Ok, I’ll start! Quick background - I’ve been flying for over 30 years, much of it in very team oriented environments (Snowbirds) - but recently I’ve begun flying a large business jet. So despite having a lot of experience, I’m new to FMS, two-crew aircraft etc. The other day we were on a trip from our home base to our principal’s second residence - the 2nd time for the same city pair in 4 days. The first trip, we had tankered fuel, but the 2nd, we decided not to. It wasn’t until doing fuel checks at TOC, and seeing a 5000 lb difference, that I realized I had messed up and recalled the wrong flight plan from ARINC 4 days prior when loading the FMS. If we had tankered fuel the 2nd flight, I may not have realized my error until deviating from our filed flight plan. I quickly brought this up to my crew using the standard terminology “um. I think I f@cked up!” We quickly checked the FMS routing against the OFP and luckily the SID and first couple waypoints were the same for both trips. We were able to amend and correct in time. Whew! The good: - We got lucky (in that the departure and first couple waypoints were identical) - SOPs for fuel checks saved the day - I recognized the error in time to correct the FMS plan and remain on the filed route - I belong to a crew where we all feel safe to admit errors The not-so-good: - human error prevailed (temporarily) and somehow we either heard what we expected to hear, or both referenced the previous days OFP while checking waypoints on the ground! - Pre-flight SOP foundations are still being built in our newly formed crew - clearly we have room for improvement in our OFP/FMS verification SOP In the Air Force, we often used a similar debriefing mantra: Did we succeed? If we did, could we have done better? If not, did we fail or did the plan fail? Or were there factors we weren’t aware of that caused the failure? In this case, it’s fair to say the failure was on the crew, and more specifically on me. That’s actually an easy one to debrief, and the path to success is cut and dry this time.