|Title:||Pilot incapacitation, Douglas DC-8-61|
|Micro summary:||The captain of this Douglas DC-8-61 was incapacitated in an unpressurized airplane flying at high altitude.|
|Event Time:||1994-03-15 at 0727 EST|
|Publishing Agency:||National Transportation Safety Board (NTSB)|
|Diversion Airport:||Cincinnati/Northern Kentucky International Airport, Covington, Kentucky, USA|
|Site of event:||Covington, KY|
|Departure:||Willow Run Airport, Detroit, Michigan, USA|
|Destination:||Hartsfield-Jackson Atlanta International Airport, Atlanta, Georgia, USA|
|Airplane Type(s):||Douglas DC-8-61|
|Type of flight:||Cargo|
|Diverted to:||Cincinnati/Northern Kentucky International Airport, Covington, Kentucky, USA|
NTSB short summary:
The captain's improper decision to conduct flight at high altitude in an unpressurized airplane, which resulted in his incapacition from depressurization sickness. A factor related to the accident was: maintenance personnel failed to properly secure the emergency exit door after it was removed to perform maintenance.
At an en route stop, company maintenance personnel opened the forward overwing emergency exit to gain access to a navigation light that needed repair. The flight engineer said that during preflight inspection, the emergency exit appeared to be in place, though he did not physically examine the exits or latches. Later, during climbout, the flightcrew was unable to pressurize the airplane. Despite objections from the other crewmembers, the captain elected to proceed with the flight. The crew donned their oxygen masks & a climb was continued to a cruise altitude at fl330. Shortly after level off, the captain became incapacitated from decompression sickness. The first officer took command & the flight diverted for an emergency landing at covington, ky. After flight, the emergency exit door was found laying inside the airplane. When checked, the exit door would not fit properly in the frame, & the door latches would not engage the latch plates on the frame, even when the handle was moved to the locked position.
NTSB factual narrative text:
On March 15, 1994, at 0727, the flight crew of an American International Airways DC-8-61, N817CK, operating as Connie [Kalitta] Flight 861, made an unscheduled landing at the Greater Cincinnati Airport, Covington, Kentucky, after the captain became incapacitated. The airplane was not damaged. The captain was hospitalized with serious injuries. Visual meteorological conditions prevailed and flight 861 was operated on an instrument flight rules (IFR) flight plan under 14 CFR Part 121.
The flight originated in Atlanta, Georgia, with an enroute stop at Charlotte, North Carolina, and then continued to Ypsilanti, Michigan. At Yipsilanti, the flight crew went to breakfast while the cargo was unloaded, and new cargo loaded on the airplane.
While on the ground, company maintenance personnel replaced the left wing navigation light on the airplane. Access to the light was gained from the cargo compartment, through the left forward overwing emergency exit, and out onto the wing.
The flight engineer (F/E) reported he did two walkarounds on the airplane and the overwing emergency exit appeared in place. He said he did not physically examine the emergency exits or latches.
Witnesses reported seeing the airplane takeoff and they thought the left forward overwing exit was not in place as the airplane became airborne.
According to flight crew interviews and written statements, the F/E was unable to maintain cabin pressurization after takeoff. The first officer (F/O) and F/E, reported there was no cockpit discussion about staying at a lower altitude until the cause of the lack of pressurization could be determined. The captain made a decision to continue the climb. The flight crew donned their oxygen masks and the flight continued. In the vicinity of FL290 both the F/O and F/E reported the captain was not responding to radio calls, however, the captain indicated via hand signals that he wanted the flight to continue the climb. The flight continued to FL330. While at FL330, the captain's condition continued to deteriorate and the F/O took command of the airplane, and requested a descent.
Once the airplane was level at 8000 feet, the flight crew was queried by air traffic if they wanted to declare an emergency. The flight crew declined to declare an emergency and requested to continue the flight to Atlanta, its planned destination. The flight crew then requested to divert to Charlotte. After being informed of the location of the Greater Cincinnati Regional Airport, the flight crew elected to divert there for landing and medical assistance for the captain. The flight landed without incident and the captain was removed and taken to a local hospital.
In a written statement made after the accident, the first officer stated:
...I took command when I felt that it was necessary without creating a feeling of mutiny. Since Captain XXXX is a strong willed person and when he is in command he is not to be questioned, I followed his orders....
In a written statement made after the accident, the flight engineer stated:
...It is my opinion that the only way to get the airplane to a lower altitude would be to override the captain by use of physical force. When the captain requested higher altitudes, the first officer and I strongly protested, both verbally and by hand signals. These protests were repeated at least three times during the climb...All protests were disregarded by the captain....
According to FAA Airmen Medical Records, the captain weighed 240 pounds and was 71 inches tall, the first officer was 66 inches tall and weighed 156 pounds, and the flight engineer was 72 inches tall and weighed 190 pounds.
Post accident examination of the airplane by FAA personnel from the Louisville Flight Standards District Office found the left forward over wing emergency exit laying on a cargo palette inside the airplane. In a written report, Mr. Jerry Brown stated:
...Company maintenance personnel installed the replacement emergency exit door. After the installation, I observed that on the exterior, the door did not fit flush with the outer surface of the fuselage...Inspection revealed that the door latch slide mechanism was not engaging the latch stop at the top of the door jam, thus preventing the door seal from forming a positive seal. The old door was reinstalled with the same results. Neither door could be pushed fully into the opening far enough to form a flush fit. After an on top-the-wing modification to one of the doors by the maintenance crew, it was reinstalled and a proper installation was attained. After the oxygen system was serviced, I functionally checked the captain's oxygen mask and found it to be operational in all positions.
In a telephone interview, Mr. Brown reported that the latches on the emergency exit door would not engage the latch plate on the door frame, even though the handle was extended to the locked position. The overwing emergency exit door would stay in place due to force fit, but it was not locked in place. There was a cargo liner on the emergency exit door that had to be bent out of the way to see if the latches were engaged. He said after to door was worked on by a company mechanic, it fit properly, and the latches engaged. Additionally, Mr. Brown said that the improperly fitting door was recessed against the fuselage and visible when viewed from outside the airplane.
The captain's oxygen mask and regulator were removed and tested by the USAF at Brooks Air Force Base. In a written report, they stated, "...Dynamic impedance tests on the regulator, hose and mask system, with proper sealing and use, yielded acceptable values...In summary, test results indicate that the performance of this oxygen regulator is consistent with factory specifications....
Examination of the minimum equipment list revealed restrictions for an unpressurized dispatch. No FAA or company restrictions were found for unpressurized flight when it originated after the dispatch, other than the flight must meet the oxygen requirements of 14 CFR Part 121. The emergency section procedures of the FAA Approved DC-8 Flight Manual contained procedures for a loss of pressurization at altitude and a descent to lower altitudes. No procedure was found for a loss of pressurization at low altitudes and a voluntary climb to high altitude.
According to the printout of the flight data recorder, the airplane had achieved an altitude of FL330, 18 minutes after takeoff. The flight stayed at that altitude for approximately 4 minutes and then initiated a descent to 10,000 feet. After 2 minutes at 10,000 feet, the descent continued to 8,000 feet.
According to the American International Airways, Inc. instructors guide, initial and recurrent ground training covered the following:
1. GENERAL SITUATION TRAINING
g. Rapid Decompression 1) Respiration 2) Hypoxia, hypothermia and hyperventilation 3) Time of useful consciousness 4) Gas expansion/bubble formation 5) Physical phenomena and actual incidents
This section is part of a group assigned 4 hours of training. According to company manuals, recurrent training is conducted using 1/2 the programmed number of hours of training. According to company records, the pilot last completed recurrent training which covered, General Emergency Training/Drills, Recurrent, on October 30, 1993.
According to Advisory Circular 61-107, dated January 23, 1991, OPERATIONS OF AIRCRAFT AT ALTITUDES ABOVE 25,000 FEET MSL AND/OR MACH NUMBERS (Mmo) GREATER THAN .75:
i. When nitrogen is inhaled, it dilutes the air we breathe. While most nitrogen is exhaled from the lungs along with carbon dioxide, some nitrogen is absorbed by the body. The nitrogen absorbed into the body tissues does not normally present any problem because it is carried in a liquid state. If the ambient surrounding atmospheric pressure lowers drastically, this nitrogen could change from a liquid and return to its gaseous state in the form of bubble. These evolving and expanding gases in the body are know as decompression sickness....
(2) Evolved Gas. When the pressure on the body drops sufficiently, nitrogen comes out of solution and forms bubbles which can have adverse effects on some body tissues. Fatty tissue contains more nitrogen than other tissue; thus making overweight people more susceptible to evolved gas decompression sickness.
(ii)...Paresthesia is a third type of decompression sickness, characterized by tingling, itching, a red rash, and cold and warm sensations, probably resulting from bubbles in the central nervous system (CNS). CNS disturbances can result in visual deficiencies such as illusionary lines or spots, or a blurred field of vision. Some other effects of CNS disturbances are temporary partial paralysis, sensory disorders, slurred speech, and seizures.
Dr. Stephen Veronneau, with the FAA Civil Aeromedical Institute (CAMI), interviewed the pilot and reviewed his medical treatment records. Dr. Veronneau reported the pilot was a smoker, and overweight. The pilot had last complete physiological training (altitude chamber) in 1982. In the Executive Summary, of his Medical, Pathological and Human Performance Factual Report, he stated:
...The fact that he was the only reported injury may be due to obesity, a known risk factor predisposing to more severe decompression illness....
|Learning Keywords:||Operations - Pilot incapacitation|
|Systems - Pressurization|
|Close match:||Explosive decompression on climb, Report on the accident to BAC One-Eleven, G-BJRT over Didcot, Oxfordshire on 10 June 1990|
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