(1)In respect of a ship or an aircraft or machinery or plant specified in sub-section (2), which is owned by the assessee and is wholly used for the purposes of the business carried on by him, there shall, in accordance with and subject to the provisions of this section, be allowed a deduction, in respect of the previous year in which the ship or aircraft was acquired or the machinery or plant was installed or, if the ship, aircraft, machinery or plant is first put to use in the immediately succeeding previous year, then, in respect of that previous year, of a sum by way of investment allowance equal to twenty-five per cent. of the actual cost of the ship, aircraft, machinery or plant to the assessee:[Provided that in respect of a ship or an aircraft or machinery or plant specified in sub-section (8-B), this sub-section shall have effect as if for the words "twenty-five per cent.", the words "twenty per cent." had been substituted:Provided further that] [ Inserted by Act 11 of 1998, Section 5 (w.e.f. 1.4.1999).] [no deduction shall be allowed under this section in respect of-(a)any machinery or plant installed in any office premises or any residential accommodation, including any accommodation in the nature of a guest house;(b)any office appliances or road transport vehicles;(c)any ship, machinery or plant in respect of which the deduction by way of development rebate is allowable under section 33; and(d)any machinery or plant, the whole of the actual cost of which is allowed as a deduction (whether by way of depreciation or otherwise) in computing the income chargeable under the head "Profits and gains of business or profession" of any one previous year.][Explanation. - For the purposes of this sub-section, "actual cost" means the actual cost of the ship, aircraft, machinery or plant to the assessee as reduced by that part of such cost which has been met out of the amount released to the assessee under sub-section (6) of section 32-AB. ] [ Inserted by Act 3 of 1989, Section 6 (w.e.f. 1.4.1989).]
