Determining when a discovered condition is the sentinel event for an urgent safety of flight problem 1

[kontiki99]

Does anyone know of any guidelines for determining when a failure or pattern of failures is a serious flight safety issue?

Typically, when damage is discovered on an aircraft, actions are taken to repair or defer the item. Sometimes, there are repeat events.

I think that too often, if an aircraft hasn't crashed or there haven't been any fatalities, responding to the safety implications of failure report can be a gut call.

Sometimes it can take a little while to recognize the severity of a problem. Sometimes it takes a while to see exactly why or how a problem is a serious safety problem.

I think questioning whether a situation is a safety problem is a good starting point. But no one wants to raise the flag and impact the operation on a fleet of airplanes with out a solid reason.

I've run into the situation a few times.

In theory, there is no difference between theory and practice; experience suggests that in practice, there is.

 

[VEBill]

Every fleet should have a formal Airworthiness program in place. In cases where it's not clear what to do, then the most likely correct answer is to make a formal report in writing. Such reports should not cause the fleet operations to be directly impacted, only to start the process of further investigation through the established Airworthiness process. It'll be the higher-ups that make the big decisions.

There should be an established process.

 

[berkshire]

Konti,
You are most likely aware of the FAA's service difficulty report form RIS- WS 8070-1 . It is used for exactly this purpose.
To collect damage and failure reports from operators, to determine whether or not a bigger problem exists.
Service difficuly reports from several operators on the same subject have been the basis for airworthiness directives.
B.E.

 

[kontiki99]

Let me try it another way. Any body know what process the FAA uses for deciding that something is so serious an AD needs to be issued? How about an immediate safety AD?



In theory, there is no difference between theory and practice; experience suggests that in practice, there is.

 

[berkshire]

Ok Konti, this is an anecdote.
I was on the wrong end of one of these AD things 39 years ago. I and another glider pilot were going to attempt a two seat glider distance record in a metal tandem two seat glider. We got towed to altitude, released and started on our way. Turning into the next thermal, the aircraft made an unusual thump. I asked the guy flying in the back seat to turn around and see what was banging around. The answer came back “The whole back of the wing is moving up and down." with this I aborted the flight and returned to the airport. Examination of the aircraft revealed that the drag fittings on the aircraft had fatigued through.
I took pictures of the damage and sent them to the manufacturer who was in the UK. The response was " The damage you report is known to us, technical bulletin No. ** applies.". This bulletin required dye check inspection of these fittings for cracks. Apparently at that time the maker had sent the information to the FAA office in Brussels, and it had not gotten to the USA because it was not deemed URGENT. I called the local inspector out, from what was then the GADO, they looked at it, and issued an immediate emergency air worthiness directive, grounding order for the rest of the type flying in the USA.
So I guess based on that, it will depend on how urgent the FAA thinks it is. and how urgent you think it is.
B.E.

 

[kontiki99]

Thanks berkshire,

Glad you made it back OK.

Just to clarify, I currently do not know of any situation that could be construed an urgent safety situation anywhere. If I felt thre were, I would ensure it was addressed without delay. The people I work for are very reasonable with regard to safety.

I asked the question to see if someone out there has been able to formulate some rapid process for consistently making that call. Very few of us have an all encompasing FEMA on hand when "things" come up.








In theory, there is no difference between theory and practice; experience suggests that in practice, there is.

 

[berkshire]

Konti,
I meant to post this link the other day, then it slipped my mind.
B.E.

http://www.faa.gov/aircraft/safety/alerts/aviation_maintenance/

 

[MNLiaison]

Kontiki99,

Came across FAA policy PS-ANM-25-05, Risk Assessment Methodology for Transport Category Airplanes, and the associated Transport Airplane Risk Assessment
Methodology (TARAM) Handbook that may provide the information you seek. From the handbook scope;

"This handbook describes the Transport Airplane Risk Assessment Methodology (TARAM). It
outlines a process for calculating risk associated with continued-operational-safety (COS) issues
in the transport-airplane fleet. It explains how to use such risk-analysis calculations when making
determinations of unsafe conditions, and selecting and implementing corrective actions."


Handbook can be found here,

http://www.airweb.faa.gov/Regulator...061f96b/$FILE/PS-ANM-25-05 TARAM Handbook.pdf

Regards

 

[dgapilot]

I've tried to find this out myself. My day job is System Safety Engineer for the Navy. The airplanes I deal with are for the most part TCd airplanes, so we rely on FAA for critical safety issues. It seems that within FAA there are no standards. Each Directorate uses their own standards for criticality and probability when determining if a AD is warranted. That is then tempered with what the manufacturer has issued for service documents. As was stated, the service difficulty program is critical in feeding fleet info to FAA. Manufacturers have a responsibility to report problems to FAA but that only works while the airplane is under warranty. Beyond that, the manufacturer has no idea what goes on out in the field.

 

[kontiki99]

My OP was actually oriented toward a more immediate time frame. I work in a 24x7 airline Engineering support group. We monitor aircraft in flight and in Maintenance around the globe. There is always one person from each discipline on duty. We have planes in the air almost 24x7.

I get walkins, phone calls, or computer requests. There have been nights when a request has forced me to consider or rule out the possibility we have a serious pattern of possible inflight safety issues.

Hypothetical example; maybe second discovery of what could be a serious inflight fire hazard.

Now, if that ever happens, I need to get people out of bed and make some pretty drastic recommendations. Certainly, I would not have the final say, but the possible impact of something like that could cost a lot too.

A false positive might damage credibility, a false negative might be even worse. The question is, how to consistantly recognize that situation you hope never happens on your shift.







In theory, there is no difference between theory and practice however, experience suggests that in practice, there is!

My posts reflect my personal views and are not in any way endorsed or approved by any organization I'm affiliated with.

 

[limey1]

If you are looking for a repeatable "quick" decision making tool in lieu of legislative specifics, could you use a probability / impact diagram?

 

[kontiki99]

Thanks Limey,

That's a great approach. Either a matrix like this one or maybe a flow diagram might work. It would have to be something that simple, I'm always getting pulled in 5 directions when I'm on shift.




In theory, there is no difference between theory and practice however, experience suggests that in practice, there is!

My posts reflect my personal views and are not in any way endorsed or approved by any organization I'm affiliated with.