The Pilots Hero
What gives Pilots the confidence to fly thousands of hours in the sky. Upwards of 10kms above the land they cruise above, what is the single thing that makes Pilots and Passengers feel safe? It’s knowing that the aircraft they fly in is safe, well maintained and in perfect condition.
It is the seldom seen aircraft engineers that keep us all safe.
A little while ago, we ran a blog piece by a young pilot called Tom Koppen (Now is the Perfect Time to Become a Pilot). Well, it turns out his old man is an Air New Zealand Aircraft Engineer!
Here, Ron Koppen tells us about the career he has chosen and has loved for almost 40 years.
The audience is yours, Ron!
Thanks John, I’m a Licensed Aircraft Engineer with almost 40 years of experience.
During my career, I have worked in Line, Light and Heavy Maintenance, both overseas and in New Zealand. I hold New Zealand and Australian Engineer’s Licences, with various type ratings as well as a Bachelor of Aviation Management from Massey University. I am currently employed by Air New Zealand as a Production Leader in Heavy Maintenance (Narrow Body Aircraft) in Christchurch.
Ron Koppen
In the 120 years since the Wright Brothers carried out the first controlled, sustained flight of a powered, heavier-than-air aircraft in 1903, aviation has made great technological progress.
The wooden framed and fabric covered aircraft powered by a 12-horsepower engine, producing just 120-130 pounds of thrust, has evolved into aircraft with wings and fuselage made of composite materials and engines that can produce 134,300 pounds of thrust.
From pilots flying by the seat of their pants, the pilots of today are relying on advanced avionic systems to provide them with data to operate the aircraft safely and efficiently.
What has not changed is that with continued operation of an aircraft in a sometimes-harsh environment, there will be deterioration of components/systems and aircraft structure. Nevertheless, the flying public expects that the complex airliners of today perform faultlessly on time, every time!
Aircraft Engineers play a key role in keeping
aircraft in an airworthy and serviceable condition.
To understand the role of the aircraft engineer, it needs to be explained how an aircraft is maintained.
To keep an aircraft not only in an airworthy and serviceable condition, but also to ensure its reliability while in operation, the aircraft is maintained according to a maintenance and reliability programme and is specific to each aircraft fleet type. In addition, the Corrosion Prevention Control Programme (CPCP) forms an important part of the aircraft’s maintenance programme.
The basis for a maintenance programme is provided by the aircraft manufacturers such as Boeing and Airbus. Elements will be added due to Civil Aviation Authority (CAA) requirements and by the operator, because of in-service experience. It is the responsibility of the operator to ensure that the aircraft is maintained in accordance with the CAA approved maintenance programme.
The maintenance programme lists tasks per aircraft system that are based on flight cycles (one flight cycle is one take-off and landing) and flight hours. As you can understand, aircraft on short and medium haul routes do more take-offs and landings than long haul aircraft. Therefore, for the first type, the maintenance programme is driven by flight cycles, whereas the latter is driven by flight hours.
These translate into A-checks, B-checks and C-checks. During these checks components are replaced because of Hard-Life (HT - time-limited installation) or On-Condition (OC, when a component is checked at regular intervals).
Another maintenance process is Condition-Monitoring (CM) and is applied to components to which the HT or OC processes are not applicable and involves the monitoring of failure rates and removals of components without a definite lifetime or wear-out period. CM assesses degradation trends of components through data analyses and measuring these against defined limits. When the trend line meets the defined unacceptable limit, removal of the component is required to prevent in-service failure. An example for this is when the oil consumption or Exhaust Gas Temperature of an engine is exceeding the limits, which could lead to an engine change.
Ron Koppen and Darren Clark reviewing the aircraft’s Technical Log
Engineers either work in Line Maintenance, carried out on the ramp/tarmac, Light Maintenance, with most of the scheduled work carried out overnight or Heavy Maintenance, which is scheduled maintenance with the aircraft out of service for several weeks in a Hangar.
Line Maintenance is the first line of defence when it comes to keeping aircraft in an airworthy and serviceable condition.
When the aircraft arrives at the gate, the aircraft engineer performs a walk-around check for obvious damage or leaks. Once the walk-around check has been completed, the engineer checks the Tech Log to see if there are any defects written up that affect the airworthiness of the aircraft.
Some defects can be easily rectified, while others are more complex and may require parts and time for repairs. If more time is required, the engineer may consult Maintenance Operational Control to request an aircraft swap to avoid a delay or cancellation. Sometimes there are defects that require parts that may not be readily available, especially at an outstation. This does not automatically mean that the aircraft is then grounded.
Each aircraft type has a CAA approved Despatch Deviations Procedures Guide which contains the Minimum Equipment List (MEL) and the Configuration Deviation List (CDL). The MEL lists all the aircraft systems that can have part of it inoperable, often when there is redundancy built in the system. The MEL details what part of the system needs to be serviceable and states the condition of any additional operational or maintenance requirements when it is applied. There are limits on how long the aircraft can operate on the MEL. The MEL dictates the timeframe using category A (specific timeframe to the defect/system), category B (3 calendar days), category C (10 calendar days) or category D (125 calendar days).
Maintenance Operations Control monitors all MEL’s and plans rectification actions. The CDL can be used to let an aircraft return to base with a landing gear door or panel removed, but this carries operational penalties (fuel burn, aircraft operating speed etc) and it is used as a last resort.
Light Maintenance will look after aircraft that Line Maintenance cannot despatch using the MEL/CDL and requires extensive troubleshooting to find the cause of a defect. This is done in a hangar environment and may involve high power engine ground runs.
Every night, there are scheduled checks from simple Line/Weekly Checks, A-checks to clearing MEL’s. The aircraft scheduled for overnight maintenance are arriving at the maintenance base at different times in the evening and need to be ready for the next morning flights, so a bit of planning is involved in positioning the aircraft in the hangar when required.
Some aircraft arrive after midnight and need to be ready for the first flight in the morning (often 06.00 hrs), and often stay at the gate.
Line Maintenance also operates as the Flying Squad, traveling to outstations when, for instance, there is a bird strike, a hard landing or flap overspeed event and inspections need to be carried out to make sure the aircraft can continue in service or need repairs.
Sometimes even an engine change needs to be carried out at an outstation and then it becomes quite a logistical operation to get tooling and a spare engine to the outstation. In my time working for Canadian Airlines working at an outstation, a DC-10 flew a replacement engine in on specially designed mounts under the wing, with the inlet covered by a special cone.
DC 10 fourth engine - Photo credit Jim Owens, Canadian Airlines
Heavy Maintenance carries out the B and C-checks and above (or C-checks combined with 6- or 12-year structural inspections) as well as Special Shop Visits (SSV) to carry out, for instance, Landing Gear Changes or small modifications.
Besides the planned tasks that are listed in the Maintenance Planning Data (MPD), often, modifications are carried out that are either mandated by the regulators via an Airworthiness Directive (and subsequently an aircraft manufacturer’s Service Bulletin) or the operator chooses to incorporate a certain modification the ensure long term in-service reliability.
Because the aircraft is scheduled for a longer period off-line, this is generally the time that larger items get replaced when they are due for an overhaul (shop visit). For larger items, you need to think of Elevators, Rudders, Engines, and Engine Thrust Reversers to name a few. There are also times that big items, such as an engine and pylon, need to be removed for access, because a defect was found requiring rectification.
Especially during the 6- and 12-year structural inspections, the aircraft gets completely stripped on the inside to check all structural members for corrosion, cracking, missing fasteners etc. During these visits, there are many challenges along the way, and it is a real team effort by the various trades to complete the aircraft on time and deliver an airworthy, safe and reliable aircraft back to the airline.
Ash Cotter and Ron Koppen discussing the rigging of an engine thrust reverser
What is it like to be an Aircraft Maintenance Engineer (AME)?
Well, it is a continuous learning process. You can do a 5-year traineeship/apprenticeship covering all aspects of the trade (mechanical or avionics) with a maintenance organisation - or gain your qualifications through the Royal New Zealand Air Force (or equivalent). There are, of course, options to choose a specialist trade such as sheet metal, composites, airframe support (workshops) or Non-Destructive Testing (NDT). During these formative years of your career, you will make great friends and I am still in touch with mates with whom I started my career with almost 40 years ago.
You will be involved in some exciting and interesting jobs, but there are also jobs where it is wet, cold, and dark when you are working outside late at night or worse - when you are assigned that toilet waste tank job that everyone else is trying to avoid!
Once you have qualified as an AME, you start gaining practical experience on the various type of aircraft and will now be able to use approved data (e.g., the maintenance manual), follow operational procedures and use the many computer applications to carry out your job and most importantly, document the maintenance you have carried out.
On top of that, as part of continuous maintenance operation and safety awareness, you are required to stay on top of the various notifications that the company and customers provide. Regular audits are carried out by the various Civil Aviation Authorities that the company holds approval from, and it is not uncommon that an auditor checks your paperwork, asks you questions about processes or carries out a spot check on your toolbox.
To become a Licensed Aircraft Engineer, you will need to sit the various exams required for the License Category associated with your trade. Once you have your basic license and enough experience, you will at some point be selected for a type rating course. You will learn about all the systems in the aircraft as well as the engines and for each technical subject, you must sit a theory exam. With practical experience in type recorded, you will have to sit the final Technical Oral examination. This generally covers technical and safety aspects of maintaining the aircraft, but may cover additional subjects (may differ per maintenance organisation), like understanding the company’s operating procedures, before being issued an aircraft type authorisation. This is when the learning really starts. You will get involved in troubleshooting, with sometimes unexpected causes.
More importantly you will be certifying work that has been carried out on the aircraft and ensuring that this is maintained using the approved data, the correct parts and procedures (such as ETOPs, duplicate inspections, independent inspections, EWIS, CDCCL etc.).
Defects must be repaired and it is expected that you make the decision with airworthiness and safety first and foremost in mind (it’s non-negotiable), but at the same time consider how your decision will affect the airline (time on the ground, reliability while in service, financial impact - in other words, is there a better way?) and impact on passengers (delays, stranded passengers).
With a license comes the responsibility of releasing an aircraft to service (RTS) when you declare the aircraft airworthy, when you sign the Technical Log to clear a defect or carry out an RTS from a Light or Heavy Maintenance Visit (A, B or C-check). This is a responsibility that I don’t think any engineer will take lightly.
In my career I have met some fantastic people, working together in trying circumstances to get the aircraft back in the air. It is during these times that it is the humour that keeps things going as well knowing that you have each other’s back.
I have had some great opportunities such as delivering a new addition to the airline’s fleet to New Zealand, being part of the A320/321NEO entry into service project, carrying out the very first A320NEO engine change (with no one having the experience), carrying out operational check-flights following maintenance, guiding TWA 727 power-backs while working in Europe (reversing the aircraft using the Thrust Reversers) and many other tales to tell.
‘In the end, you know it is all worth it, even the trying times, because you know that even pilots need heroes’.
