On September 11, 1974, at about 07:34 Eastern Standard Time (EST), 11:34 Greenwich Mean Time (GMT), Eastern Airlines flight 212, a DC-9-31, registration N8984E, crashed while on final approach into Charlotte International Airport. The Eastern 212 accident report: AAR-75/09, stated that Eastern 212 crashed due to a controlled flight into terrain – CFIT, a term given to an aircraft – mechanically and operationally sound – that is intentionally or unintentionally flown into the ground; the aircraft does not crash due to mechanical or control issues but crashes due to negligence. The National Transportation Safety Board (NTSB) determined in its Probable cause, “… that the probable cause of the accident was the flight crew’s lack of altitude awareness at critical points during the approach due to poor cockpit discipline in that the crew did not follow prescribed procedures.”
There was no denying that the two-pilot flight crew engaged in non-operational political conversations below 10,000 feet. AAR-75/09 said, the “… crew conversed on non-operational topics [or subjects]”; they engaged in talk that distracted from the landing. From the limited information drawn from the recorders, the previously concluded discussions did not distract them from the landing sequence. At 07:31:07 the non-operational conversation ended; at 07:33:57, the flight crew reacted to the pending crash. For two minutes and fifty seconds before impact, the flight crew did not engage in non-operational conversation; they were focused on the landing approach.
Flying today, flight crews are required to maintain a ‘sterile cockpit’ below ten thousand feet, meaning that the flight crew must have workable silence – no distractions. Jumpseaters and flight attendants must avoid interrupting the crews’ duties (unless for emergencies) while completing the takeoff sequence or while making the approach as the work intensifies; this applies to both instrument and visual approaches. The report stated, “This accident exemplifies the absolute necessity of strict adherence to prescribed procedures, particularly those pertaining to altitude awareness, during an instrument approach.” Non-operational talk was not the failure to adhere to prescribed procedures. In fact, it was their engagement in operational talk that doomed the flight. These conversations proved to be the ‘failure to follow prescribed procedures’.
It is nearly impossible, from report AAR-75/09, to determine at what altitude different crew conversations recorded by the cockpit voice recorder (CVR) took place at. On page eight it was stated, “The malfunction [in the flight data recorder (FDR)] rendered the vertical acceleration trace unreadable but caused little difficulty in the readout of other parameters.” From page one to page five, NTSB investigators pieced together a detailed log of actions and times chronicled of what had happened on flight 212 until the crash at 11:33:58 GMT. Although the recording of conversation and times can be followed, the altitudes at which the information was presented was confusing.
Why is this a problem? Distractions, such as the kind the NTSB said Eastern 212’s crew experienced (“poor cockpit discipline”), that led to the crash, might be compared to texting while operating a train or dialing a phone while driving. Operational consequences of pilot distractions in flight would be when they ‘bust’ an altitude (when a pilot unintentionally flies above or below their assigned altitude) or miss their air traffic control (ATC) radio transmitted instructions. There were no signs that ATC was ignored; at 07:22:00 and 07:31:09, the Eastern 212 captain acknowledged ATC’s directions to turn or descend; he responded to ATC. The flight 212 pilots knew where they were supposed to be … or thought they did.
The NTSB was correct, that the pilots failed to follow procedure. For instance, per Eastern En Route Procedures, “During descent, the pilot not flying will call out the assigned altitude upon going through the last 21,000-foot level prior to the assigned level. The last 1,000 feet should be at a target rate of 500 feet per minute.” The first officer was the flying pilot; it was his leg. The captain (pilot not flying) should have been focused on his responsibility, calling out the altitudes, at the least monitoring them. This was where the failure occurred; during an instrument approach the pilots’ attention should have been on the instruments instead of on visual ground references.
The procedure for the Final Approach Fix required, “… the pilot not flying (captain) will call out the altitude deviation from ‘bug’ speed as appropriate, and the result of the flag scan.” This, clearly, was not done; this failure alone should have called attention to another possible failure – ‘possible’ because it was never investigated – that the first officer and captain were reading two separate altitudes.
There is an ancient superstition that “bad (or good) things occur in threes”. Perhaps in this case, it came true, or as some in the Human Factors world may say, “the holes of the swiss cheese lined up”. The first contributor was the failure to follow procedure, to monitor the instruments.
There was ground fog obscuring the terrain during the approach; the pilots’ focus on ground references proved to be the second contributor to the accident. Ground fog should have had little to do with the instrument approach, but since the pilots decided to look out the window, it led to the third contributor: the distraction of the Carowinds Tower.
This approach was an instrument approach, so ground references were unnecessary, yet the flight crew discussed a 340-foot amusement park tower called the Carowinds Tower. For over one minute, the pilots’ attention was outside the cockpit and on the distant ground reference, not on the instruments. If, indeed, they did sight the Carowinds Tower, would that have given them a false sense of altitude as being over one thousand feet? From their perspective viewing the Tower, were they looking down, looking from the side or looking from a great distance? Should the Tower question have drawn their attention back to the instruments? Should this have caused the pilots to check their instruments in relation to each other?
In section 1.12 WRECKAGE, the wreckage distribution was discussed in great detail. All flight controls were in their normal positions, no evidence of fuel contamination, engine reversers were stowed, all this physical evidence pointed to a normal approach. The report did state that, “Most of the aircraft’s systems and instrumentation were destroyed.” It described how several of the captain’s instruments were reading normal but made no mention whether any investigation into the first officer’s instruments could be or had been looked into. Did the first officer not react to aural altitude warnings because his instruments read differently than the captain’s? Was the first officer, who survived, interviewed post-crash?
There was one other confusing detail: the changes in altitude as recorded by the FDR. Per AAR-75/09, at 07:31:54 the FDR recorded the aircraft at 2,750 feet; at 07:32:41, the FDR showed altitude at less than 1,000 feet. But at 07:33:17, forty seconds before impact, when the CVR recorded the first officer request, “Fifty degrees Flaps;” the altitude recorded by the FDR at this time was 1,480 feet.
It is understandable that terrain varies in height, especially in hilly or mountainous areas. Was the first officer confused into thinking the aircraft was higher than the altitude alerts called attention to? Were the two pilots’ instruments reading differently?
One last observation: in regard to the pilots’ neglect of the altitude aural warning, the report stated, “Based on pilot testimony taken at the hearing, it appears that the crew’s disregard of the terrain warning signal in this instance may be indicative of the attitudes of many other pilots who regard the signal as more of a nuisance than a warning. If this is indeed the case, the Board believes that airline pilots should reexamine their attitudes toward the terrain warning alert, lest the purpose for which the device was installed be defeated.” The takeaway from this statement was that the pilots should accept all warnings because they are designed to save lives. However, too many alerts in increasing numbers of tones might become so much noise that work contrary to their purpose. Consider a car alarm that constantly goes off or a smoke detector that senses smoke where smoke does not exist. Are all alerts necessary; do they work only when necessary? Are they overkill? Do they alert pilots to problems or are they redundant? Can important alerts be silenced or ignored too easily? These are questions for not only the airlines, but the manufacturers: Are there too many redundant alerts?
It is to be noted by reviewing the AAR-75/09 report that the NTSB, in these early days, made a great impact on aviation safety with less arbitrary input; focus was on both quality investigations and quality investigators; they used their qualified resources wisely, their experience constructively. These early investigators demonstrated that, like some cockpit warnings and alerts, less might be better.