Southern Airways 932

Southern Airways, Inc., a DC-9, N97S, operating as charter Flight 932, crashed during a landing attempt at the Tri-State Airport, Huntington, West Virginia, at approximately 1936 E.S.T., on November 14, 1970. All 75 occupants, including 71 passengers and four crewmembers, were fatally injured. The aircraft was destroyed.

The flight, chartered to transport the Marshall University football team and boosters from Kinston, North Carolina, to Huntington, West Virginia, was attempting a non-precision instrument landing approach to runway 11 at the time of the accident. The crash occurred following impact with trees on a hill approximately 1 mile west of the runway threshold. The elevation of the broken trees at the initial impact site was approximately 922 feet M.S.L. The Minimum Descent Altitude, below which a descent is not authorized until the runway environment is in sight, for this instrument approach was 1,240 feet M.S.L.

The weather at the time of the accident was: 300 feet scattered, estimated 500 feet variable broken, 1,100 feet overcast, visibility five miles, light rain, fog, smoke, wind 360° at 4 knots, altimeter setting 29.67, ceiling ragged and variable 400 to 600 feet.

Source: NTSB AAR-72-11, Excerpts

Southern Airways Charter Flight 932 (SOU 932) was scheduled as a ferry flight from Atlanta, Georgia, to Kinston, North Carolina, to return members of the Marshall University football team, the coaching staff, and other passengers to Huntington, West Virginia, from Kinston.

Source: NTSB AAR-72-11, Excerpts

The flight departed Atlanta at 1548 and arrived at Kinston at 1642. The aircraft was refueled, but no maintenance was requested or performed. Seventy passengers boarded the aircraft and the flight taxied from the ramp at 1828 with a total of 75 persons aboard.

The captain filed an Instrument Flight Rules (IFR) flight plan to Huntington, via direct Raleigh-Durham, North Carolina, direct Pulaski, Virginia, direct Huntington, at Flight Level 260 (FL260 ). The true airspeed was 473 knots and the estimated time en route was 52 minutes. The flight departed Kinston at 1838 and proceeded in accordance with the flight plan.

Source: NTSB AAR-72-11, Excerpts

SOU 932 established contact with Huntington Approach Control by advising “. . . we’re descending to five thousand.” The controller cleared them for a localizer approach to Runway 11 and added, “…the surface winds are favoring runway twenty-nine, three five zero degrees at six, altimeter two niner six seven…” the crew acknowledged this information and then the controller advised, “…the Huntington weather three hundred scattered, measured ceiling five hundred, variable broken, one thousand one hundred overcast, visibility five, light rain, fog, smoke, ceiling ragged variable four to six hundred.”

At approximately 1933, the captain said that he could fly at 130 knots, and the first officer responded that he was checking the time, and the approach should take 2 minutes, at 1934, the crew reported passing the outer marker inbound, and they were cleared to land. The wind was then reported as 360° at 7 knots. Following a discussion of the approach lighting during which the crew requested “step three,” the tower controller stated, “Roger, that’s where they are, with the rabbit (sequence flasher). Advise when you want them cut.” At approximately 1936, tower personnel observed a red glow west of the airport. When no response to subsequent radio calls was received, the tower controller initiated the emergency procedures.

The last flight to operate into Huntington prior to SOU 932 landed on Runway 11 at 1848 and departed at 1907. The captain of that flight stated that the weather was essentially as reported to him, 300 feet scattered, 500 feet variable broken. They broke out of the clouds at minimums, west of the refinery (located approximately 2 miles west of the airport). The forward visibility was good, and the runway was in sight from this point until they landed, although they did encounter some widely scattered clouds.

The aircraft initially struck trees in a hill 5,543 feet west of the runway threshold, and cut a swatch 95 feet wide and 279 feet long through the trees in a bearing of 110°, 122 feet right of the runway centerline extended. The main wreckage site was located 4,219 feet from the threshold of Runway 11, and approximately 225 feet south of the middle marker. The ground elevation at the initial tree impact was 860 feet M.S.L., and the elevation at the break in the tree at this location was 916 feet 2 inches M.S.L. This was a non-survivable accident.

Source: NTSB AAR-72-11, Excerpts

The aircraft center of gravity was within allowable limits. Based on the aircraft performance capability, there was sufficient runway available for N92S to have landed under the conditions existing at Huntington at the time of the accident.

The crew was properly certificated and qualified for the flight. The aircraft had been maintained in accordance with existing company procedures and the Federal Aviation Regulations. The investigation disclosed no malfunctions or failure in the aircraft structure, primary flight controls, or powerplants.

The Board reviewed the charter arrangements, operations specifications, and regulations governing the dispatch and conduct of this flight. Although the flight was conducted in accordance with the prescribed procedures, there is one area which is of concern to the Board.

An equivalent level of safety for “off route” operations, of the type involved in this accidents, is theoretically achieved by the increased landing minima applicable to such operations. However, the crew requirements for “off route” airport qualifications do not require the same degree of qualification as that required for scheduled operations. The reason for this is that it would not be practical to require an actual entry into every possible “off route” airport, nor would it be practical to have on hand the approved pictorial display for every possible “off route” airport. There is no evidence in this case to indicate that the crew had not sufficiently familiarized itself with the Huntington airport, surrounding terrain, and the approach and landing procedures. At the same time, there is no way to assure that the crew had actual knowledge of the foregoing prior to departure.

The flight path and profile show that the aircraft descended through the MDA approximately 2 miles from the end of the runway and that such descent was not corrected in time to avoid impact with the trees. Conversation between the captain and first officer during the 10-second period preceding the MDA passage indicates that they were beginning to see the lights on the ground, or at least the glow of the lights. It is possible that the sighting of these lights, in combination with the knowledge that they were approaching the bottom of the lowest cloud layer, could have induced the Captain to continue descent below MDA in order to see the runway environment at the earliest moment. The descent, in fact, did continue through this period, and ground witness observed the aircraft clear of clouds in this area.

It is also possible that the conduct of the approach could have been affected by a visual illusion produced by the difference in the elevation of the refinery and the airport. Approximately, 2 miles from the runway, the flight was approaching the bright lights surrounding the refinery and, as noted above, the crew was discussing at least the glow, and probably fleeting glimpses, of ground lights through the broken clouds. As the descent continued, the opportunity for ground reference through scattered clouds would have increased. Below approximately 1,100 M.S.L., the only restriction to visibility should have been the fog, smoke, and light rain.

If the approach lights or sequence flasher lights were sighted while the refinery lights were still in the field of vision, with no appreciable lights between, the pilots would have mentally visualized both light sources at the same elevation as the nearer lights. Therefore, the height above both lights would appear to be about 700 feet, whereas the actual height above the approach lights would have been only 400 feet, due to the 300-foot difference in elevation between the refinery and the approach lights. After the aircraft passed the refinery, the preconceived image would have been retained and the visual cues would have told the crew that they were approximately 300 feet higher than desired.

The remaining evidence, however, strongly suggest that the crew never obtained visual contact with the approach lights or with any part of the runway environment. The visual illusions discussed above, for example, would have prompted an increase in the rate of descent, which significantly is not reflected on the flight data recorder. Even more important, there were no comments on the cockpit voice recorder pertaining to ground lights other than those mentioned as the aircraft passed over the refinery. If any lights associated with the runway environment had been sighted, it can be presumed that some mention of the sighting would have been made. Certainly such a presumption is far more likely than the explanation that the runway environment was sighted, but that such sighting was either sufficiently obvious to negate the need for a callout or was indicated and acknowledged by nonverbal signals.

The recorded conversation also indicates that the crew was not aware that the aircraft had descended below MDA. The first officer’s comment at 1935:06 “We are two hundred above” is most logically construed as a reference to MDA. The following comment by the charter coordinator (riding in the jump seat) “Bet’ll be a missed approach” can be taken to mean that the flight was approaching MDA, yet the runway environment was still not in sight. The next statement on the recorder (“Four Hundred”) most probably means that the aircraft had reached MDA, which is 400 feet above the airport elevation. Such interpretation is consistent with the following remark of the captain (“that the approach?”), which indicates that he was asking, perhaps rhetorically, whether they had reached the farthest point to which the flight could legally descend. The first officer responded, “Yeah,” which again implies that the MDA had been reached and the runway environment was not in sight. The available evidence also indicates that a level off or missed-approach was then initiated. The swath cut through the trees, ground witnesses statements, and the flight recorder altitude trace all show that the descent was stopped, power was added, and a gradual climb was commenced. Furthermore, the first officer called out airspeed in terms of a number (“Hundred and twenty-six”) instead of a reference speed (“bug plus- - -“), which is indicative of a go-around rather than a continuing approach.

In view of the foregoing, the Board concludes that the crew never sighted the runway environment and was not aware that the flight had descended through actual MDA.

Source: NTSB AAR-72-11, Excerpts

The National Transportation Safety Board determines that the probable cause of this accident was the descent below Minimum Descent Altitude during a non-precision approach under adverse operating conditions, without visual contact with the runway environment. The Board has been unable to determine the reason for this descent, although the two most likely explanations are (a) improper use of cockpit instrumentation data, or (b) an altimetry system error.

Source: NTSB AAR-72-11, Excerpts