Air Transportation Office (ATO) chief Assistant Secretary Adelberto Yap said the two experts arrived in response to Yap’s letter relaying the complaints of local pilots on the seeming defects of the Bell-407’s rotors.
"We asked them to come here because we need their technical expertise," Yap told airport reporters.
However, ATO investigators are still eyeing "engine malfunction due to adulterated aviation fuel" as the cause of the crash based on the damage of the ill-fated helicopter owned by the JAKA Group of Companies, owned by Sen. Juan Ponce Enrile.
Yap said probers had ruled out sabotage and defective rotors in the crash since the rotor was still intact, but probers are looking at engine trouble based on initial findings.
He wrote the US-based Bell Corp. on Friday morning to relay the pilots’ complaint but in the afternoon of the same day, the JAKA Group’s Bell-407 crashed in the outskirts of Puerto Princesa City in Palawan.
"I informed the US-based Bell Corp. of the numerous complaints of pilots, primarily on their common observation that whenever they fly the Bell-407 type of helicopter, they feel as if the rotor blades are about to disengage," Yap said.
The Bell helicopter, with registry No. RP-2345, crashed into a watershed at Sitio Mabugay, Barangay Manalo in Puerto Princesa City.
Authorities identified the victims as Lualhati Reyes, mother of the Palawan governor, pilot Capt. Rene Marukot, mechanic Rodolfo Jastiva, and provincial employees Ramil Miraflores, Jun Sta. Cruz and Modesto Hilongos.