# NTSB CHI96FA264: Hoffman, Wolf, Flugzeugbau H-36, N86PS, Waukegan, IL, July 31, 1996 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: July 31, 1996, 11:28 local (16:28 UTC) - Place: Waukegan, IL - Coordinates: 42.399211, -87.849601 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.3992&lon=-87.8496&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report April 3, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 10095 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI96FA264 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10095/pdf - Page: https://openairdocs.org/ntsb/CHI96FA264 ## Probable cause failure of the pilot to maintain adequate airspeed, while maneuvering to land, which resulted in an inadvertent stalled and collision with the terrain. A factor relating to the accident was: the loose engine cowling. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - initial climb - cooling system,cowling - loose (contributing factor) - Forced landing, maneuvering - turn to landing area (emergency) - Loss of control - in flight, maneuvering - turn to landing area (emergency) - airspeed - inadequate, pilot in command (cause) - stall - inadvertent, pilot in command (cause) - In flight collision with terrain/water, maneuvering - turn to landing area (emergency) ## Analysis Shortly after the pilot of a motor-glider took off, he informed the tower that his engine cowl had come loose and he wanted to return to the airport for landing. The tower told the pilot he could land on any runway, and the pilot indicated he would land on runway 05. Subsequently, the aircraft impacted the airport infield near the intersection of runway 32 and 05. Witnesses reported the left engine cowling was flapping and making noise. The pilot flew a tight downwind for runway 32 at about 150 feet AGL, then he turned back to the west after crossing the intersection. When he came out of the turn, the altitude was about 100 feet and the wings were rocking. The motor-glider made a sharp left turn, entered a steep descent, and crashed with the left wing hitting first. Examination of the aircraft revealed flight control and engine continuity. The cylinders had compression and spark. Fuel was present. The prop hub indicated rotational scoring. The left engine cowling exhibited about a 14 inch tearing from the rear of the cowling to the front. ## Factual narrative On July 31, 1996, at 1128 central daylight time, a Hoffman H-36 motor glider, N86PS, was destroyed when it impacted the ground while attempting an emergency landing. The pilot had just departed and was attempting to return to the airport for landing after he reported to the control tower that the left engine cowling was loose. The private pilot was fatally injured. The 14 CFR Part 91 flight had departed the Waukegan Regional Airport, Waukegan, Illinois, on a local flight. Visual meteorological conditions prevailed and no flight plan had been filed. The tower transcript indicated that the pilot was cleared for takeoff on runway 32. The pilot acknowledged the clearance and departed. About 45 seconds after the takeoff clearance was acknowledged, the pilot informed the tower that, "Six Papa Sierra, we'd like to turn around and land. I have a cowl that came open." The tower responded, "Very well, ah, do what you need to do, to land." About five seconds later, the pilot again informed the tower, "Six Papa Sierra, I'd like the airport. I have a cowl that came open." The tower responded, "Six Papa Sierra, whatever it need, you need to do, just land on whatever runway." The pilot responded by saying, "Papa Sierra, I'd like...ah, 5, go north." The tower responded, "That's fine. Cleared to land runway 5." The pilot responded with an unintelligible utterance. About 30 seconds later, the tower controller instructed a Cessna to make a right turn and to keep holding. The reason for the instructions was that N86PS had crashed near the intersection of runway 32 and runway 05. A witness had viewed the accident from the Baxter aviation ramp on the south side of runway 32's departure end. He reported that the motorglider entered a tight downwind leg for runway 32 at about 150 feet. He reported that the left engine cowling on the pilot's side was open and knocking back and forth. He report the cowling was making a lot of noise and that you could not hear the engine noise. The airplane was not loosing altitude and the airplane appeared to be stable. He reported that the only thing that he could see wrong was the flapping of the cowling. He reported that the airplane crossed the intersection and was turning back to the west. The witness reported that as the motorglider came out of the turn it was at about 100 feet and the wings were rocking. He reported that the motorglider then turned real sharp and then went straight down. Another witness reported that the cowling was making an "unbelievable noise." He reported that the engine was running with no sputtering. He reported that the airplane stalled and hit left wing first, and then the left nose hit. Personnel Information The pilot was a 73 year old male, private pilot. He had about 3,495 total flight hours. He held single and multiengine land airplane ratings and an airplane instrument rating. He did not hold a glider rating but had passed a check flight in the motorglider on October 27, 1987. On August 2, 1992, the pilot passed a biennial flight review flying the motorglider. There were no further flights after August 2, 1992, recorded in the pilot's logbook. Aircraft Information The pilot was the original owner of the Hoffman H-36 motorglider. The last annual inspection was conducted on March 4, 1996. The total tach time on the aircraft was 178.8 hours. The tach time on the day of the accident read 183.7 hours. The aircraft held 21.1 gallons of fuel. The last fuel receipt indicated that the plot had last purchased fuel for the aircraft on June 12, 1996. Fuel was present at the accident site. Wreckage and Impact Information The aircraft impacted the infield of the Waukegan Airport near the intersection of runway 32 and runway 05. The aircraft's left wing tip impacted the ground about 75 feet north of runway 05. The leading edge of the left wing had crush damage, and about a 6 foot outboard section of the left wing had separated on impact. The nose impacted the ground about 35 feet from the first wing strike. The aircraft spun on its nose and slid backwards on its belly for 40 feet before it stopped. A path of oil ran from where the nose impacted the ground to where the aircraft came to rest. The wreckage was examined. Fuel was found leaking from the fuel lines. The flight controls exhibited continuity. The engine had compression and spark. The wooden propeller had one blade broken at the hub, and the second blade was intact. The prop hub had indications of rotational scoring. The leading edge of the left wing had crush damage. The nose of the aircraft had been pushed back and up into the cockpit area. The engine cowling was examined. The left section of the engine cowling exhibited about a 14 inch tearing of the cowling. The tearing was parallel to the longitudinal axis of the aircraft, and started from the aft edge of the cowling and tore forward. Both the dzus fasteners from the left cowling were missing. Medical and Pathological Information The autopsy was performed on the pilot at the Lake County Coroner's Office, 26 N. Utica Street, Waukegan, Illinois. A Forensic Toxicology Fatal Accident Report was prepared on the pilot by the Federal Aviation Administration's Civil Aeromedical Institute. The report indicated the following results: No Carboxyhemoglobin detected in blood. No Cyanide detected in blood. No Ethanol detected in blood. No drugs detected in blood. Additional Information The Federal Aviation Administration was a party to the investigation. The aircraft wreckage was released to the Waukegan Airport manager on September 5, 1996. ## Aircraft - Registration: [N86PS](https://openairdocs.org/deregistered/N86PS-1997-03-24), registration cancelled 1997-03-24, S/N 360153 (OpenAirDocs) - Reported make and model: Hoffman, Wolf, Flugzeugbau H-36 - Registry model: [Hoffman-Flugzeugbau H 36 DIMONA](https://openairdocs.org/model/hoffman-flugzeugbau-h-36-dimona) (registry code 4670101) (OpenAirDocs) - Category: Glider - Serial number: 360153 - Airframe hours: 184 - Engines: Limbach L2000EB1C 80 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Telephone Communications Inc - Airworthiness certificate: Standard, Utility - Last inspection: Annual, March 4, 1996, 5 hours before - Departed: UGN - Airport: UGN, Waukegan, runway 32, 3,751 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: unknown, unknown; seat: left; toxicology performed; flight hours: 3,495 total, 184 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 8 knots - Visibility: 30 statute miles - Lowest ceiling: 9,000 ft broken - Temperature: 70 °F, dew point 57 °F - Altimeter: 29.00 inHg - Observed at: UGN ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19960731020259A](https://openairdocs.org/incident/19960731020259A), Jul 31, 1996: Hofflu H36DIMONA, Chicago/Waukega, IL, Destroyed, 1 fatal. Engine cowling opened on takeoff. Stalled and crashed trying to return to airport. (-23) 86PS was destroyed when it impacted the ground while attempting an… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.