TWA 514’s legacy

On December 1, 1974, the Boeing 727 was inbound from Columbus, Ohio, to Washington National Airport (DCA). Because of strong easterly winds at DCA, the flight was diverted to Washington Dulles International Airport (IAD). Runway 12 at Dulles was better situated for the winds that were gusting to 40 knots that day. Ceiling at the time was 900 feet and the visibility was three miles or better. The crash occurred while the flight was still 25 miles northwest of Dulles in the smaller foothills of the Blue Ridge Mountains.

Like most major accidents, TWA 514 led to critical changes in the industry. Changes to communications between pilots and air traffic control (ATC) and development of ground proximity warning systems (GPWS) have led to today’s much higher level of safety. Instead of an air disaster every year or so back then, the United States recently went 15 years without a major crash.

Reading the National Transportation Safety Board’s (NTSB) final report on TWA 514 is also a lesson in common sense and situational awareness. Back then, three pilots crewed airliners because there was far less automation. A flight engineer staffed “the panel” behind the pilots monitoring and managing the Boeing 727’s three engines and the jet’s myriad other systems. But among the three pilots, nobody questioned why they would descend to 1,800 feet when still 25 miles northwest of Dulles. At that distance from the field, the standard three-degree glideslope would place an airplane at more than 8,000 feet above the ground.

While at 7,000 feet and 44 miles from Dulles on a heading of 80-degrees, ATC cleared TWA 514 for the VOR/DME Runway 12 which has a final approach fix altitude of 1,800 feet. he crew was cleared for the approach but wasn’t specifically given an altitude by ATC. The crew saw 1,800 feet for the final approach fix and descended immediately. The NTSB report states the crew assumed that if under radar control and cleared for the approach, they could make an unrestricted descent to the final approach fix altitude.

The final report states, “this accident resulted from a combination of conditions which included a lack of understanding between the controller and the pilots as to which air traffic control criteria were being applied to the flight while it was operating in instrument meteorological conditions in the terminal area. Neither the pilots nor the controller understood what the other was thinking or planning when the approach clearance was issued.”

This accident is what led air traffic controllers to later utilize specific phraseology when issuing IFR approach clearances, such as, “maintain 3,000 feet until established, cleared for the VOR approach to Runway One-Two.” Charting changes and altitude definitions became clearer as well. Eventually, GPWS became the norm in all jets further improving safety. The NTSB final report is excellent reading for all pilots, but especially those who operate under IFR. What sticks out in my mind, however, is the lack of vertical awareness by an experienced crew. Nobody thought that starting down more than 40 miles from the field was extremely premature?

I get that the weather and turbulence were awful and they likely just wanted to be on the ground, but descending so far out would make the flight even longer because of reduced true airspeed. For every 1,000 feet of altitude lost, a jet loses about 10 knots of true airspeed. Descending over hilly terrain also likely made the turbulence even worse as the topography helps stir up the air. Pilots should strive to preserve their altitude and fly a vertical path to mimic that of the standard 3-degree glideslope, especially when operating in mountainous terrain. As a bonus, staying high keeps you above typical low-level turbulence, lowers your noise footprint, lowers bird strike risk, and even reduces the amount of bugs that befoul your windshield.

For us big-iron drivers landing at the big airports, staying on path keeps us within Class B airspace ensuring we don’t become a conflict with VFR traffic operating below. Yes, Class B dropouts are a thing so don’t be surprised to see airliners operating outside of the confines of the Bravo (see “Career Pilot: Class B Dropouts,” October 2017 Flight Training). Don’t be in a hurry to get down, aka “dive and drive,” especially if you’re nowhere near the airport. Jet pilots in general, adhere to the 3-to-1 rule. For every 1,000 feet you need to descend, plan about 3 miles. Need to lose 8,000 feet? That’ll take about 24 miles at typical jet speeds. Anyway, with these simple guidelines, situational awareness, and plenty of skepticism, we can hopefully avoid another tragedy like TWA 514. FT