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Lookback: FAR 121 On Android


New member
Jun 2, 2014
I was wondering if there was a way to account for FAR part 117 using the lookback feature under FAR 121. It seems to me it wouldn't be that difficult to look at out/in times that are inputted and use that to calculate the rolling periods. I am sorry if that is a naive assumption but the way the times the system currently displays appear to be out of date (with regulations) and are almost useless to me.


Andy Adams

Support Engineer
Staff member
Apr 23, 2008
Wilson, NC

Unfortunately this is not that simple by a long shot. FAR 117 requires lookback as well as look forward and continuously updated calculations in order to determine legality. Additionally there are different rules and limits for reserve versus line pilots, time of day you start your flying, time zone changes, etc the list goes on and on.

To properly track all that 117 involves, requires a dedicated app designed specifically with 117 in mind.

We are currently working on APDL to resolve these issues and have learned first hand that FAR 117 is more complex than we first thought.

The 121 calculations are outdated and obsolete as you have said, however, they cannot be simply updated to meet the requirements of FAR 117.

We are confident that APDL will suit the needs of airline pilots flying under 117.