***This is an Aviation accident investigation class***
This is a continuation of weekly assignments in the previous weeks of this weekly assignment the subjects were :
*Human factor and Field Investigations
*Structural and Fire Investigations
*Aircraft Systems Field Investigations
This week the Subject is Survival Factors and Crashworthiness Field Investigations
Read the Summary below then write a paper/discussion following and focussing on the objective listed —
Crashworthiness is essentially the ability of the aircraft and its internal structures and systems to protect occupants from injury in the event of a crash. Generally, aircraft crash injury is associated with excessive acceleration forces, direct contact trauma with internal surfaces or debris, and exposure to environmental factors such as fire, smoke and toxic fumes, water, and hazardous materials. Consequently, aircraft and aircraft component designers and manufacturers work with investigative findings, human factors engineers, and research agencies, such as the FAA’s Cabin Safety Research Team, to incorporate effective crashworthiness designs to eliminate or mitigate possible sources of injury in the event of a plane crash.
In the United States, the FAA’sWilliam J. Hughes Technical Center, Civil Aeromedical Institute (CAMI), Boeing Aerospace, and other agencies, conduct extensive research on aircraft crashworthiness, human tolerance of deceleration forces, and other survivability aspects of aircraft accidents. Examples of crashworthiness research include the following:
- Evacuation researchfocuses on the efficiency of aircraft emergency evacuation, to include seating density, exit size and location, passenger flow rates through exits, and passenger and flight attendant behavior are investigated using our full aircraft cabin simulators and human research subjects.
- Fire research,to include flammability testing, such as with magnesium alloys in difficult to reach locations; full-scale burn-through rates, penetration rates of cargo liners, lithium battery fires, soot patterns, cargo fire detection systems, and electronic flight bag hazard assessments. Flammability tests for interior components (carpets, seat coverings, sidewalls and stowbins) and insulation are also the focus of fire-based research.
- Water survivalresearch analyzes effectiveness of the deployment and use of emergency egress slide-rafts and life rafts, use of seat bottom cushion floatation devices, donning and use of aviation life preservers, and in-water fatigue countermeasures. This research also focuses on evaluating new designs for personal flotation devices, life rafts, slide/rafts, and other emergency equipment.
Aircraft accident investigation seeks not only to determine what, how, and why, to prevent future occurrences, it also seeks to analyze survivability of crash events and to continue to add to the extensive body of knowledge on crashworthiness of aircraft and efficiencies/effectiveness of emergency response and airline emergency protocols. In survival factors investigations, we apply the CREEP Method as an effective tool to analyze all possible sources of injury. CREEP stands forContainer,Restraint systems,Energy absorption,Environment, andPost-crash environment. This involves considerations of (1) strength of the container (cockpit and cabin), (2) adequacy of seats, seat connection points, and seat restraint systems, (3) adequacy of energy attenuation systems, (4) injurious objects in the local environment of occupants, and (5) post-crash factors, principally fire prevention and adequacy of escape routes.
While the intent of this section is not to analyze human tolerance, a few points bear mentioning as you move forward. First, acceleration is the rate of change in velocity of a mass and is frequently stated in units of feet per second per second or feet/second2.. It is often described in units of G, which is the ratio of a particular acceleration (a) to the acceleration of gravity at sea level. Deceleration is simply a negative acceleration and is generally what we assess in crash dynamics, especially with respect to survivability and human performance.
In general, human tolerance to acceleration and deceleration is impacted by five extrinsic and four intrinsic factors. Extrinsic are those factors associated with the acceleration/deceleration itself. Intrinsic are human variables.
- Magnitude of the acceleration
- Direction of the acceleration – humans can withstand acceleration forces applied on some axes more so than others, with +Gx (forward direction) being the most human tolerant
- Duration of the acceleration
- Rate of onset
Biological variability also factors into human tolerance:
- Age of the occupant – here, youth has its advantages in human tolerance to acceleration/deceleration
- Health of the occupant
- Gender of the occupant (genders, typically, have different mass and muscle distribution)
- Physical conditioning (overall fitness can have a protective effect, to some extent)
In this discussion activity, discuss the type of artifact(s) you feel will best demonstrate achievement of the Survival Factors and Crashworthiness field investigations objectives. In addition to your discussion points, feel free to post a sample, outline, diagram, video clip, etc., of your artifact.
The intention of your portfolio artifact is to show mastery of the objectives for Survival Factors and Crashworthiness Field Investigations:
- *Demonstrate application of the CREEP Model in aircraft accident investigation.
- *Apply aircraft crash findings to crashworthiness and survival factors research.
- *Demonstrate the application of survival factors findings and recommendations in aviation safety.