21(1)If a person dies as a result of any pulmonary disease and—N.I.
(a)he was entitled, for a period which includes the date of his death, to disablement pension or gratuity in respect of pneumoconiosis or byssinosis or pneumoconiosis accompanied by tuberculosis; and
(b)the extent of the disablement in respect of which the benefit was payable was assessed for such a period at not less than 50 per cent.,
then, subject to sub-paragraph (2) below, his death shall be treated, for the purposes of this Part of this Schedule, as having been caused by the disease in respect of which the benefit was payable.
(2)Unless regulations provide otherwise, the requirements of paragraph (b) of sub-paragraph (1) above shall be treated as unsatisfied in a case where, had the physical condition of the deceased at the time of the assessment been normal, apart from the diseases mentioned in paragraph (a) of that sub-paragraph, the extent of the disablement in question would have been assessed at less than 50 per cent.
(3)This paragraph does not affect death benefit where the death occurred before 30th March 1977.