Date: 201307
Local time of day: 0601-1200
Location: ZZZ.Tower, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Light Sport Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Takeoff / Launch
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Sport / Recreational
Human factors: Situational Awareness; Time Pressure
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Air Traffic Control; Person Dispatch
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Emergency Landing on Runway XL from a departure on Runway XX. Sequence leading up to event. Preparing for a morning sport flight I had normal Briefer contact; pre-flight; warm up; and ATC communication and clearances to begin the flight (missed taking out cowl vent covers). When cleared for departure on Runway XX; noticed slightly elevated Cylinder Head Temps for a cool day; but not abnormal for a warm day. After rotation and climbing during departure; I became alarmed to see the CHT's in the 230F range and understood that there could be problem; because CHT had elevated abnormally quickly. Attention brought to engine warning light by flickering that indicated oil pressure on low side of acceptable (which this can happen with this engine for a brief second or two). Once warning light flicker stopped for oil; I could see the EIS data again indicating the CHT's was in 240F range where I decided to reduce some throttle to cool engine and make a call to ATC for landing. Before I made the call to ATC some steam or smoke was observed coming from the right side of engine area. Made the request of ATC and clearance provided to make an Emergency Landing as I was turning toward Runway XL/XYR and reducing throttle. While turning I noticed that EIS indicated that the highest CHT was at 290F; but did not appear to get higher. Communication was kept with ATC to make sure all traffic was on hold for landing on Runway XL and intersecting Runway XX; which was confirmed.  Landed close to Taxiway Echo and immediately exited on Taxiway Echo; which ATC provided clearance and communicated to do what I needed to do. I stopped on Taxiway Echo. Inspection showed cowl covers in; radiator fluid all over the engine/aircraft; and radiator overflow hose had a hole. No Fire; so began to push aircraft back to hangars. Airport staff and Emergency Crew arrived and inspected engine resulting in the same conclusion. A&P Mechanic inspected; that same afternoon; while in phone communication with the Aircraft's Distributor Mechanic.  They determined that the engine was fine and hose replacement and adding coolant was needed to repair the aircraft.Preventative Action - Be more thorough during preflight with checklist.-Be more cognizant of normal CHT Temps for different outdoor temperatures and trust instinct.




Synopsis: A LSA/Sting Sport radiator over flow hose had a hole in it so after takeoff the cylinder head temperature rose while ATC reported streaming fluid. An emergency was declared followed by a uneventful return for landing.