EASA's Scientific Study

To fulfill its legal mandate to carry out a scientific evaluation of Subpart Q, in late 2006 EASA set up an Advisory Group of aviation stakeholders, consulting them on the EASA tender document, on its selection criteria [1], the project's working methodology and the specific questions that were to be submitted to the scientists[2].

On that basis, EASA launched a tender (EASA.2007.OP.08) which resulted in a Swiss consultancy 'Moebus Aviation' being chosen which had put together a panel of 10 renowned European scientists.

After the draft final ‘Moebus report’ was presented to the Agency and stakeholders in Sept. 2008 and discussed in the Advisory Group in Nov. 2008, EASA published the results of the scientific study in January 2009. 

The report concludes that that “some of the present [EU-OPS] rules or proposed modifications of rules are in violation with one or more of these factors” i.e. factors that are known to increase pilot fatigue – and hence the risk to the safety of flight operations.

The main problem areas identified were a) the large number of pilots’ duty hours in a short time, b) long duty hours, c) night duty, d) early starts of duty, e) time-zone crossing, and f) standby duty. And it concludes that:

  • The currently allowed maximum daily flight duty period of 13-14 hours “exceeds reasonable limits” and is “not in keeping with the body of scientific evidence”; it should therefore be reduced;
  • The currently allowed maximum of 11:45 hours night duty should be reduced to 10 hours, because of the particularly fatiguing nature of work at night;
  • The currently allowed practice of 3 consecutive 60-hour weeks (i.e. 180 duty hours in 21 days) needs to be changed by setting an additional limit of 100 duty hours within 14 consecutive days (i.e. an average of 50 hours/week, instead of 60);
  • The currently allowed practice of “advancing” the end of the pilots’ weekly rest – which allows a start of duty as early as 04:00 in the morning – is “unacceptable” as “it would result in aircrew starting their week […] in a fatigued state”; hence this practice should not be allowed;
  • Stand-by at the airport is as fatiguing as flight duty, and should therefore not be considered as “rest” but normally “count 100% as flight duty when calculating the maximum flight duty period.

Moebus Aviation FTL Study - Full Report

Summary of the study's main findings

[1] These criteria were "to guarantee a high level of knowledge, competence and independence, so that their conclusions can provide for a strong scientific basis for regulating flight time limitations and rest periods in an objective way" (quote from the EASA tender). [2] EASA chose to focus the study on "the points of disagreement between the main parties affected by FTL regulations and to seek the opinion of a panel of independent experts on the right way to address these points" (quote from the EASA Tender).