This week, we celebrate the twelfth anniversary of the “Miracle on the Hudson” when Captain Chesley “Sully” Sullenberger performed an emergency landing of a US Airways jet in the Hudson River. Sully successfully guided his disabled jet into a perfect landing with no loss of life.
While Sullenberger was rightfully hailed for his skill in landing the plane in the Hudson River, there was another similar landing that took place in 1988.
As TACA Flight 110 entered clouds at about 30,000 feet, the crew initiated de-icing to protect the engines against precipitation and icing (either of which can cause a flameout, resulting in the loss of all power). Using the onboard radar, the crew selected a flight path that was supposedly between two bands of heavy precipitation. Unfortunately, this turned out to not be the case, as they encountered hail, heavy rain, and turbulence.
As the jet passed through 16,000 feet, both engines flamed out, turning the airliner into a giant glider. The pilots attempted to use the airflow generated by the plane’s descent to restart the engines but were not successful. Next they used the APU (auxiliary power unit) to restart both engines. However, the restarted engines were not able to generate sufficient thrust. Advancing the throttles only resulted in the overheating of the engines.
To avoid catastrophic failure, both engines were shut down.
At this point, the pilots began to prepare for a ditching, as any runway was just too far away.
Initially, Captain Carlos Dardano lined the plane up with a canal and prepared for a water landing. But, co-pilot Dionisio Lopez spotted a grassy area to the right of the canal, which appeared to be long enough to accommodate a jet landing. Lopez suggested that the landing be attempted there and captain Dardano agreed.
He performed a perfect dead-stick landing on the narrow grass levee (which turned out to be on property belonging to NASA). After a round of applause for the cockpit crew, all passengers safely disembarked the airliner.
The National Transportation Safety Board soon dispatched investigators to the site. One of the investigators reportedly said to the other, “Bet you’ve never investigated an intact plane before." Before an investigation could get underway, it was noticed that the jet was slowing sinking into the water-logged sod. The investigators decided to have the plane towed to a nearby NASA facility.
The NTSB subsequently determined that the aircraft had flown into a level 4 thunderstorm with water ingestion causing both engines to flame out (even though the engines had been certified to FAA standards for water ingestion). After several unproductive tests on the engines using a combination of water and ice, investigators were finally able to determine that during descent with lower engine RPM and with the aircraft suffering mild hail damage, the engines were damaged due to overheating.
To avoid similar problems in the future, several modifications were made. Sensors were added to force the combustor to continuously ignite under heavy rain or hail conditions. In addition, changes were made to better deflect hail away from the engines.
Initially, the plan was to remove the wings and then transport the aircraft by barge. However, Boeing engineers decided to do an engine change-out on site. After the needed safety modifications were made, the plane continued to fly for an additional 28 years.