Family Visitor

I am british Citizen, My Dad is not.
He is visiting me once every year and stays for 1 month ( for the last 9 years )
he got 10 years visa a year ago
I needed him to help out with my kids temporarily
so he stayed with me from the 01/08/2013 to 1/09/2013
then from 1/12/13 and will leave 4/4/14
then I want him to come back from the 21/4/14 to 22/5/14
and I should be able to sort out my child care by then
My question
when he arrives on the 22nd of April, will UKBA officer cause any problem?
any thing I can do ? cause i really need him till the end of may

It might ... but it is unlikely that it will.

Easiest thing would be for him not to leave!