NTSB CAROL · Event
Event CHI93DEE05
Aircraft involved
Probable cause & findings
THE PILOT-IN-COMMAND'S FAILURE TO MAINTAIN CLEARANCE FOM POWERLINES DURING AN AERIAL APPLICATION MANUEVER.
Factual narrative
HISTORY OF FLIGHT
On August 14, 1993, at 1650 CDT, a Weatherly Model 620 owned by Hendrickson Flying Service of Rochelle, Illinois, struck electrical transmission lines during an aerial application operation and fell to the ground near Mendota, Illinois. VFR flight conditions prevailed and no flight plan was filed. The aircraft was destroyed and the pilot received serious injuries. The flight originated at Grandpa's Farm (0C7), Mendota, Illinois, about 1630 CDT.
OTHER DAMAGE
Approximately one acre of corn was damaged by the aircraft as it skidded to a stop.
CREW INFORMATION
The pilot, Robert F. Hess, age 44, holds commercial pilot certificate No. 480627809 issued on January 31, 1989, with airplane ratings for single and multiengine land aircraft. The most recent second class medical certificate was issued to the pilot on February 2, 1993, and contained the limitation that correcting lenses be worn while exercising the privileges of his airman's certificate.
AIRCRAFT INFORMATION
Fueling records at Hendrickson Flying Service established that the aircraft was last fueled on August 14, 1993, with the addition of approximately 25 gallons of 100 octane aviation fuel. The maintenance records revealed no unresolved maintenance discrepancies against the aircraft prior to departure.
WRECKAGE AND IMPACT INFORMATION
The accident site is a triangular shaped level farm field of approximately 58 acres bordered by electrical transmission lines on the east and south sides. The pilot had made two passes from east to west, flying under the power lines, applying chemicals. As the pilot began making his third pass, the aircraft's propeller and vertical stabilizer struck the 34,000 volt transmission line on the east side of the field. The transmission line remained intact, however some of the insulation was torn off. The aircraft's vertical stabilizer separated from the empennage after contacting the transmission line and fell to the ground approximately 15 yards west of the power lines. Measurements taken by the power line repair crew placed the height of the wire at 42 feet above ground level. The lone witness reported the aircraft's nose pitched down after striking the wire. Crop damage and ground scars began approximately 50 yards west of the power lines. Impact marks in the ground indicate the aircraft crashed in a slight nose low attitude at a high vertical sink rate. Both main landing gear broke off the aircraft and the spray booms which were suspended under the trailing edge of the wings separated from their attach points. The propeller and engine struck the ground with sufficient force to break the engine mounts and destroy the chemical hopper which was located between the engine and cockpit. The fuselage came to rest approximately 120 yards west of the power lines on a southerly heading, which was about right angles to the path of flight. Both wings and the fuselage area forward of the cockpit were destroyed by impact forces. The cockpit area aft to the tail section remained relatively intact.
SURVIVAL ASPECTS
The cockpit area of the aircraft remained intact. The seat supports and restraint system suffered damage from the crash impact. The steel tubular seat supports showed some forward distortion and one support was broken at a weld joint. The shoulder harness attach point failed in a forward direction, allowing the pilot to be thrown against the aircraft instrument panel. The aircraft instrument panel was caved in with approximately the same radius that the shoulder harness attach point was bowed forward. Rescue personnel found it necessary to cut one seat support to facilitate removal of the pilot from the wreckage. THE PILOT HAD MADE TWO PASSES MANEUVERING UNDER POWERLINES ON AN AERIAL APPLICATION APPLYING CHEMICALS TO A FIELD. AS THE PILOT BEGAN MAKING HIS THIRD PASS, THE AIRPLANE STRUCK THE POWERLINES. THE AIRPLANE IMPACTED THE GROUND, SKIDDED, AND CAME TO REST APPROXIMATELY 120 YARDS FROM THE POWERLINES. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1993_CHI93DEE05.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Beyond the agency record
Search this event elsewhere.
Pre-filled searches into the sources where news + community discussion of aviation events lives. External sources are reported, not agency. Treat them as signal that something happened, not as fact about what happened.
Entity-clustered aviation events in the press — last 24 hr + 30-day archive.
Official agency record + docket.
Investigative docket: factual reports, photos, transcripts.
Long-running aviation incident database (Flight Safety Foundation).
Community NTSB synthesis blog — often has photos and witness reports.
Gold-standard aviation incident blog.
Aviation industry news search.
GA pilot forum — informed but rumor-prone.
GA pilot subreddit search.
Tail-number page — flight history (free tier limited).
AOPA Air Safety Institute search.
Mainstream press coverage. Recent events only.
Privacy-preserving news search.
External links open in a new tab. We don't ingest their content; we deep-link search queries.
Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (maintenance). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- Embry-Riddle Scholarly Commons 2026 · Journal article (IJAAA)
From Reactive to Predictive: A hybrid Trust-Mediated Adoption Framework for Data-Driven Maintenance in Distributed-Authority Aviation Environments
Modern aviation maintenance operates within increasingly data-intensive technological environments, yet the operational integration of predictive maintenance into routine decision-making remains incon…
- Semantic Scholar 2025 · Article (Applied Sciences)
Decision-Making Framework for Aviation Safety in Predictive Maintenance Strategies
The implementation of predictive maintenance (PM) in aviation presents unique challenges due to strict safety requirements, complex operational environments, and regulatory constraints.
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
Low-Resource Automatic Speech Recognition Domain Adaptation – A Case-Study in Aviation Maintenance
With timeliness and efficiency being critical in the aviation maintenance industry, the need has been growing for smart technological solutions that optimize and streamline the different underlying ta…
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
A New Trajectory in UAV Safety: Leveraging Reinforcement Learning for Distance Maintenance Under Wind Variations
In the field of aviation, safety is a critical cornerstone, and the operation of Unmanned Aerial Vehicle (UAV) systems is deeply connected with this principle.
- Embry-Riddle Scholarly Commons 2024 · Journal article (IJAAA)
Just Culture in Aviation: A Metaphorical Study on Aircraft Maintenance Students
Just Culture, a sub-dimension of safety culture, has been a prominent and debated topic in aviation safety in recent years.
- Embry-Riddle Scholarly Commons 2024 · Journal article (IJAAA)
Performance PRISM: A Comprehensive Framework For Performance Measurement In Aircraft Maintenance
Aircraft maintenance is governed by rigorous safety requirements and high operational complexity, demanding robust performance measurement frameworks to ensure optimal maintenance practices.
Browse the full corpus — academia portal ↗