content_image/516845.jpg content_image/516846.jpg
<img src='content_image/516845.jpg'>

Source: Federal Aviation Administration (FAA); OAG Absolute Aviation Advantage, 2013; BUCHair USA Inc., 2013; Airport IQ5010, 2013; and Bureau of Transportation Statistics (BTS), 2013. 

Aircraft type and engine combinations data can also be acquired from airline(s)/tenant(s) surveys of their fleets. However, while this approach would yield highly accurate results, the data is rarely available. Airline financial reports may also report these aircraft and engines information. 

When unavailable, aircraft engine assignments can be based on EDMS /AEDT default values. Table A1-4 ( Example of EDMS/AEDT Aircraft Fleet Mix ) is an example of an aircraft fleet mix / engine combination derived from the EDMS default database. 

<img src='content_image/516846.jpg'>

Source: EDMS v5.1.3; for further information on EDMS, see: 

http://www.faa.gov/about/office_org/headquarters_offices/apl/research/models/edms _model/. 

Future year aircraft fleet mix data may be obtainable from an Airport Master Plan Study and/or the FAA Aerospace Forecast for the airport. 

## A1.3.3 Time-in-mode 

Time-in-mode (TIM) data required by EDMS/AEDT includes the time an aircraft spends in each of the four operating modes (i.e., takeoff, climb out, approach, and taxi/idle) discussed previously. EDMS/AEDT calculates performance-based TIMs using flight profile data that are based on the airframe, engine, aircraft weight, and approach angle. 

Potential sources of airport-specific taxi/idle times include aircraft operators, airport operators and/or on-site measurements. Other data sources may include airport master plans, airport 

