Accident Cessna 337D Super Skymaster N2685S,
ASN logo
ASN Wikibase Occurrence # 38638
 
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:Tuesday 1 April 1997
Time:15:52 LT
Type:Silhouette image of generic C337 model; specific model in this crash may look slightly different    
Cessna 337D Super Skymaster
Owner/operator:Flight Services, Inc.
Registration: N2685S
MSN: 337-0985
Engine model:Continental IO-360
Fatalities:Fatalities: 1 / Occupants: 2
Aircraft damage: Destroyed
Category:Accident
Location:Hickory, PA -   United States of America
Phase: En route
Nature:Executive
Departure airport:Waynesburg, PA (WAY
Destination airport:North Lima, OH (4G4)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
The pilot of the unpressurized airplane was cleared to climb to 25,000 feet by air traffic control (ATC) and he was observed going through the assigned altitude and leveling at 27,700 feet. Then the aircraft was observed at 26,000 feet, and subsequent contact was lost. The pilot did not respond when ATC queried him about exceeding his assigned altitude. The aircraft sustained an inflight breakup during an uncontrolled descent, and came to rest in a tree. According to the surviving passenger, the airplane was refueled and a portable oxygen bottle was filled prior to takeoff. She stated that they were going to take aerial photographs at four separate locations during this flight. She said that they shot three of the locations and landed at Williamsburg, Pennsylvania where the pilot filed a flight plan and setup the portable oxygen system for their use during the next flight. They departed and climbed to 10,000 feet, and the pilot told her to put her oxygen mask on, and he did the same. The last altitude she remembered the pilot calling out was 20,000 feet, and he asked her how she was doing and if she felt okay and she said yes. When asked, 'who turned on the oxygen?' she stated that she did, started to but wasn't sure how, so, the pilot reached back and turned it on. She said she knew it was on because she could feel the cool air and that there was a little valve in both lines and they went from red to green indicating the oxygen was flowing. She said that she remembered him saying that they had just crossed 20,000 feet and she began feeling dizzy, she said that her eyes would not focus, and that she felt like she was cross eyed. She said she told the pilot that she was dizzy but she thought that he was talking to the tower because he did not respond. She recalled that she felt better when she closed her eyes, when she did, that was the last thing she clearly remembered until after the crash. Analytical testing of the contents of each cylinder used to fill the pilot's oxygen bottle found that they contained compressed breathing air at about 21 percent oxygen instead of aviation oxygen. Postmortem examination revealed the pilot's death was a result of hypoxic hypoxia due to insufficient oxygen reaching the blood.

Probable Cause: Servicing of the pilots portable oxygen system with compressed air, which resulted in pilot incapacitation due to Hypoxia.

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: IAD97FA060
Status: Investigation completed
Duration: 2 years and 9 months
Download report: Final report

Sources:

NTSB IAD97FA060

Location

Revision history:

Date/timeContributorUpdates
24-Oct-2008 10:30 ASN archive Added
21-Dec-2016 19:23 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
08-Apr-2024 16:11 ASN Update Bot Updated [Time, Operator, Other fatalities, Departure airport, Source, Narrative, Category, Accident report]

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org