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NextGen - How will you manage the transition?

With all the changes planned, upgrading your tech can seem overwhelming. Small steps are the way forward, suggests Brian Wilson.

Brian Wilson   |   12th August 2014
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Brian Wilson Brian Wilson

Brian Wilson is the National Key Accounts Manager at Gogo Business Aviation, an industry-leading...
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As a dedicated runner over the last 40 years (covering races ranging from five kilometres to the Marathon), I have learned that mentally it’s better to just take one mile at a time. Standing at the starting line thinking about covering 26.2 miles can be intimidating. Breaking the distance down into smaller, manageable segments eases your anxieties and gives you confidence to achieve your overall goal.

The same approach can be used when figuring out how you are going to manage the transition to ensure your flight department and aircraft meet all the requirements of NextGen. Imagine standing at your starting line having received an email from the Aviation Director asking for an update on:
• LINK 2000+
• TCAS 7.1
• RPN.

You can multiply this task accordingly if you have numerous different airframes in your flight department. And the above acronyms only cover the equipment aspect! You will still need to account for Pilot training (textbook and operational); Minimum Equipment List (MEL); Amendments; and Letters of Authorization (LOA) for “N” registered aircraft. Your reply to the Aviation Director should stipulate, “This will be an allhands team-effort, and we had better get started now!”

By way of a quick primer, this sophisticated upgrade should only be performed by a quality-approved repair station with demonstrable ability to do the job right. The repair station should be instantly able to answer your questions without “getting back to you”. Does it have the resources to complete the certification path (both on the equipment and operability approval process)?

Step 1: FMS Upgrade

As an operator, you will need to do your homework prior to performing these sequential upgrades to ensure the equipment and software is covered under the pending STC. I recommend that you first focus on your Flight Management System (FMS), budgeting this upgrade at your next MX interval, along with transponder wiring provisions for Automatic Dependent Surveillance–Broadcast (ADS-B).

Future Air Navigation Systems (FANS) will require your FMS to have Wide Area Augmentation System (WAAS)/Controller Pilot DataLink Communication (CPDLC) abilities. WAAS is needed so that the position updates to your transponders are adequate for ADS-B operation. CPDLC allows the crew to communicate with ATC using short, scripted messages which typically include flight level changes, position reporting and departure and arrival clearances.

Many larger airframes already have WAAS-enabled computers. If yours does, you still need to confirm they meet the standards for the mandate. Since these upgrades can be quite costly, some repair stations are opting to install a third stand-alone FMS to save on cost and still comply with the mandate.

In most cases a third standalone FMS will come with a remote Course Deviation Indicator (CDI) and new Data Transfer Unit (DTU). If available panel space becomes an issue; consider requesting a portable DTU in lieu of a fixed mounted version.

It is important to remember the FMS associated with your FANS solution does not have to be coupled to the instrumentation. For clarification - updating your existing FMS to WAAS does provide other immediate benefits like Localizer Performance with Vertical guidance (LPV) approaches; it’s just “not” required for FANS if you choose the third FMS option.

The new FMS will also handle the requirements of Automatic Dependent Surveillance - Contract (ADS-C) by reporting the current aircraft position via satellite or VHF datalink to ATC. ADS-C improves the surveillance of en route aircraft and provides the path to reduced, and even potential elimination of annoying HF transmissions.

Step 2: CVR, Satcom & DMU

After the FMS upgrade and ADS-B provisional wiring have been completed we can focus on the next step. Hopefully your next major MX inspection falls into a new calendar and budgetary year allowing new funds to be allocated for the Cockpit Voice Recorder (CVR), Satcom and Data Management Unit (DMU) modifications. Again, you should always seek to confirm the upgrade is part of a certified solution.

CVRs by definition were designed to record all aural sounds in the cockpit over the preceding 30 minutes. FANS-compliant CVRs must have two hours of recording time, and must be able to record the text messages (CPDLC) sent by the FMS. Some CVRs can be upgraded by the vendor while most will need to be replaced.

A word of caution for those with upgradeable units: since the DMU will also be changed it is important to verify compatibility of the two units. You can do this by asking the manufacturer if the CVR and the new DMU are on their ‘approved’ list. Units on the list have not only passed the compatibility test, they also have the software written to extrapolate the data from the CVR.

Many aircraft already have a DMU on board, providing basic datalink information. Currently these legacy units are not upgradeable; vendors have been very slow to provide an upgrade solution, and most engineering companies have decided to use new FANSapproved units.

All of the certification paths, I have reviewed have confirmed this to be true. Link 2000+ which is already activated in portions of Europe requires a specific ship-set of messages transmitted from a VHF Digital Link Mode 2 (VDL-2) transceiver. Your new DMU should have this internal feature to ensure you don’t need another unit installed at a later time.

Since this is a VHF line-of-sight transmission, prepare and budget for the possibility of a new antenna on the lower aft fuselage. A possible money-saving tip would be to have a coaxial relay installed so the existing Aerodrome Flight Information Service (AFIS) unit and new DMU could share the same existing antenna. Some configurations only allow the crew to transmit flight plans and other specific data through the existing AFIS system.

The same communication functionality must be provided by your Satellite Communications (Satcom) system when flying over the ocean and outside of line-of-sight coverage. For those fortunate enough to already have modified your legacy voice-only Satcom system for one capable of sending and receiving data you might already be FANS compliant. Others will have to put aside funds to modify their system or install a compatible FANS Over Iridium (FOI) system.

FANS requires a dedicated channel to the cockpit to ensure the crew can send and receive CPDLC messages. Vendors who are vested in the Satcom industry continue to introduce new solutions that should surely benefit the operators with a more affordable path. Choices include a remote DataLink Unit (DLU) featuring a built-in Iridium transceiver that bolts onto an existing system. Another offers cost incentives to upgrade the existing system and add a Data Interface Unit (DIU) to meet compliance.

Essentially, it is important to remember that you have choices when it comes to the Satcom and you should always ask “why” if you are told your current system will be replaced.

In addition, visual alerts must be in view of both crew members and an aural alert atypical to any other sound is required in the cockpit to ensure the crew is cognizant of any message sent by ATN to the aircraft.

ADS-B: Don’t Wait

Automatic Dependent Surveillance - Broadcast (ADS-B) is either something you need to budget for immediately or can be put off for a while, based on where you fly your aircraft. This “broadcast” sends the aircraft’s position, identification, altitude, velocity and other critical information to ATC.

Countries like Australia and areas in the Asia Pacific regions already require your aircraft to be ADS-B equipped. Europe will follow in 2017 and the United States in 2020. I cannot stress highly enough, however, the importance of not waiting to the last calendar month to get this task done. Not only do you receive the benefits of increased situation awareness and safety for you and your passengers, but there simply is not enough installation capacity to meet the deadline if you wait to the last minute.

ADS-B upgrades require a STC, and your transponders will have to be replaced or modified to meet the mandate. As mentioned above, a new WAAS-compliant FMS will provide the needed position updates critical for proper operation. New wiring will also be required between the FMS and the transponders, and in addition, regulations require an annunciator to warn the crew in the event the system is not able to broadcast the necessary data.

TCAS 7.1: Don’t Underestimate

The European Union will implement Traffic Collision Avoidance System (TCAS) change 7.1 for retrofit aircraft in December 2015. Do not underestimate the costs needed to perform this upgrade as many existing TCAS processors will need to be replaced, and STCs will need to be amended.

Units that can be modified will probably require sending to the manufacturer, so schedule this during an MX event and expect a part-number change. This software update allows the processor to automatically compute and command “reversal” avoidance manoeuvres in the rare case that two aircraft were given similar evasive coordinates.


We have all heard the statement; the work is not complete until the paperwork is done! This holds true for NextGen. You will need to set aside the funds, and just as importantly commit the time required to get the crew trained, the manuals revised, and seek approval for the infamous Letter of Authorization (LOA).

Regulatory agencies have seen a recent increase in requests for LOA approvals for FANS. I anticipate the number of requests will continue to increase in the coming months as the deadline looms closer. Couple this with an agency that is short-staffed and probably will not be adding additional personnel, and a warning begins to form not to let this issue slide to the deadline...

I have also heard that the level of knowledge for NextGen varies greatly from agency to agency. It is said that there is no better time to prepare than the present. I hope you heed this writer’s warning not to procrastinate and get your transition plan for NextGen in order now.


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