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July 2015 U.S. Department of Transportation (DOT) Docket Operations West Building

– Ground Floor, Room W12

- 140 1200 New Jersey Avenue, SE Washington, D.C. 20590

(also submitted electronically)

Dear DOT Representative:

The attached Maintenance of the Transition® Light Sport Aircraft is submitted as supplemental information to the Docket FAA

- 2014

- 0935, Petition for Exemption for the Terrafugia Transition® to provide an Increased Level of Crashworthiness and Functional Safety . This information includes the answers to many frequently asked questions about the maintenance of the Transition®, clarifying the fact that while the Transition® is capable of both flying and drivi ng, it is primarily an LSA airplane from a maintenance perspective. Thank you for your continued consideration of Terrafugia’s petition,

Carl Dietrich, Ph.D. CEO/CTO Terrafugia Inc. 23 Rainin Rd Woburn, MA 01801 +1

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# Maintenance of the Transition® Light Sport Aircraft

Given the dual functionality of the Transition®, Terrafugia is often asked how it will be treated

– as a car or as an airplane

– from a maintenance perspective. Simply put, consistent with the overarching design philosophy of the vehicle, the Transition® is fundamentally an airplane that can drive and as such will be maintained as a Light Sport airplane. This means that the maintenance program for the Transition® will be consistent with the requirements of 14 CFR Part 43 a nd ASTM F2483.


## Maintenance Authorization

 Who can perform maintenance on a Transition®? Per the requirements of 14 CFR § 43.3 and ASTM F2483, depending on the type of maintenance conducted, the following parties may perform work on a Transition®:

o Owner ( if h olding, at minimum, a Sport Pilot license )

o LSA Repairman

o Aircraft and Powerplant (A&P) Mechanic

.

 What work can the owner/operator perform on the Transition ®? If the owner/operator has received appropriate training and an endorsement from a Terrafugia auth orized service center, s/he will be able to perform the following routine maintenance tasks:

o Covering a scratch in the finish

o Changing the oil

o Patching and inflating a tire

o Changing a tire/wheel

o Changing the belt on the Continuously Variable Transmission ( CVT)

o Uploading software updates to the (non

- flight critical) vehicle computer

.

 What special training or experience does an A&P need to work on the Transition®? Terrafugia recommends that anyone servicing the Transition® have experience with carbon fiber

c omposite materials and Rotax engines. A lack of composite experience may result in Terrafugia recommending that, if no other A&P can be found to address the issue, parts be replaced that could otherwise have been repaired by a qualified individual. A lac k of experience with Rotax engines may result in Terrafugia recommending that, if no other A&P can be found to address the issue, the A&P attend a basic maintenance course on the engine such as those offered through Lockwood Aviation’s Aero Technical Insti tute 1

.

1 Other acceptable training courses may be found. Lockwood Aviation’s Aero Technical Institute is onl ine here: http://training.lockwood.aero/2 3 Rainin Road T: 781

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 What resources will be available to qualified maintenance personnel that might not have experience with a Transition® aircraft? Terrafugia will make available a Maintenance Manual per the specifications of ASTM F2483 § 5. As required, this document will include the following general items:

o Equipment list

o Sources to purchase replacement parts

o List of disposable replacement parts, e.g. , belts, filters, and tires

o Engine specifications

o Weight and balance information

o Tire inflation pressures

o Approved oil s and capacities

o Recommended fastener torque values

o General safety information

o Instructions for reporting possible safety of flight concerns found during inspection or maintenance operations.

It will also include the following sections:

o Structures, which i ncludes necessary information on the wing and its folding mechanism

o Engine

o Fuel System

o Propeller

o Utility Systems

o Instruments and Avionics

o Electrical System

o Structural Repair

o Painting and Coatings

o Revisions

o Feedback Form.

The Maintenance Manual will also include the information necessary

– i ncluding checklists if appropriate, required parts, recommended special tools, and the necessary level of certification

– to perform annual and 100

- hour inspections, the owner maintenance tasks listed previously, and an y other Minor maintenance tasks.
Beyond the Maintenance Manual, Terrafugia will provide a website with basic information to assist experienced mechanics as well as a service phone number to discuss individual repair and maintenance needs.

 What will be cons idered Major vs. Minor repairs and maintenance? Per ASTM F2483, Minor maintenance tasks are those tasks that have procedures in the Transition® Maintenance Manual. A Major repair is any operation that is not covered in the Transition® Maintenance Manual.2 3 Rainin Road T: 781

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## Road Usage

 What happens if the Transition® breaks down while driving? If the failure is not something that can be dealt with safely onsite ( i.e ., more severe than running out of gas), the operator should request a flatbed tow truck to transport the aircr aft to the nearest qualified aircraft maintenance location, likely a Fixed Base Operator (FBO) at an airport with an A&P or LSA Repairman on site.

 Does the Transition® come with a spare tire? The operator may choose to carry a spare tire/wheel, jack, and associated hardware in the cargo area of the Transition®, but the additional weight would be considered part of the useful load of the aircraft. Terrafugia intends to recommend that instead, the operator carry a light

- weight tire patch kit, which would mi nimize the impact to the useful load

.

 Can the owner/operator mix 100LL (Avgas) and Premium Unleaded (91+ AKI) in the tank? While it is acceptable to mix fuels in the Transitio n®, if 100LL is used a majority of the time, the oil will need to be changed mor e frequently than if Premium Unleaded is used. Terrafugia will recommend using 91 AKI or higher unleaded gasoline (typically “Premium Unleaded”) , as t he engine and fuel system of the Transition® are designed to accept standard levels of ethanol in automotive gasoline.

 Do driving hours count toward flight maintenance schedules? Yes. Molt Taylor’s Aerocar established a precedent with the CAA/FAA for allowing the driving hours to be counted as a fraction of the flight hours since lower power settings were used for driving, but the Transition® uses a larger range of power than the Aerocar when driving. Thus , su ch de

- rating is not appropriate , and all engine hours will be counted towards the airplane’s maintenance schedule.

 How will the Transition® be inspected by state motor vehicle departments for legal road use? The Transition® will be registered as a car in addition to being registered as an aircraft, and it will be required to undergo annual automotive inspections in the states that require such i nspections. The inspectors will be able to plug into the Transition’s OBD

- II port , which will provide the necessary system diagnostics that cannot be determined by visual inspection.


## Pre

- Flight Inspection

 Who is responsible for ensuring that there is no d amage from driving on the road prior to a flight? The pilot of the Transition® has ultimate responsibility for its safe operation , so i t is the pilot’s responsibility to identify any possible road damage during the pre

- flight inspection . The Transition® p rompts the operator to conduct a preflight inspection during the conversion from car to plane, and the design further encourages a preflight b y requiring manual removal of the side mirrors (a process that requires the pilot to get out of the aircraft).2 3 Rainin Road T: 781

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 What is the recommended threshold for grounding an aircraft during a preflight inspection? If the damage to the aircraft is more significant than bug splatter or scratches to the finish, the pilot should not fly. In particular, if the pilot notices any ch ange in the shape of the vehicle or damage to the carbon

- fiber skin, the Transition® should be inspected by a qualified A&P or LSA Repairman.

 What precautions have been taken to minimize road damage and/or make it obvious that such damage has occurred to the pilot when conducting a pr e - flight inspection? The Transition® has wheel pants that should help reduce the frequency of road debris impacting other parts of the vehicle. The location of the propeller towards the rear of the vehicle further reduces the likelihood of road debris impacting the propeller blades. The finish material of the Trans i tion® makes scratches that could come from such impacts highly visible , increasing the probability that the pilot will see them during a pre

- flight inspection.