Analysis on Critical Factors of Survival Ditching Cases

Ong, Si Qing (2020) Analysis on Critical Factors of Survival Ditching Cases. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Ditching, in a more general term refers to emergency water landing on water. It happens when the aircraft is unable to land on the runway as planned. It may occur in sea water or fresh water. It is more often to occur in the case of the aircraft experiencing engine failure at one of the engines or sometimes total lost in all engine. Ditching commonly split into four phases which is the approach, the impact, the landing and floatation phase. Landing phase and floatation phase will normally be focused as floatation phase only held for less than 30 minutes due to the breakage of fuselage during ditching. In some cases, there is even no floatation time where the aircraft sank into the water directly because of great impact. The parameters such as the aircraft take-off weight, the descent angle as well as the descent rate will greatly affect the impact onto the water during impact phase. Ditching can be further categorized as planned and unplanned ditching. Cases like “Caribbean ditching” occur in 1970, “Cessna aircraft ditching” occur in 2003, “Hudson river ditching” occur in 2009 are all significant cases that cannot be forgotten. There are many ditching cases throughout these years, yet the concern is still on the increment of survival rate of ditching cases. Therefore, case analysis which is undone before plays a role in determining the critical factor of the ditching cases so that it can be set as a guideline or improvement in future aircraft. The analysis done may be also an improvement in the training of crews in handling emergency cases like ditching. The analysis done through collecting all the data from accident reports into a spreadsheet where it will then be used in the program written to obtain the impact loading of the ditching. Lastly, the technical data collected and the impact load calculated can contribute themselves for aircraft manufacturer in manufacturing an aircraft as well as providing a more complete technical data sheet for the aircraft engineer. The safe ditching attitude is found where the descent rate should be below 1000ft/min and the impact load to aircraft weight ratio should be lower than 0.5.