ADVISORY CIRCULAR
AC No: AC 103-7
Date: 1/30/84
Initiated
by: AFO-820
Subject: THE ULTRALIGHT VEHICLE
1. PURPOSE. This advisory circular provides guidance to the
operators of ultralights in the United States. It discusses the
elements which make up the definition of ultralight vehicles for
the purposes of operating under Federal Aviation Regulation (FAR)
Part 103. It also discusses when an ultralight must be operated
as an aircraft under the regulations applicable to certificated
aircraft.
2. BACKGROUND.
a. The number of ultralight vehicles and participants in
the various aspects of this sport has increased dramatically in
recent years. All indications are that this growth will
continue. The presence of these vehicles in the national
airspace has become a factor to be considered in assuring the
safety of all users of the airspace.
b. On October 4, 1982, a new regulation (Part 103)
applicable to the operation of ultralight vehicles became
effective. This regulation defines those vehicles which may be
operated as "ultralight vehicles" and provides operating rules
which parallel those applicable to certificated aircraft. The
Federal Aviation Regulations regarding aircraft certification,
pilot certification, and aircraft registration are not applicable
to ultralight vehicles or their operators.
c. Ultralight vehicle operations may only be conducted as
sport or recreational activity. The operators of these vehicles
are responsible for assessing the risks involved and assuring
their own personal safety. The rules in Part 103 are intended to
assure the safety of those not involved in the sport, including
persons and property on the surface and other users of the
airspace. The ultralight community is encouraged to adopt good
operating practices and programs in order to avoid more extensive
regulation by the Federal Aviation Administration (FAA).
3. DEFINITIONS. For the purpose of this advisory circular, the
following definitions apply:
a. Ultralight Vehicle. This refers to ultralights meeting
the applicability for operations under Part 103.
b. Recognized Technical Standards Committee. This term
refers to a group of at least three persons technically qualified
to determine whether a given ultralight meets the requirements
for operations under Part 103, as follows:
(1) It is recognized by a national pilot
representative organization,
(2) It is comprised of persons not directly associated
with the manufacture and/or sale of the make of ultralight being
inspected, and
(3) It conducts its review and documents the findings
in accordance with the guidance provided in this circular.
4. WHAT DOES THIS MEAN FOR THE PERSON WHO WANTS TO FLY UNDER
PART 103?
a. You are Responsible for Your Personal Safety.
Certificated aircraft are designed, flight tested, manufactured,
maintained, and operated under Federal regulations intended to
provide an aircraft of consistent performance, controllability,
structural integrity, and maintenance. An ultralight vehicle is
not subject to Federal aircraft certification and maintenance
standards. This means that the costs of purchasing and
maintaining an ultralight vehicle may be considerably less than
the purchase of a certificated aircraft. There is no assurance
that a particular ultralight vehicle will have consistent
performance, controllability, structural integrity, or
maintenance. Your safety, and potentially that of others,
depends on your adherence to good operation and maintenance
practices. This includes proper preflight techniques, operation
of the vehicle within the manufacturer's recommended flight
envelope, operation only in safe weather conditions, and
providing safety devices in anticipation of emergencies. Part
103 is based on the assumption that any individual who elects to
fly an ultralight vehicle has assessed the dangers involved and
assumes personal responsibility for his/her safety.
b. You are Limited to Single-Occupant Operations. Part 103
is based on the single-occupant concept; operation by an
individual who has assumed all responsibility for his/her
personal safety. Pilots of ultralight vehicles subject to Part
103 are not required to have training or previous experience
prior to the operation of these vehicles. You should consider
receiving adequate training prior to participation.
c. You are Limited to Recreation and Sport Purposes.
Operations for any other purposes are not authorized under the
applicability of Part 103.
d. You are Limited as Necessary for the Safety of Other
Persons and Property. Part 103 consists of operating rules which
were determined necessary for the safety of other users of the
airspace and persons on the surface. These rules were developed
in consideration of the capabilities of the vehicles and their
pilots. It is your responsibility to know, understand and comply
with these rules. Ignorance of the regulations pertaining to the
activities you pursue is not an acceptable excuse for violating
those regulations.
e. You are Responsible for the Future Direction the Federal
Government Takes With Respect to Ultralight Vehicles. The action
of the ultralight community will affect the direction Government
takes in future regulations. The safety record of ultralight
vehicles will be the foremost factor in determining the need for
further regulations.
5. FAA CONTACT POINTS. The FAA will provide clarification of
particular subject areas, information, and assistance pertaining
to the operations of ultralight vehicles through the following
contacts:
a. Flight Standards Field Offices. Flight Standards
District Offices (FSDOs), General Aviation District Offices
(GADOs), and Manufacturing and Inspection District Offices
(MIDOs) are the FAA field offices where information and
assistance are available regarding the operation of ultralight
vehicles, acceptable methods of complying with Part 103
requirements, and compliance with other regulations should it
become necessary to operate an ultralight as a certificated
aircraft.
b. Air Traffic Control Facilities. FAA Air Traffic Control
facilities are located throughout the United States and maintain
jurisdiction over the use of the controlled airspace in their
particular area. To obtain authorization to operate from or into
the airspace designated in Section 103.17, contact must be made
with the controlling facilities.
c. Flight Service Stations. These facilities provide
operational information to pilots, such as weather briefings,
advisory information regarding the status of facilities, etc.,
and are the most accessible of the FAA points of contact. They
can provide additional information regarding how to reach the
other points of contacts mentioned here.
d. Airports District Offices. These offices inspect
airports certificated under Part 139 of the FARs to determine
whether an airport is safe for public use. Persons wanting to
establish new airports or flight parks, or operate ultralight
vehicles from Federally-funded airports, may contact these
offices for assistance.
6.-9. RESERVED.
SECTION 1. WHAT IS AN ULTRALIGHT VEHICLE?
10. SCOPE AND CONTENTS. This section discusses the elements
contained in Section 103.1 which make up the definition of an
"ultralight vehicle" and the proper way to assure that Part 103
applies.
11. APPLICABILITY OF PART 103.
a. Probably the single most critical determination which
must be made is whether or not your vehicle and the operations
you have planned are permitted under Part 103. The fact that you
are operating a vehicle which is called or advertised as a
"powered ultralight," "hang glider," or "hang balloon" is not an
assurance that it can be operated as an ultralight vehicle under
Part 103. There are a number of elements contained in Section
103.1 which make up the definition of the "ultralight vehicle."
If you fail to meet any one of the elements, you may not operate
under Part 103. Any operations conducted without meeting all of
the elements are subject to all aircraft certification, pilot
certification, equipment requirements, and aircraft operating
rules applicable to the particular operation.
b. The FAA realizes that it is possible to design an
ultralight which, on paper, meets the requirements of Section
103.1, but in reality does not. However, the designers,
manufacturers of the kits, and builders are not responsible to
the FAA for meeting those requirements. Operators of ultralights
should bear in mind that they are responsible for meeting Section
103.1 during each flight. The FAA will hold the operator of a
given flight responsible if it is later determined that the
ultralight did not meet the applicability for operations under
Part 103. Be wary of any designs which are advertised as meeting
the requirements for use as an ultralight vehicle, yet provide
for performance or other design innovations which are not in
concert with any element of Section 103.1. The FAA may inspect
any ultralight which appears, by design or performance, to not
comply with Section 103.1.
c. If the FAA Determines Your Ultralight Was Not Eligible
for Operation as an Ultralight Vehicle. If your ultralight does
not meet Section 103.1, it must be operated in accordance with
applicable aircraft regulations. You will be subject to
enforcement action ($1000 civil penalty for each violation) for
each operation of that aircraft.
12. ELEMENTS MAKING UP THE DEFINITION OF AN ULTRALIGHT VEHICLE.
a. Single Occupancy. An ultralight cannot be operated
under Part 103 if there is more than one occupant or if it has
provisions for more than one occupant.
b. Sport or Recreational Purposes Only. An ultralight
cannot be operated under Part 103 if it is operated for purposes
other than sport or recreation or if it is equipped for other
uses.
c. No Airworthiness Certificate. An ultralight cannot be
operated under Part 103 if it has been issued a current U.S. or
foreign airworthiness certificate.
d. Unpowered Vehicles. An unpowered ultralight cannot be
operated under Part 103 if it weighs 155 pounds or more.
Balloons and gliders are unpowered vehicles.
e. Powered Vehicles. A powered ultralight cannot be
operated under Part 103 when it has an empty wight of 254 pounds
or more; has a fuel capacity exceeding 5 U.S. gallons; is capable
of more than 55 knots airspeed at full power in level flight; and
has a power-off stall speed which exceeds 24 knots.
13. SINGLE OCCUPANT.
a. The Rationale for Allowing Single-Occupant Operations
Only. One aspect of the rationale for allowing ultralight
vehicles to operate under special rules which do not require
pilot and aircraft certification is the single-occupant
limitation. The assumption is made that a person who elects to
operate an uncertificated vehicle alone is aware of the risks
involved. This assumption does not necessarily hold true for a
passenger. Because the pilot qualifications for ultralight
vehicle operations are not Federally controlled or monitored, the
single-occupant requirement is a necessary component to the
continuation of the policies and regulations which allow the
operation of ultralight vehicles free from many of the
restrictions imposed on the operation of certificated aircraft.
b. Guidelines Regarding Seating Arrangements Which Should
be Considered when Purchasing or Operating an Ultralight Vehicle.
(1) Any provisions for more than one occupant
automatically disqualify an ultralight for operations under Part
103.
(2) Some powered ultralights were originally
manufactured with bench or "love" seats with only one seatbelt,
but have been advertised as two-place in the ultralight
periodicals. They are not eligible for operations under Part
103. While no maximum width standards for the size of a "single"
seat have been established at this time, most manufacturers are
providing seats which have a width of 18 to 22 inches. Any seat
notably wider than 22 inches raises a question as to whether the
ultralight is intended for single occupancy.
(3) An ultralight with provisions for more than one
occupant can only be operated as a certificated aircraft, even
when occupied by only one person. In addition to the previously
stated aircraft certification and registration requirements, the
pilot must hold a medical certificate and at least a student
pilot certificate with the proper endorsements for solo
operations. At least one occupant during two-occupant operations
must hold at least a private pilot certificate.
c. Two-place Ultralight Operations under Part 103. The
AOPA Air Safety Foundation, Experimental Aircraft Association,
and the United States Hang Gliding Association have been granted
exemptions from the applicable aircraft regulations to authorize
use of two-place ultralights under Part 103 for limited training
purposes and for certain hang glider operations. Except as
authorized by exemption, no person may operate an ultralight
under Part 103 with more than one occupant.
14. RECREATION AND SPORT PURPOSES ONLY (SECTION 103.1(b)).
a. The Rationale for Only Allowing Recreation and Sport
Operations Under Part 103. In combination with the
single-occupant requirement, the limitation to recreation and
sport operations only is the basis for allowing ultralight
vehicle operations under minimum regulations. The reason for
allowing the operation of these vehicles without requiring
aircraft and pilot certification is that this activity is a
"sport" generally conducted away from concentrations of
population and aircraft operations.
b. Determining Whether a Particular Operation if for
Recreation and Sport Purposes. There are several considerations
that are necessary in determining whether a given operation is
conducted for recreation or sport purposes:
(1) Is the flight undertaken to accomplish some task,
such as patrolling a fence line or advertising a product? If so,
Part 103 is not applicable.
(2) Is the ultralight equipped with attachments or
modifications for the accomplishment of some task, such as banner
towing or agricultural spraying? If so, Part 103 does not apply.
(3) Is the pilot advertising his/her services to
perform any task using an ultralight? If so, Part 103 does not
apply.
(4) Is the pilot receiving any form of compensation
for the performance of a task using an ultralight vehicle? If
so, Part 103 does not apply.
c. Examples of Operations Which are Clearly Not for Sport
or Recreational Purposes.
(1) Aerial Advertising. Part 103 does not apply to
operations that include the towing of banners and the use of
loudspeakers, programmed light chains, smoke writing, dropping
leaflets, and advertising on wings; nor does it apply to the use
of interchangeable parts with different business advertisements
or flying specific patterns to achieve maximum public visibility.
(2) Aerial Application. Part 103 does not apply to
operations that include using an ultralight to perform aerial
application of any substance intended for plant nourishment, soil
treatment, propagation of plant life or pest control. An
ultralight with an experimental certificate as an amateur
aircraft could be used to perform this function under specific,
limited circumstances. Paragraph 35b provides more detail on
this subject.
(3) Aerial Surveying and Patrolling. Patrolling
powerlines, waterways, highways, suburbs, etc., does not come
under Part 103. The conduct of these activities in an ultralight
must be in compliance with applicable aircraft regulations as
outlined in paragraph 34. Local, state, or Federal government
entities may operate an ultralight as a "public aircraft." This
is discussed in greater detail in paragraph 35a.
(4) Carrying parcels for hire.
d. Examples of Situations Involving Money or Some Other
Form of Compensation Allowable Under the Recreation and Sport
Limitation.
(1) Rental of Ultralight Vehicles. Renting an
ultralight vehicle to another person is permissible.
(2) Receiving a Purse or Prize. Persons participating
in sport or competitive events involving the use of ultralights
are not prohibited from receiving money or some other form of
compensation in recognition of their performance.
(3) Authoring Books About Ultralights. Persons are
not prohibited from flying ultralights and then authoring books
about their experiences, for which they ultimately receive
compensation.
(4) Receiving Discount on Purchase of an Ultralight.
There is no prohibition which would prevent you from taking
advantage of any discount on the price of an ultralight a company
might offer where its logo or name appears on a portion of the
vehicle. You cannot, however, enter into any agreement which
might specify the location, number, or pattern of flights
contingent on the receipt of that discount. Any operation under
such an agreement could not be conducted under Part 103.
(5) Participation in Airshows and Events. You may
participate in airshows and other special events where persons
are charged for viewing those events, so long as you receive no
compensation for your participation. This does not hold true
where you stand to benefit directly from the proceeds as the
organizer or producer of the event.
15. AIRWORTHINESS CERTIFICATE (SECTION 103.1(c)).
a. If your ultralight has been issued an airworthiness
certificate, you cannot operate it as an ultralight vehicle under
Part 103. An ultralight cannot be operated interchangeably as a
certificated aircraft and an ultralight vehicle.
b. If you want to operate your ultralight under Part 103,
you must turn in, to the issuing authority, any airworthiness
certificates currently issued for the craft.
c. You may operate an ultralight as a certificated aircraft
if you obtain the proper certification. If you do not already
hold an airworthiness certificate, you should consult paragraph
31 for further guidance.
d. An ultralight is eligible for operation under Part 103,
even where the same make and model is also being issued
airworthiness certificates, so long as all elements of the
definition of an ultralight vehicle contained in Section 103.1
are satisfied. As an example, assume that there is a model which
would meet the definition of an ultralight vehicle being
manufactured in Canada and is issued a Canadian airworthiness
certificate. If you purchased one, you would have to turn in the
airworthiness certificate to the Canadian authorities before
operating it in the United States under Part 103.
16. UNPOWERED ULTRALIGHT VEHICLES.
a. Unpowered Ultralight Vehicles Eligible for Operation
Under Part 103. All forms of gliders and free balloons weighing
less than 155 pounds and meeting all other requirements of 103.1
are eligible for operation under Part 103.
b. Unpowered ultralights eligible for operations under Part
103 are not required to be operated under that Part. In some
cases, you can obtain certification of your glider or free
balloon as an experimental aircraft.
c. Computing the Empty Weight of an Unpowered Ultralight
Vehicle.
(1) Gliders. The fuselage, wings, structure, control
surfaces, harnesses, and landing gear, etc., are included in this
determination. Parachutes and all personal operating equipment
and harnesses associated with their use are not included.
(2) Free Balloons. The envelope, lines, harnesses,
gondola, burner, and fuel tank are included in this
determination. Parachutes and all personal operating equipment
and harnesses associated with their use are not included. The
weight of the fuel, in the case of a hot-air balloon, or any
logical amount of removable ballast, when intended for control of
the buoyancy of a gas balloon, is not included in the weight
specified in Section 103.1(d).
d. Free Balloons are Considered "Unpowered." A balloon,
for Part 103 eligibility, is considered an unpowered ultralight,
regardless of whether it drops ballast to ascend or uses heated
air. The burner on a hot-air balloon is used to raise the
temperature of the air in the envelope allowing the balloon to
rise. This can be compared to the glider's use of lifting air as
a means of ascending. In both cases, no method of horizontal
propulsion is employed and a loss of the lifting force will cause
the vehicle to descend to the surface.
17. POWERED ULTRALIGHT VEHICLES.
a. "Powered" Ultralights Eligible For Operation Under Part
103. All ultralights with a means of horizontal propulsion which
also meet the provisions of Section 103.1 are eligible; this
includes ultralight airships, helicopters, gyrocopters, and
airplanes.
b. A powered ultralight eligible for operation under Part
103 is not required to be operated under that Part. You may
elect to certificate and operate it as an experimental aircraft.
The applicable procedures and regulations are explained in
Advisory Circular 20-27C, Certification and Operation of Amateur-
Built Aircraft.
18. POWERED VEHICLE WEIGHT.
a. Items Excluded From the Computation of the Empty weight
of a Powered Ultralight Vehicle.
(1) Safety Devices Which are Intended for Deployment
in a Potentially Catastrophic Situation. Parachutes and some
associated additional equipment necessary for their operation
meet this criteria. Other devices, such as seatbelts, roll
cages, instruments, or wheel brakes, are considered part of the
airframe and are included in the empty weight.
(i) Up to 24 pounds of weight associated with the
parachute system may be excluded by the FAA without requiring a
separate weighing of the system components.
(ii) No weight allowance will be given for any
component of the parachute system if, when it was operated, the
parachute was not carried and attached to the ultralight at the
reinforced points/fittings provided.
(2) Floats Used For Landings On Water. Only the
weight of the floats and any integral, external attachment points
are excluded. All other items associated with attachment of the
floats to the airframe are included in the vehicle's empty
weight. Up to 30 pounds per float may be excluded by the FAA
without requiring substantiation of the float's actual weight.
This exclusion was allowed under the rationale that
float-equipped ultralights would not usually be operated in the
vicinity of airports and large concentrations of people and,
thus, would be even less of a safety hazard than those which had
conventional landing gear. While amphibious capability would
appear to negate somewhat that rationale, some allowance for the
"float" capability is made.
(i) Amphibious Floats. Up to 30 pounds per float
may be excluded by the FAA. The weight of all attached items
associated with the installation and operation of the landing
gear is included in the calculation of the dry, empty weight
specified in Section 103.1(e)(1). Satisfactory evidence of the
weight of those components must be available.
(ii) Amphibious Fuselage. Where the fuselage is
intended to function as a float during water landings, up to 30
pounds (the average weight of a single float) is allowed by the
FAA to be excluded from the empty weight where the ultralight is
capable of repeated water takeoffs and landings. (Operators may
be required to demonstrate the water operational capability of
their vehicle in order to receive an allowance for the added
weight.) Up to 10 pounds per outrigger float and pylon is also
allowed by the FAA.
(iii) "Float" provisions not discussed here
should be reviewed with FAA personnel at a Flight Standards field
office.
b. Acceptable Methods for Determining the Weight of an
Ultralight. The completely assembled ultralight should be taken
to a draftless location and placed on:
(1) A Single Scale. A determination may be made on a
calibrated scale which has sufficient weighing surface to
accommodate the ultralight resting fully on that surface without
any stabilizing assistance, or
(2) Two or More Scales. A determination may be made
on two or more calibrated scales if they are located at all
points where the ultralight contacts the surface when parked and
it is resting fully on those scales without any stabilizing
assistance. In this case, the sum of the scales will be used.
19. MAXIMUM FUEL CAPACITY OF A POWERED ULTRALIGHT VEHICLE. The
maximum fuel capacity for a powered ultralight vehicle is 5 U.S.
gallons. Any powered ultralight with fuel tank(s) exceeding this
capacity is ineligible for operation as an ultralight vehicle.
a. Determination of Fuel Capacity. The total volume,
including all available space for usable and unusable fuel in the
fuel tank or tanks on the vehicle is the total fuel capacity.
The fuel in the lines, pump, strainer, and carburetor is not
considered in a calculation of total volume.
b. Use of an Artificial Means to Control Capacity.
(1) Tanks which have a permanent standpipe or venting
arrangement to control capacity are permitted, but may be subject
to demonstration of the capacity if there is any reason to doubt
that the arrangement is effective.
(2) A temporary, detachable, or voluntarily-observed
method for restricting fuel capacity, such as a "fill-to" line,
is not acceptable.
20. MAXIMUM LEVEL FLIGHT SPEED OF A POWERED ULTRALIGHT VEHICLE.
The maximum speed of an ultralight vehicle at full power in level
flight cannot exceed 55 knots.
a. The 55 knots specified in Section 103.1(e)(3) is a
performance limitation, not a speed limit. It is not a speed
limit that a pilot has to observe. The vehicle, as configured
(exposed drag areas, engine power output, and propeller
efficiency), cannot be capable of driving through the air in
level flight at full power faster than 55 knots. It is also not
a structural never-exceed speed (Vne). The vehicle may well be
structurally capable of higher airspeeds.
b. The use of "voluntarily observed" or arbitrarily
specified maximum airspeeds, such as a red line on the airspeed
indicator, is not acceptable where the ultralight is capable of
more than 55 knots in level flight.
c. Acceptable Methods of Determining the Maximum Level
Flight Airspeed of an Ultralight.
(1) A calculation, using the information in Appendix
1, is an acceptable method for making this determination.
NOTE: The engine manufacturer's maximum horsepower rating
will be used for all computations associated with maximum
level flight speeds (unless the operator can provide
documentation from the engine manufacturer that a method of
derating an engine will result in a predictable reduction in
horsepower).
(2) A series of three or more full-power level runs in
both directions along a 1,000-foot course under specified
conditions could be used by a recognized technical standards
committee to make this determination. The average speed derived
should be adjusted for atmospheric conditions other than sea
level on a standard day.
NOTE: While these guidelines contain provisions allowing
flight testing to establish eligibility for operations under
Part 103, the FAA has provided charts in Appendixes 1 and 2
which encompass most normal aircraft design factors without
requiring flight testing. Any flight testing to establish
eligibility for operations under Part 103 is done at the
risk of the participants.
(3) A calibrated radar gun may also be used. Again, a
series of full-power level runs as described in subparagraph c(2)
could be used by a recognized technical standards committee to
make this determination.
d. Use of an Artificial Means to Limit the Maximum Level
Flight Airspeed.
(1) An artificial means of restricting the total power
output of an engine in order to lower the maximum level flight
speed at full power would be acceptable if the method used to
restrict the power available is one which cannot be modified,
bypassed, or overridden in flight and the pilot or operator can
provide the FAA, on request, satisfactory evidence that the
vehicle meets the requirement of Section 103.1(e)(3).
NOTE: Vehicles which require artificial restrictions to
power or propeller arrangements may incur a substantial
penalty in terms of takeoff, climb, and absolute
performance. This factor should be considered when
assessing the safety of ultralight vehicle operations,
especially at high altitude locations.
(2) As a general guideline, a method is unacceptable
if it can be modified, bypassed, or overridden in any way while
sitting in the pilot seat so as to further increase the power.
There may be some ultralights which could be operated as
ultralight vehicles if such restrictions are employed to meet the
requirements of Section 103.1(e)(3). If you change or modify the
restricting elements, your vehicle may be ineligible for use
under Part 103.
(3) The use of voluntarily-observed restrictions, such
as a lower power setting, instead of using all available power,
is unacceptable.
e. Use of a Less Efficient Propeller/Shaft Arrangement.
The use of a less efficient propeller/shaft arrangement to lower
the maximum level flight speed at full power is acceptable, if
the operator or pilot can provide the FAA, on request,
satisfactory evidence that the vehicle meets the requirements of
Section 103.1(e)(3). If you change or modify that arrangement to
increase the efficiency, your vehicle may be ineligible for use
under Part 103.
f. Use of an Aerodynamic Restriction. The use of an
aerodynamic restriction, such as a limiting device to pitch
control travel on a canard arrangement, automatically deployed
speed brakes, or a strut installed for drag purposes only, is
acceptable, provided a recognized technical standards committee
has evaluated the resulting maximum full-power level flight
speeds at a pilot weight of 170 pounds and determined that the
vehicle is not capable of maintaining level flight above 55
knots. (Again, modification of that arrangement may render the
vehicle ineligible for use under Part 103.)
NOTE: Vehicles using aerodynamic restrictions to limit
maximum speed may have undesirable flight characteristics
when operated near the controllability limits.
21. MAXIMUM POWER-OFF STALL SPEED OF A POWERED ULTRALIGHT
VEHICLE. The maximum power-off stall speed of an ultralight
vehicle cannot exceed 24 knots (28 mph).
a. Acceptable Methods of Determining the Power-Off Stall
Speed of an Ultralight Vehicle.
(1) A calculation, using the information provided in
Appendix 2, is an acceptable method of providing satisfactory
evidence that your vehicle meets this requirement.
NOTE: For the purpose of all stall speed calculations, the
pilot's weight will be considered to be 170 pounds and the
fuel tank(s) filled (6 lbs./gal.).
(2) This speed can also be determined by a recognized
technical standards committee which can take the average speed
from a series of power-off stalls using existing flight test
procedures.
b. Use of High-Lift Devices to Lower Stall Speed to 24
Knots. Slots, slats, flaps, and any other devices which would
lower the stall speed are acceptable. A determination of the
resulting average stall speed by a technical standards committee
is acceptable evidence of compliance.
22. DOCUMENTATION OF A TECHNICAL STANDARDS COMMITTEE'S FINDINGS.
If an ultralight is found by a recognized technical standards
committee to meet the requirements of Section 103.1 with respect
to the items specified in paragraphs 18 through 21, the committee
should issue a document confirming its findings. (See Appendix 4
for an example of this documentation.)
23. CONTENTS OF THE DOCUMENT. To be acceptable, the document
will contain, as a minimum, the:
a. Name and address of the person requesting the
determination.
b. Type/model and general description of the ultralight,
including any installed equipment.
c. Empty weight of the ultralight, showing the allowances
given for parachutes, floats, and fuel, and how it was
determined.
d. Fuel capacity and how it was determined.
e. Maximum speed at full power in level flight and how it
was determined, including a description of any method
incorporated to limit the power or thrust output or the ability
of the vehicle to fly in level flight at more than 55 knots.
(This description should allow an inspector reviewing the
document to determine that the limiting devices are still
operational.)
f. Maximum power-off stall speed and how it was determined,
including a description of any lift devices used.
g. Typed or printed names of the committee members, their
signatures, and the name of the organization which recognizes
their committee.
24. CONTACTS WITH FAA INSPECTORS. Most ultralight operators
will probably only encounter FAA field inspectors during
accident, incident, or public complaint investigation. On
initial contact, the inspector will usually ask for your pilot
certificate and the aircraft airworthiness certificate. You
should inform the inspector that you are operating your
ultralight under Part 103 and provide evidence that it meets the
applicability of Section 103.1.
a. Failure to Provide Satisfactory Evidence. If you cannot
provide this evidence, or if the evidence provided is not
satisfactory, your ultralight will be considered an aircraft
subject to all applicable aircraft regulations and you will be
subject to all requirements applicable to the operator. It is
your responsibility to prove that your ultralight and any
operations you may have conducted meet the applicability for
operation under Part 103. Until you do, the FAA will proceed
with any enforcement investigation resulting from your inability
to provide that proof.
b. "Satisfactory Evidence."
(1) The use of the graphs provided in Appendixes 1 and
2 will be acceptable for determination of the maximum level
flight speed and power-off stall speed if your ultralight has no
special limitations to maximum speed or power and no special
high-lift devices.
(2) An FAA-certificated aircraft mechanic or repair
station may also weigh your ultralight and provide a weight
document similar to that provided for aircraft, listing the
components and attachments of the ultralight when weighed. An
FAA-certificated mechanic may also make the determinations in
paragraphs 18 through 21 and issue the documentation outlined in
paragraph 23, provided that the maximum speeds were determined
through the use of the graphs provided in Appendixes 1 and 2.
(3) A recognized technical standards committee's
findings documented as provided in paragraph 23 will usually be
considered acceptable. A committee may issue their findings in
relation to a given model of ultralight which are then included
by the manufacturer in the sale of the ultralight. The
subsequent operators of that model of ultralight may use those
findings without having another inspection made, provided that
there are no changes or modifications to the configuration,
components, engine, or propeller arrangements of the basic model
originally reviewed by the committee and any artificial means of
restricting maximum airspeed is installed and operational.
c. FAA Ultralight Inspection Authority. The FAA has the
legal authority to inspect any ultralight, whether it is operated
as an aircraft under Part 91 or as an ultralight vehicle under
Part 103. In the case of an ultralight operated under Part 103,
this authority will usually be exercised only when an inspector
has reason to doubt the validity of the evidence provided by the
operator or that the ultralight still conforms to the findings
contained in that evidence.
(1) Refusal to Allow the Inspection. Refusal to allow
the inspector to inspect the ultralight would be a violation of
the Federal Aviation Act of 1958, as amended, and the applicable
FAR, and would result in enforcement action.
(2) Usual Content of the Inspection. The inspector
may ask you to show compliance with Section 103.1 by measuring
the capacity of the fuel tank, weighing the vehicle, measuring
the wing, stabilizing and control surface areas, and showing that
any artificial means required to restrict the maximum airspeed
are installed, operational, and cannot be bypassed. Further
checks may be made in situations where the inspector has reason
to doubt the effectiveness of any restriction to maximum
airspeed.
25.-29. RESERVED.
SECTION 2. HOW TO CERTIFICATE AND OPERATE
AN ULTRALIGHT AS AN AIRCRAFT
30. SCOPE AND CONTENTS. This section outlines the regulations
which are applicable to the operation of ultralights as
certificated aircraft and provides general information regarding
how to comply with the regulations.
31. AIRCRAFT CERTIFICATION. A person who chooses to operate an
ultralight as a certificated aircraft has two options for
airworthiness certification of the vehicle, depending primarily
on the configuration of the vehicle or kit when purchased, as
follows:
a. Completely Assembled at the Factory, or Assembled by the
Purchaser From a "Bolt-Together" Kit With Little or No
Fabrication Operations. An ultralight in this category would be
eligible for airworthiness certification only for the purpose of
exhibition in the experimental classification. Application for
an experimental certificate for exhibition may be made to the
nearest Flight Standards field office.
b. Major Portion (Over 50%) Fabricated by the
Builder/Purchaser, Either from Raw Materials to the Builder's Own
Design or From a Partially Prefabricated Kit. A vehicle shown to
meet the provisions of this category would be eligible for
airworthiness certification as an amateur-built aircraft, in
addition to eligibility for experimental exhibition. Detailed
information pertaining to amateur-built aircraft requirements are
in FAA Advisory Circular 20-27C, Certification and Operation of
Amateur-Built Aircraft. Applications for such certification may
be made to the nearest Flight Standards field office.
32. REGISTRATION. An ultralight that is to be certificated and
operated as an aircraft is subject to the registration and
marking requirements applicable to aircraft. The applicant
should contact the nearest Flight Standards field office to
obtain the required forms and information concerning the
procedures to be followed. Advisory Circular 20-27C also
contains information concerning registration and marking
requirements as they apply to amateur-built aircraft.
33. PART 61 (CERTIFICATION: PILOTS AND FLIGHT INSTRUCTORS).
Part 61 of the Federal Aviation Regulations contains the
regulations which define the certificates and ratings which
pilots must hold to function as a pilot of a certificated
aircraft in the United States. It also outlines the minimum
experience levels and standards to qualify for those certificates
and ratings. The minimum levels of pilot currency for certain
operations are also contained in Part 61.
34. PART 91 (GENERAL OPERATING AND FLIGHT RULES). Part 91
contains the general operating rules (Subpart A), flight rules
(Subpart B), and maintenance rules (Subpart C) which are
applicable to all certificated aircraft operations. Pilots of
certificated ultralight aircraft must comply with Part 91. No
certificated aircraft can be operated under Part 103. The flight
rules of Subpart B are the minimum standards for flight
operations except where the operating limitations of the
particular aircraft establish more stringent standards. The
majority of the rules contained in Subpart A and Subpart C will
not apply to operations of certificated ultralight aircraft;
however, a thorough review of these regulations should be
conducted to determine those applicable to a particular type of
ultralight aircraft.
35. SPECIAL FLIGHT OPERATIONS. There are some special
operations of ultralight aircraft that are allowed under present
regulations.
a. "Public" Aircraft. An ultralight may be used
exclusively in the service of a Federal, state, or local
government without an airworthiness certificate. (The pilots do
not have to hold pilot certificates.)
(1) The ultralight must be properly registered with
the FAA and display appropriate registration markings, and
(2) All operations must be conducted in accordance
with the applicable operating and flight rules of Part 91.
b. Aerial Agricultural Application. A farmer owning an
amateur-built experimentally certificated aircraft may use that
aircraft for aerial agricultural applications over his/her own
property, provided that,
(1) The ultralight is certificated as an amateur-
built aircraft and does not have any operating limitations
prohibiting agricultural operations;
(2) The pilot holds at least a private pilot
certificate and successfully completes a knowledge and skill test
as specified in Section 137.19(e); and
(3) The farmer holds at least a Private Agricultural
Operator Certificate under Part 137 and all operations are
conducted in accordance with that regulation.
36.-50. RESERVED.
/s/ Kenneth S. Hunt
Director of Flight Operations
APPENDIX 1. DETERMINING MAXIMUM LEVEL FLIGHT
AIRSPEED OF ULTRALIGHTS.
The information contained in this appendix is intended to assist
in a determination of an ultralight's capability to comply with
Section 103.1(e)(3). The maximum speed of an ultralight as
computed with this information may be accepted as a portion of
the "satisfactory evidence" specified in Section 103.3(b). When
using this information, no additional drag factors should be
considered and no extra value should be given any of the factors
provided. There is already a "cushion" built into the
computation to account for the factors affecting the maximum
speed capability of an ultralight. No drag-producing element
should be counted under more than one drag factor category.
STEP ONE - Compute the total drag factor (See page 2 for further
breakdown of the values assigned to each category.)
1. Pilot Drag Factor (Select one).................._______
* Not Enclosed
- prone.................................. 1.2
- supine................................. 4.5
- seated upright......................... 5.5
* Partially Enclosed
- lower half of body enclosed............ 3.5
- only head exposed...................... 2.5
- streamlined, head behind windshield.... 2.0
* Totally Enclosed
- streamlined fuselage................... 1.5
- boxy fuselage.......................... 2.0
2. Wing Drag Factor (total square feet of upper
surface = ______ x 0.01)......................._______
3. Stabilizing & Control Surface Drag Factor (total square feet
of one side of each surface = _____ x 0.014)..._______
4. Exposed Wire Drag Factor (total wires over 4 feet long and
45 to 90 degrees to airflow = _____ x 0.05)...._______
5. Exposed Struts Drag Factor (total struts over 4 feet long
and 45 to 90 degrees to airflow excluding those associated
with landing gear = _____ x 0.4).............._______
6. Landing Gear Drag Factor (includes associated
struts)........................................_______
* Faired, fixed gear (number of wheels = _____ x 0.3)
* Unfaired, fixed gear (number of wheels = _____ x 0.5)
7. Engine Drag Factor (select one)................._______
* completely exposed = 2.5
* partially exposed = 1.5
* some components exposed = 0.5
8. SUBTOTAL ABOVE DRAG FACTORS........................._______
9. SUBTOTAL OF DRAG FACTORS FROM PREVIOUS PAGE........._______
10. Allowance for Induced and Interference Drag (multiply
subtotal of drag factors _____ x .20)............._______
11. COMPUTED TOTAL DRAG FACTORS (add items 9 and 10)...._______
PROCEED TO CHART ON PAGE 3
CONSIDERATIONS IN ASSIGNMENT OF DRAG FACTOR VALUES:
1. Pilot drag factors. "Supine" is a sitting position with the
legs extended forward, nearly in line with the lower part of the
body. "Seated upright" is a sitting position where the lower
legs extend downward. "Only head exposed" includes all semi or
fully streamlined vehicles having a small windshield which does
not deflect the airflow away from the pilot's face.
"Streamlined, head behind windshield" includes those ultralights
which, from a viewing position in front of the vehicle, the
pilot's body is not exposed to the airflow. Where a two-place
vehicle is being operated under an exemption, side-by-side
seating doubles the factor for the fully-exposed groupings and
the "lower half of body enclosed" category. No additional credit
is given for the other categories under partially or fully
exposed. Also, no additional credit is given to tandem
arrangements.
2. Wing drag. This includes all horizontal flying surfaces,
including canards (but excluding any other stabilizing or control
surface). The total square feet of upper surface of the wing, as
determined from a manufacturer's specification or through rough
measurement (length x width) is used in this calculation.
3. Stabilizing and control surface drag. This includes
horizontal and vertical stabilizers, rudders, elevators, and
ailerons. The total square feet of exposed surfaces (one side
only) is used in this calculation.
4. Exposed wire and strut drag. The number of wires or struts,
not associated with the landing gear, which are OVER 4 FEET LONG
with an angle of 45 to 90 DEGREES TO THE AIRFLOW are counted and
multiplied times the given values. Those wires and/or struts
located behind the pilot/engine/wing (usually making up portions
of the rear fuselage or empenage) are not counted. Wires or
struts located parallel to and behind other wires or struts in
the airflow are not counted if they do not flare uniformally away
from any common attaching point, achieving a minimum separation
of at least 8 inches.
5. "Fixed landing gear drag. Regardless of size of wheels or
length of struts, the values shown in the chart are applicable.
"Faired" wheels are those which have one-third or more of the
wheel surface covered in the front and on the sides.
6. Engine drag. Engines in front of the wing without fairing
and those in back, which protrude noticeably into the airflow
above or below the wing, are considered completely exposed.
Those with streamlined fairings not located in the fuselage or
behind a semi streamlined pilot cockpit are considered partially
exposed. Faired engines positioned in the front or rear of a
fully streamlined fuselage with components such as air filters
and mufflers exposed are treated under "some components exposed."
Faired or unfaired engines located in the turbulent area directly
behind the pilot's body or the vehicle's fuselage are also
considered under this grouping.
STEP TWO - Determine the maximum airspeed of the vehicle through
the use of the chart below.
INSTRUCTIONS:
1. Enter the bottom of the chart at the engine
manufacturer's maximum horsepower rating of the
installed engine. (Example: 45 horsepower).
2. Proceed directly up the horsepower line until
encountering the total drag factor curve computed for
the ultralight (Example: 15).
3. Note horizontal line which also intersects at that
point, proceed to the left along that line to the edge
of the graph, read maximum airspeed (Example: 53.5).
----------------------------------------------------------------
FIGURE NOT INCLUDED
----------------------------------------------------------------
APPENDIX 2. DETERMINING POWER-OFF STALL SPEED
OF ULTRALIGHTS
The information contained in this appendix is intended to assist
in a determination of an ultralight's ability to comply with
Section 103.1(e)(2), a maximum power-off stall speed which does
not exceed 24 knots. Computations made in accordance with the
information provided may be accepted as satisfactory evidence of
compliance. When using this information, no factors other than
those provided here should be considered. (The values provided
here are for relatively square, rectangular wings; they are not
valid for noticeably swept or tapered wings.) Relevant
considerations for this computation are:
1. Empty weight. The dry empty weight of the vehicle (excluding
floats and/or parachutes), as established through some form of
evidence satisfactory to the inspector, should be used.
2. Pilot weight. The pilot's weight will be assumed to be 170
pounds. In the event that an ultralight is being operated under
exemption allowing two-occupant operations, the pilots' weight
will be assumed to be 340 pounds.
3. Fuel weight. The weight of the fuel (6 pounds per gallon) is
included and for the purpose of this computation will be assumed
to be filled to capacity.
4. Wing area. The total wing area (square feet) should be
determined. Ailerons and flaps may be included, but canards
(which generally have a higher stall speed than the main wing)
are excluded.
STEP ONE - Add the weight factors.
Example: Empty weight......240 lbs.
Pilot weight......170 lbs.
Fuel weight........30 lbs.
440 lbs.
STEP TWO - Divide the total weight by the total wing area to
obtain the wing loading of the vehicle.
Example: Weight = 440
----------------
Wing Area = 151 = 2.9 (Wing Loading)
STEP THREE - Select, from the wing profiles provided below, the
lift factor which applies to the ultralight in question.
Lift Factor Wing Profile Wing Description
1.4 Single/double surface
with camber of less than
7 percent (see Appendix
3) and all symmetrical
and semi symmetrical
airfoils without flaps,
regardless of camber.
1.6 Relatively flat-bottom,
double surface wings with
camber of 7 percent or
more.
1.8 Single surface with
camber of 7 percent or
more or double surface
with flaps extending up
to 50 percent of the
total wingspan.
2.0 Double surface with flaps
extending more than 50
percent of total
wingspan.
STEP FOUR - Determine the power-off stall speed of the ultralight
through the use of the chart below.
INSTRUCTIONS:
1. Enter the bottom of the chart at the computed wing
loading of the ultralight (Example: 2.9).
2. Proceed straight up the wing-loading line to the point
where it intersects the applicable lift factor curve
(Example: 1.6).
3. Note horizontal line which also intersects at that
point, proceed to the left side of the chart via that
line. Read power-off stall speed (Example: 23.2
knots).
----------------------------------------------------------------
FIGURE NOT INCLUDED
----------------------------------------------------------------
NOTE: If your computed wing-loading point is lower than
the applicable lift factor line at the base of the
chart, the stall speed would be lower than
provided on the chart.
APPENDIX 3. DETERMINING UPPER SURFACE
CAMBER OF A WING.
Relevant considerations for this computation are:
1. Chord or chord line - an imaginary straight line joining the
extremities of the leading edge and the trailing edge. For the
purpose of this computation, this imaginary line will be measured
midway between the tip of the wing and the wing root.
2. Camber - the curvature of a wing. For the purpose of this
computation, only the camber of the upper surface (above the
chord line) of the wing is considered.
STEP ONE - Determine the mid-point of the wing and measure the
mean chord line.
----------------------------------------------------------------
FIGURE NOT INCLUDED
----------------------------------------------------------------
STEP TWO - At the mid-point of the wing, determine the chord line
horizontal position on the airfoil profile (assuming straight
line from the extreme forward point on the leading edge to the
extreme rearward point of the trailing edge).
----------------------------------------------------------------
FIGURE NOT INCLUDED
----------------------------------------------------------------
STEP THREE - Measure the distance from the chord line to the
highest point of camber on the upper surface.
----------------------------------------------------------------
FIGURE NOT INCLUDED
----------------------------------------------------------------
STEP FOUR - Divide the measurement obtained in step one into the
measurement obtained in step three.
Example: Upper surface camber = 8 inches
----------
Mean chord line length = 100 inches = 8% camber
APPENDIX 4. SAMPLE DOCUMENTATION OF TECHNICAL
STANDARDS COMMITTEE FINDINGS
(INSTRUCTIONS: Complete all blanks; insert N/A in blanks
not applicable to this particular review; check off other
applicable items (x) as provided.)
ISSUED TO: ____________________ ULTRALIGHT
ADDRESS: ____________________ MAKE/MODEL: ________________
____________________ SERIAL NUMBER: ________________
REGISTRATION
NUMBER: ________________
ENGINE MAKE/MODEL: ____________ PROPELLER
ENGINE MANUFACTURER'S MAKE/MODEL: ________________
RATED HORSEPOWER: ___________ PROPELLER
DIAMETER: _________________
PROPELLER PITCH: ______________
FUEL fuselage
CAPACITY: tank _____ wing tank _____ other _____ TOTAL: _____
----------------------------------------------------------------
-GROSS EMPTY WEIGHT......................................________
- Exclusion for parachute system weight.......______
( ) hand-deployed
( ) ballistically deployed
( ) installed and operational
( ) standard allowance weight given
( ) parachute system weighed separately
- Exclusion for floats........................______
( ) weighed in landplane configuration only
( ) weighed in floatplane configuration only
( ) standard allowance for floats-only given
( ) standard allowance for amphib floats given
( ) standard allowance for amphib fuselage given
( ) standard allowance for outrigger floats given
( ) all floats weighed separately
FLOAT MAKE/MODEL: __________________
- Fuel on board at weighing...................______
TOTAL WEIGHT ALLOWANCES........................______
NET EMPTY WEIGHT (minus weight allowances)..............________
----------------------------------------------------------------
MAXIMUM FULL-POWER LEVEL FLIGHT SPEED (calculated by AC 103-7,
Appendix 1).........................................________
( ) engine manufacturer maximum rated horsepower used
( ) derated horsepower of engine = _____, per engine
manufacturer's specs
DEMONSTRATED MAXIMUM FULL-POWER LEVEL FLIGHT SPEED......________
( ) timed (average of a series of three level runs in both
directions)
( ) radar gun (average series of level runs per timed
instructions)
( ) speed adjusted to sea level conditions
( ) artificial restriction ( ) power ( ) propeller
( ) aerodynamic
DESCRIPTION OF RESTRICTION (should be included on the back of
this form in sufficient written and graphic detail for an FAA
inspector or other qualified person to ascertain that the
restriction is in place and operational)
----------------------------------------------------------------
MAXIMUM POWER-OFF STALL SPEED (calculated AC 103-7, Appendix
2)......................................................________
operating weight used = ______ maximum coefficient of lift
used = ______
DEMONSTRATED POWER-OFF STALL SPEED......................________
( ) average of six or more stalls (in level flight, with an
airspeed reduction of approximately one knot per second
until stall occurs
( ) high lift devices installed ( ) flaps ( ) slots ( ) other
----------------------------------------------------------------
CONFIGURATION:
( ) provisions for one occupant only
( ) seat width 22 inches or less (inside measurement)
( ) single seatbelt/shoulder harness
( ) single controls located logically for a person
sitting in the center of the seat
( ) no equipment is installed which could logically be
construed as for a purpose other than sport/recreation of
the operator, such as:
( ) towing hitches
( ) agricultural equipment
( ) advertisement on the wings
----------------------------------------------------------------
AIRWORTHINESS CERTIFICATION:
( ) no U.S. or foreign airworthiness certificate is currently
issued to this particular ultralight unit
( ) this ultralight has not been registered with the U.S.
federal government
----------------------------------------------------------------
LIST OF INSTALLED INSTRUMENTS AND EQUIPMENT:
----------------------------------------------------------------
OTHER:
----------------------------------------------------------------
ISSUED BY:
( ) A & P Mechanic; Name __________________ Certificate
Number ________________
----------------------------------------------------------------
DATE OF ISSUANCE OF THIS DOCUMENT: __________________