By David Kenny
The hazards of winter flying aren’t limited to in-flight icing and slippery runways. In warm, moist regions like the Gulf Coast, fog becomes more likely in the cooler months as overnight temperatures drop toward dew points that stay relatively high. It can come up quickly; it can spread for miles, or be impenetrable by the water’s edge but nonexistent 10 miles inland. Pilots flying into coastal airports at night need to stay sharp and flexible, ready to divert if conditions unexpectedly deteriorate.
About 10:20 p.m. on Dec. 10, 2009, a Piper PA-30 Twin Comanche crashed into the Laguna Madre, the narrow body of water separating the Texas mainland from South Padre Island. The airplane was destroyed and both men on board were killed. The pilot was attempting a visual approach to the Charles R. Johnson Airport in Port Mansfield, a nontowered field with no weather reporting facilities and no charted instrument approaches.
They had originally departed without a flight plan from a private field at the far end of the north-Texas panhandle; the pilot subsequently filed IFR en route. At the time of the accident, they had been airborne for more than four hours.
The pilot held flight instructor certificates for airplane single-engine land, multiengine land, and instrument airplane. He had gotten them quickly. His one and only medical application, submitted less than a year and a half before, listed no flight experience, as he hadn’t yet begun his training. He had taken his most recent checkride the preceding March, about halfway between the accident date and the date of his medical. At that time he had listed 314 hours of total flight experience, including 249 as pilot in command and 151 of dual received. He’d claimed 63 hours of night flight and 68 hours of instrument time, 44 of them in “flight training devices.”
Initial contact with Valley Approach Control was made descending through 6,500 feet for 6,000 feet. After confirming that Port Mansfield had no instrument approaches, the pilot mentioned his four-hour flight and said that “everything I’ve pre-flight planned showed it to have twenty-five hundred foot ceilings when we were getting there.” He asked if we could “proceed down to two thousand and take a look.” The controller cleared him to descend to 2,000 feet at pilot’s discretion and fly directly to the field.
This wasn’t unreasonable. A commercial flight about 16 miles to the southeast reported bases at 2,300, and Brownsville, 45 miles to the south, was also reporting 2,300 overcast. But at Harlingen, 27 miles from Port Mansfield and further inland, the overcast layer was solid at 1,200. The controller cleared the Twin Comanche to descend and maintain 1,600 and report the field in sight.
As the airplane descended, radio contact became sporadic. The controller advised that the airport was at 12 o’clock and nine miles, then eight, then six. After a broken transmission suggested the pilot had located the field, the controller asked him to “squawk ident if you see the airport.” Thirteen seconds later, the controller confirmed “ident observed” and cleared him for the visual approach.
Radar-track data showed the airplane descending to 800 feet as it passed west of the field on a course consistent with a downwind leg for Runway 30. It made a left turn and descended through 600 before it was lost to radar. A commercial fisherman in the channel that night described the weather as “very foggy,” with visibility of half a mile. A witness who lived near the airport said the noise of the engines woke him from a sound sleep. He was unable to see the airplane after he went outside, but could hear it near “the edge of the water” and thought the pilot was “looking for the runway.” He estimated visibility at 350 yards. Examination of the wreckage suggested that it hit the water in a shallow descent with the wings level and both engines at similarly reduced power settings. The gear and flaps were extended.
Airlines prohibit their crews from attempting circling approaches in IMC, and many corporate and charter operators do likewise. Trying to keep the runway in sight in poor visibility at low altitude pulls the pilot’s attention away from the instruments just when the margin for error in attitude and airspeed is dwindling to zero. It isn’t clear whether the pilot ever saw the runway, or mistook other lights in the vicinity for the airport beacon. It does seem likely that keeping the runway in sight while flying a tight traffic pattern in low visibility at night was a lot to ask of even a more experienced pilot, and that an earlier decision to divert would have come out better. Multiple straight-in approaches were available into Harlingen, where the visibility was reported to be 10 miles beneath the overcast.