Investigation Summary
The accident involved a high-speed Zlin 242L (N5ZA) performing a straight-in approach and a Cessna 172P (N99063) flying a right-hand traffic pattern. The local controller (LC) at Waukegan, who did not have access to radar, attempted to sequence the Zlin as number one for landing based on the pilot's report that he was crossing the shoreline. However, radar data later revealed the Zlin pilot had significantly underestimated his distance from the shore, reporting he was crossing it when he was actually 0.8 miles away. This led the controller to believe the Zlin was further ahead than it actually was. The controller instructed the student pilot in the Cessna to turn base and then final, which placed her directly in front of and below the faster-moving Zlin. Due to the high-wing design of the Cessna and the low-wing design of the Zlin, both pilots likely had their view of the other aircraft obstructed by their own airframes. The Zlin pilot reported having 'the traffic' in sight just before the collision, but investigators believe he was actually looking at a third aircraft (another Cessna) in a different traffic pattern.
Final Conclusions
The National Transportation Safety Board determined the probable cause was the Zlin pilot's failure to maintain clearance from the other airplane. Contributing factors were the pilot's poor visual lookout and the local controller's failure to provide effective sequencing. The NTSB also noted that the lack of a radar display system at Waukegan Regional Airport prevented the controller from verifying the aircrafts' actual positions, forcing reliance on imprecise pilot reports.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Private N5ZA — Moravan Z242L · N5ZA
American Flyers N99063 — Cessna 172P · N99063
Crew Experience
Captain
Private pilot certificate holder Bob Collins, age 57.
Student Pilot
Sharon Hock, age 31, who had 1 hour as PIC.
Systems & Failure Modes
Visual Flight Rules (VFR)
Both aircraft were operating under VFR, which places the primary responsibility for maintaining aircraft separation on the pilots through 'see and avoid' principles.
Air Traffic Control (Non-Radar)
The tower operated without radar, meaning the controller relied entirely on visual observation and pilot position reports to sequence traffic.
Interesting Facts
- 01The Zlin 242L is a low-wing aircraft, while the Cessna 172P is a high-wing aircraft.
- 02Waukegan Regional Airport did not have a radar display for controllers at the time of the accident.
- 03The Zlin impacted the roof of the Midwestern Regional Medical Center and exploded.
- 04The Cessna struck a tree and sidewalk before coming to rest on a residential street.
- 05Visibility was 10 miles, but the controller reported hazy conditions near the lake.
Safety Actions & Advisories
Radar Installation Recommendation
The NTSB highlighted that a radar display system at Waukegan could have prevented the collision by allowing the controller to see the actual positions of the aircraft.