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Aftermarket MRO


Maintenance, repair, and overhaul solutions for business aircraft operators.

By Shannon Forrest
President, Turbine Mentor ATP/CFII.
Challenger 604/605, Gulfstream IV, MU2B

Jet Aviation operates a worldwide network of FBOs in conjunction with MRO facilities.
Maintenance techs have a deep lexicon of terms that are obscure to those outside the circle of knowledge. Most pilots are aware of commonly used maintenance terms like MEL (minimum equipment list) and TBO (time between overhauls), but they may not be familiar with those used to define very specific capabilities and regulatory designations.

Typically, larger flight departments are able to afford an entire maintenance department, complete with a director, inspector, and parts manager, as well as several technicians – some of whom have specializations ranging from avionics to sheet metal repair.

Pilots fortunate enough to work in such environments care little about the inner workings behind the scenes – they’re not concerned about hot sections, routine inspections, and prescribed maintenance intervals.

Whether a replacement part is from an original equipment manufacturer (OEM) or a parts manufacturer approval (PMA) provider, and installed in-house or by a maintenance, repair, and overhaul (MRO) provider is irrelevant.

In truth, they may not even know what any of this means. They just want everything to work as designed so they can get their passengers to the destination safely and efficiently.

Duncan Aviation offers a multitude of PMA and STC options that can be applied as part of routine maintenance or aftermarket retrofitting.

OEM maintenance solutions

Top-tier flight departments that have the highest operating budgets also tend to have the newest aircraft, and along with a new aircraft comes an incentivized maintenance package from the manufacturer.

One of the best known factory maintenance plans is FalconCare by Dassault. The manufacturer describes it as a comprehensive maintenance cost program designed to help customers better manage their maintenance budgets through stable, predictable costs related to parts, labor, and even AOG onsite events, with coverage up to, and including, C inspections.

In the automotive world this is comparable to buying a brand new luxury car at a dealership and then adding the extended warranty and pre-paying for things like oil changes, tire rotations, and tuneups in advance of the maintenance interval coming due.

Whether it’s an airplane or a car, factory-originated maintenance plans can be a financial win, lose, or draw. One advantage of OEM maintenance plans is the use of OEM parts. Ironically, the main disadvantage is the same – the use of OEM parts. In the car analogy, this is like getting your vehicle serviced at the dealership where you bought the car and using replacement parts they provided.

Granted, they are OEM-certified parts, but they come at a substantial markup. An alternative would be to take your luxury car to an independent shop that specializes in your make and model. Doing so usually comes at a reduced labor price, because dealership service departments tend to charge more per hour.

The one caveat that will have a pronounced effect on cost is the ability to acquire parts. If a shop can get equivalent less expensive parts outside of the OEM production process, it can pass the savings along to the customer. In most cases, this works, but there is one German luxury car manufacturer which maintains a tight hold on parts design and distribution.

Even when using an independent repair shop, the parts must be purchased from the OEM. By design (non-standard battery dimensions, for example), only OEM parts will work. As expected, these parts are priced to guarantee very high profit margins.

Clay Lacy Aviation performs a full range of MRO services ranging from new interiors to scheduled heavy maintenance.

Parts manufacturer approval

Prior to the 1990s aircraft manufacturers held a similar parts monopoly. This lasted until PMA made the leap from a nascent concept into a widespread practice. PMA certification is an FAA approval that allows a manufacturer to produce a new or replacement part for an aircraft.

In order to satisfy PMA requirements, a part must meet FAA standards and pass rigorous testing. PMA parts can be used in lieu of OEM parts, and have a few advantages over their OEM counterparts. Lower cost is one such benefit.

Another one is the ability to obtain aircraft replacement parts when they’re no longer made by the OEM (legacy aircraft, for example), or when there’s difficulty obtaining an OEM part because of manufacturing or supply chain issues.

Keeping the mx log book

Knowing the maintenance lingo may be important for pilots working in smaller flight departments that don’t have a dedicated maintenance team, those managing an aircraft for a single individual, or an owner also acting as an operator.

In many of these situations the pilot, rather than the technician, is the one responsible for planning, scheduling, and obtaining any required maintenance. Pilots know the abbreviation FBO for fixed base operator. The counterpart on the maintenance side is MRO – a catch-all term for an organization (or facility) that self-identifies as a provider of some aspect of maintenance, repair, and overhaul.

There’s no universal standard for the term, and, as a result, an MRO can consist of one mechanic who works exclusively on single-engine, fabric-wing biplanes, or 300 maintenance techs who handle anything from turbine seaplanes to transport-category 4-engine jets.

A manufacturer can also be an MRO. And so can a business that operates independently of the manufacturer.

West Star Aviation’s 120,000 sq ft of hangar space in ALN can handle the largest business jets in the fleet.

Part 145 Repair Stations

It’s easy to assume that, if an organization advertises services using the MRO title, it’s authorized (and qualified) to do all work that falls under those auspices, but that’s not the case. “Repair Station” is an FAA authorization issued under Part 145 that permits specific kinds of maintenance.

Repair Station approval falls into 6 categories – airframe, powerplant, propeller, radio, instrument, and accessory. Airframe is further subdivided into small composite, large composite, small sheet metal, and large sheet metal. Engine has 3 subsets – reciprocating below 400 hp, reciprocating above 400 hp, and turbine.

By default, a Repair Station is an MRO, but not the other way around. Independent MROs with Repair Station credentials can provide maintenance solutions for those who prefer to avoid manufacturer-managed organizations.

In addition, an MRO can provide PMA parts. An MRO can exist as a standalone, be associated with an FBO, or be some hybrid thereof. Clay Lacy Aviation applies an MRO/FBO philosophy. Its FBO services are available at OXC (Oxford CT), SNA (Santa Ana CA), and VNY (Van Nuys CA). Clay Lacy Aviation performs everything from light line maintenance to heavy inspections and overhauls.

One thing to keep in mind with a combined MRO/FBO model is that not all services are available at all locations. For example, only 2 of the Clay Lacy locations are Embraer authorized service centers. Major maintenance, like overhauls, modifications, inspections, and retrofits, is almost always scheduled well in advance, which allows for planning to fly the aircraft to a specific destination.

Western Aircraft has 45 manufacturer authorizations to support the King Air, including parts, interiors, engineering, and structures capabilities.

Duncan Aviation received its first PMA authorization more than 30 years ago. The company maintains an online PMA library, which is accessible via a Web portal and searchable by aircraft make, model, or PMA category.

If you find yourself in need of a Hawker Beechcraft 400 airframe sealing ring late on a Friday evening, Duncan may be your only option. The company offers complete MRO services at 3 locations – BTL (Battle Creek MI), LNK (Lincoln NE), and PVU (Provo UT).

Jet Aviation is a well-known MRO/FBO combination that started as a one hangar business in Basel, Switzerland in 1967.

Today, the company has more than 50 locations all over the world. As an FBO, Jet Aviation delivers the level of service one would expect for executive travel. For instance, its BED (Bedford MA) location contains an executive lounge and conference room, crew lounge and snooze room, flight planning/weather service terminal.

It has 3 heated hangars that can accommodate aircraft up to the size of a Gulfstream G650 and Bombardier Global 7000. US Customs is available, as well as rental cars and catering. Jet Aviation BED is a Part 145 Repair Station and holds EASA Part 21J and 21G design and production authority, with the ability to service fixed- and rotary-wing aircraft.

Some MRO entities offer FBO-like services, but have more of a reputation as a maintenance provider than a true FBO. West Star Aviation was founded in 1947 (as Walston Aviation) in ALN (East Alton IL). The present-day company is made up of a host of maintenance acquisitions, and maintains a presence at ALN, APA (Centennial, Denver CO), ASE (Aspen CO), CHA (Chattanooga TN), CXO (Conroe, Houston TX), GJT (Grand Junction CO), MSP (Intl, Minneapolis–St Paul MN), PCD (Perryville MO), and PWK (Exec, Chicago IL).

Fuel and ramp services are available at ALN and GJT, but the PCD location really hits home the fact that West Star is at heart an MRO facility. The PCD facility is considered the company’s Midwest MRO site, and consists of 120,000 sq ft of hangar and office space spread across 4 buildings.

West Star Aviation’s Repair Station certification covers the gamut of executive jets (Bombardier Challenger and Global, Cessna Citation, Dassault Falcon, Embraer, Gulfstream, Hawker, Learjet), as well as turboprops (Conquest, King Air, Piaggio P180). A 28,000 sq ft paint facility with a state-of-the-art downdraft filtration system completes the setup.

Elliott Aviation is an authorized dealer for Raisbeck performance systems, as well as a maintenance provider on the Blackhawk engine.

Unexpected mx events

Unscheduled, unexpected, and unplanned maintenance are known in the industry by the worst 3 letters a pilot can hear – AOG (aircraft on ground), meaning something is broken and the aircraft can’t fly.

Unless you’re fortunate to work for a company that has a spare aircraft crewed up, ready, and waiting to salvage the mission, you must find a qualified technician and perhaps even parts.

Western Aircraft, located at BOI (Boise ID), is an FAA Certified Repair Station. In addition, the company is an authorized service center for Beechcraft, Cessna, Dassault, Embraer, King Air, Kodiak, Pilatus, and Piper. FBO services, including snooze rooms, showers, courtesy cars, and complimentary snacks and refreshments, are delivered from a private terminal at BOI.

According to Western Aircraft, they stock more than 20,000 FAA-approved line items, representing more than $15 million in aftermarket and proprietary parts. Immediate inquiries are driven by a 1-800 number, and orders are filled day or night. An AOG based on a component malfunction is especially problematic.

Manufacturing disruptions during the Covid shutdowns of 2020 and 2021 created a parts shortage, so having the ability to acquire parts from an MRO provider in a timely manner is advantageous for flight departments.

The avionics issue

Avionics has become another unexpected problem. Microchip and processor shortages have created an enormous backlog of orders for new equipment, which has caused shops to roll back appointments by several months. Elliott Aviation is an MRO/FBO that’s established a world-class reputation in the field of avionics.

The company holds STCs for several types of aircraft on a wide range of products, including enhanced ground proximity warning systems (EGPWS), terrain awareness and warning systems (TAWS), traffic alert and collision avoidance systems (TCAS), flight management systems (FMS), Wi-Fi, and flat-panel systems.

For retrofit and replacement, technicians develop professional wiring diagrams using CAD technology, which provides a clean design and serves as a playbook for installation. This methodology equates to a shorter down time.

A large inventory of aftermarket avionics gives flight departments additional options, which could be a temporary solution while waiting for the supply chain logjam to improve. Something “newer” may be better than “brand new” for the time being.

Closing remarks

For the most part, MRO lies outside the daily purview of the pilot, most of whose time is spent flying the airplane with little attention to the mechanical aspects unless something breaks. As a result, it’s easy to become myopic when it comes to how and where maintenance is accomplished.

Factory-based maintenance is often the default, and although that’s a viable option, it’s not the only one. Independent (non-factory based) MRO/FBOs can deliver reliable, cost-effective maintenance solutions ranging from AOG events to overhauls and major modifications.

Shannon Forrest is a current line pilot, CRM facilitator, and aviation safety consultant. He has more than 10,000 hrs TT and holds a degree in behavioral psychology.