Are F 28 & F 100 same family re: fleet commonality?

[rettir]

It is my understanding that the F 100 is a stretched F 28. Though it has different engines. I could not find via the search function if this question has been ask & answered before.

Thanks in advance for clarification.

[Sami]

Not the same, and for all I can see is because of the different speed profile they have (which has been also a deciding factor in some other similar cases). They are marked at 0.7 and 0.73.

F70/F100 is not just a stretch, but also otherwise modernized. But for the sake of fleet commonality, it would fit into the same group if they were to use the same speeds.