23 Rainin Road T: 781-491-0812 www.terrafugia.com

Woburn, MA 0181 F: 781-491-0282 info@terrafugia.com

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 driving, 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

+1-781-491-0812
23 Rainin Road T: 781-491-0812 www.terrafugia.com

Woburn, MA 0181 F: 781-491-0282 info@terrafugia.com

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 and 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 holding, 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 

authorized 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 

composite 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 lack 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 Institute1.

 

1 Other acceptable training courses may be found. Lockwood Aviation’s Aero Technical Institute is online here: 

http://training.lockwood.aero/
23 Rainin Road T: 781-491-0812 www.terrafugia.com

Woburn, MA 0181 F: 781-491-0282 info@terrafugia.com

 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 oils 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 includes 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 – including 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 any 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 considered 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.
23 Rainin Road T: 781-491-0812 www.terrafugia.com

Woburn, MA 0181 F: 781-491-0282 info@terrafugia.com

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 aircraft 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 minimize 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 Transition®, if 100LL is used a majority of the time, the 

oil will need to be changed more frequently than if Premium Unleaded is used. Terrafugia will 

recommend using 91 AKI or higher unleaded gasoline (typically “Premium Unleaded”), as the 

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,

such 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 

inspections. 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 damage from driving on the road prior to a 

flight?

The pilot of the Transition® has ultimate responsibility for its safe operation, so it is the pilot’s 

responsibility to identify any possible road damage during the pre-flight inspection. The 

Transition® prompts the operator to conduct a preflight inspection during the conversion from 

car to plane, and the design further encourages a preflight by requiring manual removal of the 

side mirrors (a process that requires the pilot to get out of the aircraft). 
23 Rainin Road T: 781-491-0812 www.terrafugia.com

Woburn, MA 0181 F: 781-491-0282 info@terrafugia.com

 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 change 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 pre-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 

Transition® makes scratches that could come from such impacts highly visible, increasing the 

probability that the pilot will see them during a pre-flight inspection.