Tailwise

No serrature of abdominal outline, but bony scales present or dermo-hæmal processes under true scales as figured above, overlapping and having short end pointing tailwise from pectoral to anal fin.

Source: wiktionary

If the Soviet missile were toppled, would it still go off if it hit sidewise or tailwise?

Source: wiktionary

It was at this point the plane gave its lurch and slid tailwise down into the water until its rear fuselage struck the sandy sea bed.

Source: wiktionary