Date: 202008
Local time of day: 0601-1200
Location: SPI.Tower, IL
Flight conditions: VMC
Weather elements / visibility: 10
Light: Dawn
Aircraft: J3 Cub
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Training
Flight phase: Takeoff / Launch
Airspace: Class E ZZZ
ATC / advisory: CTAF SPI
Second aircraft: TBM 700/TBM 850
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Air Traffic Control Fully Certified; Flight Crew Multiengine; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Situational Awareness; Communication Breakdown
Anomaly: Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Procedure; Airspace Structure; Airport
Primary problem: Airport

Narrative: I was conducting tail wheel training.  During my training process; I focus on directional control which involves practice runs at takeoff speed where the student learns the control one at a time building up to a takeoff.  I was going down runway 31 and runway 13 because the other runways were closed.  I was using that runway because the winds were light out of the south and normally I use a runway not in use to avoid active traffic.   That said; I did probably maybe six or seven runs up and down runway 31 which put me on the runway over 30 minutes.  I made radio calls for each run at each end before turning around.  Once the student was used to all of the controls of the airplane; I decided we were ready for a takeoff which was made off of runway 13.  The wind at the time was calm and on the ASOS was 150@4 knots.  Since airport doesn't have a calm runway I figured that would be fine considering it was closest aligned with the wind.  On the takeoff; I was maybe 200 feet above the ground and the student mentioning seeing two lights out the front of the airplane.  Once I identified the aircraft departing the opposite direction from runway 31 at our altitude but out climbing us.  If we had continued at each other the other aircraft would of cleared us by 100 to 200 feet vertically and by the time we turned we were 400 foot separated.  There were some quick words exchanged over the radio which was emotional at best.  Later I thought about why we didn't hear or see each other.  At the end of runway 13; there is a depression.  In that depression; someone at the end of runway 31 cannot see someone either waiting or departing runway 13.  You really cannot see the end of runway 13 when departing runway 31.  There also is enough of a depression that radio communications either break up or don't continue once you get out of the line of sight of aircraft at runway 31 or if aircraft make a taxi/departure call in the hangars.  The departure aircraft was an overnight departure that was placed in the hangars for based aircraft because the transient hangar was full.  That said; airport probably could use a calm wind runway to prevent accidents such as this. Airport could also use a radio type device that bounces radio transmissions to the depression area for aircraft departing runway 13.  This would of been fixed with the tower open but nobody really was at fault with the runways all closed; etc.  I'm happy we both as pilots used see and avoid.




Synopsis: Piper J3 Instructor reported a NMAC with traffic departing opposite direction resulting in taking evasive action.