According to Aviation Safety Network database (Link), the said aviation accident was the 2nd worst at that time and currently the 5th. The worst at that time was the one which occurred in May 1964, now the 3rd deadliest, with 80 fatalities (including 1 on the ground). (See the details of May 1964 and June 1987 accidents. Retrieved 02-11-2021.)
On the other hand, it might be the country's worst commercial aviation accident at that time. It was reported that, in 1967, another plane of same aircraft type and from same operator crashed in northern Luzon, with 56 deaths. (Refer to cited news articles.) However, it was proved unverified as there is no such accident in the said database.
Det Norske Veritas Report No. 97-2053, Annex 1: Passenger Vessel Evacuation Descriptions, sec. I.4.1, p. I.36, FSA of HLA on PassengerVessels, C8065\annex 1.doc 1 November 2001. http://research.dnv.com/skj/Fsahla/Annex1.pdfArchived September 30, 2018, at the Wayback Machine
Det Norske Veritas Report No. 97-2053, Annex 1: Passenger Vessel Evacuation Descriptions, sec. I.4.1, p. I.36, FSA of HLA on PassengerVessels, C8065\annex 1.doc 1 November 2001. http://research.dnv.com/skj/Fsahla/Annex1.pdfArchived September 30, 2018, at the Wayback Machine