What happened
On April 15, 2018, a mid-air collision occurred at the Schwäbisch Hall airfield during the final approach phase. The aircraft involved were a Cirrus SR20 and a W.D. Flugzeug-Leichtbau D4 Fascination.
The pilot of the Cirrus SR20 had arrived from Stuttgart, intending to perform an ILS approach to runway 28 as preparation for an upcoming IFR check flight. Due to a high volume of traffic, including IFR arrivals and glider operations, the pilot had been waiting for approximately 90 minutes. After several aborted approaches, the pilot finally commenced a long final approach at approximately 16:15.
Simultaneously, the pilot of the D4 Fascination was joining the pattern for landing. The air traffic controller had assigned a landing sequence designating the Cirrus SR2 and as number one and the D4 Fascination as number two. During the maneuver, the pilot of the D4 Fascination crossed the approach baseline and then turned back into the final approach.
As the Cirrus SR20 approached at approximately 120 knots, it closed in from the rear right of the D4 Fascination, which was traveling at approximately 80 knots. The two aircraft collided in the short final phase. Both aircraft struck the ground and were destroyed, and both pilots were killed in the accident. The wreckage of the D4 Fascination caught fire upon impact.
The investigation
The BFU investigation examined radar data, radio communications, and flight parameters from the Cirrus SR20's avionics. The investigation also reviewed the airfield's operational procedures and the pilots' experience and medical certifications.
Investigators analyzed the sequence of events through the transcription of radio traffic, which revealed that the air traffic controller had identified the Cirrus SR20 as the lead aircraft in the sequence. The investigation also noted that while the aircraft were equipped with Mode-S transponders, neither aircraft was equipped with a collision avoidance system.
Findings
Several contributing factors led to the collision:
- The high volume of mixed VFR, IFR, and glider traffic at SchwäSBisch Hall created a complex operational environment.
- The air traffic controller's assignment of the landing sequence led both pilots to believe the other aircraft was in a different position, causing a failure in effective traffic monitoring.
- The pilot of the Cirrus SR20 was performing a solo ILS approach, which resulted in a high workload and reduced situational awareness.
- The pilot of the D4 Fascination crossed the approach baseline and re-entered the final approach instead of performing a missed approach or leaving the area.
- The lack of collision avoidance systems on both aircraft prevented the pilots from detecting the closing speed and conflict.
- Potential sun glare from the southwest may have further hindered the pilots' ability to maintain visual lookout.