"AIR CRASHES AND MIRACLE LANDINGS: 85 CASES – HOW AND WHY"
TACA Deadstick Landing on Grass Levee (New Orleans, 1988)
The captain was going to ditch in the water but at the last moment saw a relatively flat grass levee on the bank. He landed there with no loss of life despite having only one eye.
TACA Flight 110, May 24, 1988
TACA, a small airline based in El Salvador and founded in 1931, was so proud of its brand-new Boeing 737-3 that when Flight 110 encountered severe hail, the pilots’ first concern was that it might damage the paintwork.
The flight had taken off in fine weather from Belize City with thirty-eight passengers and seven crew, but on crossing over the Gulf of Mexico, known for its fickle weather, the weather radar showed storms ahead. The pilots tried to skirt the parts shown in red, with the heaviest rain, and keep to the areas shown in green and yellow, where the rain would be less intense. Though the captain, Carlos Dardano, and second officer, Dionisio Lopez, were relatively young, they were very experienced. Sitting in the jump seat was a senior training pilot, who had come along get some experience of being on a new 737. As they approached their destination, New Orleans, they commenced their descent from thirty-five thousand feet. They saw a gap, shown in green and yellow areas, with red ones on either side ahead, and entered the cloud at thirty thousand feet, having turned on the engine anti-icing and engine auto-ignition so that an engine would immediately restart should it flame out.
As they descended lower and lower, they were surprised at the amount of rain, turbulence, and especially hail, despite it not having been displayed as red on their radar. That was because since hail is dry, it does not show up properly on radar. At sixteen thousand feet, both engines flamed out almost simultaneously, leaving them gliding without even electrical power for their instruments, other than a few key ones with battery backup. Their radio was out, so they could not communicate with air traffic control (ATC). They started the auxiliary power unit (APU) in the tail, but that took time to power up, at which point, with electricity for their communications, they could discuss possible landing places with ATC. They were low in dense air and had the engines windmilling at the right speed for restarting but were unsuccessful Getting desperate, they finally managed to restart them using the engine starters with electric power supplied by the APU. Sighing with relief, they prematurely informed ATC they no longer needed to come down immediately and would continue to New Orleans. ATC gave them the course for that.
However, the engines were not producing any meaningful thrust. Worse, when the pilots opened the throttles to push more fuel in, the engines overheated to the point where it was obvious they would catch fire or explode, which meant they had to be shut down immediately and definitively. (The overheating was because it was a hot start—that is, excess fuel in the engine was catching fire. The pilots cannot be blamed, because at such a low height they could not take their time and allow it to bleed away.)
They were at three thousand feet with just three minutes left. They had dismissed the suggestion by ATC of coming down on a highway, for, with vehicles on it, the maneuver would be fraught with danger, both for those in the aircraft and on the ground. The only serious option was to ditch in one of the wide waterways. One lay straight ahead, and the captain aimed to ditch near the bank. Then, as they came down below two thousand feet, copilot Lopez pointed out the grass-covered levee to the side on the right. Perhaps to get a clearer view and make sure the ground there was as flat and obstacle free as it appeared, Captain Dardano may have continued to aim for the water before doing a deft sideslip to line up with the levee.
Passing over the wall at the near end, he touched down perfectly and with no reverse thrust to help bring the thirty-seven-ton airliner to a halt by delicate application of the brakes to prevent it skidding out of control. There was no fire and all on board evacuated safely via the slides, with only one very minor injury. Truly remarkable. With one engine completely replaced and the other repaired, two test pilots flew the aircraft, with just enough fuel to reach the airport, off the levee.
CFM56 Engine Used Worldwide There was great concern, for the CFM56 engine was used in many aircraft worldwide in addition to the ubiquitous 737. The fact that such a reliable engine could in certain circumstances flame out in a storm, with subsequent problems when restarted, was very troubling.
The investigators had the engine maker redo the acceptance tests, but no matter how much water they injected, they could not get the engines to stop. They then studied the readings on the TACA cockpit data recorder and noticed that when the engines flamed out the aircraft was beginning its descent into New Orleans under low power. The test was therefore repeated at low power settings and showed that a large amount of water in the core—simulating the presence of hail—did make it flame out.
Minor modifications were made to CFM56 engines, including better pathways to bleed away water, reshaping fan blades to help divert small hail particles from the core, and a sensor to make the ignitors fire automatically in heavy rain or hail.