N370MM

Substantial
Fatal

MOONEY AIRPLANE CO INC M20TNS/N: 31-0071

Accident Details

Date
Thursday, September 10, 2015
NTSB Number
ERA15LA349
Location
Atlantic City, AO
Event ID
20150910X75635
Coordinates
37.634948, -72.861251
Aircraft Damage
Substantial
Highest Injury
Fatal
Fatalities
1
Serious Injuries
0
Minor Injuries
0
Uninjured
0
Total Aboard
1

Probable Cause and Findings

A loose oxygen line, which was not detected by maintenance personnel during a recent annual inspection, that allowed oxygen to escape and drain the oxygen canister more quickly than the pilot expected. This reduced the pilot's availability of supplemental oxygen and led to his experiencing hypoxia and the airplane subsequently flying on autopilot until it eventually lost power due to fuel starvation.

Aircraft Information

Registration
N370MM
Make
MOONEY AIRPLANE CO INC
Serial Number
31-0071
Engine Type
Reciprocating
Year Built
2007
Model / ICAO
M20TNM20P
Aircraft Type
Fixed Wing Single Engine
No. of Engines
1

Registered Owner (Historical)

Name
MOIR MICHAEL
Address
2444 SW OPAL LAKE RD
Status
Deregistered
City
GAYLORD
State / Zip Code
MI 49735-8792
Country
United States

Analysis

HISTORY OF FLIGHTOn September 10, 2015, about 1448 eastern daylight time, a Mooney M20TN airplane, N370MM, impacted the Atlantic Ocean off the coast of Atlantic City, New Jersey. The commercial pilot was fatally injured, and the airplane sustained substantial damage. The airplane was owned by the pilot and the flight was being conducted as a 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions existed near the accident site about the time of the accident, and an instrument flight rules flight plan had been filed. The flight originated from Gaylord Regional Airport (GLR), Gaylord, Michigan, about 1200 and was destined for Atlantic City International Airport (ACY), Atlantic City, New Jersey.

According to the pilot's logbook and a fuel receipt, he flew the accident airplane for 1 hour on September 7, 2015, and then fueled the airplane with 11.4 gallons of 100LL aviation fuel. There were no other fuel transactions or flights between that time and the day of the accident. The pilot reported in his flight plan that there was sufficient fuel onboard the airplane for 6 hours of flight.

According to Federal Aviation Administration (FAA) Minneapolis Air Route Traffic Control Center (ARTCC) records, the airplane departed GLR about 1200, and at 1214:04, the pilot checked in and informed the controller that he was climbing from 17,600 to 21,000 ft mean sea level (msl). The controller then instructed the pilot to climb to 25,000 ft msl, and the pilot read back the assigned altitude and continued toward the destination.

About 23 minutes later, while the autopilot-equipped airplane was in cruise flight, the ARTCC controller attempted to contact the pilot with a frequency change; however, the pilot did not respond. The controllers' repeated attempts to contact the pilot throughout the remainder of the flight were unsuccessful as the airplane continued flying a straight course toward ACY at 25,000 ft msl. According to radar data, at 1438 and while about 5 miles northwest of ACY, the airplane began descending from 25,000 ft msl and continued to descend at an average descent rate of about 1,600 ft per minute on a southeast heading until it impacted the Atlantic Ocean about 8 minutes later. As the airplane was descending, two F-16 airplanes departed ACY to relay search and rescue information, and the pilots subsequently found debris. PERSONNEL INFORMATIONAccording to the pilot's logbook, he held a commercial pilot certificate with airplane single-engine land, multiengine land, and instrument airplane ratings. His most recent FAA third-class medical certificate was issued on October 26, 2013, with no limitations. He recorded 4,900 hours of total flight experience, 2.5 hours of which were in the 90 days before the accident. AIRCRAFT INFORMATIONAccording to FAA records, the airplane was manufactured in 2007 and registered to the pilot in December 2007. The most recent annual inspection was performed on June 12, 2015, at which time it had accumulated 472.2 total hours of time in service.

According to the Pilot's Operating Handbook (POH), the airplane was equipped with extended range tanks where fuel was "carried in two integrally sealed sections of the forward, inboard area of the wing." The total usable fuel capacity was 102 gallons, 51 gallons per side. The pilot could set the fuel selector valve to the "left" tank, "right" tank, or "off" position via a recessed three-position handle aft of the console on the floor.

The airplane was also equipped with a four-place oxygen system that provided supplementary oxygen necessary for continuous flight at high altitude. Four oxygen outlets were provided in the overhead panel between the pilot and copilot seats. Oxygen would flow from the outlets only when a mask hose was connected. The pilot's mask was a permanent rebreathing-type mask with a vinyl plastic hose and a built-in microphone for radio communication while using oxygen. The oxygen cylinder filler valve was located under a spring-loaded door aft of the baggage door. When in service, the 77.1 cubic-ft tank could supply at least 11 hours of oxygen for a pilot-only operation depending on flight altitude. The airplane was equipped with an oxygen system quantity indicator in the pilot's arm rest. According to a receipt from the most recent annual inspection, the oxygen bottle was serviced at that time. Further, according to stickers placed on the oxygen regulator and the tank, they were both overhauled in May 2013.

Review of the Mooney 100 Hour-Annual Inspection Guide revealed that it included an inspection of the "oxygen system for leaks, proper ON/OFF valve operation & filler for safety of operation…" METEOROLOGICAL INFORMATIONAt 1454, the weather reported at ACY indicated variable wind at 4 knots, 10 miles visibility, few clouds at 700 and 3,400 ft above ground level, temperature 24°C, dew point 22°C, and an altimeter setting of 29.75 inches of mercury. AIRPORT INFORMATIONAccording to FAA records, the airplane was manufactured in 2007 and registered to the pilot in December 2007. The most recent annual inspection was performed on June 12, 2015, at which time it had accumulated 472.2 total hours of time in service.

According to the Pilot's Operating Handbook (POH), the airplane was equipped with extended range tanks where fuel was "carried in two integrally sealed sections of the forward, inboard area of the wing." The total usable fuel capacity was 102 gallons, 51 gallons per side. The pilot could set the fuel selector valve to the "left" tank, "right" tank, or "off" position via a recessed three-position handle aft of the console on the floor.

The airplane was also equipped with a four-place oxygen system that provided supplementary oxygen necessary for continuous flight at high altitude. Four oxygen outlets were provided in the overhead panel between the pilot and copilot seats. Oxygen would flow from the outlets only when a mask hose was connected. The pilot's mask was a permanent rebreathing-type mask with a vinyl plastic hose and a built-in microphone for radio communication while using oxygen. The oxygen cylinder filler valve was located under a spring-loaded door aft of the baggage door. When in service, the 77.1 cubic-ft tank could supply at least 11 hours of oxygen for a pilot-only operation depending on flight altitude. The airplane was equipped with an oxygen system quantity indicator in the pilot's arm rest. According to a receipt from the most recent annual inspection, the oxygen bottle was serviced at that time. Further, according to stickers placed on the oxygen regulator and the tank, they were both overhauled in May 2013.

Review of the Mooney 100 Hour-Annual Inspection Guide revealed that it included an inspection of the "oxygen system for leaks, proper ON/OFF valve operation & filler for safety of operation…" WRECKAGE AND IMPACT INFORMATIONThe airplane was located by the United States Coast Guard off the coast of Atlantic City, New Jersey, in about 45-ft-deep water. On September 12, 2015, the airplane was recovered and moved to a salvage facility to facilitate further examination.

The fuselage was severely impact damaged. The inboard 2-ft-long section of the left wing remained attached to the fuselage. The outboard section of the left wing was impact separated and not recovered. The empennage was impact separated from the fuselage. The vertical stabilizer and rudder remained attached to the empennage. The bottom 1-ft-long section of the rudder exhibited impact damage. The left horizontal stabilizer and elevator remained attached to the empennage at all attachment points. The left and right elevator counterweights were impact separated and not recovered. The right horizontal stabilizer and elevator remained attached to the empennage but was impact damaged in the positive direction. The right wing was impact separated from the fuselage and not recovered. Control cable continuity was confirmed from the rudder and elevator to the cockpit through control tube fractures and separations. In addition, control continuity was established from the yoke to both wing roots through control tube fractures and separations.

Both front seats remained attached to the fuselage. Two oxygen lines were secured to the top portion of the cabin. An oxygen pulse oximeter was located in the cabin area of the wreckage, and the pilot was found wearing an oxygen mask. A Hobbs meter was located in the aft section of the fuselage and indicated 477.2 hours of flight time.

The engine was impact separated from the airframe. The rocker box covers were removed, and engine continuity was confirmed from the propeller through the aft section of the engine. All three propeller blades were bent; two of the blades were bent in the same direction, and the third blade was bent in the opposite direction. The fuel line from the fuel manifold valve to the fuel metering unit was removed, and a drop of fluid was noted coming out of the line. The fluid had an odor similar to 100 LL aviation fuel. There were no preimpact anomalies noted with the engine that would have precluded normal operation.

An oxygen tank was located aft of the aft bulkhead. An elbow fitting that was connected to the oxygen regulator assembly, which connected an oxygen line to the tank, was found loose. The fitting could be moved in both directions by hand without resistance.

Three Garmin G1000 SD cards were removed from the wreckage and sent to the NTSB Recorders Laboratory for data download. The G1000 SD cards contained firmware versions and navigation databases that did not record data. No accident data were recovered from the SD cards. ADDITIONAL INFORMATIONPerformance Calculations

According to the POH, the fuel consumption for the flight using best-power performance data at 25,000 ft pressure altitude, depending on the selected manifold pressure and outside air temperature, would have been between 12.0 and 22.6 gallons of fuel per hour.

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Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ERA15LA349