47D Gotchas Flashcards
Engine Horsepower
10 Min Limit… 4,867 hp
2.5 Min Limit… 5,069 hp
Rotor Tach Markings
91… minimum transient (red line)
97-101… green arc
102-105… transient (yellow arc)
106… max transient power ON (red line)
108… max during autorotation (red line)
111… max transient (red line)
Flight Hydraulic Pressure Markings
2500psi… lower red line
2500-3200psi… green arc
3200psi… upper red line
Utility Hydraulic Pressure Markings
2500psi… lower red line
2500-3500psi… green arc
3500psi… upper red line
Utility and Flight Control Hydraulic Temp Markings
95-120C… yellow arc
120C… red line
PTIT Limits (Tha Realist)
MCP… 816
30 Min Max… 854
10 Min Max… 899
2.5 Cont… 932
12 Sec Cont… 943
N1 Limits (Tha Realist)
Ground Idle Min… 50%
Max… 111%
N1 over 111% is an engine overspeed
Emergency Fuel (100LL)
Emergency fuel shall not be used for more than 6 hours cumulative time.
Use of Shall, Should, and May
Shall… mandatory requirement
Should… nonmandatory but preferred method of accomplishment
May… an acceptable method of accomplishment
Flight Controls out of Neutral
It is possible for the ground to forward rotor blade clearance to be 4 feet 4 inches
Blade Chord
32 inches
“Warning”
An operating procedure, practice, etc. which if NOT correctly followed, could result in personal injury or loss of life
“Caution”
An operating procedure, practice, etc. which, if not strictly observed, could result in damage to or destruction of equipment
“Note”
An operating procedure, condition, etc. which is essential to highlight
Aerobatics Defined (also, prohibited)
Intentional maneuvers beyond 30* Pitch and/or 60* Roll
Bank Angle Limits
With working CGI, they are limited by CGI but not to exceed 60* bank.
When using altitude hold, limit bank angle limits to 45* max.
With inop CGI, use bank angle limits defined in Fig 2-5
Bleed Band Actuator
Primary mode… HMU uses P3 pressure to control bleed band actuator, causing the band to snap open and closed
Reversionary mode… HMU uses fuel pressure as controlling medium, causing the band to modulate (slowly open or close)
Fig 3-4 SE Service Ceiling Contingency Power “Note”
Chart based on aircraft flying Vy to provide a max of 100fpm climb for given pressure altitude and temp
Fuel/Oil/Hydraulic Filter LRBs
All filters can be bypassed except for the 3 hydraulics Pressure filters
Dual Engine Fires
Fight one fire at a time. If both Fire Pull Handles are out and agent is discharged, it will be sent to both engines at an unknown ratio (not 50/50)
Engine Transmissions
The engine transmissions are interchangeable
XMSN OIL PRESS light with normal pressure indications
The aft shaft doesn’t have a pressure transducer but does have a pressure switch that illuminates the XMSN OIL PRESS light at 10psi or less. This could cause the XMSN OIL PRESS light to illuminate whole the gauge shows normal pressure ranges
Batt Switch on, only source of electrical power
With the batt switch on, the essential, switched battery, and hot battery busses are energized. Regardless of switch position, the switched battery and hot battery busses are powered directly by the battery.
Pitot Heat Switch
When placed ON, it provides power for the pitot tubes AND yaw ports
Rotor Blades
Chord is 32 inches, outer 54 inches leading edge covered with nickel for erosion protection
EPUSHA Operations
Multiple EPUSHA operations can deplete the battery to the point where APU can’t be started. The number of EPUSHA operations should not exceed five.
Jet Pumps (Fuel System)
Are used to evacuate fuel within the refueling manifold back into the main tank. The jet pump is activated when the forward boost pump in each main tank is first turned ON after pressure refuel
ENG FAIL Parameters
Power turbine shaft failure = N2>Nr by more than 3%
N1 underspeed = N1 below 48%
Engine flameout
Overtemp start abort (PRI only)
FADEC PRI and REV failure
Lights on with Gen Fail and no cross tie
GEN OFF
FUEL PRESS
RECT
AFCS
Forward and Aft Stationary Rings Composition
Forward is aluminum
Aft is steel
LCT Conditioner/Processor
Conditioner in fwd pylon, receives signal from fwd fixed link and sends it to processor
Processor in Aft pylon, takes the larger of the 2 signals (fwd and aft) and sends it to the CGI in cockpit
Utility and Flight Control Hydraulics Interchangeability
The temp sensor, thermal switch, and relief valve are interchangeable between the 1, 2, and utility hydraulic reservoir coolers
Utility Hand Pump Emergency Use
Hand pump can be used in an emergency to provide pressure to aircraft utility subsystems as long as the Emergency Utility Pressurization Valve is open (located to right of hand pump)
Generator 2 Second Delay
Delay turning the second generator on for 2 seconds. This Delay will give DECU time to sample power without causing a soft fault.
Centering Device Release Switch (cyclic)
When pressed:
1. Mag brakes in pitch roll and yaw are released
2. Heading hold and bank angle hold are MOMENTARILY released
3. HDG select is DISENGAGED
AFCS Built In Test Equipment (BITE)
For ground troubleshooting only. ECLs must be in the STOP position for the BITE to function
Quantity of LRBs
37 total
16 in front
21 in back
(16 to drive, 21 to drink)
NR% Selector
Rotary switch which provides different rrpm control
Only works in primary mode
100% has detent
Can select 97%-103%
ECLs must be in fly
Cbox Aux Oil Flow
Reservoir
Pump
Relief valve on no. 2 side of xmsn
Pushed through aux filter on front of xmsn
Gears and bearings
Scavenged through no. 2 side debris screen on bottom of cbox
Reservoir
Cbox Main Oil Flow
Reservoir
No. 1 pump
Filter on top of xmsn
Cooler
Filtered by inlet screen on no. 1 side of xmsn
Gears and bearings
Scavenged through no. 1 debris screen on bottom of cbox
Reservoir
Engine XMSN OIL Flow
Reservoir
Pump
Filter on back of cbox
Cooler
Jet protection screen on back wall behind xmsn
Gears and bearings
Scavenge pump sucks it back through debris screen on cbox
Reservoir
Fwd XMSN Main Oil Flow
Reservoir
Tube connected to pump screen
Main Oil filter
Cooler
Inlet screen on no.1 side of xmsn
Passes pressure transducer line
Passes Main Oil Pressure switch no.1 side of xmsn
Gears and bearings
Reservoir via gravity
Fwd XMSN Aux Oil Flow
Reservoir
Pump pulls oil through debris screen
Aux Oil filter
Aux pressure switch
Gears and bearings
Reservoir, via gravity
Aft XMSN Main Oil Flow
Reservoir
Tube connected to pump screen
Main Oil filter
Cooler
Inlet screen filter on no.1 side xmsn
Passes Main Oil Pressure switch no.1 side xmsn
Passes Pressure transducer line
Sent to generators and Scavenged by Main Oil pump
Sent to Gears and bearings
Sent to aft vert shaft Thrust bearing
Reservoir, via gravity
Aft XMSN Aux Oil Flow
Reservoir
Pulled through debris screen by aux pump
Aux Oil filter
Passes aux pressure switch
Gears and bearings
Reservoir, via gravity
APU vs. Generators Wires
(6 vs. 4)
Both generators are 3 phase, each phase on apu gen has its own ground, while all 3 phases on main generator share a common ground
Why 3 Phase Generators?
Each phase is capable of producing peak voltage of 115vac. With the generator phase output being cyclical, set 120* apart from each other, it allows the electrical components to receive a continuous and smooth 115vac at all times
What does 400 Hz mean?
It means the generators complete 400 cycles per second, with one cycle starting at 0vac, peaking at 115vac, dropping 0vac, continuing down to 115vac, and then rising back up to 0vac, completing the cycle. This allows our gyros and fuel pumps to be smaller since they too will be spinning at 400 cycles per second
How much KVA is required to power the entire electrical system, everything turned on, with as much of an electrical demand on the system as possible?
15Kva
What is the max Hz the generators can produce?
420Hz. The generators are incapable of producing a high enough frequency that could cause harm to the systems components. Therefore, the GCU only monitors for under-frequency, as well as over-voltage and under-voltage.
Why is Min Rotor Transient 91%?
The GCU will shutoff the generator if rotor rpm decays to 82-85% for more than 3-7 seconds due to under-frequency conditions. 91% is the rrpm that the GCU will bring the generators back online.
Black Donuts with APU Gen Feeder Lines Going Through Them
Those are the negative current transformers for the apu gen. They are used in conjunction with the apu gen positive current transformer (located in No. 2 PDP) to allow the apu gcu to detect a feeder fault
What does the Battery power when it is plugged in, batt switch off?
Hot Battery Bus:
•hydraulic level indication
•APU emergency control
Switched Battery Bus:
•mag brakes (all axis)
•ramp and cabin lighting
•emergency exit lights
•refuel station
•forward XMSN oil level light
Why is it called the Switched battery bus?
It is powered regardless of battery switch position. Instead, it gets its name because it switches over to being powered by the T/Rs once AC power is available.
Dual purpose of reverse current cutout relay?
- Prevent reverse current from going to the T/Rs
- Illuminate the RECT 1/2 lights if there isn’t current flowing through them. When there is normal flow of current going through them they will extinguish the RECT 1/2 light
Fixed and Centrifugal Droop Stops
Forward Fixed: limit flap to 4.5* to 5*
Aft Fixed: limit flap to 5.5* to 6*
Aft Centrifugal Droop Stops: limit flap to 1.25* to 1.75*
•Disengaged at 67% RRPM
•Engaged at 56% RRPM
