Is An Indian owned aeroplane operating between Singapore and Dubai included/excluded in Domestic Income of India?

Yes,

It will be included in domestic factor income as it is a part of the domestic territory of India.

Explanation:-

Aeroplane owned by Indian, operating between any countries comes under the domestic territory  of India

The profits earned by the residents and non-residents (foreign companies) within the domestic territory of India is included in the domestic income.

All incomes and profits generated by all within the domestic territory of India will be included in the domestic income of India.