Thanks Bilal Siddiqui for the paper!!!

The FAA conducts research to ensure that commercial and general aviation is the safest in the world. They post data and statistics on their website that can be found here < http://www.faa.gov/data_research/ >. You can also find a great deal of info on the FAA AVIATION SAFETY INFORMATION ANALYSIS AND SHARING (ASIAS) SYSTEM < http://www.asias.faa.gov/pls/apex/f?p=100:1: >. The NTSB issues an accident report following the investigation. These reports are available online for reports issued since 1996. Their info is here < http://www.ntsb.gov/investigations/reports_aviation.html >.

Thanks Thomas Sather for your answer.

At design stages, ARP4754a and ARP4761 are referred, but purely an industry practice. The tools used are FTA or Markov Chains to derive specified hazard probability.

Thanks Vasanth Thanigaivelu. Yes, ARP4754a and ARP4761 are referred at design stages of civil aircraft and systems. What I really need are algorithms for the onboard estimation of flight safety margins and risk factors resulting from off-nominal conditions related to Loss-of-Control (LOC) events and actions taken (or not taken) to mitigate them. In the paper "Future Integrated Systems Concept for Preventing Aircraft Loss-of-Control Accidents" (see http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100031283.pdf), Christine M. Belcastro pointed out that "there does not appear to be a comprehensive definition of flight safety that can be quantified, measured, or estimated in an attempt to explicitly assure safe flight." This makes me confused. What is the difference between the "safety" in ARP4754a and the "flight safety" in Christine M. Belcastro's paper?

The "safety" in these standards are probabilistic calculation made to convince the FAA (or any certifying agencies that refer to these standards/guidelines) that our "aircraft design" is safe to fly. The ARP guidelines help us to interpret AC25.1309 (System and Design Analysis), this again is only true for design stages albeit the numbers used to arrive at those probability numbers are to be substantiated (either through a legitimate database or through extensive reliability analysis). The flight safety that you are looking for has many a parameter into account, In my guess, it has to be In-flight Health Management system which may or may not provide mitigation actions. The algorithm as suggested by the paper is open to discussion and the parameters to be used are widely based on experience of that aircraft, the 787 has such features of Health Management, (http://www.boeing.com/boeing/Features/2013/07/bca_airplane_health_mgmt_07_30_13.page) whether or not to improve such features to provide Aircraft Loss-of-Control details is upto research I believe.

Thanks Vasanth Thanigaivelu for your nice explanations on "safety" and "flight safety".

This could be useful. Prof.M.R.Ananthasayanam

Thanks Lalitya Dhavala for your excellent answer. You are right, flight safety is a complex network of people, events and risks. Basically, I am doing some research on flight safety assessment of an aircraft subject to faults, failures, or even wing damage, when the aircraft is in-air. But I am always confused by the words of "flight safety" and "aircraft safety". Isn't there any difference between "flight safety" and "aircraft safety"?

Thanks Lalitya Dhavala, your answer really helps a lot..

Hi,

You have to assume that the Aircraft design engineering is sound.

Errors can start from a myriad of occurrences, from paperwork to construction.

Proven aircraft models used across different airlines can vary in safety from ongoing maintenance,  economic consideration , bad morale, procedures enforced, bad logistics supply, quality control, regional operator. etc.

Each accident is normally resultant in a chain of events that often any 1 could be intercepted, and indeed once identified from crash and data, these are rectified asap.

It is hard to define safety unless every aspect is considered as to the operator.

If you can advise your need, maybe a flow chart could be constructed? I am sure that this resource already exists.  I know military have such but you would not be able to access?

I hope this helps.

Best wishes with your research............Jinny