Use of Controller-Pilot Data Link Communications During Different Flight Phases

Testing the Acceptance of CPDLCs during flight.

This study by Lin was a survey of pilots that explored the effects of using Controller-Pilot-Controller data communications (CPDLCs) equipment during different phases of flight and the role that has on pilot’s workload and situational awareness. For this simulated experiment, eight experienced airline pilots with knowledge of data communications systems participated. This article will recapitulate those results in a meta-analysis.

The data displayed in illustration 1 shows the mean score of all eight pilots from the survey on a scale of 1 to 5. (1) being the pilot strongly disagrees that CPDLCs should be used during that particular phase of flight; and (5) being the pilot strongly agrees that CPDLCs should be used during that phase of flight. The experiment mentioned was a simulated flight that all participants did (as explained in the methods section) where the participants were tested using CPDLCs during all phases of flight. Participants were given questionnaires before and after that experiment.

Illustration 1: Mean responses from questionnaire before and after experiment with standard deviation
Before Experiment After Experiment Total
Flight Phase Mean StdDev Mean StdDev Mean StdDev
Take-Off 2.25 1.04 2.25 1.00 2.25 0.99
Climb 2.50 1.07 2.81 1.05 2.71 1.04
Cruise 4.88 0.35 4.44 0.73 4.58 0.65
Descent 3.00 1.07 3.06 1.06 3.04 1.04
Approach 2.00 0.53 2.44 1.03 2.29 0.91


From this data we can compare and contrast the levels of acceptance. Firstly the results reveal there is no significant differences between the responses before and after the experiment (F(1.103)=0.24, p>0.05), however the difference between phases of flight were significant (p<0.01). Pilots were more accepting to use CPDLCs during the cruise (Mean=4.58, Standard Deviation=0.65), whereas they were least accepting of using the system during take-off (Mean=2.25, Standard Deviation=0.99).
The standard deviations show that in general, pilots tended to agree on the acceptance level of CPDLCs because of the relatively small 'spread'. However on close inspection, pilots had more varied opinions on the use of CPDLCs during climb and descent where the total SD is greater than 1.00. Whereas they were generally in agreement for the use of CPDLCs during take-off, cruise, and approach; where the total SD for all three phases were less than 1.00.

Study's Scope

The researcher only recruited pilots with sufficient experience with the datalink and flight experience. Due to difficulty recruiting such pilots for the study the researcher was only able to test eight pilots (four crews) from different airlines for this experiment. The findings for this study may then be very limited in scope and may not reflect the opinions of a larger spectrum of pilots from all over the world.


Research approach

This study explores the use of communications equipment, specifically "Controller-Pilot Data Link Communications", during different phases of flight as perceived by airline pilots.


A small sample of 8 pilots (4 crews) from four different airlines in the Asian region were used. Half were captains and the other half were first officers. The average (mean) age was 40.38 with a spread (standard deviation) of 7.2. The mean flight time experience of all 8 pilots was 6981.25 hours. All had normal or corrected visual acuity. All have sufficient experience using CPDLC during their career.


Three independent variables were evaluated during this study: communications medium, flight phase, and the role in the cockpit.

Communications Medium:

  • Voice Communications
  • Data Link

Flight Phase:

  • Take-off
  • Climb
  • Cruise
  • Descent
  • Approach

Cockpit Roles:

  • Pilot flying (PF)
  • Pilot non-flying (PNF)


The study required each pilot to;

  1. Do a questionnaire using a Likert-type scale with five anchors each (strongly disagree [1], disagree [2], neutral [3], agree [4], strongly agree [5]) to determine the pilots perception with regards to using CPDLC during different phases of flight.
  2. Do a standard 1 hour simulated flight sector (the experiment) and during each phase of flight the crew uses 2 forms of communications medium.
  3. Redo the same questionnaire used before the experiment.

Data analysis

This article extrapolates and analysis the data focusing on the use of CPDLCs during the different phases of flight and explaining the meaning of the descriptive statistics.

1. Lin, C.J. (2012). Effects of controller-pilot communication medium, flight phase and the role in the cockpit on pilots' workload and situation awarenes. Safety Science, 50(9)

Contributors to this page


J. Scott
ID: 09093636

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