If an identified hazard is capable of causing 250 fatalities and causing $50 mil
ID: 407743 • Letter: I
Question
If an identified hazard is capable of causing 250 fatalities and causing $50 million in property damage and other losses, what is its severity code? If this hazard is associated with certain model of aircraft with an expected service life of 25 years, what is the exposure code, given that the fleet has 200 aircraft and the hazard is estimated to be likely to result in an accident no more than once per 5 million flying hours (assume 2,000 flying hours per aircraft annually)? What is the TREC? What would be the estimated losses associated with this hazard over the life of the system? Book:SYSTEM SAFETY FOR THE 21ST CENTURY
Explanation / Answer
Answer:
Total loss = 250 fatalities + $50 Million in other damages
Since approx. 1 fatality ~ $500,000 so 250 fatalities = 125 Million
Total Loss= $ 125 M + $50 M = $ 175 M
Severity Code = 8 i.e. $100 M – $1 B
Answer:
Exposure = (aircrafts in fleet * service life * estimate of accident) / [(100,000 hours / unit) * annual flying hours per aircraft]
= 200 * 5,000,000*25/ 100,000*2,000
= 25*5 / 1 = 125
Therefore, Exposure Code = 9
TREC = Severity Code + Exposure code = 8+9 = 17
Total Risk exposure i.e. TRE = 5 * 10 ^ (TREC-5)
TRE = $ 5 * 10^12