CPDLC message; querying the expected response time database, using the query request, for an expected response time for the received CPDLC message; and retrieving a query result from the expected response time database that includes the expected response for the CPDLC message. The set duration of the timer may be equal to the expected response time retrieved from the expected response time database.

In another embodiment, a flight deck system in an aircraft for enhancing controller pilot datalink communication (CPDLC) operation is provided. The flight deck system comprises a controller configured to: access an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs, wherein the expected response times are searchable via input of a flight operation center (FOC) name and an uplink element number, wherein the expected response time database is preloaded onto the aircraft before flight or downloaded onto the aircraft during flight; receive a CPDLC message having a CPDLC message type from an FOC having an FOC name; generate a query request for the expected response time database that includes the FOC name for the FOC from which the CPDLC message originated and an uplink element number that corresponds to the CPDLC message type of the CPDLC message; query the expected response time database, using the query request, for an expected response time for the received CPDLC message; retrieve a query result from the expected response time database that includes the expected response for the CPDLC message; generate a timer function that causes the display of a timer (e.g., countdown timer) on an aircraft display device that has a set duration based on (or equal to) the expected response time; signal the aircraft display device to display the timer; monitor communications from flight crew for a response to the CPDLC message; signal the aircraft display device to end the display of the timer when a communication has been detected within the set duration that is responsive to the CPDLC message; signal the aircraft display device to display a Respond ASAP indication when a communication has not been detected within the set duration that is responsive to the CPDLC message; and signal the aircraft display device to end the display of the Respond ASAP indication when a communication has been detected that is responsive to the CPDLC message.

Claim 1:
A flight deck system in an aircraft (<NUM>) for enhancing controller pilot datalink communication, CPDLC, operation, the flight deck system comprising: an aircraft display device (<NUM>) in the aircraft; and
a controller configured to:
receive a CPDLC message (<NUM>) having a CPDLC message type from a flight operation center, FOC, having an FOC name;
retrieve an expected response time for the CPDLC message;
generate a timer function that causes the display of a timer on the aircraft display device that has a set duration based on the expected response time;
signal the aircraft display device to display the timer (<NUM>);
monitor communications from flight crew for a response to the CPDLC message; and,
signal the aircraft display device (<NUM>) to end the display of the timer (<NUM>) when a communication has been detected within the set duration that is responsive to the CPDLC message;
characterised in that the expected response time is retrieved from an expected response time database containing expected response times for a plurality of CPDLC message types for FOCs.