C172 pilot reported loss of engine power on departure; resulting in a return to land.

Attributes
ACN	1682624
Time
Date	201909
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Flight Plan	None
Component
Aircraft Component	Reciprocating Engine Assembly
Person 1
Function	Pilot Flying Single Pilot
Qualification	Air Traffic Control Fully Certified Flight Crew Commercial Flight Crew Multiengine
Experience	Air Traffic Control Radar 1 Flight Crew Last 90 Days 113 Flight Crew Total 430 Flight Crew Type 367
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Clearance

Narrative:

After a full and complete pre-flight; and a run-up with no issues. Shortly after departure from runway xxr; there was a significant loss in engine output from 2;400 RPM to 1;800 RPM. The first thing was to fly the airplane; request priority handling from ATC and find a place to land. After ATC gave priority and the airfield was within range with the remaining engine power to get to glide range if the engine completely failed. Runway xyl was requested and given by ATC; they had to divert departing traffic to the south; traffic was in sight and no factor and I landed on runway xyl with no issue.in the future; I will be sure to complete the emergency procedures checklist as well; which asks for the auxiliary fuel pump to be turned on which I was unable to complete before we were cleared for runway 11L; and due to the low proximity to the ground; the density of the population of the area; and enough engine power to make the airfield. I landed before being able to troubleshoot.

Original NASA ASRS Text

Title: C172 pilot reported loss of engine power on departure; resulting in a return to land.

Narrative: After a full and complete pre-flight; and a run-up with no issues. Shortly after departure from Runway XXR; there was a significant loss in engine output from 2;400 RPM to 1;800 RPM. The first thing was to fly the airplane; request priority handling from ATC and find a place to land. After ATC gave priority and the airfield was within range with the remaining engine power to get to glide range if the engine completely failed. Runway XYL was requested and given by ATC; they had to divert departing traffic to the South; traffic was in sight and no factor and I landed on Runway XYL with no issue.In the future; I will be sure to complete the Emergency Procedures checklist as well; which asks for the AUX fuel pump to be turned on which I was unable to complete before we were cleared for Runway 11L; and due to the low proximity to the ground; the density of the population of the area; and enough engine power to make the airfield. I landed before being able to troubleshoot.

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.