# NTSB CHI03IA096: Cessna 208B, N1114N, Saginaw, MI, March 19, 2003 - Type: NTSB incident investigation - Classification: Incident · Minor injuries · Incident investigation · Final report - Date: March 18, 2003, 22:25 local (Mar 19, 2003, 03:25 UTC) - Place: Saginaw, MI - Coordinates: 43.532775, -84.079719 - Nearby events: https://openairdocs.org/map.md?lat=43.5328&lon=-84.0797&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 30, 2003 - Report: Approved by Office Director - Parties: FAA -- Grand Rapids FSDO - NTSB case key (mKey): 56769 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI03IA096 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56769/pdf - Page: https://openairdocs.org/ntsb/CHI03IA096 ## Probable cause Failure of the engine bleed air pressure regulator. A contributing factor was the anti-chaffing tape on the air supply line. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - bleed air system,governor - failure,total (cause) - bleed air system,lines - overtemperature (contributing factor) ## Analysis The pilot executed an emergency landing after reporting smoke in the cockpit. The aircraft sustained minor damage during the incident. The pilot was treated at a local hospital and released. Shortly before landing the pilot reported noticing smoke in the cockpit. He reported he opened a vent, which cleared the smoke, and subsequently landed without incident. After landing, however, the vent did not adequately clear the smoke. He taxied to the ramp and emergency personnel assisted him from the aircraft. Rescue personnel reportedly examined the aircraft for the source of the smoke. Although they noted an occasional odor, it was not strong enough to indicate a definite origin. There was no evidence of a fire. A post-incident review determined the engine bleed air pressure regulator had failed, allowing unregulated bleed air into the deice system. The temperature of the unregulated P3 air may be as high as 607 degrees Fahrenheit. The bleed air is routed through a supply line which runs through the left side door post. The line is constructed of thin-walled aluminum tubing and is wrapped in anti-chaffing tape. The source of the smoke was the tape which became overheated due to the unregulated bleed air. The pressure regulator and pneumatic supply line were replaced. The aircraft was subsequently returned to service and, after monitoring several flights, the problem did not recur. ## Factual narrative On March 18, 2003, at 2225 eastern standard time, a Cessna 208B (Caravan), operated by Mid Atlantic Freight Inc. and piloted by a commercial pilot, experienced smoke in the cockpit. The aircraft sustained minor damage during the incident. The pilot executed an emergency landing on runway 5 (8,002 feet x 150 feet, asphalt) at MBS International Airport (MBS), Saginaw, Michigan. MBS was the intended destination. The 14 CFR Part 135 cargo flight was operating on an instrument flight rules (IFR) flight plan at the time of the incident. Visual meteorological conditions prevailed. The pilot sustained minor injuries. The flight departed Cherry Capital Airport (TVC), Traverse City, Michigan, about 2145. The pilot's written statement noted that, prior to landing at MBS, he noticed a "sweet smell in the cockpit." He stated he did not notice any smoke at that time. However, a few minutes later, he turned on a flashlight and noticed a slight haze in the cockpit. He reported he opened a vent, which cleared the smoke. He subsequently landed without incident. After landing, however, the vent did not adequately clear the smoke, according to the pilot. He noted that he taxied to the ramp and emergency personnel assisted him from the aircraft. He reported being taken to a nearby hospital, where he was treated and released. Airport fire and rescue personnel reported that the pilot drifted "in and out of conciousness" upon exiting the aircraft. The aircraft was reportedly examined for the source of the smoke. Although they noted an occasional odor, it was not strong enough to indicate a definite location, according to the incident report. No evidence of a fire was reported. The pilot reported similar incidents occurred twice before, although not as severe. Each time the problem was referred to a mechanic and the pilot reported he was told the problem had been fixed. A post-incident review by a mechanic determined the pneumatic supply line for the aircraft deice boots started to smoke after about 10 minutes with the engine running at a high power setting. Further investigation determined the engine bleed air pressure regulator had failed, allowing unregulated bleed air into the deice system. The temperature of the unregulated P3 air may be as high as 607 degrees Fahrenheit, according to the manufacturer. The supply line is routed from the engine, through the left side door post, to the left wing. The line is constructed of thin-walled aluminum tubing and is wrapped in anti-chaffing tape, according to the aircraft manufacturer. The mechanic stated the source of the smoke was the tape. The pressure regulator and pneumatic supply line were replaced. Additional damage to the outboard deice boot on the left wing was repaired. The aircraft was subsequently returned to service and, after monitoring several flights, the problem did not recur. ## Aircraft - Registration: N1114N (not matched to a registry record) - Reported make and model: Cessna 208B - Category: Airplane - Serial number: 208B0406 - Airframe hours: 6220 - Engines: Pratt & Whitney PT6A 675 horsepower turbo prop - Damage: Minor damage - Flight: Part 135 - Operator: Mid Atlantic Freight, Inc. - Registered owner: Atlantic Aero Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, February 7, 2003, 85 hours before - Departed: TVC, Traverse City, MI - Destination: MBS, Saginaw, MI - Flight plan: IFR - Airport: MBS, MBS International, runway 5, 8,002 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; last flight review February 26, 2003; seat: front; flight hours: 4,821 total, 3,330 in this make and model ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 40° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 32 °F, dew point 23 °F - Altimeter: 30.07 inHg - Observed at: MBS ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20030318005769I](https://openairdocs.org/incident/20030318005769I), Mar 18, 2003: Cessna 208B, Saginaw, MI. (-23) On March 18, 2003, at 0425Z, atlantic aero inc., N1114N, 10 minutes remaining of flight, pilot experienced smoke in the cockpit. The pilot indicated he… 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.