Two Pennsylvania State Police troopers killed in the line of duty 35 years ago in York County were honored at a memorial service Friday.Cpl. Paul Almer and Trooper Wayne Bilheimer were in a helicopter searching for a missing person on April 12, 1989, when the aircraft hit power lines and crashed into the Susquehanna River.Bilheimer's son, Adam, spoke about this dad and how his family has been since the accident. He also spoke about the support they received."The state police treat us like family. They helped and helped, getting us through the whole process," he said."I knew them through their entire career. I worked many shifts with them as their patrol partner and later as their supervisor. You always knew they had your back. You can count on them 100%," retired Cpl. Ed Rowlands said."The passing of Cpl. Almer and Trooper Bilheimer was a tremendous loss for their families, friends in the department and the citizens of Pennsylvania. While their loss has been felt by so many, they will always be remembered for the extraordinary lives that they lived," Major Kreg Rodrigues said."Their sacrifice they made that day will never be forgotten – not to the family members, not to the troopers that worked that day and not to the generations of troopers that came after them," Trooper James Grothey said.Changes were made as a result of the crash.Power lines along the river now have aviation markers to make sure the lines can be seen.Also, state police helicopters were equipped with devices that would cut power lines if a similar incident were to occur.Video below: From the archives - News 8's report on the crash