As a student pilot I try to keep record of all my flights, total hours, costs and number of landings in Google Sheets. As a safety measure our aviation safety agency (EASA) requires pilots to perform a minimum of 3 take-offs and landings within 90 days in order for them to take passengers on a flight.
Even though I fly very regularly, I would still like to know exactly how many days I have left since the last time I've performed 3 take-off's and landings.
In my spreadsheet I have a column for the date of each flight and a column which sums up the amount of landings that were made (as shown in the extract below).
My goal is to count column D from the bottom to top until the value sums up 3 and read back the related date on the same row (in red).
What have I done so far?
I have been experimenting with COUNTIF, ARRAY, INDEX, SUMIF and a combination of them but I'm out of clues. That is why I am reaching out to you.
The best I came up with (Q42 is a cell with value '3' in it). Unfortunately it leaves much to be desired:
=COUNTIF(ArrayFormula (SUMIF (ROW(D2:D19); "<=" &ROW(D2:D19); A2:A19)); "<=" &Q42)