User submissions need pre-check
We take customer data into our systems, and also have suffered from poor data causing issues in the past. These issues are now mitigated by having submission systems to check and reject any data not conforming to the required format or standards.
I would have thought it a fairly easy procedure to verify flight plans are good at the point of submission, since this should not be a time or mission critical point in the process.
Biting the hand that feeds IT
