Rain, winds and rough mountain terrain hampered the weeks long search, and it may take at least three days more to recover the remains of the victims, officials said.
Constante Foronda of Isabela's disaster response office said the families of the victims, who were all Filipinos, have been notified of the discovery of the wreckage. "They're very sad but at least they now have closure," he told reporters.
The crash was among a series of accidents involving small aircraft in the country in recent months.
NEW PHILIPPINES PRESIDENT FIGHTING BACK AGAINST CHINA'S INCURSIONS
A wreckage of a Philippine plane was found with all six people aboard dead. The plane went missing Jan. 24. (Fox News)
An air and sea search by Philippine authorities backed by the United States and Malaysia is continuing for a helicopter carrying five people, including a patient and a nurse, which went missing last week in western Palawan province, officials said.
All those aboard are Filipinos except for the nurse, who is American, said Eric Apolonio, the civil aviation agency's spokesperson, citing a report from a rescue coordination center.
Last month, a plane carrying two Australian energy consultants and two Filipino crew members crashed on the slopes of Mayon volcano after taking off from Albay province on its way to Manila, killing all those aboard, officials said.
The wreckage was found after a high-risk search by authorities and mountaineers on the slope of one of the country's most active volcanos.