£. 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 tor 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 $ 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.
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.
Par 23 13
(1) Refusual 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 anended, 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 $ 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.
14 Par 24
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:
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-LVC, ertification 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 experiencę levels and standards to qualify for those certificates and ratings.
The minimum levels of pilot currency for certain operations are also contained in
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 ilight 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 Par 30 15
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 § 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.
Bennest 5 theret Kenneth S. Hunt Director of Flight Operations 16 Par 34
Appendix 1 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 = × 0.01)..
Stabilizing & Control Surface Drag Factor (total square feet of one side of each surface = × 0.014).
4. Exposed Wire Drag Factor (total wires over 4 feet long and 45 to 90 degrees to airflow = × 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] = × 0.4).
6. Landing Gear Drag Factor (includes associated struts).
*Faired, fixed gear (number of wheels = - × 0.3) *Unfaired, fixed gear (number of wheels = × 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....
Appendix 1
9. SUBTOTAL OF DRAG FACTORS FROM PREVIOUS PAGE.
10. Allowance for Induced and Interference Drag (multiply subtotal of drag factors × .20).....
11. COMPUTED TOTAL DRAG FACTORS (add items 9 and 10) PROCEED TO CHART ON PAGE 3 CONSIDERATIONS IN ASSIGNMENT OF DRAG FACTOR VALUES:
forward, nearly in line with the lower part of the body'"only head exposed" includes 1. Pilot drag factors. "Supine" is a sitting position with the legs extended 'Seated upright" is a sitting position where the lower legs extend downward.
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.
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.
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 semistreamlined pilot cockpit are considered partially exposed.
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.
1/30/84 AC 103-7 Appendix 1 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).
70 10 65 60 55 50 (knots) 45 40 10 20 30 40 50 60 70 BHP - Horsepower
Appendix 2 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.l(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:
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 Ibs.
Pilot weight. .170 lbs.
Fuel weight.. ..30 1bs.
440 1bs.
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 semisymmetrical 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.
Appendix 2
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).
29 28 27 26 25 24 23 D 22 (knots) 21 20
1.0 2.0 3.0 4.0 5.0 6.0
WING LOADING 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.
1/30/84 AC 103-7 Appendix 3 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.
WING WING ROOT 100" TIP STEP IWO - 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).
- - _CHORDLINE STEP THREE - Measure the distance from the chord line to the highest point of camber on the upper surface.
STEP FOUR - Divide the measurement obtained in step one into the measurement obtained step three.
Example: Upper surface camber 8 inches Mean chord line length = 100 inches = 8% camber 1