Heli- Cargo transport. Drop precision?

[Vrede]

Anyone that's able to get drop precision over 70%? I think I'm doing it perfectly sometimes and don't get any failures, the cargo integrity at 100 and execution time at 100, but still not enough to get "S rank", which is required for the last heli cert.
Is there something wrong with the precision you think, or am I just doing it wrong?

[Twix2000]

Same here. I get every time 67%