I understand that it is best to use a duffel bag to pack and Iit must weigh no more than 27 lbs. I will be traveling on small planes in Tanzania and Kenya. Is it okay to take a duffelbag with wheels and a handle?

As long as you can pack it within your size and weight limitations, should be fine. And if you have flight connections and /or layovers having wheels is convenient. However check you weights-- most rolling duffles weigh AT LEAST 3 lbs more than a regular duffle, empty. But if you pack light, go for it...

If the rolling duffel is the kind with a small flat (no real verticle component) flexible frame it will be fine. On small planes bags are mostly stuffed into very tight, odd-sized spaces. Stiff frames can be bent or broken by other bags and/or the efforts to jam them in.

You know, 27 lb. adds up in a hurry. And there are so many people in Africa who benefit from helping you if you need help and can't carry your 27 lb. that you really don't need to waste the weight and space with those wheels. The tiny cargo area has to be packed tight with the soft luggage and your wheels can easily smash someone's souvenir.
Really - plain soft duffle bags are what will make your pilot's heart sing. (I saw one girl have to leave a oversized bag behind - follow the rules and everyone is happier).

Lucretia:

A duffel with wheels will be fine in Kenya. I can't answer about Tanzania.

I took two large duffels, 32" Delsey Helium Light and 30" J World Sports, both with wheels. I was taking a lot of gifts and couldn't fit everything into one duffel. The weight of both duffels was 30 kilos (approximately 60 pounds) and I didn't have a problem either flying to Amboseli or Samburu on Air Kenya.

The only disadvantage I found with the duffels is that on large planes Kenya Airways, KLM, etc. all the duffels were usually the last off the plane.

Jan

Sorry, I was answering for Botswana and South Africa - Jan is one of our experienced Kenya travelers so her advice is to be listened to!