Herbert sees a ~$500 million fix for Boeing, but is "not yet adjusting" 2019 estimates. The analyst says, "as a base case, we see the immediate fix as a ~$500M investment. We then see the grounding leading to a ~$1B in monthly lost FCF from delivery delays and the potential loss of advancements on in-process aircraft (eventually recovered). We then see the potential monthly risk of up to another ~$1B depending on how much of the airline operating revenues BA ultimately reimburses. We expect this to be a much smaller number than the potential, but we do expect some recovery here paid by Boeing to the airlines for the disruption."