31.2.2.1.1 A rapid descent at the “maximum operating limit speed” of the airplane with the flaps and landing gear up.
31.2.2.1.2 A rapid descent with the flaps and landing gear down, at the maximum permissible speed for this configuration. If it appears that any other condition is likely to be critical on a particular airplane, it should also be investigated.
31.2.2.2 In the flight tests specified above, it will be permissible to institute emergency ventilating procedures immediately prior to or following the discharge of carbon dioxide, provided such procedures can be accomplished easily and quickly by the flightcrew, and do not appreciably reduce the effectiveness of the fire protection system.
31.2.2.3 If the measured carbon dioxide concentrations exceed three percent by volume (corrected to sea level, standard day conditions), protective breathing equipment should be provided for each flight crewmember on flight deck duty.
31.2.2.4 Appropriate emergency operating procedures should be entered in the AFM.
31-2
CHAPTER 32. EQUIPMENT: GENERAL
32.1 Equipment: Function and Installation—§ 25.1301.
32.1.1 Explanation.
32.1.1.1 Certification of the installation of modern avionics/electrical systems on airplanes can be summarized, generally, by stating that the systems/equipment must:
32.1.1.1.1 Perform its intended function (§ 25.1301);
32.1.1.1.2 Be adequately protected for failure conditions (§ 25.1309);
32.1.1.1.3 Be arranged to provide proper pilot visibility and utilization (as appropriate) (§ 25.1321);
32.1.1.1.4 Be protected by circuit breakers to preclude failure propagation and/or minimize distress to the airplane’s electrical system (§ 25.1357); and
32.1.1.1.5 Be installed in a manner such that operation of the system will not adversely affect the simultaneous operation of any other system (§ 25.1431).
32.1.1.2 Accordingly, the recommended flight test procedures for equipment covered in subpart F of part 25 (excluding powerplant instruments, airspeed calibration, safety equipment, and lights) are grouped together under this section and are organized as follows:
Paragraph 32.1.2, communication systems.
Paragraph 32.1.3, navigation systems.
Paragraph 32.1.4, instruments and displays.
Paragraph 32.1.5, sensors and warning systems.
Paragraph 32.1.6, recording systems.
Paragraph 32.1.7, engine interfacing systems (autothrottle, power/thrust rating, ATTCS, etc.).
Paragraph 32.1.8, stability augmentation systems.
Paragraph 32.1.9, all weather operation (reduced visibility) systems.
32.1.1.3 Section 25.1301 refers to each item of installed equipment. Type certification involving equipment approvals is governed by Title 49 United States Code, section 44704. That section requires the Administrator to make, or require the applicant for a type certificate to make, such tests “necessary in the interest of safety.” Tests may be 32-1
necessary in order to allow the Administrator to find that the aircraft is properly designed and manufactured, performs properly, and meets the regulations and minimum standards prescribed under section 44701(a) of Title 49. “Optional equipment,” however, is not a term that is meaningful under the Act in connection with the type certification of any given airplane. Where equipment or a system is a part or appurtenance of the airplane and is designed to aid and will obviously be used by the crew, the statutorily required tests and findings are the same, regardless of whether or not it is characterized as optional. Moreover, the regulatory requirement of § 21.21(b)(2) specifies that the Administrator must find that no feature or characteristic of the airplane makes it unsafe for the category in which certification is requested. Therefore, the extent to which that equipment needs to be tested or evaluated, in order that the Administrator may make the necessary finding with respect to the whole airplane, is a technical determination within the engineering and operational expertise of the Administrator. (For further information, see AC 20-168.)
32.1.1.4 Criteria and requirements for flight should consider the applicant’s engineering analysis and laboratory (simulator) test program. The combination of analysis, laboratory, and flight evaluation will form the whole of the certification requirement and, as such, should be in harmony and provide full evaluation. The flight evaluations supplement the analysis and simulation as required in both the representative operating conditions of the airplane and for analysis of the airplane modes of operation and configuration conditions.
32.1.1.5 The requirement for demonstrating safe operation should normally include induced failures during flight. The requirement for failure demonstrations is also an outgrowth of the analysis and laboratory test results submitted by the applicant and is a result of the particular design being evaluated
(e.g., consideration should be made for multiple channel systems specifically designed to be self-adaptive to failure conditions).
Performance and malfunctions testing should include those flight conditions and airplane configurations that have been identified to be the most critical by analysis and/or test. Such items as weight, CG, speed, altitude, flaps, slats, gear, speed brakes, and airplane system degradation should be considered.
32.1.1.6 The amount of flight testing should be determined through the cooperative efforts of the assigned project personnel. It is recommended that the procedures that follow be used as a guide in preparing for the flight testing of an initial certification program. Follow-on items relevant to system derivative certification may result in considerably reduced flight testing.
However, sufficient testing should be accomplished to assure satisfactory performance. When ground or flight test data, available from similar previously approved installations, are sufficient to properly evaluate a system’s performance, additional testing may not be required. In the 32-2
absence of such data, additional testing or analysis should be presented to substantiate the areas potentially affected.
32.1.1.7 Particular attention should be given to those installations where an external piece of gear, such as an antenna, could affect the flight characteristics. All installations of this nature should be evaluated by the flight test pilot.
32.1.1.8 Installations that can or may change the established limitations, flight characteristics, performance, operating procedures, or any required systems require approval by an FAA ACO flight test branch. New installations of equipment in the cockpit, or modifications that affect existing equipment in the cockpit, should be evaluated through the cooperative efforts of the FAA, the project engineer, and the assigned flight test pilot, and assessed for the need of an FAA flight test demonstration.
32.1.1.9 Throughout the systems/equipment evaluation, the operation of annunciators should be assessed to determine that proper conspicuity and display are provided to the appropriate flight crewmember. Any mode of operation selected by a manual action, or automatically, should be positively identified. Any submode should be evaluated to determine the need for annunciation.
32.1.2 Procedures—Communication Systems.
32.1.2.1 Very High Frequency (VHF) Systems.
32.1.2.1.1 Airplanes to be Operated Above 18,000 Feet.
Intelligible communications should be provided between the airplane and facilities throughout circle-turns within 160 NM of an FAA approved ground facility and above minimum radio line-of-sight with no intervening terrain. Bank angles up to 10° on all headings should be used. Drop outs that are relieved by a reduction in bank angle at the same relative heading to the station are satisfactory. It is suggested that the “Long Range Reception Test” of paragraph 32.1.2.1.4 below be conducted first. If this test is successful, the circle-turns (within 160 NM) of this paragraph need not be conducted. Skidding turns may be used to minimize turn radius.)
32.1.2.1.2 Airplanes to be Operated Below 18,000 Feet.
For airplanes limited to operation below 18,000 feet, intelligible communications should be provided as given in paragraph 32.1.2.1.1 above, except that the distance from the ground facility need not exceed 80 NM.
32-3
32.1.2.1.3 Antenna Coverage Measurement.
If the antenna is located on the airplane centerline, tests may be conducted using only one direction of turn. When antenna radiation pattern data are available, flight testing in a 360° turn may not be necessary, if satisfactory communication is achieved during checks in the vicinity of the predicted bearings and bank angles of worst performance.
32.1.2.1.4 Long Range Reception.
At a distance of at least 160 NM (or 80 NM for airplanes to be operated below 18,000 feet) from the ground facility antenna on a heading and above radio line-of-sight, perform a right and/or left 360° turn at a bank angle of at least 10°. Communicate with the ground facility every 10° of turn to test the intelligibility of the signals received at the ground station and in the airplane. The minimum line-of-sight altitude for 160 NM is approximately 17,000 feet. and for 80 NM is approximately 4,000 feet.
Radio line-of-sight distances versus flight level (or altitude) are given in table 32-1 below.
32-4
Table 32-1. Radio Line-of-Sight Distance versus Flight Level or Altitude
Flight Level or Altitude in Feet Radio Line-of-Sight in Nautical Miles Flight Level or Altitude in Feet Radio Line-of-Sight in Nautical Miles FL500 275.0 FL260 198.3 FL490 272.3 FL250 194.5 FL480 269.5 FL240 190.6 FL470 266.7 FL230 186.5 FL460 263.8 FL220 182.4 FL450 260.9 FL210 178.2 FL440 258.0 FL200 173.9 FL430 255.1 FL190 169.5 FL420 252.1 FL180 165.0 FL410 249.1 17,000 160.4 FL400 246.0 16,000 155.6 FL390 242.9 15,000 150.6 FL380 239.8 14,000 145.5 FL370 236.6 13,000 140.2 FL360 233.4 12,000 134.7 FL350 230.1 11,000 129.0 FL340 226.8 10,000 123.0 FL330 223.4 9,000 116.7 FL320 220.0 8,000 110.0 FL310 216.6 7,000 102.9 FL300 213.0 6,000 95.3 FL290 209.5 5,000 87.0 FL280 205.8 4,000 77.8 FL270 202.1 3,000 67.4 32-5
32.1.2.1.5 High Angle Reception.
Repeat the above test at a distance of 50 to 70 NM from the ground station and at an altitude of 35,000 feet, or the maximum operating altitude of the airplane (20 to 30 NM for airplanes to be operated below 18,000 feet).
32.1.2.1.6 Approach Configuration.
With the landing gear extended and the flaps in the approach configuration, demonstrate intelligible communications between the airplane and the ground facility.
32.1.2.1.7 Electromagnetic Compatibility (EMC).
With all systems operating in flight, if practicable, verify, by observation, that no adverse effects are present in the required flight systems.
32.1.2.2 High Frequency (HF) Systems.
32.1.2.2.1 Acceptable communication should be demonstrated by contacting one or more ground stations on several of the frequencies allowed by HF propagation conditions. Distances may vary from 100 to several thousand NM, and at least one over-the-horizon communication link should be established via ionospheric propagation. When a new HF antenna installation is being evaluated, the test should be conducted at an altitude of not less than 90 percent of the maximum altitude to check for possible corona arcing at the antenna.
32.1.2.2.2 The effect of precipitation static should be considered. This type of static is normally found in areas of high cirrus clouds, dry snow, dust storms, etc.
32.1.2.2.3 EMC should be evaluated with all systems operating in flight, if practicable, to verify, by observation, that no adverse effects are present in the required flight systems.
32.1.2.3 Audio Systems.
32.1.2.3.1 Acceptable communications should be demonstrated for all audio equipment, including microphones, speakers, headsets, interphone amplifiers, and public address systems. If provisions for passenger entertainment are included, adequate override of the music/audio by the cockpit crew attendants, or by prerecorded announcements, should be demonstrated. All modes of operation should be tested, including operation during emergency conditions (e.g., emergency descent with oxygen masks) with all airplane engines running, all airplane pulse equipment transmitting, and all electrical equipment operating. Flight tests, except as described in paragraph 32.1.2.3.2 below, are generally not necessary unless airstream noise is considered a factor or unless excessive 32-6
feedback with cockpit speakers is encountered during ground tests, which makes cockpit sound levels questionable.
32.1.2.3.2 If a flight evaluation of the PA system is deemed to be necessary (or the prudent thing to do), PA announcements should be made from each handset station, including the cockpit, with the airplane operated at mid to high altitude at speeds approaching VMO/MMO.
32.1.2.3.3 EMC should be evaluated with all systems operating during flight, verify, by observation, that no adverse effects are present in the required flight systems.
32.1.2.4 Aircraft Communications Addressing and Reporting System (ACARS).
32.1.2.4.1 ACARS is an addressable VHF digital data link system that permits communication between the airplane and a ground-based facility. The display medium is a printer and/or electronic multifunction display.
32.1.2.4.2 Acceptable performance should be demonstrated by verifying that pre-flight loaded data is retained in memory during power interrupts generated during transfers from ground to APU power, from APU to engine generators, and during cross-tie switching in all possible combinations.
32.1.2.4.3 Verify that simultaneous transmission of ACARS data and VHF voice communication is satisfactory and is free of interference between the two independent VHF systems, considering frequency and VHF antenna isolation. Exercise all possible switching combinations.
32.1.2.4.4 If the selective calling system (SELCAL) can be initiated by the ground station via the ACARS data link, demonstrate performance of that function by observing that the cockpit aural and visual indications are proper.
32.1.2.4.5 If the flight management system (FMS) database or operational program can be accessed in flight by ACARS, exercise all interface functions to demonstrate performance of the intended function.
32.1.2.4.6 ACARS should not cause interference with the operation of any of the airplane’s radio/navigation systems. Particular attention should also be devoted to non-interference with flight guidance takeoff and approach functions, particularly autoland, since these are likely flight regimes for ACARS transmissions.
32.1.2.5 SELCAL.
Verify performance of intended function of the SELCAL by receipt of VHF and HF (if appropriate) calls from ground stations.
32-7
32.1.2.6 Satellite Communications (SATCOM).
[Reserved]
32.1.2.7 Portable Battery-Powered Megaphones.
32.1.2.7.1 Conduct hearing range and intelligibility tests on the airplane to demonstrate that the amplified speech is heard and clearly understood throughout the interior cabin region served by the megaphones, with the engines off and with all significant conditions associated with an accident (including the presence of passengers and the normally attendant confusion din) appropriately simulated.
32.1.2.7.2 Verify that the megaphone reliably performs its intended function and is designed:
For ease of handling, and use, with one hand;
With sufficient acoustical feedback suppression; and With a volume control.
32.1.3 Procedures: Navigation Systems.
32.1.3.1 Very High Frequency Omnidirectional Range (VOR) Systems.
32.1.3.1.1 These flight tests may be reduced if adequate antenna radiation pattern studies have been made and these studies show the patterns to be without significant holes (with the airplane configurations used in flight, i.e., flaps, landing gear, etc.). Particular note should be made in recognition that certain propeller RPM settings may cause modulation of the course deviation indication (prop-modulation). This information should be presented in the AFM.
32.1.3.1.2 The airborne VOR system should operate normally with warning flags out of view at all headings of the airplane (wings level) throughout the airspace within 160 NM of the VOR facility (for airplanes to be operated above 18,000 feet), from the radio line-of-sight altitude to within 90 percent of the maximum altitude for which the airplane is certified or the maximum operating altitude.
32.1.3.1.3 The accuracy determination should be made such that the indicated reciprocal agrees within 2°. The test should be conducted over at least two known points on the ground such that data are obtained in each quadrant.
Data should correlate with the ground calibration and in no case should the absolute error exceed ±6°. There should be no excessive fluctuation in the course deviation indications.
32-8
32.1.3.1.4 En Route Reception.
Fly from a VOR facility rated for high altitude along a radial at an altitude of 35,000 feet. (or to within 90 percent of the airplane maximum certificated altitude or the maximum operating altitude) to a range of 160 NM (80 NM for airplanes not to be operated above 18,000 feet). The VOR warning flag should not come into view, nor should there be deterioration of the station identification signal. The course width should be 20° ±5° (10° either side at the selected radial). If practical, perform an en route segment on a Doppler VOR station to verify the compatibility of the airborne unit. Large errors have been found when incompatibility exists.
32.1.3.1.5 Long Range Reception.
Perform a right and/or left 360° turn at a bank-angle of at least 10°, at an altitude above the radio line-of-sight, and at a distance of at least 160 NM (80 NM for airplanes to be operated below 18,000 feet) from the VOR facility. Signal dropout should not occur as evidenced by the malfunction indicator appearance. Dropouts that are relieved by a reduction of bank angle at the same relative heading to the station are satisfactory. The VOR identification should be satisfactory during the left and right turns.
Skidding turns may be used to minimize turn radius.
32.1.3.1.6 High Angle Reception.
Repeat the turns described in paragraph 32.1.3.1.5 above, but at a distance of 50 to 70 NM (20 to 30 NM for airplanes not to be operated above 18,000 feet) from the VOR facility and at an altitude of at least 35,000 feet. (or to within 90 percent of the maximum certificated altitude of the airplane or the maximum operating altitude).
32.1.3.1.7 En Route Station Passage.
Verify that the TO-FROM indicator correctly changes as the airplane passes through the cone of confusion above a VOR facility.
32.1.3.1.8 VOR Approach.
Conduct VOR approach(es) with gear and flaps down. The facility should be 12-15 NM behind the airplane with the approach conducted after a 30° radial change over the station. Use sufficient maneuvering in the approach to assure the signal reception is maintained during beam tracking.
32.1.3.1.9 EMC.
EMC should be evaluated with all systems operating in flight, to verify by observation that no adverse effects are present in the required flight systems.
32-9
32.1.3.1.10 Identifier.
The audio identifier should be checked, as should the decoded identifier, if equipped with a digital bus.
32.1.3.1.11 Station tuning.
Evaluate various methods of station tuning, including automatic and manually through an FMS. Also, a check for proper indications for loss of signal or receiver failure should be done.
32.1.3.2 Localizer Systems.
32.1.3.2.1 These flight tests may be reduced if adequate antenna radiation pattern studies have been made, and those studies show the patterns to be without significant holes. A significant hole is one that is greater than 10 decibels (dB) from the average within 30° horizontally and 15° vertically of the nose of the airplane.
32.1.3.2.2 The signal input to the receiver, presented by the antenna system, should be of sufficient strength to keep the malfunction indicator out of view when the airplane is in the approach configuration (landing gear extendedapproach flaps) and at least 25 NM from the station. This signal should be received for 360° of airplane heading at all bank angles up to 10° left or right, at all normal pitch attitudes, and an altitude of approximately 2,000 feet.
32.1.3.2.3 Satisfactory results should also be obtained at bank angles up to 30°, when the airplane heading is within 60° of the inbound localizer course. Results should be satisfactory with bank angles up to 15° on headings from 60° to 90° of the localizer inbound course, and up to 10° bank angle on headings from 90° to 180° from the localizer inbound course.
32.1.3.2.4 The deviation indicator should properly direct the airplane back to course when the airplane is right or left of course.
32.1.3.2.5 The station identification signal should be of adequate strength and sufficiently free from interference to provide positive station identification, and voice signals should be intelligible with all electrical equipment operating and pulse equipment transmitting.
32.1.3.2.6 Localizer Intercept.
In the approach configuration and at a distance of at least 25 NM from the localizer facility, fly toward the localizer front course, inbound, at an angle of at least 50°. Perform this maneuver from both left and right of the localizer beam. No flags should appear during the time the deviation indicator moves from full deflection to on-course.
32-10
32.1.3.2.7 Localizer Tracking.
While flying the localizer inbound and not more than 5 miles before reaching the outer marker, change the heading of the airplane to obtain full needle deflection; then fly the airplane to establish localizer on-course operation. The localizer deviation indicators should direct the airplane to the localizer on-course. Perform this maneuver with both a left and a right needle deflection. Continue tracking the localizer until over the transmitter. Acceptable front course and back course approaches should be conducted to 200 feet or less above the threshold.
32.1.3.2.8 EMC.
With all systems operating in flight, verify by observation that no adverse effects are present in the required flight systems.
32.1.3.3 Glideslope Systems.
32.1.3.3.1 These flight tests may be reduced if adequate antenna radiation pattern studies have been made, and those studies show the patterns to be without significant holes. A significant hole is one that is greater than 10 dB from the average within 30° horizontally and 15° vertically of the nose of the airplane.
32.1.3.3.2 The signal input to the receiver should be of sufficient strength to keep the warning flags out of view at all distances up to 10 NM from the final approach fix. This performance should be demonstrated at all airplane headings between 30° right and left of the localizer course. The deviation indicator should properly direct the airplane back to the glideslope path when the airplane is above or below the path.
32.1.3.3.3 Interference with the navigation operation should not occur with all airplane equipment operating and all pulse equipment transmitting. There should be no interference with other equipment as a result of glideslope operation.
32.1.3.3.4 Glideslope Interception.
Fly the localizer course inbound, at the altitude at which the glideslope beam intercepts the final approach fix, and at least 10 NM from the fix.
The glideslope deviation indicator should be centered (±25 percent of full scale) at the final approach fix. There should be no flags from the time the needle leaves the full-scale fly-up position until it reaches the full-scale fly-down position.
32.1.3.3.5 Glideslope Tracking.
While tracking the glideslope, maneuver the airplane through normal pitch and roll attitudes. The glideslope deviation indicator should show proper operation with no flags. Acceptable approaches to 100 feet or less above the threshold should be conducted.
32-11