SR20 instructor and student pilot reported they diverted to the nearest suitable airport when the engine began to lose oil pressure.
Synopsis
SR20 instructor and student pilot reported they diverted to the nearest suitable airport when the engine began to lose oil pressure.
Narrative
Aircraft had normal indications throughout the ground; departure; and enroute phase. Preflight indicated 4.7 Q and student inputted 1 quart which totaled 5.7 and was visually verified. Engine was hot and a hot start was accomplished. Takeoff power indicated 80 PSI and shortly after takeoff indicated ~76 PSI. Engine was smooth and no vibrations were noticed throughout cruise. Upon reaching ZZZZZ (IAF for RNAV XX ZZZ1) instructions were to hold due to traffic saturation allowing limited instrument approaches. IFR was cancelled and I (instructor) decided to depart north to complete maneuvers while under flight following. Steep turns and slow flight were completed and recovered from according to procedures. No nonstandard situations were noticed during maneuvers. Upon recovering I gave the student intersection holding instructions northwest of ZZZ [VOR] while at 4500. As student was calculating holding a CAS message was annunciated indicating a low oil pressure caution. The indication was verified as the PSI dropped at a steady rate. (Approximately 1 PSI / 15s) As a result I took control of the aircraft advised ATC of our situation and proceeded direct ZZZ1. Soon after I realized ZZZ was the closest runway to our present position by 5 miles; pointed the aircraft in that direction and advised ATC of our intentions where we then received [priority handling]. At this point we were 20 nm from this airfield. Due to mountainous terrain and the sheer lack of landing spots I maneuvered the aircraft to stay within gliding distance of the river and its less than ideal landing spots. I was then switched over to Tower in which they assigned me Runway XY as winds favored that but requested Runway XZ to limit time in the air. A shallow descent was initiated to limit altitude loss but also to decrease time in the air as it was realized the steady decrease in PSI was the threat. Upon reaching ~ 5nm northwest of ZZZ an oil temperature caution was encountered agreeing with the PSI loss power was then reduced as instructed by QRH which the student ran while I flew. The approach was purposefully high and fast to ensure enough energy to make the airfield. Upon ensuring the airfield was made flaps 50 were introduced and subsequently flaps 100. At this point the aircraft indicated 13 PSI as seen by the backseater. When power was idle PSI indicated 0 but engine was still on. Runway was purposefully overshot and several steep S turns were performed at Vref. The aircraft touched down on Runway XZ and was subsequently shut off by me. Speed was kept up and we were able to clear the hold short lines. We were met by emergency services including police; fire; and ambulance who were all accommodating. There was no noticeable leak under the plane initially until approximately 30 mins after landing droplets were seen spread out on the tarmac under the plane. Oil dipstick was verified closed but oil quantity was not checked. No noticeable oil leak inside cowling.
Second reporter narrative
We were planning to fly to ZZZ1 to fly multiple approaches for training purposes. They said it wasn't possible to do multiple so we wanted to go for one. We got cleared for the RNAV XX. When we were in the hold the clearance got cancelled because of other incoming traffic. We were told to expect the next clearance in 20 minutes. We decided to head north for to practice airwork. When we were done with airwork we got a low oil pressure CAS message. At this point we were around 30 NM north of ZZZ1. The terrain didn't allow for a safe CAPS deployment. CFI and pilot in command (PIC) took controls and notified ATC about our situation and that we needed a straight in for Runway XX. The oil pressure kept dropping and we weren't sure if we would make it to ZZZ1 so we requested a direct to the nearest air strip which was ZZZ at the time. Since we still weren't sure if we would make it to the airfield we didn't fly a straight line; we broke off to the east; since the terrain over there allowed for a safe CAPS deployment in case of an engine failure. The oil pressure went all the way down to 12 PSI at full throttle and the oil temperature also kept rising. We shut down the engine right after touchdown and used the remaining speed to taxi off the runway.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.