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How to Upgrade Your Aircraft Practically (Part 3)

The common sense approach to upgrading your private jet

Ken Elliott   |   24th February 2017
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Ken Elliott Ken Elliott

Ken Elliott is an avionics veteran of 40 years and more recently has focussed on NextGen. His...
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Ken Elliott continues his series, uncovering the nuts and bolts of upgrading your aircraft to meet upcoming mandates, or to improve its performance and capability generally…

In our previous article, we addressed the general approach to upgrading your aircraft to meet upcoming mandate and operational requirements. In this article, we crack open the different layers of specific jet aircraft upgrades.

Any aircraft modification is like a Matryoshka doll, having multiple layers within. It takes a peeling back of the layers to reveal its complexity. To illustrate what is required, we take an example of one system and walk through the process of accomplishing the upgrade.

In this series, we are focusing on legacy aircraft upgrades using the latest compliant technology. Initially we will cover the preparation and some of the aspects owners need to consider.

Organization Designation Authorization

An upgrade begins with the certification effort undertaken on the first aircraft of type and ends with an approval of required specifications and data issued by the certifying agency. The certification effort can be completed by:

• The aircraft Original Equipment Manufacturer (OEM);
• A Maintenance Repair Organization (MRO) or Repair Station (FAA approved) that may simply repair and install avionics; or
• A facility acting under the Organization Designation Authority (ODA) process that could also be either of the above.

Ultimately, however, the upgrade must be approved by the FAA.

How Organization Designation Authorizations Exist as Entities

OEMs are commonly tied to their own aircraft models. MROs are restricted to those aircraft they are approved, trained and equipped to support (under Repair Station approvals), while ODAs, if stand alone, may be somewhat aircraft agnostic focusing on engineering and certification.

ODAs embedded in maintenance provider Repair Stations will align their effort to internal maintenance programs. Stand-alone ODAs, on the other hand, have the independence to align themselves to multiple Repair Stations, developing system solutions across multiple aircraft platforms.

The FAA delegates some of its functions, allowing greater autonomy for industry providers to self-regulate, certify their own activity and regularly monitor implementation using a rigid auditing process. The ODA effort facilitates this delegation, and each ODA ‘organization’ has an Approved Procedures Manual that must be faithfully followed.

The ODA submits a certification plan to the FAA for approval and completes most of the project’s many steps that normally would be undertaken by the FAA. The big advantage of having an ODA process is that schedules, costs and risks can be controlled by (and within) the organization.

Note that even ODAs embedded in MROs or the aircraft OEM need to have operational independence across several functions.

Because they are delegated by the FAA, they must have a behavioral model that includes an independent oversight capacity, thereby insuring compliance. So, several companies structure their ODA to operate as a self-controlled entity, while rolling engineering up under the same compliance-related umbrella.

However, the independent ODA that is not functioning as a repair station aligns itself with multiple MROs and Avionics Shops. Providing the relationship is good and the price-structuring reasonable, this can work seamlessly for the aircraft operator.

The Repair Station (MRO or Avionics Shop) is the customer interface and obtains the certification data from the ODA. Using the approved data that list all equipment changes and describes in detail the upgrade process, the Repair Station provides a proposal to the operator and if selected, completes the upgrade.

The data package is a Supplemental Type Certificate (STC). In the previous article, we covered how an Approved Model List (AML) STC allowed the application of a single STC, developed on one model of aircraft, to be applied across a wider spectrum of aircraft models, including by a variety of different aircraft manufacturers.

Typical ADS-B Out Equipage Interface Arrangement

An ADS-B STC Upgrade Example

Consider upgrading to ADS B Out, which is applicable across a wide spectrum of aircraft operating in multiple classes of airspace and must be installed and approved by January 1, 2020.

Returning to the data package, one company stands out from the crowd in its ability to provide a straightforward and effective range of AML STCs. Using a single AML STC, CMD Flight Solutions has been able to cover a broad swath of specific aircraft models from multiple FAA Part 25 aircraft manufacturers.

While not alone in its ability to provide ADS-B solutions for legacy aircraft, CMD has stuck to a straight-forward formula and a minimalized certification effort, providing affordability to legacy aircraft operators that would normally have to invest greater dollars in their ADS-B upgrade.

CMD has both FAA and EASA certified ADS-B Out solutions covering business jets, piston and regional carrier aircraft. Their formula starts with the aircraft’s existing transponders, pairing them to their respective WAAS-LPV GPS/FMS and other devices that may be supplied or upgraded, and ending up with the ability to annunciate ADS-B Fail.

Where transponders are not compatible for ADS-B Out, they are replaced with newer and more capable equipment.

The solution provides a path for GPS position data reaching the transponder and any required existing equipment upgrades, along with the means to annunciate failure of the ADS-B function.

If ADS-B In is added/included, the issue of traffic display extends the engineering, certification and integration task. In the structural example used for this article, Figure 3 demonstrates how all the parties work together to supply an ADS-B solution for the operator.

Relationship between Operator and ADS-B Integration Team

There is a strong relationship across this team, including between the equipment providers and the operator, once the aircraft has been delivered. Equipment providers will offer direct service to operators, covering warranty, database subscriptions and some software changes.

For business jets and most turboprops today, the main avionics suites are manufactured by Rockwell Collins, Honeywell and Garmin. However, many legacy aircraft are equipped with third party Flight Management Systems (FMS) where companies such as Universal Avionics and FreeFlight have made significant inroads.

Compatible transponders for our example include:

  • Rockwell Collins TDR-94/94D
  • Honeywell Primus II Radio Suite (including transponder)


Compatible FMS or GPS sensors for our example include:

  • Universal UNS-1(Series)w FMS
  • Honeywell GNSSU
  • Rockwell Collins GPS-4000S
  • FreeFlight 1203C
  • Honeywell/Bendix King KGS-200


Under the CMD solution, a multiple array of subsets combine different equipage over a significant number of aircraft types and configurations. This is just one ADS-B Out example using two separate solution integrations for the different transponders identified above. Also, from time to time, aircraft are required to install new transponders because their existing equipment is not upgradeable.

Additionally, some aircraft require minor adjustments to the strict requirements of an STC. Accordingly, Repair Station engineering will tailor the STC installation data to the specific aircraft, while approving the upgrade via a local field approval process. Alternately the change may require a minor amendment to the existing STC, with the Repair Station seeking approval through the owner of the existing STC.

Remember that an STC incurs its own cost. The STC fee is usually designed to recover the non-recurring engineering and certification cost of its development. While not having to pay the full cost of the STC, operators can expect to share in the recovery of initial costs.

The Real World

There is the ideal world as laid out in a typical upgrade overview, and then there is the real world that is sometimes alluded to within the terms and conditions of a proposal. The upgrade to an aircraft, seen or not seen, will be contingent upon several caveats. Long before an aircraft taxis onto the MRO ramp, there are several key steps that must be completed if you wish to avoid a big surprise.

Current prints (wiring diagrams) provided to engineering: Often prints do not include the integration of systems added since the aircraft’s initial delivery. These earlier changes can dramatically impact the engineers’ approach to the new integration. The prints may reveal clues to an engineer such as indications of previous work not adequately documented elsewhere.

Maintenance records that include all equipment, model, part number and serial number information: From adequate records, a proposal can reflect the compatibility of equipment and its suitability for the upgrade. Just one digit different in the part number of an avionics unit can mean the difference between a minor box modification and a complete replacement.

A thorough record of all modifications, including the location of hardware (e.g., boxes and antennas): Because the new STC will be strict in its requirements, a box or antenna position can be shown to be in a specific location. The need to move it can result in greater cost and work effort. Provide the opportunity for an MRO representative to physically review the STC against your aircraft ahead of the installation. Table A lists several aircraft-specific aspects of an upcoming installation that an MRO would need to know.

Aircraft Physical Situation & Panel Upgrades
Establish if other work needs to be accomplished: Avionic upgrades provide great opportunities to complete other work such as inspections, service alerts, engine and APU checks, interior rework, limited paint and more. Having to access various aircraft zones once and not twice saves on interior repair and refurbishment expense. Having multiple trades in the same zone at the same time can involve significant pre-planning, so knowing about other tasks ahead of the aircraft’s arrival can be very helpful to the MRO.

So, the real world of aircraft upgrades is driven by planning tasks to be accomplished, communicating intentions effectively and providing important aircraft life-cycle information. A face-to-face with the ‘lead’ for each required trade, all in the same room and long before the work is started, can be very meaningful. Some of the trade and skills that should be in the room include:

  • Engines, APU and Accessories
  • Airframe
  • Avionics
  • Customer Service Representative (CSR)
  • Quality Control/Inspection
  • ODA Certification and Engineering
  • Interiors and Cabin Systems
  • Program Lead.


Smaller shops specializing in just avionics, or with limited services will have less representation around the table. Failing the opportunity for a face-to-face, a web call could be helpful to coordinate and ensure all aspects of the upgrade are covered.

Planning Aircraft Arrival at MRO

Assuming the contract is in good shape and all terms are acceptable, an agreeable schedule is then established. The date of arrival for an aircraft to taxi-in to the MRO is predicated by several factors, not including those driven by operator constraints. Some of the factors impacting MRO schedules will be:

  • The site schedule for previously committed work and hangar space;
  • Manpower available to work on your aircraft, which will become an increasing factor as we draw closer to the ADS-B Out equipage deadline of 2020;
  • Equipment availability from the vendors;
  • Schedule with the vendor for sending equipment to the MRO for upgrades and service;
  • Schedule of trades, some of which may be subcontracted;
  • Schedule of uncommon parts that may require special manufacture;
  • Schedule of other trades such as interior and airframe;
  • Certification and engineering schedule.


Specifically for avionics, there are five main skill sets in a decent size shop that will be involved with the aircraft. These include Certification, QA & Inspection; Engineering; Sheet Metal; Installers (wiring) & Checkout; Service (repair and equipment test); and Customer service.

Each has a very important role, and each must be scheduled to be available for your aircraft. A similar structure is implied for all other trades. A schedule can become complex quickly if the operator elects to bundle several tasks during a single visit. Downtime and cost savings may be significant when bundling tasks, but the risk for incurring unanticipated issues and delay become much greater without proper planning.

Garmin Cockpit Panel

If we consider an older aircraft, say pre-2000, the installation may be complex because the aircraft will have undergone technology revision since its initial build. Several mandates had compliance deadlines between 1995 and 2005. Some of these pre-existing mandates included:

  • TCAS I or II
  • TAWS or EGPWS
  • 406 MHz ELT
  • RVSM
  • PBN (Earlier RNP Requirements)
  • WAAS LPV
  • CPDLC (in anticipation of)
  • 8.33 KHz Communication Radios
  • FM Immunity Navigation Receivers
  • Cockpit Voice & Flight Data Recording.


‘Nice-to-have’ upgrades also have impact. Many of these are still migrating into older aircraft platforms and include:

  • Flat Panel Displays
  • Cabin Entertainment & Management
  • LED Lights
  • Winglets
  • Electronic Flight Bags
  • Satcom
  • High Speed Data & On-Board Wi-Fi
  • Enhanced Vision (some with Head-Up Display)
  • Synthetic Vision & Moving Maps
  • Weather and other Data Services.


Pre-existing mandates and “nice-to-have” upgrades alone demonstrate the transformation that has taken place in legacy cockpits.

The new mandates, including ADS-B Out, FANS with data recording and PBN (RNP), each require intrusive integration of new wiring and other trades into the cockpit and elsewhere. So, even with the best of pre-planning, be prepared for at least one item of additional work and cost once you arrive at the MRO if you are operating an older platform.

For our example of an ADS-B Out upgrade, the typical owner of a legacy aircraft can expect to experience equipment, wiring, minor structure and annunciator changes. The possibility exists for further work on antennas and integration to existing systems.

In Summary

By focusing on pre-planning and explaining scheduling issues that integrators face, operators may better understand (and more importantly) better prepare for their upgrades. The ADS-B Out requirement affects most of us and is a good example of an upgrade process.
Smart operators are also preparing for or completing FANS Datacom at the same time as ADS-B Out, especially as equipage integration is shared. FANS includes the use of ADS-C, allowing oceanic surveillance.

Also, FANS and ADS-B both require the integration of the aircraft Flight Management System (FMS). Separately, some operators are including ADS-B In where it is available. While not a requirement, it significantly enhances the services provided by ADS-B and is considered a wise use of the budget.

In the next instalment of how to upgrade your aircraft practically, continuing with issues associated with the ADS-B Out mandate, we will walk through the steps, issues and considerations the owner needs to know once the aircraft arrives on the integrator’s ramp and begins the complete installation that follows.

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Read more about: Upgrades | ADS-B | Avionics Mandates

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