This document includes questions and answers that pertain to the ARPA-E Funding Opportunity Announcement (FOA) entitled "Exploratory Topics: Targeted Topics: D - Predictive Real-time Emissions Technologies Reducing Aircraft Induced Lines in the Sky (PRE-TRAILS)".  The full solicitation on the Exploratory Topics: Targeted Topic: D - PRE TRAILS FOA and additional information can be found on the ARPA-E Funding Opportunity Exchange website (https://arpa-e-foa.energy.gov).