AC 120-28D Appendix 7 07/13/99
6. CATEGORY III INSTRUMENT APPROACH AND LANDING OPERATIONS Sample Operations Specifications Paragraph C060:
C060, Category III Instrument Approach and Landing Operations.
The certificate holder is authorized to conduct Category III instrument approach and landing operations to the airports and runways listed in subparagraph g. using the procedures and minimums specified in this paragraph and shall conduct no other Category III operations.
a. Category III Approach and Landing Minimums. The certificate holder is authorized to use the following Category III landing minimums for the aircraft listed below at authorized airports and runways, provided the special limitations in subparagraph g are met. These minimums are the lowest authorized at any airport.
1. Category III Fail-Passive Operations Airplane M/M/S DH Lowest Authorized RVR ************************************************************************
2. Category III Fail-Operational Operations Airplane M/M/S DH/AH Lowest Authorized RVR **********************************************************************
b. Required Category III Airborne Equipment. The flight instruments, radio navigation equipment, and other airborne systems required by the applicable Section of the Code of Federal Regulations (CFR) must be installed and operational for Category III operations at or above RVR 600. The additional airborne equipment listed or referenced in the following table is also required and must be operational for Category III operations below RVR600.
Airplane M/M/S Additional Equip.
& Special Provisions
c. Required RVR Reporting Equipment. The certificate holder shall not conduct any Category III operation unless the following RVR reporting systems are installed and operational for the runway of intended landing.
(1) For Category III landing minimums as low as RVR600 (175 meters), the Touchdown Zone, Mid, and Rollout RVR reporting systems are required and must be used. Touchdown Zone and Mid RVR reports are controlling for all operations. The Rollout report provides advisory information to pilots.
(2) For Category III landing minimums below RVR600 (175 meters) using fail-passive rollout control systems, the Touchdown Zone, Mid, and Rollout RVR reporting systems are required and must be used.
All three RVR reports are controlling for all operations.
AC 120-28D 07/13/99 Appendix 7
(3) For Category III landing minimums below RVR600 (175 meters) using fail-operational rollout control systems, the Touchdown Zone, Mid, and Rollout RVR reporting systems are normally required and are controlling for all operations. If one of these RVR reporting systems is temporarily inoperative, these operations may be initiated and continue using the two remaining RVR reporting systems. Both RVR reports are controlling.
d. Pilot Qualifications. A pilot-in-command shall not conduct Category III operations in any airplane until that pilot has successfully completed the certificate holder's approved Category III training program, and has been certified as being qualified for Category III operations by one of the certificate holder's check airmen properly qualified for Category III operations or an FAA inspector. Pilots in command who have not met the requirements of Section 121.652 shall use high minimum pilot landing minima not less than RVR1800.
e. Operating Limitations. The certificate holder shall not begin the final approach segment of an instrument approach procedure, unless the latest reported controlling RVR for the landing runway is at or above the minimums authorized for the operation being conducted. If the aircraft is established on the final approach segment and the controlling RVR is reported to decrease below the authorized minimums, the approach may be continued to the AH/DH applicable to the operation being conducted. Unless all of the following conditions are met, the certificate holder shall not begin the final approach segment of a Category III instrument approach:
(1) The airborne equipment required by subparagraph b. is operating satisfactorily.
(2) All required elements of the Category III ground system, except sequence flashing lights, are in normal operation. A precision or surveillance radar fix, a NDB, VOR, DME fix, its published Waypoint, or a published minimum GSIA fix, may be used in lieu of an outer marker.
(3) All Category III operations using minimums below RVR600 shall be conducted to runways which provide direct access to taxi routings equipped with serviceable taxiway centerline lighting which meets U.S. or ICAO criteria for Category III operations.
(4) The crosswind component on the landing runway is 15 knots or less.
(5) The runway field length requirements, the special operational equipment requirements, and the special limitations listed or referenced in the following table are met. If required runway field length factors are listed in this table, the required field length is established by multiplying these factors by the runway field length required by the provisions of Section 121.195(b) or 14 CFR Part 135, Section 135.385(b), as appropriate.
Airplane Make/Model/Seri es Category III Required Field Length Special Operational Equipment or Special Limitations RVR not less than RVR700 RVR600 RVR less than RVR600
f. Missed Approach Requirements.
AC 120-28D Appendix 7 07/13/99
(1) For Category III approaches with a fail-passive landing system a missed approach shall be initiated when any of the following conditions exist:
(a) At the DH, if the pilot has not identified the required visual references with the touch down zone or touch down zone lights to verify that the aircraft will touch down in the touch down zone.
(b) At or before the DH, if the controlling RVR is reported below the lowest RVR authorized for fail passive operations.
(c) If, after passing the DH, visual reference is lost or a reduction in visual reference occurs which prevents the pilot from continuing to verify that the aircraft will touch down in the touch down zone.
(d) When a failure in the fail-passive flight control system occurs prior to touch down.
(e) If the pilot determines that touch down cannot be safely accomplished within the touch down zone.
(f) When any of the required elements of the ground system becomes inoperative before arriving at DH.
(g) The crosswind component at touchdown is expected to be greater than 15 knots.
(2) For Category III approaches with a fail-operational landing and rollout control system, a missed approach shall be initiated at or before AH when any of the following conditions exist:
(a) A failure occurs in one of the redundant systems in the aircraft before reaching the AH.
(b) Any of the required elements of the ground system becomes inoperative. However, Category III approaches and landings may be continued even though the sequence flashers and the approach lights became inoperative.
(c) The crosswind component at touchdown is expected to be greater than 15 knots.
(3) The preceding subparagraphs f.(1) and (2) do not preclude continuation of a higher minimum Category approach if the system failures do not affect the systems required for the higher approach minimums.
g. Authorized Category III Airports and Runways. The certificate holder is authorized to conduct Category III operations at the airports and runways listed in the following table.
Airport Ident Runways Special Limitations
AC 120-28D 07/13/99 Appendix 7
7. IFR LOWER THAN STANDARD TAKEOFF MINIMUMS, 14 CFR PART 121 AIRPLANE OPERATIONS - ALL AIRPORTS.
Sample Operations Specifications Paragraph C078:
IFR Lower Than Standard Takeoff Minimums, 14 CFR Part 121 Airplane Operations - All Airports.
Standard takeoff minimums are defined in paragraph C056 of these operations specifications. The certificate holder is authorized to use lower than standard takeoff minimums under the following provisions and limitations. Runway visual range (RVR) reports, when available for a particular runway, shall be used for all takeoff operations on that runway. All takeoff operations, based on RVR, must use RVR reports from the locations along the runway specified in this paragraph.
a. When takeoff minimums are equal to or less than the applicable standard takeoff minimum, the certificate holder is authorized to use the lower than standard takeoff minimums described below:
(1) Visibility or runway visual value (RVV) 1/4 statute mile or touchdown zone RVR 1600, provided at least one of the following visual aids is available. The touchdown zone RVR report, if available, is controlling. The mid RVR report may be substituted for the touchdown zone RVR report if the touchdown zone RVR report is not available.
(a) Operative high intensity runway lights (HIRL).
(b) Operative runway centerline lights (CL).
(c) Runway centerline marking (RCLM).
(d) In circumstances when none of the above visual aids are available, visibility or RVV 1/4 statute mile may still be used, provided other runway markings or runway lighting provide pilots with adequate visual reference to continuously identify the takeoff surface and maintain directional control throughout the takeoff run.
(2) Touchdown zone RVR 1000 (beginning of takeoff run) and rollout RVR 1000, provided all of the following visual aids and RVR equipment are available.
(a) Operative runway centerline lights (CL).
(b) Two operative RVR reporting systems serving the runway to be used, both of which are required and controlling. A mid-RVR report may be substituted for either a touchdown zone RVR report if a touchdown zone report is not available or a rollout RVR report if a rollout RVR report is not available.
(3) Touchdown zone RVR 500 (beginning of takeoff run), mid RVR 500, and rollout RVR 500, provided all of the following visual aids and RVR equipment are available.
(a) Operative runway centerline lights (CL).
(b) Runway centerline markings (RCLM).
(c) Operative touchdown zone and rollout RVR reporting systems serving the runway to be used, both of which are controlling, or three RVR reporting systems serving the runway to be used, all of which are controlling. However, if one of the three RVR reporting systems has failed, a takeoff is authorized, provided the remaining two RVR values are at or above the appropriate takeoff minimum as listed in this subparagraph.
b. At foreign airports which have runway lighting systems equivalent to U.S. standards, takeoff is authorized with a reported touchdown zone RVR of 150 meters, mid RVR of 150 meters, and rollout
AC 120-28D Appendix 7 07/13/99 RVR of 150 meters. At those airports where it has been determined that the runway lighting system is not equivalent to U.S. standards, the minimums in subparagraphs a(1) or (2), as appropriate, apply.
c. In circumstances when the touchdown zone RVR reporting system has failed, is inaccurate, or is not available, the certificate holder is authorized to substitute pilot assessment of equivalent RVR for any touchdown zone RVR report required by this operations specification paragraph provided that:
(1) The pilot has completed the approved training addressing pilot procedures to be used for visibility assessment in lieu of RVR, and
(2) Runway markings or runway lighting is available to provide adequate visual reference for the assessment.
d. Additional provisions for takeoff guidance systems--all airports, if applicable. Not withstanding the lower than standard takeoff minimums specified in subparagraph a of this operations specification, the certificate holder is authorized to use the takeoff minimums specified for the aircraft and airports listed in this subparagraph provided the special provisions and conditions described below are met. The certificate holder shall conduct no other takeoffs using these takeoff minimums.
(1) Special provisions and limitations.
(a) Operative runway centerline lights (CL)
(b) Operative high intensity runway lights (HIRL)
(c) Serviceable runway centerline markings (RCLM)
(d) Front course guidance from the localizer must be available and used (if applicable to guidance systems used)
(e) The reported crosswind component shall not exceed 10 knots.
(f) Operative touchdown zone, and rollout RVR reporting systems serving the runway to be used, both of which are controlling, or three RVR reporting systems serving the runway to be used, all of which are controlling. However, if one of the three RVR reporting systems has failed, a takeoff is authorized, provided the remaining two RVR values are at or above the appropriate takeoff minimum as listed in this subparagraph.
(g) The pilot-in-command and the second-in-command have completed the certificate holders approved training program for these operations.
(h) All operations using these minimums shall be conducted to runways which provide direct access to taxi routings which are equipped with: operative taxiway centerline lighting which meets U.S. or ICAO criteria for Category III operations; or other taxiway guidance systems approved for these operations.
(2) Authorized airplanes using takeoff guidance systems--all airports. The certificate holder is authorized to use the following takeoff minimums for the airplanes listed below. (if subparagraph d is not authorized, use N/A in the Airplane M/M/S column):
Airplane M/M/S Lowest Authorized RVR Required Takeoff Guidance System
AC 120-28D 07/13/99 Appendix 8 APPENDIX 8
IRREGULAR TERRAIN ASSESSMENT The following information describes the operational evaluation process, procedures, and criteria applicable to approval of flight guidance systems (e.g., autoland or “pilot-in-the-loop” manual flight guidance systems) to support Category III procedures and minima at airports identified in the FAA Order 8400.8 and “Category II/III Status List” as having irregular underlying approach terrain.
Background. FAA type design approval of flight guidance systems provides for generic performance evaluation of autoland capability or “pilot-in-the-loop” manual flight guidance capability through simulation with reference terrain conditions, and flight testing at a few particular locations. This is to verify suitability of the design analysis. When an aircraft is type certificated (or STC'd) for use of a flight guidance systems, it is not the intent, nor is it practical that each model of aircraft, flight guidance system, radar altimeter type, NAVAID receiver type, etc., be tested at each conceivable location that it could potentially be used in operation, domestic and foreign. Additionally, NAVAID performance itself
(e.g., ILS system) may vary somewhat from location to location or time to time due to different ATS critical area protection procedures to assure NAVAID performance (e.g., to minimize reflective interference). While type design certification by FAA, and frequent flight inspection by FAA or foreign authorities, addresses generic system performance, specific operational review and approval of particular aircraft type/site autoland performance is necessary when minima are predicated on use of autoland or other manual flight guidance system (e.g., head-up- display (HUD)) use. This is especially important at airports with irregular pre-threshold terrain (e.g., cliffs, valleys, sea walls) in the area of final approach, within approximately 1500 ft. of the landing threshold.
At typical airports/runways that are not considered to be "special terrain" (e.g., those not restricted by FAA Order 8400.8 and the CAT II/III Status List) the review and approval process usually consists of verifying the operator’s report of performance for a small number of "line landings" using the flight guidance system in weather conditions better than those requiring use of Cat II or lower minima. This is true whether the review and approval is for a new operator or aircraft type at a particular runway, or is for a “follow-on” operator or aircraft type starting service at a runway previously found suitable for a particular type aircraft and system. If the review and approval is for a "special terrain" runway, particularly for a first of an aircraft type or system to base Category II or Category III minima on using a particular flight guidance system at that runway, then a specific evaluation including an operational demonstration is generally necessary.
This paper describes the general evaluation process, procedures, and criteria to be applied for such cases.
Since circumstances often are unique in assessing aircraft/ flight guidance system/site performance, this summary represents an acceptable method. It is not the only method that may be proposed by FAA or an applicant. Credit may be applied for relevant testing by the manufacturer, for similar airborne systems, or for performance at similar locations (e.g., subsequent special terrain airport approvals). Certain aircraft/ flight guidance system combinations may require more extensive testing when an aircraft may exhibit unique characteristics at a particular runway (e.g., transient Radio Altimeter failure indication due to disagreement or unlock, inappropriate auto throttle response, inconsistent flare performance).
Accordingly, before establishing test requirements with a manufacturer or operator for special terrain airports or particular runways, the proposed evaluation plan should be coordinated with AFS-400. This should be done prior to agreement by the Principal Operations Inspector or Principal Avionics Inspector with the operator on the testing to be done and data to be collected.
AC 120-28D Appendix 8 07/13/99 Flight Guidance System Evaluation Process At Special Terrain Airports or Runways That Are Proposed For Category III Procedures Or Minima A. Case I - First of a Type/Model at Any Special Terrain Airport/Runway.
Case I , First of a Type/Model, applies to the first Special Terrain airport/runway to be approved for a particular type (e.g., first L1011 autoland approval for irregular terrain at any airport – such as first L1011 use of KSEA Runway 16R, if not otherwise previously approved at KSEA, or any other “Special terrain airport” such as KCVG, KDEN, or KPIT).
1). Evaluation objective. Assess and verify normal flight guidance system performance from an operational perspective, and identify miscellaneous factors needed for a safe Cat III operation (e.g., alert height or decision height identification).
2). Procedure. Perform at least 4 to 6 successful evaluation landings in typical atmospheric conditions regarding wind and turbulence, using the applicable operational aircraft configuration, with a representative aircraft from the fleet, (e.g., a typical aircraft maintained using routine maintenance practices, not specially configured, not specially tested, or otherwise not specially selected from the operator’s fleet). If the flight guidance system may be susceptible to an uncertain performance characteristic (e.g., long flare in a tailwind condition, pitch/throttle coupling oscillation during flare) the evaluation should take place when the system may be put to an appropriate test of the applicable crosswind, tailwind, headwind, wind gradient, or other critical condition applicable, consistent with the operator’s proposed conditions or limits and the AFM’s demonstrated conditions or limits.
Confirm the initial assessment of 4 to 6 data recorded evaluation landings, with subsequent successful initial operational landings (typically the first 25 or more) as reported by the operator (e.g., data recording or other special observation, other than by the regularly assigned flightcrew, is not required).
3). Evaluator(s). A person qualified to assess flight guidance system function and performance should conduct these evaluations as the FAA observer (e.g., typically an Category III qualified and experienced APM of a Category III authorized operator, a qualified AFS-400 representative, a qualified AEG representative, or an appropriate FAA National Resource Specialist (NRS)). FAA may designate other suitably qualified representatives to assess flight guidance system function and performance as necessary
(e.g., suitably qualified check airman, fleet manager, FAA DER).
4). FGS Performance/Data Recording. Generally, some form of quantitative data should be recorded and reviewed as verification of performance. Methods used in the past include, but are not limited to either method a, or method b, or method c below or any combination:
a) Method A - Data Recording and Observation. Record pertinent flight guidance system performance data using a DFDR or a Quick reference recorder, or equivalent, which has ability to record the parameters shown below. The recording should be at a sufficiently high sample rate (e.g., at a rate > 1 sample per second), for the part of the flight path of interest (typically from 300’HAT through de-rotation after touchdown).
/elevenoclock barometric altitude
/elevenoclock radio altitude
/elevenoclock radio altitude rate (h dot)
AC 120-28D 07/13/99 Appendix 8 /elevenoclock glide slope error
/elevenoclock vertical speed
/elevenoclock elevator command
/elevenoclock pitch attitude
/elevenoclock throttle position
/elevenoclock airspeed
/elevenoclock Mode transition or engagement Manual observations may be made for touchdown point (lateral, longitudinal), wind profile from 1000 ft. to surface (e.g., from an INS or IRS that is capable of displaying winds at typical approach speeds).
b) Method B - Review of Manufacturer’s Data. A review of the manufacturer’s data from flight guidance system development flight testing at the same special terrain runway, or equivalent, may be used to confirm items shown in 5) below.
c) Method C - Photo recording. Photo recording of pertinent instruments or instruments and outside view, with a video camera or equivalent, allowing post flight replay and review of indications noted in Method A above.
5) Data review and Analysis. The final approach, flare, and touchdown profile should be reviewed to ensure suitability of at least each of the following.
a) Suitability of the resulting flight path
b) Acceptability of any flight path displacement from the nominal path (e.g., Glide slope deviation, deviation from nominal flare profile),
c) Proper mode switching
d) Suitable touchdown point,
e) Suitable sink rate at touch down,
f) Proper flare initiation altitude
g) Suitable flare “quality” (e.g., no evidence of early or late flare, no overflare or underflare, no undue “pitchdown down” tendency at flare initiation or during flare, no flare oscillation, no abrupt flare, no inappropriate pitch response during flare, no unacceptable floating tendency, or other unacceptable characteristic that a pilot could interpret as failure or inappropriate response of the flight guidance system and disconnect, disregard, or contradict the FGS),
h) No unusual flight control displacements (e.g., elevator control input spikes, or oscillations),
AC 120-28D Appendix 8 07/13/99
i) Appropriate throttle retard (e.g., no early or late throttle retard, no failure to retard, no undue reversal of the retard, no undue pitch/throttle coupling),
j) Appropriate speed decay in flare (e.g., no unusually low speed risking high pitch attitude and tail strike, no excessive float, appropriate speed decay even if well above Vref at flare initiation due to planned wind or gust compensation ),
k) Proper mode initiation or mode transition relating to altitude or radio altitude inputs, such as crosswind alignment initiation, if applicable (e.g., Appropriate radio altitude (RA) trigger of crosswind alignment, to be sure that an appropriate mode transition occurs, even though underlying approach terrain may be irregular).
6) Miscellaneous Issues.
a. Determine acceptability of any variable radio altitude (RA) indications. Regarding Alert Height (AH) or Decision Height (DH) identification, determine the acceptability of any variable radio altitude (RA) indications or displays (e.g., considering variability due to underlying terrain variability in the last stage of the approach near Alert Height or Decision height). Assure that display indications are sufficiently stable and continuous to readily identify or define AH or DH. If an Inner Marker is to be used to establish Alert Height or Decision Height, determine if the inner marker function is adequate.
b. Address any anomalies occurring during the assessment (e.g., autopilot trip, firm landing, flare oscillation). Additional testing may be needed to clearly identify and resolve any particular problem identified.
c. Determine if special training, or other operational constraints are needed to accommodate peculiar approach or flare characteristics (e.g., require visual reference at flare initiation, apply a 50 ft. DH).
d. Authorization for use should occur only after repeated successful landings have been demonstrated and any anomalies experienced have been resolved.
B. Case II - Subsequent Special Terrain Airport/Runway Authorization for a Particular Type.
Case II addresses the “First of a Model” at a particular runway, but at a subsequent “Special Terrain Airport” runway (e.g., After an aircraft type has already been successfully demonstrated at some special terrain airport runway – such as the first ever B767 type FGS use at KPIT Rwy 28L, after prior approval at KSEA).
1) Evaluation objective. Same as Case I
2) Procedure. Same as Case I.
3) Evaluator(s). Same as Case I.
4) FGS Performance/Data Recording - Data recording is not generally required. However, if the results of landings are marginal or unacceptable, the data recording and assessment procedures applicable to Case I may be needed to assess any remedial action required.
5) Data review and Analysis. Same as Case I.
6) Miscellaneous Issues. Same as Case I.
AC 120-28D 07/13/99 Appendix 8 C. Case III - Subsequent Operator Use of a Particular Special Terrain Airport/Runway and Type Combination.
A Certificate Holding District Office (CHDO) (e.g., POI, PAI, APM) may review a request for an operator to use a particular Special Terrain Airport/runway and aircraft type, and with AFS concurrence, approve subsequent airline operation of a particular type at that special terrain airport/runway. Any authorization should be based on 25 or more successful "line" landings reported by the operator requesting authorization in weather conditions not requiring credit for FGS system use. The experience reported by operator should include no unsuccessful landing attempts or failures. If problems or failures are reported, then Case II or Case I procedures may be needed to resolve potential unique aircraft configuration effects, procedural effects, maintenance effects, or other effects.
D. Case IV – “Not-For-Credit” Use of Special Terrain Airport/Runway and Type Combinations.
“Not-For-Credit” use of “Special Terrain Airport/Runway and Type Combinations” applies to operators desiring to use an FGS (e.g., Autoland or Flight Guidance HUD) at a Special Terrain Airport/Runway, but not for any landing minima credit.
In this instance, a representative of the CHDO may evaluate the use during first line operations or specify that an operator representative (e.g., technical pilot, qualified management pilot, or check airman who is experienced with flight guidance system operation and performance) assess and verify adequate flight guidance system performance. This assessment should be completed prior to initiating routine operational use of the flight guidance system to touchdown at each “Special Terrain” runway. It is desirable, but not necessary, that a qualified APM, or equivalent, witness each "special terrain airport" evaluation.
The CHDO should request and review flight guidance system reports from line crews for at least the first 5 line landings to confirm appropriate performance. If problems occur, processes for cases I through IV may be needed to resolve problems depending on the severity and cause of problem (e.g., maintenance problem, unusual winds, lack of ATS critical area protection, problem with a modification to the FGS, use of a different associated component, such as substitution of a different and incompatible radar altimeter model).
A “Not-For-Credit” evaluation may be done in line operation as long as no previous reported problems have been noted with the same or similar aircraft type, and no NOTAM’s or other restrictions preclude such operations. If problems have been reported for the same or similar type, treatment as Case I through III, as applicable above, may be appropriate.
NOTE: Unless otherwise restricted by an operator or CHDO, flight guidance system operations “Not-for-Minima-Credit” may generally be conducted on any ILS runway that does not have a restricting note on the approach plate (e.g., localizer unusable for rollout, glideslope unusable below xxx ft. AGL) and that has an adequate glide slope threshold clearance height (TCH) suitable for the aircraft type). If problems are noted in the operator’s evaluation, the operator should specify that flight guidance system use should not be accomplished at that site to touchdown. This may be done through a flightcrew bulletin or equivalent.
Conversely, an operator may publish a list of runways approved for flight guidance system use to touchdown, or through rollout.
AC 120-28D 07/13/99 Appendix 9 APPENDIX 9
TAKEOFF SYSTEM PERFORMANCE AFTER LIFTOFF Takeoff system operation should be continuous and smooth through transition from the runway portion of the takeoff to the airborne portion and reconfiguration for en route climb. The criteria found in this paragraph is not unique to low visibility takeoff systems, but such systems must meet these requirements in addition to those found in Section 6.1.1 of Appendix 2. The pilot must be able to continue the use of the same primary display(s) for the airborne portion as for the runway portion. Changes in guidance modes and display formats must be automatic.
a) If the probability of the takeoff system presenting misleading guidance to the pilot is not Extremely Improbable, it must be shown that loss of the airplane will not occur if the takeoff system presents misleading guidance, whether caused by performance anomaly or malfunction. Compliance with this requirement can be demonstrated by showing that the display of misleading guidance information is Improbable when the flightcrew is alerted to the condition by:
• suitable annunciation means, or
• by information from other independent sources (e.g., primary flight references) available within the pilot's primary eye-scan area.
NOTE: For takeoff systems using a Head Up Display (HUD) to present takeoff guidance, the head down instrument panel is typically not within the pilot's primary eye-scan area.
Thus, annunciations displayed in locations near the HUD field of view, such as the glare shield, may be found suitable, if they are clear, conspicuous and unambiguous to the pilot while focused on using the HUD.
b) The display of misleading guidance for takeoff shall be Extremely Improbable if no alternate means are available to detect the malfunction or to assess alternate sources of the guidance information, or if the transition to an alternate means of guidance is impractical.
c) The vertical axis guidance of the takeoff system during normal operation shall result in the appropriate pitch attitude, and climb speed for the airplane considering the following factors.
Normal rate rotation of the airplane to the commanded pitch attitude, at VR-10 knots for all engines and VR-5 knots for engine out, will not result in a tail-strike.
The system should provide commands that lead the airplane to smoothly acquire a pitch attitude that results in capture and tracking of the All-Engine Takeoff Climb Speed, V2 + X. X is the All-Engine Speed Additive from the AFM (normally 10 knots or higher). If pitch limited conditions are encountered, a higher climb airspeed may be used to achieve the required takeoff path without exceeding the pitch limit.
d) For engine-out operation, the system should provide commands that lead the airplane to smoothly acquire a pitch attitude that results in capture and tracking of the following reference speeds:
V2, for engine failure at or below V2. This speed should be attained by the time the airplane has reached 35 ft. altitude.
Airspeed at engine failure, for failures between V2 and V2 + X.