AC 90-89A

U.S. Department of Transportation Federal Aviation Administration Advisory Circular 1 Initiated by: AFS-340 DATE: 5/24/95 AC NO: 90-89A

AMATEUR-BUILT AIRCRAFT AND ULTRALIGHT

FLIGHT TESTING HANDBOOK

U.S. Department of Transportation Federal Aviation Administration Advisory Circular i Subject: AMATEUR-BUILT AIRCRAFT Date: 5/24/95 AC No: 90-89A & ULTRALIGHT FLIGHT Initiated by: AFS-340 Change:

TESTING HANDBOOK

1. PURPOSE. This advisory circular (AC) sets forth suggestions and safety related recommendations to assist amateur and ultralight builders in developing individualized aircraft flight test plans.

2. CANCELLATION. AC 90-89, Amateur- Built Aircraft Flight Testing Handbook, dated September 18, 1989, is cancelled.

3. RELATED READING MATERIAL. A list of selected reading material on amateur-built/ ultralight flight testing and first flight experience may be found in appendix 3.

4. BACKGROUND.

a. The Federal Aviation Administration (FAA), the Experimental Aircraft Association (EAA), and the United States Ultralight Association (USUA) are concerned and committed to improving the safety record of amateur-built and ultralight aircraft.

b. The FAA Administrator, T. Allen McArtor, and EAA President, Paul H. Poberezny, signed a Memorandum of Agreement on August 1, 1988, which addressed the need for educational and safety programs to assist amateur-builders in test flying their aircraft. In accordance with that agreement, this AC provides guidelines for flight testing amateurbuilt aircraft.

c. As part of the FAA’s continuing efforts to improve the safety record of all types of general aviation aircraft, this AC has been revised to include flight testing recommendations for canard-type and ultralight aircraft.

5. DEFINITIONS. The following terms are defined for use in this AC.

a. Amateur-built aircraft means an aircraft issued an Experimental Airworthiness Certificate under the provisions of Federal Aviation Regulations (FAR) § 21.191 (g).

b. The term ultralight means a vehicle that meets the requirements of FAR § 103.1.

c. The term ultralight in this AC also means a two-place training vehicle of 496 pounds or less, operating under an EAA or USUA exemption to FAR Part 103.

d. For the purpose of this AC, both an amateur-built aircraft and a ultralight vehicle will be referred to as an ‘‘aircraft.’’

6. DISCUSSION.

a. This AC’s purpose is the following:

(1) To make amateur-built/ultralight aircraft pilots aware that test flying an aircraft is a critical undertaking, which should be approached with thorough planning, skill, and common sense.

(2) To provide recommendations and suggestions that can be combined with other sources on test flying (e.g., the aircraft plan/kit manufacturer’s flight testing instructions, other flight testing data). This will assist the amateur/ultralight owner to develop a detailed flight test plan, tailored for their aircraft and resources.

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b. The flight test plan is the heart of all professional flight testing. The plan should account for every hour spent in the flight test phase and should be adhered to with the same respect for the unknown that all successful test pilots share. The time allotted for each phase of a personalized flight test plan may vary, and each phase may have more events or checks than suggested in this AC. The goals, however, should be the same.

c. The two goals for an amateur builder/ ultralight owner should be as follows:

(1) At the end of the aircraft’s flight test phase, the aircraft will have been adequately tested and found airworthy and safe to operate within its established operational envelope.

(2) Incorporation of the flight test operational and performance data into the aircraft’s flight manual so the pilot can reference the data prior to each flight.

7. REQUEST FOR INFORMATION.

a. This AC is designed as a reference document to assist in preparing a flight test plan for an amateur-built or ultralight aircraft.

(1) The suggestions and recommendations in chapters 1 through 6 are for conventionallydesigned aircraft with an air-cooled, 4-cycle, reciprocating engine that develops less than 200 horsepower with a fixed pitch propeller.

(2) Chapter 7 deals with flight testing recommendations for canard aircraft.

(3) Chapters 8 through 10 address flight testing considerations for ultralight vehicles under FAR Part 103 and two-seat ultralight training vehicles of less than 496 pounds empty weight operating under an exemption to FAR Part 103.

b. Because of the large number of existing amateur-built/ultralight aircraft designs and new designs being introduced each year, the FAA encourages public participation in updating this document.

Send comments, suggestions, or information about this AC to the following address:

U.S. Department of Transportation Federal Aviation Administration Flight Standards Service (AFS-340) 800 Independence Ave, SW.

Washington, DC 20591

c. Suggestions also may be sent to AFS-340 by FAX (202) 267-5115.

d. After a review, appropriate comments, suggestions, and information may be included in the next revision of this AC.

8. TO OBTAIN COPIES OF THIS AC. Order AC 90-89A from:

U.S. Department of Transportation Property Use and Storage Section, M-45.3 Washington, DC 20590.

William J. White Deputy Director, Flight Standards Service

iii THIS PAGE IS INTENTIONALLY LEFT BLANK, SO THAT THE TOC CAN BE ON PAGE iii PER PLACEMENT IN DOCUMENT.

iv 5/24/95AC 90-89A THIS PAGE IS INTENTIONALLY LEFT BLANK, SO THAT THE TOC CAN BE ON PAGE iii PER PLACEMENT IN DOCUMENT.

CONTENTS Page CHAPTER 1. PREPARATION

Section 1. Homework1

Section 2. Airport Selection2

Figure 1 - Runway Length Chart3

Section 3. Emergency Plans and Equipment4

Section 4. Test Pilot6

Section 5. Medical Facts For Pilots7

Section 6. Transporting The Aircraft To the Airport9

Section 7. Assembly and Airworthiness Inspection10

Section 8. Weight and Balance14

Figure 2 - Empty Weight CG15

Figure 3 - Take Off CG16

Figure 4 - Additional Equipment Added17

Section 9. Paperwork18

Section 10. Powerplant Tests19

Section 11. Additional Engine Tests22

Section 12. Propeller Inspection25

Figure 5 - Propeller Tracking26

CHAPTER 2. TAXI TESTS

Section 1. Low Speed Taxi Tests29

Section 2. High Speed Taxi Tests30

CHAPTER 3. THE FIRST FLIGHT

Section 1. General33

Section 2. The Role of the Chase Plane34

Section 3. Emergency Procedures35

Section 4. First Flight36

Section 5. First Flight Procedures37

CHAPTER 4. THE FIRST 10 HOURS

Section 1. The Second Flight41

Section 2. The Third Flight41

Section 3. Hours 4 through 1041

CHAPTER 5. EXPANDING THE ENVELOPE

Section 1. General45

Section 2. Hours 11 through 2045

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Figure 6 - Climb Airspeed and Altitude Graph47

Figure 7 - Best Rate of Climb Speed Graph48

Section 3. Hours 21 through 35: Stability and Control Checks49

Figure 8 - Static Stability49

Figure 9 - Time50

Section 4. A Word or Two About Flutter52

vi 5/24/95AC 90-89A CONTENTS—Continued Page

Section 5. Spins54

Section 6. Accelerated Stalls56

CHAPTER 6. PUTTING IT ALL TOGETHER: 36 HOURS TO ———?

Section 1. Maximum Gross Weight Tests57

Section 2. Service Ceiling Tests58

Section 3. Navigation, Fuel Consumption, and Night Flying59

CHAPTER 7. THOUGHTS ON TESTING CANARD TYPE AMATEUR-BUILT AIRCRAFT

Section 1. Canards63

CHAPTER 8. ULTRALIGHT AIRFRAME INSPECTION

Section 1. Differences67

Section 2. The Test Pilot68

Section 3. Pre-flight Airframe Inspection68

CHAPTER 9. ULTRALIGHT ENGINE/FUEL SYSTEM INSPECTION

Section 1. Engine Inspection71

Section 2. Fuel Systems72

CHAPTER 10. ULTRALIGHT TEST FLYING RECOMMENDATIONS

Section 1. Three Recommendations75

Section 2. Airport Selection75

Section 3. Taxiing76

Section 4. First Flight Differences76

Section 5. Emergency Procedures77

Appendix 1. Sample Checklist for a Condition Inspection .................................................................

(7 pages)1

Appendix 2. Addresses for Accident/Incident Information .................................................................

(1 page)1

Appendix 3. Additional References on Flight Testing .........................................................................

(4 pages)1

1 CHAPTER 1. PREPARATION ‘‘The Laws of Aerodynamics are unforgiving and the ground is hard.’’ Michael Collins (1987) SECTION 1. HOMEWORK ‘‘If you have no plan--you have no goal.’’ Harold Little, Aircraft Manufacturer (1994)

1. OBJECTIVE. A planned approach to flight testing.

a. The most important task for an amateurbuilder is to develop a comprehensive FLIGHT TEST PLAN. This PLAN should be individually tailored to define the aircraft’s specific level of performance. It is therefore important that the entire flight test plan be developed and completed BEFORE the aircraft’s first flight.

b. The objective of a FLIGHT TEST PLAN is to determine the aircraft’s controllability throughout all the maneuvers and to detect any hazardous operating characteristics or design features. This data should be used in developing a FLIGHT MANUAL that specifies the aircraft’s performance and defines its operating envelope.

2 5/24/95AC 90-89A SECTION 2. AIRPORT SELECTION ‘‘An airport should be chosen with the same care and consideration as getting a second doctor’s opinion.’’ Fred Wimberly, EAA Flight Test Advisor (1994)

1. OBJECTIVE. To select an airport to test fly the aircraft.

a. The airport should have one runway aligned into the prevailing wind with no obstructions on the approach or departure end. Hard surface runways should be in good repair and well maintained to avoid foreign object damage (FOD) to the propeller and landing gear. Grass fields should be level with good drainage. Avoid airports in densely populated or developed areas and those with high rates of air traffic. The runway should have the proper markings with a windsock or other wind direction indicator nearby.

b. To determine an appropriate runway, use the chart in figure 1 (sea-level elevation), or the following rule-of-thumb:

c. The ideal runway at sea-level elevation should be at least 4,000 feet long and 100 feet wide.

For each 1,000 feet increase in field elevation, add 500 feet to the runway length. If testing a high performance aircraft, the airport’s runway at sealevel should be more than 6,000 feet long and 150 feet wide to allow a wider margin of safety. Other considerations, such as power to weight ratio, wing design, and density altitude, also should be factored into the equation for picking the best runway for the initial flight testing.

20 WING LOADING, LOS PER SQ.FT. 12 10 500 1000 1500 2000 8500 3000 3500 4000 1500 A - Distance to takeoff at minimum smooth lift-off speed, fly for 5 seconds at that speed without climbing, land and stop straight ahead.

B - Distance to reach minimum smooth lift-off speed.

C - Distance covered in 5 seconds of flight at minimum smooth lift-off speed.

D - Distance to stop from minimum smooth lift-off speed (includes air and ground distance).

E - Distance to takeoff at slow approach speed and climb thereafter at an angle of 1 in 20 to 50 ft. altitude -this distance will allow most airplanes to accelerate to normal climb speed before crossing end of runway.

Take-off Distance in Feet FIGURE 1. Runway Length Chart

d. Identify emergency landing fields located within gliding distance from anywhere in the airport pattern altitude. Since engine failures are second only to pilot error as the major cause of amateur-built aircraft accidents, preparations for this type of emergency should be a mandatory part of the FLIGHT TEST PLAN.

e. It is advisable to perform flight tests from an airport with an active unicom or tower, even if the aircraft does not have an electrical system or is not equipped with a radio. Even at an uncontrolled field, a communications base should be improvised For both situations, a hand held radio with aviation frequencies and a headset with a mike and a pushto-talk switch on the stick/yoke is recommended.

Good radio communications improves the overall level of safety and reduces cockpit workload.

f. The FAA recommends airport selection criteria include the availability of hangar space and ramp areas. These facilities will provide protection from inclement weather and vandalism while the aircraft is being tested, maintained, and inspected.

g. The airport should have a telephone and fire fighting equipment, the latter being in compliance with relevant municipal codes (e.g., fire codes).

h. Explain the Flight Test Program and EMERGENCY PLANS to the airport manager or owner. They may be able to assist the amateurbuilder in obtaining temporary hangar space, providing ground/air communications, and supplying emergency equipment for use during the flight test.

4 5/24/95AC 90-89A SECTION 3. EMERGENCY PLANS AND EQUIPMENT ‘‘The object of the game, gentlemen, is not to cheat death: the object is not to let him play.’’ Patrick Poteen, Sgt. U.S. Army

1. OBJECTIVE. To develop a FLIGHT TEST PLAN which contain two sets of emergency plans;

one for IN-FLIGHT emergencies and another for GROUND emergencies.

a. The IN-FLIGHT emergency plan should address the following:

(1) Complete engine failure or partial failure, especially after take off

(2) Flight control problems and severe outof-rig conditions

(3) Fire in the engine compartment or cockpit

b. The GROUND EMERGENCY plan should be developed to train the ground crew and/or the airport fire department crash crew on the following:

(1) The airplane canopy or cabin door latching mechanism

(2) The pilot’s shoulder harness/seat belt release procedure

(3) The location and operation of the fuel shut-off valve

(4) The master switch and magneto/ignition switch location and OFF position

(5) Engine cowling removal procedures to gain access to the battery location or for fire fighting

(6) The battery location and disconnect procedures

(7) Fire extinguisher application and use

(8) How to secure the ballistic parachute system

c. Ground Crew. Every test of an amateurbuilt aircraft should be supported by a minimum ground crew of two experienced individuals. The ground crew’s function is two-fold:

(1) To ensure that the aircraft is in airworthy condition for safe operation

(2) To provide assistance to the test pilot in an emergency

d. The Airport.

(1) If the airport does not have a fire rescue unit, it is suggested the ground crew have a four wheel drive vehicle equipped with a portable radio, first aid kit, metal-cutting tools, and a fire extinguisher. A minimum of one person should be trained in first-aid.

(2) If the airport provides a fire rescue unit, the test pilot should ensure the rescue unit and the ground crew are trained and competent in performing ground emergency functions as identified in the FLIGHT TEST PLAN.

(3) Suggestion. For a small donation, some local volunteer fire and rescue companies will provide the amateur-builder with a standby crew during the initial critical portions of the flight test phase.

e. Hospital Location. The ground crew should know the location and telephone numbers of the hospitals and fire rescue squads in the vicinity of the airport AND the flight test area. If the test pilot is allergic to specific medications, or has a rare blood type, a medical alert bracelet or card should be carried or worn to alert medical personnel of the condition.

f. Fire Extinguisher. Fire extinguisher’s should be available to the ground crew, and a fire extinguisher should be securely mounted in the cockpit within easy reach of the test pilot. A fire axe, or other tool capable of cutting through the canopy, also should be positioned in the cockpit.

g. Fire Protection. There is always danger of a flash fire during test flights. To prevent burns, the pilot should wear an aviation/motorcycle helmet, NOMEX coveralls/gloves and smoke goggles. If NOMEX clothing is not available, cotton or wool clothing will offer some protection from heat and flames. Pilots should never wear nylon or polyester clothing because synthetic materials melt when exposed to heat and will stick to the skin.

h. Pilot Protection. A modern aviation/motorcycle helmet, a properly installed shoulder harness, a well designed seat, a clean cockpit design free of protruding components/sharp edges, NOMEX clothing, smoke goggles, and a memorized emergency plan ensure safety during flight testing.

i. Parachute. The decision to wear a parachute depends on the type of aircraft being tested. Some aircraft have forward hinged canopies that are not equipped with quick release pins or have pusher propellers which increase the chance of injury to the pilot while exiting the aircraft. Other aircraft designs may pose no exit problems. If the decision is made to wear a parachute, check that it has been recently packed (within 120 days) by a qualified parachute rigger. Ensure that the chute has not been exposed to rain/moisture and when worn, does not interfere with cockpit management. The test pilot should be thoroughly trained on how to exit the aircraft and deploy the parachute.

j. Ballistic Chutes. Ballistic chutes are the latest development in dealing with in-flight emergencies. A ballistic chute is attached to the aircraft and when activated, lowers the whole aircraft and the pilot to the ground at the rate of descent of approximately 20 feet per second.

(1) Deployment Scenarios:

(i) structural failure

(ii) mid-air collision

(iii) stall/spin

(iv) loss of control/icing

(v) engine failure over bad terrain

(vi) pilot incapacitation

(2) Installation Considerations: The builder should consider the following when installing a ballistic chute:

(i) Matching the chute with the aircraft’s size, weight, and V ne speed (check with the chute manufacturer)

(ii) How the chute will be positioned and mounted

(iii) The chute’s effect on the aircraft’s weight and balance before deployment and aircraft’s touchdown attitude after deployment

(iv) Compatibility of the opening loads and the aircraft’s structural design limits