Limitations (Not Complete) Flashcards
AEO Limitations (L1)
Torque Limitations
All use of 112-117% Tq in excess of 6 seconds is to be reported for maintenance action.
A flight is defined as the elapsed time from aircraft wheels off the ground to wheels on the ground.
Max Continuous- 100%
Max 1 hour- 100% (1hr/flt)
Max 5 mins- 100% (>90kts) (5min/flt)
30 minute rating- 106.5% (See Note 1)
2.5 minute rating- 112% (See Note 2)
Transient (Gearbox)- 117% for 6 sec
Note 1: At airspeeds 90kts and below, 106.5% Tq permitted for 30 minutes per occurrence. Engine parameters remain restricted to max 5 mins rating per flight.
Note 2: At airspeeds 50kts and below, 112% Tq permitted for 2.5 minutes per occurrence. Engine parameters remain restricted to max 5 mins rating per flight.
AEO Limitations (L1)
Nf% Limitations
A flight is defined as the elapsed time from aircraft wheels off the ground to wheels on the ground.
Max Continuous- 104.6%
Max 1 hour- 104.6% (1hr/flt)
Max 5 mins- 104.6% (>90kts) (5min/flt)
Transient (Engine)- 114.4% for 20 sec
Ground Idle- See Note 4
Autorotation- 107.3%
Note 4: Operation between 58% and 77% Nf is limited to 20 seconds maximum.
^Remember the washing machine in the kitchen dit.
AEO Limitations (L1)
NgC% Limitations
A flight is defined as the elapsed time from aircraft wheels off the ground to wheels on the ground.
Max Continuous- 90%
Max 1 hour- 95% (1hr/flt)
Max 5 mins- 100% (>90kts) (5min/flt)
Ground Idle- 40%
Note 6: An EECU degraded fault may be accompanied by a torque and/or NgC split. Power turbine speed may increase as power is reduced. The power turbine observed speed limit is raised to 107.2% at engine conditions below the maximum continuous rating when there is an EECU degraded warning present.
AEO Limitations (L1)
TIT °C Limitations
A flight is defined as the elapsed time from aircraft wheels off the ground to wheels on the ground.
Max Continuous- 818 °C
Max 1 hour- 853°C (1hr/flt)
Max 5 mins- 882°C (>90kts) (5min/flt)
Starting- 840°C
Ground Idle- 570+2A (See Note 5)
Note 5: A = Ambient Temperature °C
Twin Engine Cruise (TEC) Limitations (L1)
TEC Limits
Defined as operations with No 3 engine intentionally shutdown for the purpose of extended range cruise. The following limits apply to TEC:
CAUTION: The AMS and EECU do not distinguish between TEC and OEI conditions, and default to engine OEI ratings and limits. Consequently, in TEC the EECU will not limit at the AEO max 5 mins rating.
- Deliberate operation above TEC max continuous rating is prohibited.
- Maximum pressure altitude is 10,000ft
- Minimum safe height AGL/ASL must be calculated to account for height loss following engine failure during TEC, based on a two minute allowance for restarting No 3 engine.
- Aircrew must monitor engine and torque to ensure limits are respected, particularly when using BAR, RAD and VS autopilot modes.
- Maximum continuous period TEC is 3 hours.
- No 3 engine must be run at FLIGHT for a minimum of 10 minutes between separate periods of TEC.
- Maximum cumulative duration of TEC between No 3 engine oil level checks is 6 hours.
- Use of AFCS Transition down (TD1 & TD2), Transition Up (TUP) modes is prohibited.
- Flight in engine icing conditions is prohibited.
- USL operations are prohibited.
Twin Engine Cruise (TEC) Limitations (L1)
TEC Limitations (NgC%, TIT, Nf% and Tq%)
Defined as operations with No 3 engine intentionally shutdown for the purpose of extended range cruise. The following limits apply to TEC:
CAUTION: The AMS and EECU do not distinguish between TEC and OEI conditions, and default to engine OEI ratings and limits. Consequently, in TEC the EECU will not limit at the AEO max 5 mins rating.
Max Continuous (3 hours), Max 1 Hour (1 hour/flt) and Transient (6 secs) all remain the same as AEO limitations.
One Engine Inoperative (OEI) (Engine failure, Training and Engine Test) and Two Engines Inoperative (TEI) (Engine failure) Limitations (L1R)
Torque Limitations
Max Continuous- 112%
Max 1 hour- 112% (1hr/flt)
Max 5 mins- 112% (5min/flt)
Max Contingency- 125% (See Note 1 & 2)
Transient- 136% for 20 sec
Note 1: The use of Max Contingency OEI rating is not permitted for training and/or engine testing.
Note 2: Restricted to 2.5mins per application OEI.
One Engine Inoperative (OEI) (Engine failure, Training and Engine Test) and Two Engines Inoperative (TEI) (Engine failure) Limitations (L1R)
NgC% Limitations
Max Continuous- 90%
Max 1 hour- 95% (1hr/flt)
Max 5 mins- 100% (5min/flt)
Max Contingency- 107% (See Note 1 & 2)
Note 1: The use of Max Contingency OEI rating is not permitted for training and/or engine testing.
Note 2: Restricted to 2.5mins per application OEI.
One Engine Inoperative (OEI) (Engine failure, Training and Engine Test) and Two Engines Inoperative (TEI) (Engine failure) Limitations (L1R)
Nf% Limitations
Max Continuous, Max 1 hour, Max 5 mins, Max Contingency- 104.6%
Note 1: The use of Max Contingency OEI rating is not permitted for training and/or engine testing.
Note 2: Restricted to 2.5mins per application OEI.
One Engine Inoperative (OEI) (Engine failure, Training and Engine Test) and Two Engines Inoperative (TEI) (Engine failure) Limitations (L1R)
TIT°C Limitations
Max Continuous- 818°C
Max 1 hour- 853°C (1hr/flt)
Max 5 mins- 882°C (5min/flt)
Max Contingency- 915°C (See Note 1 & 2)
Note 1: The use of Max Contingency OEI rating is not permitted for training and/or engine testing.
Note 2: Restricted to 2.5mins per application OEI.
Rotor Limitations (L1R)
POWER ON Nr%
High Transient- 105% “Rotor High” >105%
High Normal- 103%
Nominal Governed- 102%
Low Normal- *100%** “Rotor Rotor” <100%
Low Transient- 98%
Low Emergency- 85% (See Note 1)
Note 1: Emergency use only following an engine failure.
Note 2: AMS may generate erroneous rotor speed audio warnings and IDU Nr indications, cross check IDU with ISIS rotor speeds to confirm validity.
Rotor Limitations (L1R)
POWER OFF Nr%
High Transient- 116.5% “Overspeed” >116.5%
High Normal- 110% “Rotor High” >110.5%
Low Normal- 95% “Rotor Rotor” <94.5%
Low Transient- 90%
APU (L2)
(Shortened, read FRCs for full info)
CAUTION 1: Prolonged running of the APU may cause airframe damage and should be minimized.**
CAUTION 2: APU operation prohibited with MRB folded (or spreading/folding) unless thermal blanked fitted to No 3 MRB.
CAUTION 3: if MRB thermal blanked detaches whilst APU is running, APU must be switched OFF immediately and blades inspected for damage.
Starting APU wind limits:
-Red 120 through ahead to Green 120- 50kts
-Red 120 through astern to Green 120- 35kts
With No3 MRB thermal blanked fitted:
-Red 30 through ahead to Green 30- 20kts
-Red 30 to Red 90- 10kts
-Green 30 to Green 90- 10kts
The number of APU starts limited to a maximum of 6, each with a 30 second cooling period. After 3 starts, allow a 5 minute cooling period. After a further 3, a 30 minute cooling period must be allowed and seek engineering advice. Number of starts also limited by battery storage temperature (L18).
APU in flight:
- APU may be operated throughout the flight envelopes. (see Notes 1 & 2)
- The EMRG/NORM switch must be selected to EMRG (Note 3)
- Operation of the ECS from APU bleed air in flight is prohibited.
Note 1: APU cannot be guaranteed to provide sufficient air to restart engine above 10,000’ density altitude.
Note 2: When the APU is operating, time spent hovering in green winds OR between 40-60kts in forward flight should be kept to a minimum.
Note 3: Selection of EMRG facilitates automatic take over of ESS BUSbars.
Initial Engine Start/Relight (L2R)
- GI or FLIGHT must be selected within 15 seconds of selecting engine FUEL to ON.
- An engine must not be started with TIT >300C
- if any engine control system failure warnings are present, do not start.
- Ground starts from OFF to FLIGHG are not permitted except for No 1 ENG in ACC drive. Oil temperature must be at least 40C above ambient temperature.
- Engine operation above GI must not be carried out until engine oil pressure is 8.4bar or below. However, Nf avoid band takes precedence.
- Engines must not be started on the ground in wind speeds (inc Gusts) >50kts from forward of the beam, and 25kts aft of the beam.
