COntents Take a closer look 'Oldie but a goodie': but is it still airworthy? 2 Your aircraft, your responsibility 5 In black and white: the regulations 6 How do I take a closer look? 7 ~e a closer look How old is your aircraft? Is it a child of the swinging '60s, a souvenir from the '70s, a classic from the '80s,or a '90s 'newbie'? Is it a fabric-covered design from the. heroic 1930s? Whatever it is, we'll make one prediction: unless you are a classic car enthusiast, your aircraft is likely to be the oldest large machine you operate. This is not necessarily a problem, but as the registered operator you need to be aware of three things: The difference between maintenance and airworthiness What your responsibilities are, and what CASA's role is in maintenance and airworthiness, and How you take a closer look at your aircraft. Who can I go to for help?,8 Resources 9 2011 Civil Aviation Safety Authority Australia. For further information visit www.casa.gov.au/ageingaircraft Disclaimer: CASA makes no representations or warranties as to the completeness or accuracy of the information contained in this document. CASA assurfies no liability for any loss or damage caused as a result of reliance on this document. The document is provided only for guidance and is not a substitute for legislation or other official documents.., 1104.1476
'oldie but a goodie': but is it still airworthy? There's been little discernable change in the low rate of new aircraft acquisitions over the last three decades, so ageing aircraft are here to stay. The Australian Transport Safety Bureau has found the average fixed-wing aircraft (single or multi-engined under 5700kg) is approaching 40 years old. Age distribution of the GA fleet Average age of registered piston engine fleet State of the fleet State of AOC fleet approx 40 years and rising... (approx 14,000 aircraft) potentially 8,700 aircraft of concern (approx 1,800 aircraft) potentially 700 aircraft of concern Unfortunately, it is unlikely that your standard scheduled maintenance can detect or offset the effects of ageing. CASA's ageing aircraft fact-finding team found some disturbing results when it took a closer look at ageing aircraft in Australia. An aircraft can be completely and fully maintained as per the manufacturers' documentation, or CASA Schedule 5, with all the boxes ticked, but still be un-airworthy. This is because chronologically old aircraft have, in many cases, outlasted the maintenance systems created for them. The original maintenance documentation that came with the aircraft when it was new assumed a finite design life, typically 20 years. Many aircraft have now passed their assumed design lives by significant margins, and therefore the original maintenance data may no longer be appropriate, as they may not be comprehensive enough to take account of ageing aircraft issues. Fatigue cracking, in particular, has a nasty characteristic of accelerating exponentially over time, after a certain period. It can transform into a major airworthiness problem over a period of months, or sometimes only weeks. III!II It can't be assumed that this is an ideal or healthy situation, but there's one important thing to stress at the outset: CASA fully supports the ongoing operation of ageing aircraft, providing it can be done safely. Safety requires knowledge. As well as a general expertise in maintenance, it requires detailed type-specific knowledge, which, understandably, not all operators possess. You may have only owned the aircraft for a few years and may not know its systems and 'little ways' as thoroughly as the previous operator - or the original operator. ii~~!iiii Ii.limm 11I Generic fatigue crack graph That's why CASA is working to give aircraft owners and registered operators a better sense of the issues affecting their aircraft. These issues include airframe stress, electrical and functional systems deterioration and corrosion....,
Knowing how to manage ageing aircraft safely includes basic concepts in the science of aircraft ageing such as: the 'bathtub curve' of predicted reliability, and its implications, why fatigue inspections are importarlt, different types of corrosion, and how they affect an aircraft's structural integrity, and how wiring and functional system degradation occurs. Cracks, corrosion and wiring decay are one set of problems. You might call them 'known unknowns' because you can reasonably anticipate they will occur on an aircraft of a certain age. However, there's another set of more insidious problems that could be called 'unknown unknowns'. They are problems you don't know your aircraft has, and cannot anticipate. Not knowing what to look for, you have to look twice as hard. Some 'unknown unknowns' that have caused frightening incidents, or worse, in GA aeroplanes, include collapsing pilot seat frames, locked-up autopilot override clutches and the breakdown of bladder-style fuel tanks, causing false fuel gauge readings. The trend seems to be that as aircraft age they find new and unanticipated ways to fail. The potential consequences of age-related problems in an aircraft include catastrophic failures followed by often-fatal crashes; in-flight emergencies; increased repair costs and, for commercial operators, foregone revenue as ageing aircraft sit on the ground. Unfortunately, they are often waiting for spares that are no longer manufactured. I '1\. J. \ Your aircraft,' your resrx:>nsibility As an aircraft owner/registered operator you need to understand your responsibility to keep your aircraft airworthy. In general, the way to do that is to take a closer look. at the aircraft and its system of maintenance. It may sound as though CASA is 'picking on' older aircraft and their operators. It is not. This issue applies to all aircraft, new or old, because the set of problems called 'ageing aircraft' depends on many things. The sad facts: All aircraft are ageing from the day they leave the factory. Every aircraft therefore is an ageing aircraft. Newer ones just haven't been exposed to ageing issues for as long. Every part of the aircraft is ageing. It's not just an airframe is~ue, but one that affects systems and parts, including avionics, electrical systems, fuel systems, hydraulic systems, controls, seats, windows, doors and locks. Every aircraft ages at a different rate due to a range of variables. These can include hours, cycles, pressurisation cycles (where applicable) operating environment, storage environment, loading, accident damage, maintenance standard, and pilot handling style. Every aircraft requires different management strategies to maintain airworthiness and cost-effectiveness at different stages of its life. To paraphrase George Orwell's Animal Farm: 'All aircraft are ageing, but some are more ageing than others.' Consider the following. If your aircraft: is more than several years old, has flown a significant number of hours, is, or has been, operated in or near a corrosive,environment, has accumulated many take-offs and landings, or is not supported by an adequate continuing airworthiness program that takes account of ageing aircraft issues. In these circumstances it is highly likely you will need to do something to address its age-related problems.
In black and white:.the regulations Just so you're in no doubt that your ageing aircraft (whether older or newer) is your responsibility, here's what the regulations say: CAR 39 (1) The holder of the certificate of registration for a Class A aircraft must ensure that all maintenance required to be carried out on the aircraft (including any aircraft components from time to time included in or fitted to the aircraft) by the aircraft's approved system of maintenance is carried out when required by that system. CAR 41 (1) The holder of the certificate of registration for a class 8 aircraft must ensure that all maintenance required to be carried out on the aircraft (including any aircraft components from time to time included in or fitted to the aircraft) by the aircraft's maintenance schedule is carried out when required by that schedule. In other words, the registered operator is responsible for the airworthiness and maintenance control of the aircraft to ensure its safe operation. This means that the registered operator (owner) is required to: (a) (b) Maintain the aircraft in an airworthy and serviceable condition so that it can be operated safely. Review the aircraft maintenance plan regularly to make sure it is still effective for the aircraft and reflects any changes that have been made to the aircraft, the way the aircraft is operated, or even where the aircraft is located. How do I take a closer look? What do I look for? How do I find it? Who can I go to for help? You, or your LAME, should be looking for the hidden signs of ageing. These may be in the parts of the aircraft that are regularly inspected, or they may be in parts of its structure that rarely see the light of day. You are looking for: corrosion cracking deteriorated wiring previous repairs, which mayor may not have been adequate airframe structural damage, such as skin rippling subtle misalignment of fuselage, nacelles or control surfaces. As well as physically inspecting the aircraft, you may also need to take a closer look at its maintenance data/history. These can tell you the aircraft's history and reveal whether it has led a life of heavy duty in harsh conditions, or enjoyed a relatively pampered existence as the pride and joy of a fastidious private owner. Know its past and you could predict your aircraft's future. How do I find more information on taking a closer look? More information on how you can recognise these signs is available on CASA's website: www.casa.gov.au/ageingaircraft
who can I go to for help? Manufacturers - can provide information relating to the design assumptions made when the aircraft's system of maintenance was first conceived. LAMEs - can inform you on how best to maintain your aircraft and potentially offer second opinions on your current system of maintenance. Ask your LAME: what checks are included in regular maintenance, how these should be extended to cover off on potential ageing aircraft issues, and what parts of the aircraft are currently not being inspected? Never assume that regular maintenance will reach the level of thoroughness necessary to maintain airworthiness. Engineers (CAR 35 and/or CAR 42M and CAR 42R) - can inform you of modifications and additional maintenance that may be required to improve your aircraft's level of safety when it comes to ageing. CAR 35: A person authorised to approve the design of a modification or a repair to an aircraft. CAR 42M: A person authorised to approve a system of maintenance such that it adequately provides for the continued airworthiness of an aircraft. CAR 42R: A person authorised to make a change to an approved system of maintenance. Type certificate holders - can provide access to the official design data relating to your aircraft. Type clubs - These are a repository of expertise that can provide you with type-specific information relating to your aircraft, and lessons learned by owners of similar aircraft. Non-destructive testing (NOT) specialists - can develop inspection processes that may assist you to continue to operate your aircraft safely without it needing significant disassembly. Rerources Useful sites for advice on managing your ageing aircraft Aeroclub pty Ltd (Australia) www.aeroclub.com.au Aircraft Airworthiness and Sustainment Conference (Australia) www.ageingaircraft.com.au/aasc.html (Conference papers available online) Aircraft Owners & Pilots Association (Australia) www.aopa.com.au Aircraft Owners and Pilots Association (USA) www.aopa.org AOPA Air Safety Institute Online Ageing Aircraft Course (USA) www.aopa.org/asf/osc/loginform.cfm?course=agingaircraft&project_code=& Antique Aeroplane Association of Australia (AAAA) www.antique-aeroplane.com.au Australian Institute for Non Destructive Testing (Australia) www.aindt.com.au Australian Licensed Aircraft Engineers' Association (ALAEA) www.alaea.asn.au Australian Transport Safety Bureau www.atsb.gov.au/aviation. aspx Federal Aviation Administration (USA) www.faa.gov National Institute for Aviation Research at Wichita State University (USA) www.niar.wichita.edu/faaagingaircraft Recreational Aviation Australia (RA-Aus) www.auf.asn.au Regional Aviation Association of Australia www.raaa.com.au Sport Aircraft Association of Australia Inc www.saaa.com