4. FORWARD FLIGHT-POWER ON.
a. Level flight. (**)
b. Maneuvers.
FIGURE AC 27.MG 11-7 (continued)
(1) 40 percent VH
(2) 60 percent VH
(3) 80 percent VH
(4) VH
(5) VNE
(1) Full power climbs. (**)
(2) Cyclic pull-ups.
(3) Normal acceleration from climb airspeed to 90 percent VH.
(4) Turns, right and left over a range of bank angles and speeds up to the lesser of VH or VNE and including:
(5) Control reversals at 90 percent VH.
(6) Deceleration from 90 percent VH to descent airspeed.
(1) Partial power descent. (*)
(2) Normal approach
(3) Steep Approaches (to landing) or Flare FIGURE AC 27.MG 11-7
i) Minimum side of main rotor RPM tolerance (RPM -) ii) Maximum side of main rotor RPM tolerance (RPM +)
i) (RPM +) ii) (RPM -)
i) (RPM +) ii) (RPM -)
i) (RPM +) ii) (RPM -)
i) (RPM +) ii) (RPM -)
i) All engines operative.
ii) One-engine-inoperative.
i) 60 percent VH.
ii) 90 percent VH.
i) Right at 60 percent VH and 90 percent VH.
ii) Left at 60 percent VH and 90 percent VH.
i) Longitudinal.
ii) Lateral.
iii) Rudder.
i) All engines.
ii) One engine out.
AC Page MG 11 - 21
AC 27-1B, Chg 1 2/12/03 (continued)
5. POWER TRANSITIONS.
a. All engines operating to one engine out.
(1) In full power climb.
(2) At 90 percent VH.
b. One engine out to all engines operating in powered descent.
c. All engines operating to autorotation.
(1) At 60 percent VH.
(2) At maximum forward transition speed.
d. Stabilized autorotation to all engines operating at normal autorotation airspeed.
6. AUTOROTATION.
a. Stabilized. (1) At 70 percent VNE.
(2) At VNE.
b. Turns at 70 percent and 100 percent VNE.
(1) Right.
(2) Left.
c. Cyclic pull-up.
d. Control reversals. (1) Longitudinal.
(2) Lateral.
(3) Rudder.
(**) side slip conditions should be considered (*) max slope angle and aircraft headings should be considered Page MG 11 - 22
FIGURE AC 27.MG 11-8
LIFTING HELICOPTER LOAD MEASUREMENT in addition to normal conditions CONDITION %RATED LOAD % VNE
ROTOR START VERTICAL LIFT 100 87 HOVER including spot turns sideward and rearward flight and control reversal.
100 87 CRUISE with load 100 100 87 100 100 90 87 90 CRUISE no load 100 90 CLIMB max. rate DECELERATIONS max. rate
GROUND IDLE
SHUTDOWN AC Page MG 11 - 23
AC 27-1B, Chg 1 2/12/03 FIGURE AC 27.MG 11-9. EXAMPLE OF TWIN TURBINE USAGE SPECTRUM Notes:
1. Altitude, temperature, center of gravity, and weight variations may be appropriate where justified by service data; otherwise the worst case must be assumed throughout.
2. This spectrum is an example only; all probable types of operation must be accounted for unless prohibited--see Section 3.
CONDITION % of time Nb per hour ON GROUND inc START UP 3.5 5 TAXIING 3.5 APPROACH 5 2 NORMAL 3.5 UNDER HEAVY SLOPE 0.75 FLARE 0.375 1 QUICK-STOP 0.375 1 Dur. 14 (s) SPOT-TURN 1 5 30°/S/NORM (STOP)/RIGHT 0.32 1.6 Yaw speed rep.
80.00% 30°
15.00% 45°
5.00% max Stop rep.
80.00% normal
20.00% max 30°/S/NORM (STOP)/LEFT 0.32 1.6 30°/S/MAX (STOP)/RIGHT 0.08 0.4 30°/S/MAX (STOP)/LEFT 0.08 0.4 45°/S/NORM (STOP)/RIGHT 0.06 0.3 45°/S/NORM (STOP)/LEFT 0.06 0.3 45°/S/MAX (STOP)/RIGHT 0.015 0.075 45°/S/MAX (STOP)/LEFT 0.015 0.075 MAX/NORM (STOP)/RIGHT 0.02 0.1 MAX/NORM(STOP)/LEFT 0.02 0.1 MAX/MAX (STOP)/RIGHT 0.005 0.025 MAX/MAX (STOP)/LEFT 0.005 0.025 Dur. 7.2 (s) LANDING 1.5 5 NORMAL 1.482 5.94 1/20 hours slope 8° 1/100 hours slope 10° ON SLOPE/8DEG/RIGHT 0.0043 0.0145 ON SLOPE/8DEG/LEFT 0.0043 0.0145 8DEG/NOSE-UP 0.0038 0.0125 8DEG/NOVE-DOWN 0.0043 0.0145 ON SLOPE/10DEG/NOSE-UP 0.0006 0.002 COMB.SLOPE 0.0006 0.002 Dur. 11 (s) AUTOROTATION 1 1 Speed rep.
5.00% 70Kts
20.00% 70Kts
30.00% 70Kts
25.00% 120Kts
15.00% 135Kts
5.00% VNE RPM rep.
10.00% Mini
50.00% Nomi
36.00% Maxi
4.00% Maxi.trans VERTICAL 0.05 0.05 40 KTS 0.2 0.2 70 KTS 0.3 0.3 120 KTS 0.25 0.25 135 KTS 0.15 0.15 VNE 0.05 0.05 Dur. 36 (s) TAKE OFF 1.5 5 Dur. 11 (s) NORMAL 0.8892 2.964 60.00% Normal
40.00% Quick 1/20 hours slope 8° 1/100 hours slope 10° QUICK 0.5928 1.976 ON SLOPE/8DEG/RIGHT 0.0043 0.0145 ON SLOPE/8DEG/LEFT 0.0043 0.0145 ON SLOPE/8DEG/NOSE-UP 0.0038 0.0125 ON SLOPE/8DEG/NOVE-DOWN 0.0043 0.0145 ON SLOPE/10DEG/NOSE-UP 0.0006 0.002 COMB.SLOPE 0.0006 0.002 DESCENT 1.5 2 PARTIAL POWER/STD/STD 0.96 1.28 Speed rep.
80.00% Partial power
20.00% VNE Side slip PP values rep.
60.00% 5°
30.00% 10°
8.00% 15°
2.00% 20° PARTIAL POWER/5 DEG/RIGHT 0.072 0.096 PARTIAL POWER/5 DEG/LEFT 0.072 0.096 PARTIAL POWER/10 DEG/RIGHT 0.036 0.048 PARTIAL POWER/10 DEG/LEFT 0.036 0.048 Side slip rep.
80.00% Without
20.00% with PARTIAL POWER/15 DEG/RIGHT 0.0096 0.0128 PARTIAL POWER/15 DEG/LEFT 0.0096 0.0128 Side slip VNE values rep.
90.00% 5°
10.00% 10° PARTIAL POWER/20 DEG/RIGHT 0.0024 0.0032 PARTIAL POWER/20 DEG/LEFT 0.0024 0.0032 VNE AT MCP/STD/STD 0.24 0.32 VNE AT MCP/5 DEG/RIGHT 0.027 0.036 VNE AT MCP/5 DEG/LEFT 0.027 0.036 VNE AT MCP/10 DEG/RIGHT 0.003 0.004 VNE AT MCP/10 DEG/LEFT 0.003 0.004 Page MG 11 - 24
FIGURE AC 27.MG 11-9. EXAMPLE OF TWIN TURBINE USAGE SPECTRUM (continued) CONDITION % of time Nb per hour CLIMB 3 4 MCP 75 KTS/STD/STD 1.8 2.4 Climb rep.
75.00% 75 Kts
25.00% Vertical Side slip values rep.
80.00% 05 10
18.00% 15 20
2.00% 25 30 MCP 75 KTS/05-10 DEG/RIGHT 0.18 0.24 MCP 75 KTS/05-10 DEG/LEFT 0.18 0.24 MCP 75 KTS/15-20 DEG/RIGHT 0.0405 0.054 MCP 75 KTS/15-20 DEG/LEFT 0.0405 0.054 MCP 75 KTS/25-30 DEG/RIGHT 0.0045 0.006 Side slip rep.
80.00% Without
20.00% with MCP 75 KTS/25-30 DEG/LEFT 0.0045 0.006 TOP/VERTICAL 0.75 1 Dur. 27 (s) LEVEL FLIGHT 56.5 80% MCP/STD/STD 12.4 Speed rep.
28.3% 80% MCP
36.3% 90% MCP
35.4% MCP Side slip rep.
80.00% Without
20.00% with 80% MCP/5 DEG/RIGHT 1.08 80% MCP/5 DEG/LEFT 1.08 80% MCP/10 DEG/RIGHT 0.54 80% MCP/10 DEG/LEFT 0.54 80% MCP/15 DEG/RIGHT 0.144 80% MCP/15 DEG/LEFT 0.144 Side slip typ rep.
60.00% 5°
30.00% 10°
8.00% 15°
2.00% 20° 80% MCP/20 DEG/RIGHT 0.036 80% MCP/20 DEG/LEFT 0.036 90% MCP/STD/STD 16.3 90% MCP/5 DEG/RIGHT 1.26 90% MCP/5 DEG/LEFT 1.26 90% MCP/10 DEG/RIGHT 0.63 90% MCP/10 DEG/LEFT 0.63 90% MCP/15 DEG/RIGHT 0.21 90% MCP/15 DEG/LEFT 0.21 MCP/STD/STD 17 MCP/5 DEG/RIGHT 0.9 MCP/5 DEG/LEFT 0.9 MCP/10 DEG/RIGHT 0.45 MCP/10 DEG/LEFT 0.45 MCP/15 DEG/RIGHT 0.15 MCP/15 DEG/LEFT 0.15 PULL-UP 0.22 1.1 PULL-UP/VNE 0.01 0.05 PULL-UP/LEVEL FLIGHT 80%MCP 0.1 0.5 PULL-UP/LEVEL FLIGHT 90%MCP 0.1 0.5 PULL-UP/AUTOROTATION 0.01 0.05 Dur. 7.2 (s) HOVERING 10 10 HOVERING/IGE 9 9 HOVERING/OGE 1 1 Dur. 36 (s) TRANSITION 4.52 19.6 TRANSITION/CLIMB TO VMAX 0.292 5 TRANSITION/90%MCP TO V.DESC(ISO-V) 0.292 5 TRANSITION/LEVEL.F TO AUTO.(65 KTS) 0.292 0.5 TRANSITION/FORW.F AFTER REAR.F 0.06 0.1 TRANSITION/HOVERING TO FWD FLIGHT 3 5 Dur. 22 (s) TRANSITION/PITCH INCREASE(65 KTS) 0.292 2 TRANSITION/PITCH DECREASE(65 KTS) 0.292 2 Dur. 3.6 (s) AC Page MG 11 - 25
AC 27-1B, FIGUR TURNS TURNS/60% MCP/ Chg 1 2/12/03 E AC 27.MG 11-9. EXAMPLE OF TWIN TURBINE USAGE SPECTRUM (continued) CONDITION % of time Nb per hour 8 30 NZ 1.2G/RIGHT 0.2667 1 Speed rep. Nz rep TURNS/60% MCP/NZ 1.2G/LEFT 0.2667 1 10.00% 60% MCP 10 >1.2g TURNS/60% MCP/NZ 1.4G/RIGHT 0.0989 0.3709 30.00% 80% MCP 20 1.2g TURNS/60% MCP/NZ 1.4G/LEFT 0.0989 0.3709 35.00% 90% MCP TURNS/60% MCP/NZ 1.6G/RIGHT 0.0330 0.1237 25.00% MCP TURNS/60% MCP/NZ 1.6G/LEFT 0.0330 0.1237 TURNS/60% MCP/NZ 1.8G/RIGHT 0.0013 0.005 Nb per hour TURNS/60% MCP/NZ 1.8G/LEFT 0.0013 0.005 20 1.2g 1.4/1.6g rep.
TURNS/60% MCP/V.LIM +0.1G/RIGHT 0.00013 0.0005 7.4175 1.4g 75.00% 1.4g TURNS/60% MCP/V.LIM +0.1G/LEFT 0.00013 0.0005 2.4725 1.6g 25.00% 1.6g TURNS/80% MCP/NZ 1.2G/RIGHT 0.8 3 0.1 1.8g TURNS/80% MCP/NZ 1.2G/LEFT 0.8 3 0.01 V.lim+0.1G TURNS/80% MCP/NZ 1.4G/RIGHT 0.2967 1.1126 TURNS/80% MCP/NZ 1.4G/LEFT 0.2967 1.1126 TURNS/80% MCP/NZ 1.6G/RIGHT 0.0989 0.3709 TURNS/80% MCP/NZ 1.6G/LEFT 0.0989 0.3709 TURNS/80% MCP/NZ 1.8G/RIGHT 0.004 0.015 TURNS/80% MCP/NZ 1.8G/LEFT 0.004 0.015 TURNS/80% MCP/V.LIM +0.1G/RIGHT 0.0004 0.0015 TURNS/80% MCP/V.LIM +0.1G/LEFT 0.0004 0.0015 TURNS/90% MCP/NZ 1.2G/RIGHT 0.9333 3.5 TURNS/90% MCP/NZ 1.2G/LEFT 0.9333 3.5 TURNS/90% MCP/NZ 1.4G/RIGHT 0.3461 1.298 TURNS/90% MCP/NZ 1.4G/LEFT 0.3461 1.298 TURNS/90% MCP/NZ 1.6G/RIGHT 0.1154 0.4327 TURNS/90% MCP/NZ 1.6G/LEFT 0.1154 0.4327 TURNS/90% MCP/NZ 1.8G/RIGHT 0.0046 0.0175 TURNS/90% MCP/NZ 1.8G/LEFT 0.0046 0.0175 TURNS/90% MCP/V.LIM +0.1G/RIGHT 0.0004 0.00175 TURNS/90% MCP/V.LIM +0.1G/LEFT 0.0004 0.00175 TURNS/MCP/NZ 1.2G/RIGHT 0.6667 2.5 TURNS/MCP/NZ 1.2G/LEFT 0.6667 2.5 TURNS/MCP/NZ 1.4G/RIGHT 0.2473 0.9272 TURNS/MCP/NZ 1.4G/LEFT 0.2473 0.9272 TURNS/MCP/NZ 1.6G/RIGHT 0.0824 0.3091 TURNS/MCP/NZ 1.6G/LEFT 0.0824 0.3091 TURNS/MCP/NZ 1.8G/RIGHT 0.0033 0.0125 TURNS/MCP/NZ 1.8G/LEFT 0.0033 0.0125 TURNS/MCP/V.LIM +0.1G/RIGHT 0.0003 0.0013 TURNS/MCP/V.LIM +0.1G/LEFT 0.0003 0.0013 Dur. 9.6 (s) SPECIAL TURNS 0.76 2.025 TURNS/VNE(30DEG)/*/RIGHT 0.0038 0.01 TURNS/VNE(30DEG)/*/LEFT 0.0038 0.01 TURNS/VNE IN AUTO.(30DEG)/*/RIGHT 0.00094 0.0025 TURNS/VNE IN AUTO.(30DEG)/*/LEFT 0.00094 0.0025 TRANSITION/TURN IN TRANSITION/*/RIGHT 0.3753 1 TRANSITION/TURN IN TRANSITION/*/LEFT 0.3753 1 Dur. 14 (s) Page MG 11 - 26
FIGURE AC 27.MG 11-9. EXAMPLE OF TWIN TURBINE USAGE SPECTRUM (continued) CONDITION % of time Nb per hour LATERAL FLIGHT 2 8 Dur. 9 (s) 5 KTS/*/RIGHT 0.095 0.38 Lat.Back rep. Speed rep.
5 KTS/*/LEFT 0.095 0.38 95.00% Lateral 10.00% 5 kts 10 KTS/*/RIGHT 0.095 0.38 5.00% Backward 10.00% 10 kts 10 KTS/*/LEFT 0.095 0.38 10.00% 15 kts 15 KTS/*/RIGHT 0.095 0.38 40.00% 17 kts 15 KTS/*/LEFT 0.095 0.38 10.00% 19 kts 17 KTS/*/RIGHT 0.38 1.52 5.00% 21 kts 17 KTS/*/LEFT 0.38 1.52 5.00% 25 kts 19 KTS/*/RIGHT 0.095 0.38 5.00% 35 kts 19 KTS/*/LEFT 0.095 0.38 5.00% max 21 KTS/*/RIGHT 0.0475 0.19 21 KTS/*/LEFT 0.0475 0.19 25 KTS/*/RIGHT 0.0475 0.19 25 KTS/*/LEFT 0.0475 0.19 35 KTS/*/RIGHT 0.0475 0.19 35 KTS/*/LEFT 0.0475 0.19 VMAX/*/RIGHT 0.0475 0.19 CONDITION % of time Nb per hour VMAX/*/LEFT 0.0475 0.19 VMAX/*/REARWARD 0.1 0.4 100 AC Page MG 11 - 27
AC 27-1B, Chg 1 2/12/03
INTENTIONALLY
LEFT
BLANK
Page MG 11 - 28
CHAPTER 3
AIRWORTHINESS STANDARDS
NORMAL CATEGORY ROTORCRAFT
MISCELLANEOUS GUIDANCE (MG)
AC 27 MG 12. § 27.865 (Amendment 27-36) EXTERNAL LOADS.
This AC MG paragraph material is now contained in AC 27.865B, in Subpart D.
Page MG 12 - 1
AC 27-1B, Chg 1 2/12/03 Page MG 12 - 2
CHAPTER 3
AIRWORTHINESS STANDARDS
NORMAL CATEGORY ROTORCRAFT
MISCELLANEOUS GUIDANCE (MG)
AC 27 MG 13. SYSTEMS CERTIFICATION CONSIDERATIONS.
a. Supporting Systems.
(1) Purpose. The purpose of this AC paragraph is to provide guidance on how to show compliance to Part 27 regulations as they apply to supporting systems for other systems that provide required functions. The systems that require support from supporting systems are defined as dependent systems in the following guidance.
Application of recent technology is one of the predominant causes of more dependent/supporting systems relationships. More systems are employing technology that is dependent on supporting systems such as electrical, hydraulic, and/or other power sources or signal inputs. Certification of systems that are dependent on supporting systems to provide required functionality must consider the issues associated with this interdependent relationship.
(2) Definitions.
(i) Integrity. The term “integrity” for the purpose of this AC paragraph includes the hardware quality requirements, including reliability (availability); as well as the software level requirements, as defined in RTCA/DO-178B.
(ii) Criticality. The term “criticality” refers to the five levels of criticality addressed in this document in paragraph AC 27.1309.d.(2)(ii)(B).
(iii) Supporting System(s). The term “supporting system(s)” as used in this paragraph means any system(s) that provides an input to another “dependent” system, such that these dependent system(s) cannot function correctly without that input being present/correct.
(iv) Dependent System(s). The term “dependent system(s)” as used in this paragraph means any system/s that receives an input from another system or sensor.
(3) Related Documents.
Page MG 13 - 1
AC 27-1B, Chg 1 2/12/03
(i) Federal Aviation Regulations (FARs) Paragraphs 27.1301, 27.1309,
27.1351, and 27.1435.
(ii) Standards - Latest revision of RTCA/DO178 and RTCA/DO 160; Parts of SAE documents ARP4754 and ARP4761.
(4) History: Applications of recent technology for systems have, in many cases, resulted in systems that are dependent on one or more supporting system(s) for inputs such as power or signal sources of any type. This relationship creates concerns for recognition that the criticality of the supporting system may be higher because of its role of supporting a dependent system of high criticality. The example of Liquid Crystal Displays (LCD) for engine instruments, in particular, has caused concern about the integrity of the supporting electrical power system. Past designs for engine instruments did not require electrical power for operation, but present designs with LCDs do require electrical power. Additionally, engine instruments of those older helicopter designs were driven from a mixture of sources such as independent wet line, pneumatic, and electrical drive (Tach Generator) inputs, and thus had independent failure modes from the sensor/power input aspect(s). This means that the integrity of the electrical power supplied to the dependent system must be commensurate with the level of integrity as required for the highest criticality engine instrument application(s). This also stimulates the concern that the electrical power system can become a common point for failure of all engine instruments simultaneously, as well as anything else powered by the electrical system. For this example, these considerations represent an increase of integrity requirements for the electrical power system over previous designs of electrical systems for VFR helicopters. In the past, these electrical systems did not support required functions of higher criticality and were allowed to be simple in design with low design integrity and susceptible to single point faults. Application of recent technologies for systems resulting in dependent systems that require supporting systems must address the concerns for higher integrity and single point faults.
(5) Discussion: Integrity of supporting systems must be sufficient to support the required integrity of their associated dependent systems. The relationship of supporting systems to dependent systems is similar to an analogy of them being links in a chain, where the weakest link must be able to support the required integrity level that is consistent with the associated criticality category assessment. This principle is not new, but there may not be recognition that systems previously accepted at low integrity levels may not be acceptable because of their new role as supporting system(s). New emphasis must be applied to determine acceptability of previous designs that have become supporting systems through application of new technology or changes of system architecture. This is particularly true for derivative designs, or changes to existing design by either supplemental type certificate (STC) or field approval, where new technology system applications, or system architecture changes have been applied, that created a dependent/supporting system relationship. The main concerns are for systems such as electronic displays that are installed and supported by nonupgraded systems, such as single source and/or low reliability power generation and distribution systems. However the concerns related to supporting syst ems are not Page MG 13 - 2