A group of airline pilots is asking that the Boeing 737 Max should not resume service until early next year.
Pilots from Southwest Airlines are warning that the troubled plane should remain grounded until March.
The largest operator of the 737 Max planes, Southwest announced it would not fly until January 2020.
Jon Weaks, A union president, is reported that the plane will return to the skies in January, at the soonest.
Regulators will certify the ground jet to begin flying again sometime before January.
Test pilots are at least one month out and a review of new 737 Max software by federal regulators if not more.
Once the ban has been lifted, reintroducing the 737 Max is expected to take about 45 days.