A scan of Lima newspapers this (10 Jan) evening indicate the aircraft has not been located and the search has been called off for the night. At least three helicopters and a Twin Otter have been involved in intermittent searches but mostly grounded by weather.
Chachapoyas is in the eastern foothills of the Andes and it can rain there for weeks on end. Teams totalling about 180 men headed by army and police are conducting searches on foot in extremely difficult hilly terrain with few roads. Much of it is still densely forested and wreckage just disappears beneath the tree canopy. The aircraft was approximately three minutes from landing and Lima newspapers quote the (radarless) tower staff as saying the last transmission from the aircraft was "entering base"; no indication of anything untoward.
I believe this aircraft was one of two to four F-28s purchased by the Peruvian airforce in the early 70s and operated commercially by what eventually became Aeroperu, the country's national airline. Very tough, manoueverable little birds and at the time an ideal step up from the Faucett DC-3s and -4s that served the semi-paved strips in the eastern highlands, still inaccessible to Faucett's new 1-11s.