Narrative:

This event happened during the [association's] landing practice. After a thorough pre-flight inspection and an uneventful run-up; the aircraft seem to show all proper indications regarding engine instruments. ZZZ ground was contacted by lead aircraft; we were heat 1 flight of 4. My position was number 3. We taxied to runway xx in order to practice power-off landings. Upon being cleared for takeoff as a flight of four; we all sequenced and provided proper spacing. We were briefed to conduct touch-and-go's as long as safety is not compromised. Upon completing my first landing; flaps were retracted; power was applied and engine instruments such as oil temperature; oil pressure; rpm; and airspeed are showing proper indications (in the green). Upon reaching an altitude of about 700 ft. AGL a sudden loss in oil pressure was indicated by the oil pressure gauge. The RPM remained constant; and the oil temperature remained constant (cool lower green arc). ZZZ tower was contacted initially due to pilot stress; [priority handling was requested]; and an immediate crosswind was initiated. RPM remained constant; but no oil pressure was present. The aircraft landed successfully and taxied to the ramp. Post flight inspection was conducted; and the aircraft was in airworthy condition; no visible oil inside cowling or in any area. The aircraft had 6 quarts of oil (normal) within the required 5-8 quarts. An a&P mechanic was contacted; removed the cowling; I explained the situation to him; he hypothesized that perhaps it was pieces of the rubber gaskets from the magnetos in the oil pan that were blocking the flow of oil. Airport operations was contacted as well as the rescue truck. ZZZ tower acted professional; and took the appropriate actions. The problem arose when realizing the loss of oil pressure.it was discovered through the constant check of engine gauges (4 greens) oil temp; oil pressure; rpm; airspeed.contributing factors are perhaps procedures regarding pieces of the rubber gaskets from the magnetos to fall into the oil pan.corrective actions are to not hesitate to declare an emergency; especially if outside of your comfort zone. I did not like the indication of lack of oil pressure; therefore I decided to declare an emergency and come back to land.human performance considerations:as a competitor; the spirit of safety through education; a perfect example that led to my decision to [request priority handling] was an FAA safety seminar that I attended; with master cfii [name]. He made it clear to us that it is ok to [request priority handling] and that he has done it several times. That and the proper training from my CFI that allowed me to carry my procedures even after more than 200 hours from receiving my private pilot license.a recommendation would be to instead of initially had declared an urgency; immediately [request priority handling] if an event of similar nature were to occur.

Related reports:

Google
 

Original NASA ASRS Text

Title: C172 pilot reported a sudden loss of oil pressure shortly after takeoff that resulted in an expedited landing.

Narrative: This event happened during the [association's] landing practice. After a thorough pre-flight inspection and an uneventful run-up; the aircraft seem to show all proper indications regarding engine instruments. ZZZ Ground was contacted by lead aircraft; we were Heat 1 flight of 4. My position was number 3. We taxied to Runway XX in order to practice power-off landings. Upon being cleared for takeoff as a flight of four; we all sequenced and provided proper spacing. We were briefed to conduct touch-and-go's as long as safety is not compromised. Upon completing my first landing; flaps were retracted; power was applied and engine instruments such as oil temperature; oil pressure; rpm; and airspeed are showing proper indications (in the green). Upon reaching an altitude of about 700 ft. AGL a sudden loss in oil pressure was indicated by the oil pressure gauge. The RPM remained constant; and the oil temperature remained constant (cool lower green arc). ZZZ Tower was contacted initially due to pilot stress; [priority handling was requested]; and an Immediate crosswind was initiated. RPM remained constant; but no oil pressure was present. The aircraft landed successfully and taxied to the ramp. Post flight inspection was conducted; and the aircraft was in airworthy condition; no visible oil inside cowling or in any area. The aircraft had 6 quarts of oil (normal) within the required 5-8 quarts. An A&P mechanic was contacted; removed the cowling; I explained the situation to him; he hypothesized that perhaps it was pieces of the rubber gaskets from the magnetos in the oil pan that were blocking the flow of oil. Airport operations was contacted as well as the rescue truck. ZZZ tower acted professional; and took the appropriate actions. The problem arose when realizing the loss of oil pressure.It was discovered through the constant check of engine gauges (4 greens) oil temp; oil pressure; rpm; airspeed.Contributing factors are perhaps procedures regarding pieces of the rubber gaskets from the magnetos to fall into the oil pan.Corrective actions are to not hesitate to declare an emergency; especially if outside of your comfort zone. I did not like the indication of lack of oil pressure; therefore I decided to declare an emergency and come back to land.Human performance considerations:As a competitor; the spirit of safety through education; a perfect example that led to my decision to [request priority handling] was an FAA SAFETY seminar that I attended; with Master CFII [name]. He made it clear to us that it is OK to [request priority handling] and that he has done it several times. That and the proper training from my CFI that allowed me to carry my procedures even after more than 200 hours from receiving my private pilot license.A recommendation would be to instead of initially had declared an urgency; immediately [request priority handling] if an event of similar nature were to occur.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.