Gulfstream IV

Gulfstream IV OPERATING MANUAL AIR CONDITIONING 2A-21-10: General The air conditioning system for the Gulfstrearn IV is designed to provide all areas within the pressure vessel vrith a safe and comfortable temperature and pressure (cabin altitude) throughout the aircraft's operating envelope. The system employs a 'dual pack" concept and. although each pack is controlled separately, failure of one pack still leaves the remaining pack capable of supplying conditioned air to both cabin and cockpit. if required. To achieve this function, the air conditioning system provides the flight crew with a means to accomplish the following: • Control. regulate and monitor the amount of conditioned air within the pressure vessel to achieve and maintain selected or preprogrammed cabin pressure (altitude), while still allowing exchange of the air at regular intervals for occupant comfort. This is accomplished by modulation of a single outflow valve. The outflow valve is automatically controlled by the cabin pressure controller in the normal operating mode, but can be controlled manually. • Select and control bleed air entering and exiting two environmental control system refrigeration pack assemblies, referred to as the Left and Right ECS Packs. Source air into the ECS Packs is provided to a bleed air manifold by either external air or APU air (while on the ground), or by the aircraft's engines (on ground or in flight). Through use of an isolation valve. air from the bleed air manifold can be directed to either ECS Pack. This results in a constant mass of conditioned air for all areas within the pressure vessel. • Control the temperature of conditioned air delivered to the cockpit and cabin areas (referred to as zones) within the pressure vessel. This is done using the two ECS packs to cool incoming air and deliver it to a conditioned air manifold. Valves mix hot bleed air with cold conditioned air to modulate the temperature of the air coming from the manifold into the pressure vessel. Cockpit control and indication is also provided. The Air Conditioning system is divided into the following subsystems: • 2A-21-20: Pressurization Control System • 2A-21-30: Airflow and Temperature Control System 2A-21-20: Pressurization System 1. General Description: The pressurization system controls. regulates and monitors the amount of conditioned air within the pressure vessel to achieve and maintain a safe and comfortable cabin pressure (cabin altitude), up to the airplane's maximum operating altitude. While normally preprogrammed. cabin altitude can also be controlled manually. Cabin conditioned air is also exchanged at regular intervals for occupant comfort. With airflow supplied from the ECS packs. the pressurization system maintains cabin altitude by regulating the amount of air exhausted overboard through a single outflow valve. Once the flight crew has programmed the system. operation is virtually automatic. The pressurization system is capable of maintaining a cabin altitude of 6.550 feet at a maximum inflight altitude of 45.000 feet. Sea level cabin pressure can be PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page I May 30;02 Revision 7 EFTA01105877 GUIISI Main IV OPERATING MANUAL maintained to a maximum inflight altitude of 22,000 feet. If cabin altitude should exceed 10.000 feel, warnings and annunciations are provided to the flight crew so that appropriate action may be taken. The pressurization system performs the following functions: • Automatically maintains selected cabin altitude through isobaric pressurized operation • Automatically limits maximum cabin pressure differential • Provides safety pressure relief operation • Provides negative (vacuum) pressure differential control • Allows manual barometric correction for pre-programmed Landing Field Elevation (LFE) • Permits manual cabin altitude control through control of the outflow valve • Automatically limits cabin altitude ratepf -change to a maximum of 3.000 leet•per•minute (FPM) during pressurization and depressurization • Provides crew•selected cabin altitude rate•of•change • Regulates and smooths cabin pressurization to prevent pressurization surges or 'bumps' • Provides rapid cabin ventilation for smoke removal Normally the pressurization system limits cabin pressurization differential to 9.55 ±0.1 psid. As differential pressure reaches 9.55 psid, an amber CABIN DFRN 9.6 caution message is displayed on the Crew Advisory System (CAS) and the pressurization system begins limiting outflow valve closure. If the pressurization system malfunctions and cannot limit maximum cabin pressure differential to 9.5510.1 psid. a safety valve limits pressure differential to 9.7 10.1 psid. As differential pressure reaches 9.8 psid. a red CABIN DFRN 9.8 warning message is displayed on CAS. The pressurization system receives information from the two Air Data Computers (ADC #1 and ADC #2). It also uses the Weight•On•Wheels (WOW) system (commonly referred to as the nutcracker system) to control various system operating modes. Under typical flight conditions, the fright crew programs the system prior to takeoff. Apart from selection of the FLIGHT/LANDING mode switch or adjustment of LFE. system operation is virtually automatic. Major components of the pressurization system are: • Cabin Pressurization Transducer • Cabin Pressure Outflow Valve • CABIN PRESSURE CONTROL Panel • Cabin Pressurization Selector Panel • Cabin Pressure Safety Valve • Cabin Rate Pressure Switch • Cabin Pressure Warning Switch • Cabin Differential Pressure / Altimeter / Rate•of•Climb Indicator 2. Description of Subsystems, Units and Components: (See Figure 1.) 2A-21-00 Page 2 May 30,102 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105878 Cu!Stream IV OPERATING MANUAL A. Cabin Pressurization Transducer: The solid-state cabin pressurization transducer is the heart of the pressurization system. Located in the electronics area of the entrance compartment, produces the output signal to the outflow valve motor based on the following input data: • Inputs from the cabin pressurization selector panel • Corrected static pressure data from the ADCs (or Digital Air Data Computers (DADCs)) • FLIGHT or GROUND mode from the nutcracker system • Sensed cabin pressure from inside the pressure vessel To prevent undesired outflow valve movement from transient power surges. the transducer obtains a clean. stable supply of power from an Electromagnetic Interference (EMI) filter installed in the radio rack. Within the transducer are circuits that limit cabin differential pressure in flight to 6.550 feet with an airplane altitude of 45.000 feet. B. Cabin Pressure Outflow Valve: A single pressurization outflow valve is installed under the lower shelf of the radio rack. It is an electrically-controlled. motor-driven valve that determines the amount of cabin air exhausted overboard, thus controlling cabin pressurization. It is capable of moving from fully open to fully closed in approximately ten (10) seconds. The outflow valve is a butterfly type valve with an electro-mechanical actuator and a potentiometer that provides valve position information to the position indicator on the CABIN PRESSURE CONTROL panel. Within the actuator are a DC motor with DC brakes. an AC motor with AC brakes and a motor-generator. The AC motor, which operates the outflow valve in the Automatic (AUTO) mode, responds to signals from the cabin pressurization transducer. The DC motor operates the outflow valve in the MANUAL mode by responding to signals from the CABIN PRESSURE CONTROL panel manual control knob. Both motors are capable of extremely slow or fast operation, or at any intermediate speed required by the controlling device. During normal system operation (AUTO mode), the cabin pressurization transducer opens and closes the outflow valve using the AC motor. While the AC motor is in operation, the DC motor brake engages to prevent DC motor movement. The motor-generator in tum provides a rate-of-change signal back to the cabin pressurization transducer. With the system in MANUAL mode, the manual control knob provides a DC signal to position the outflow valve. The AC motor brake engages to prevent AC motor movement. Although the motor-generator is inactive. the potentiometer still provides valve position information to the valve position indicator. In the unlikely event that both Essential AC and Essential DC bus power sources are lost, the outflow valve will cease operation and remain at the last position commanded. PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 3 May M(02 Revision 7 EFTA01105879 Gulfstream IV OPERATING MANUAL C. CABIN PRESSURE CONTROL Panel: (See Figure 3.) The CABIN PRESSURE CONTROL panel. located on the cockpit overhead panel. has controls and indicators for: • Manual control of the outflow valve • Position of the outflow valve • Selection of either FLIGHT or LANDING pressurization schedules • Selection of either AUTO or MANUAL mode of operation • Selection of either ADC #1 or ADC #2 to supply static pressure information to the pressurization transducer The cabin pressure control panel operates on 28V DC from the Essential DC bus and 115V AC. 400 Hz from the Essential AC bus. D. Cabin Pressurization Selector Panel: (See Figure 4.) Automatic operation of the pressurization system requires crew inputs on the cabin pressurization selector panel. located on the copilot's flight panel. It contains control knobs and indicator tapes for setting the following: • FLIGHT: flight plan's maximum aircraft altitude and corresponding cabin altitude to be maintained • BARO CORR: barometric pressure correction to local conditions (28.00 to 31.00 inches of mercury) • LDG: preprogrammed LFE (.1.000 to +15.000 feet) • RATE: cabin altitude rate.of•change for climb and descent in FPM (minimum UP: 50 FPM. minimum DOWN: 30 FPM. maximum UP: 2.000 FPM. maximum DOWN: 2.000 FPM) Each control knob is connected to a variable resistor and gear train that drives the indicator tape. Once programmed. the cabin pressurization selector panel supplies driving signals to the pressurization transducer. E. Cabin Pressure Safety Valve: A pressurization safety valve. located below the radio rack. provides safety pressure relief. vacuum relief and pressurization rate limiting. Because it operates entirely on cabin and ambient pressure. it is independent of all other components in the pressurization system and requires no external power source. Should the AUTO or MANUAL control mode of the pressurization system malfunction and cabin pressure builds up to approximately 9.7 30.1 psid. the safety valve will open. It then modulates to limit cabin pressure to the safety relief pressure of 9.8 psid. F. Cabin Rate Pressure Switch: The cabin rate pressure switch functions strictly as a safety device by sensing the rate at which the cabin altitude is increasing (losing pressure). If a failure should occur that results in rapidly rising cabin altitude. the rate switch inhibits automatic (AC) control of the outflow valve and shifts to manual (DC) control. This would occur at loss rates of approximately 3.000 FPM. 2A-21-00 Page 4 May 3W02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105880 Gulfstream IV OPERATING MANUAL G. Cabin Pressure Warning Switch: The cabin pressure warning switch. located on the right side of the entrance compartment. is an aneroid-operated switch that reacts to cabin altitude. If cabin altitude exceeds 9.250 /750 feet. the switch causes a red CABIN PRESS LOW warning to be displayed on CAS and, if installed. on the Standby Warning Lights Panel (SWLP). H. Cabin Differential Pressure / Altimeter / Rate-of-Climb Indicator: (See Figure 5.) The cabin differential pressure / altimeter rate-of-climb indicator is located on the overhead panel above the CABIN PRESSURE CONTROL panel. It provides the following indications: (1) Cabin Differential Pressure: The cabin differential pressure indicator (labeled DFRN PRESS) is driven by the cabin pressurization transducer. The display indicates cabin differential pressure to the nearest 1/100th psid on a four digit display. If cabin differential pressure reaches 9.6 psid, an amber CABIN DFRN-9.6 caution message is displayed on CAS and an amber light above the indicator will illuminate. If differential pressure reaches 9.8 psid. a red CABIN DFRN-9.8 warning message is displayed on CAS and a red light above the indicator Ml illuminate. (2) Cabin Altimeter: The cabin altitude indicator (labeled CABIN ALT) is located adjacent to the differential pressure indicator. It displays cabin altitude in feet (FT) on a five digit display. (3) Cabin Rate•of-Change Indicator: The cabin rate-of-change indicator (labeled RC) is located beneath the cabin altimeter. It displays cabin altitude rate-of-change in FPM on a four digit display. A plus or minus sign precedes the digits to show cabin climb or descent. 3. Modes of Operation: A. Automatic Operation Mode: Automatic operation of the cabin pressurization system can best be understood by using a typical flight scenario shown in Figure 2 as an example. In this scenario. the crew begins their flight with a standard sea level field pressure altitude and progresses through closing the doors. engine start. taxi out, takeoff. climb to cruise. cruise, descent to approach altitude. executing the approach. landing, engine shut down and opening the doors. The flight crew initially sets 45.000 feet on the FLIGHT scale of the cabin pressurization selector panel. This results in the adjacent CABIN scale reading of 6.550 feet, the isobaric cabin altitude that corresponds to the maximum differential pressure of 9.41 psid. The cabin RATE dial is set at 500 FPM UP, resulting in the adjacent DOWN scale reading 300 FPM. The average rate of climb to 45.000 feet is approximately 2,700 FPM. with a cabin rate of climb of 500 FPM. The departure runway field elevation altitude is then programmed into the LDG (Landing) dial. Destination runway field elevation altitude (4.000 feet in this example) is set during descent. At this point, the pressurization system is programmed for automatic operation and. assuming the AUTO/MANUAL switch is in AUTO. the system will operate in automatic mode when electrical power is applied PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 5 May M.(02 Revision 7 EFTA01105881 Gull:stream IV OPERATING MANUAL to the aircraft. With the airplane on the ground, the AUTONANUAL switch in AUTO and the FLIGHT/LANDING switch in LANDING, the outflow valve will cycle open as soon as electrical power is applied. This is due to the absence of airflow and the cabin pressurization transducer sensing an on-ground condition from the nutcracker. With the main entrance door still open at this point, there is no pressure buildup. A negligible pressure increase (approximately 0.05 psid. equalling pressure drop across the outflow valve) occurs after closing the main entrance door, remaining negligible through engine start, APU shutdown and transfer of air source to the engines. During taxi, the pressure remains low until lineup in preparation for takeoff. At this point, the flight crew selects the FLIGHT position on the FLIGHT/LANDING switch on the CABIN PRESSURE CONTROL panel. With the FLIGHT position selected, the outflow valve immediately begins to close under rate control. 'holding' at approximately 0.25 psid of pressure buildup. This 'holding". known as ground differential pressure control. serves to minimize the possibility of 'pressure bumps' during takeoff. As soon as the aircraft becomes airborne, the nutcracker system sends an inflight signal to the cabin pressurization transducer. The transducer in tun commands the outflow valve to close, thus pressurizing the cabin at the programmed rate of 500 FPM UP until the maximum differential pressure of 9.55 ±0.10 psid is reached. The cabin altitude remains stable within ±25 feet of the final cabin altitude. in this case 6.550 feet at an aircraft altitude of 45,000 feet. Stability is maintained provided the aircraft does not climb above 45.000 feel. the maximum allowable altitude of the aircraft. In preparation for descent, the flight crew enters the destination runway field elevation altitude (4.000 feet in this example) in the LDG window. A discriminator circuit is incorporated within the cabin pressurization transducer to prevent inadvertent programming of an isobaric cabin altitude (CABIN value) lower than the landing field altitude (LDG value). This feature prevents landing with excessive cabin differential pressure. If the discriminator circuit detects a LDG value higher than the CABIN value, it allows the LDG value to override the CABIN value and control that outflow valve. This is the only instance in which the LDG value can override the FLIGHT position on the FLIGHT/LANDING switch while in the AUTO mode. When ready to descend, the FLIGHT/LANDING switch is positioned to LANDING. Noting that the cabin rate of climb was preprogrammed to be 300 FPM DOWN prior to takeoff, the flight crew adjusts the BARO CORR (barometric correction), if necessary. This completes the descent programming. As the aircraft descends. the system automatically begins to open the outflow valve until a descent rate of 300 FPM is reached. Cabin pressure is maintained at approximately 400 to 500 feel below the actual LFE, or at approximately 0.25 psid. Upon touchdown. the nutcracker system signals the cabin pressurization transducer of an on-ground condition. causing the outflow valve to be driven fully open. With the outflow valve fully open, cabin pressure drops to a negligible pressure of approximately 0.05 psid until the air supply is shut off. 2A-21-00 Page 6 May 30+02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105882 Gulfstream IV OPERATING MANUAL B. Manual Operation Mode: To operate the pressurization system manually. the AUTO/MANUAL switch. located on the CABIN PRESSURE CONTROL panel, is selected to MANUAL. This causes the MANUAL switch legend to illuminate amber, the illumination of an amber light (referred to as the motor power indicator) above the AUTO/MANUAL switch and display of an amber CABIN PRES MANUAL caution message on CAS. The outflow valve may then be controlled by the flight crew. using its DC motor, by means of a knob on the CABIN PRESSURE CONTROL panel. The knob is spring-loaded to return the vertical position. labeled MAN HOLD, when released. Rotating the knob toward OPEN drives the valve open: rotating the knob toward CLOSE drives the valve closed. The manual control knob circuit is designed such that the further the knob is moved away from MAN HOLD toward OPEN or CLOSE. the more pulses are applied to the motor. i.e.. the faster the valve moves in that direction. The amber motor power indicator above the AUTO/MANUAL switch will blink in proportion to the speed of the pulses applied to the motor. Valve position is shown by an indicator to the right of the control knob. The indicator displays outflow valve position at all times, whether in AUTO or MANUAL modes of operation. When desired valve position is attained. releasing the knob will retum the knob to MAN HOLD and the outflow valve will hold (stop) in that position. To return system to automatic mode. the AUTO/MANUAL switch is selected to AUTO. The annunciations will be extinguished and the MAN HOLD knob function will become inoperative. NOTE: On aircraft having ASC 295 incorporated, loss of AC power will automatically switch the pressurization system to MANUAL control. This causes the MANUAL switch legend to illuminate amber. the illumination of an amber motor power indicator above the AUTO! MANUAL switch and display of an amber CABIN PRES MANUAL caution message on CAS. C. Cabin Pressure Safety Valve Limiting Mode: Should the AUTO or MANUAL control mode of the pressurization system malfunction and cabin pressure builds up to approximately 9.7 ±0.1 psid. the safety valve will open. It then modulates to limit cabin pressure to the safety relief pressure of 9.8 psid. D. Depressurization Rate Limiting Mode: Depressurization rate limiting prevents excessive rates of pressure loss. as might occur. for instance. if a malfunction drives the outflow valve to the full open position. Detection of an excessive rate of pressure loss triggers the cabin rate pressure switch. in turn causing the outflow valve to be driven fully closed and automatic control of the system is inhibited. The MANUAL legend of the AUTO/MANUAL switch illuminates amber and an amber CABIN PRES MANUAL caution message is displayed on CAS. The flight crew can restore the system to automatic operation after PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 7 May 30:02 Revision 7 EFTA01105883 Gulfstream IV OPERATING MANUAL depressurization rate limiting by first hard selecting the AUTO/MANUAL switch to MANUAL. enabling normal manual control. Reset is then completed by hard.selecting the AUTO/MANUAL switch to AUTO. E. Pressurization System Check: The flight crew normally performs the following pressurization system check in the course of their normal procedures: (1) Ensure the main entrance door is open. (2) Configure APU BLEED AIR. L ENG BLEED AIR and R ENG BLEED AIR as required. (3) Select the FLIGHTiLANDING switch to LANDING (green). (4) Select the AUTO/MANUAL switch to AUTO (green). (5) Select the ADC #1/ADC #2 switch to ADC #1 (green). (6) Verity the outflow valve is OPEN on the position indicator. Perform system check as follows: (7) Select the FLIGHTiLANDING switch to FLIGHT (green). (8) Verity the outflow valve is driving toward CLOSE. At the midway point: (9) Select the ADC #1/ADC #2 switch to ADC #2 (amber). (10) Verity the outflow valve drives fully to CLOSE. (11) Select the FLIGHTiLANDING switch to LANDING (green). (12) Verity the outflow valve is driving toward OPEN. At the midway point: (13) Select the ADC #1/ADC #2 switch to ADC #1 (green). (14) Verity the outflow valve drives further toward OPEN. Before the valve reaches fully OPEN: (15) Select the AUTO/MANUAL switch to MANUAL (amber). Verify amber -cabin pressure manual' light illuminates. (16) Verity manual control of outflow valve to OPEN and CLOSE positions using the manual control knob. (17) Select the AUTO/MANUAL switch to AUTO (green). (18) Verity the outflow valve drives fully OPEN if not already fully OPEN. Set final configuration as follows: (19) Select the FLIGHTiLANDING switch to LANDING (green). (20) Select the AUTO/MANUAL switch to AUTO (green). (21) Select the ADC #1/ADC #2 switch to ADC #1 (green). (22) Verity the outflow valve is OPEN on the position indicator. (23) Verify amber 'cabin pressure manual light is extinguished. 4. Controls and Indications: (See Figure 4 and Figure 5.) A. Circuit Breakers (CBs): Circuit Breaker Name: CB Panel: Location: Power Source: ESS AC Bus. oA CABIN PRESS 115V PO D.11 2A-21-00 Page 8 May 3n2 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105884 Gulfstream IV OPERATING MANUAL Circuit Breaker Name: CB Panel: Location: Power Source: CABIN PRESS 28V PO 8-11 ESS DC Bus CABIN PRESS IND PO A-12 ESS DC Bus B. Warning (Red) CAS Messages: CAS Message: SWLP Indication Cause or Meaning: CABIN DFRN-9.8 None Cabin differential pressure approaching upper limit (9.8). CABIN PRESSURE LOW CAB PRESS LOW Cabin altitude has climbed above limits (9250 ft ±750 ft). C. Caution (Amber) CAS Messages: CAS Message: Cause or Meaning: CABIN DFRN.9.6 Cabin differential pressure has reached 9.6 psi. CABIN PRES MANUAL Cabin pressurization controller has been switched to MANUAL control. either automatically or manually. D. Other Annunciations: Indication: Cause or Meaning: Amber Cabin Pressure Manual Light System in MANUAL control mode. Amber MANUAL Legend On AUTO/ MANUAL Switch System in MANUAL control mode. Amber ADC #2 Legend On ADC #1 , ADC #2 Switch ADC #2 providing static pressure signal to transducer. 5. Limitations: A. Flight Manual Limitations: (1) Cabin Pressurization Control System: (a) Maximum Cabin Pressure Differential Permitted: 9.80 psi (b) Maximum Cabin Pressure Differential Permitted For Taxi. Takeoff Or Landing: 0.3 psi (2) Bleed Air System: Do not operate above 41.000 ft without both engine bleeds ON and each engine being bled by either the air conditioning system or engine cowl anti-ice. See Section 0501.10. Air Conditioning System Shut Down Or Inoperative. B. Operational Data: Function: Value: Normal Maximum Pressure Differential 9.55 t.0.1 psi Safety Pressure Relief 9.70 ±0.1 psi Maximum Negative Differential -0.25 psi Pressurization Rate Limiting 3.000 FPM Depressurization Rate Limiting 3.000 FPM PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 9 May 30:02 Revision 7 EFTA01105885 Gulfstream IV OPERATING MANUAL Function: Value: Ground Differential Reference Signal 0.5 In Hg Rateof•Change Control tiff% of selected value at all cabin altitudes Barometric Correction Range 28.00 to 31.00 In Hg Absolute Pressure Cabin Aftitude.lsobaric Programming Range .1000 to 15 000 feet . Landing Altitude Selection Range •1000 to 15,000 feet Rate.of•Change Selection Range Minimum: • 50 FPM UP • 3spiniFuPniM:D°WN Max• 2000 FPM UP • 2000 FPM DOWN Rate to Maximum Differential Control Transition Not to exceed 50 feet with no overshoot beyond the final control value. Final Absolute Control Pressure Within 140 feet of selected value at all cabin inflow rates from outflow valve flow of 5 ppm to maximum flow. 2A-21-00 Page 10 May 301)2 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105886 Gulfstream IV OPERATING MANUAL orsth .140.5 (MIA 0A9I T Fl 1- 188:30k - RC 610/ 14 2080is CABIN DIFF PRESS XDUCER CABIN PRESS IND ESS DC BUS l_ STATIC I- CABIN I- XDUCER CABIN PRESS WARNING SW 9 250 ± 750 FT EICAS 0-0- DAU 1 A (:>2,©172,3- B CAB DFRN-9.8 CABIN PRESSURE LOW CABIN PRES MANUAL CAB DFRN-9.6 -v SG 1/2/3 C A S B SWLP CAB PRESS LOW DAU 2 I CABIN RATE PRESS r_ SIN 3000 FPM CABIN MAX DEPRESS LIMITER CANNPan CONTROL MAN HOLD dRa 0 AC POWER DC POWER FLOM ATV 4107 VAMS4 01,Q4 At* AU10 uvTA .:011 MODE LICair laVf)ING WIC 0 0 PATE DI 1,4101 4, POSITION INDICATION CABIN PRESSURIZATION SELECTOR AUTO SELECTION 1 CABIN PRESS 115V ESS AC BUS CABIN PRESS 78V., ESS DC BUS PITOT STATIC PITOT I I Il l NO.1 ADC STATIC NO.2 ADC I I CABIN CABIN 1 n AUTO OUTPUT AMBIENT OUTFLOW VALVE (ELECTRONIC) I PRESSURIZATION TRANSDUCER EMI FILTER CABIN PRESS NUTCRACKER C RELAY 111 IThe._.\ I ---- PRESSURIZATION LIMITER 3000 FPM MAX STATIC DATA FLT GND 4 STATIC SAFETY VALVE (PNEUMATIC) 25859C01 Cabin Pressure Control System Block Diagram Figure I 2A-21-00 1 1 12 Ivh, 21; 1;2 EFTA01105887 Gulfstream IV OPERATING MANUAL TYPICAL FLIGHT PLAN TAKEOFF FIELD = SEA LEVEL ALTITUDE 29.92 IN. HG PRESSURE CRUISE ALTITUDE = 45,000 FT LANDING FIELD = 4,000 FT ALTITUDE COCKPIT SELECTOR SETTINGS BEFORE TAKEOFF FLIGHT PLAN MAX. ALTITUDE = 45,000 FT (6,550 ISO) BARO. CORRECTION = 29.92 IN. HG RATE = 500 FPM UP (300 FPM DOWN) FLIGHT / LANDING SWITCH = LANDING AUTO / MANUAL SWITCH = AUTO SEA LEVEL NUTCRACKERS TO FLIGHT tO 40 ‘ 93 dexSC Q. Or it SW s.> 00° it 00° F TAXI / TAXEOFF \ AO* (TAXI/TAKEOFF 1 T i• 1 0 DIFF AIRCRAF I CABIN .05 PSI .25 PSI O ti CRUISE 45000 FT (9.41 PSI) ISOBARIC CABIN-6550 FT 7 SWITCH TO LANDING LANDING FIELD BAROMETRIC CORRECTION IF REQUIRED O 306 ag9e/Ay P itite Pelf O "TOQE.O 400-500 FT 43/4+O So# LANDING FIELD 4,000 FT ALT TAXI .05 PSI RATE CONTROLLED tt`l ott: 0 DIFF. 25860O00 Typical Flight Profile Figure 2 2A-21-00 Page 13 / 14 May 30/02 EFTA01105888 MOTOR POWER INDICATOR Illuiminates anther to indicate DC power Is provided to the outflow valve motor in the MANUAL mode. Flashes proportionate to amount MAN HOLD knob is rotated. MAN HOLD In MANUAL mode, provides DC motor control of outflow valve position. Knob is spring- loaded to HOLD. Outflow valve mains in last selected position. ( FLIGHT/ LANDING • Allows selection of pressurization schedule. • FLIGHT (Green): Closes outflow valve; commences and maintains pressurization schedule. • LANDING (Green): Opens outflow valve: commences and maintains depressurization schedule. AUTO/ MANUAL OUTFLOW VALVE POSITION INDICATOR Pointer moves to indicate outflow valve butterfly position. Functional in all modes of operation. (ADC #1 / ADC #2 • Allows selection of the ADC to supply static pressure information to the pressurization transducer. • ADC #1 (Green): Primary ADC • ADC #2 (Amber). Alternate ADC. • Used to select and display pressurization system mode of operation. • AUTO (Green): Automatic mode; normal mode of operation. Pressurization transducer controls outflow valve. • MANUAL (Amber) Manual mode of operation has been hard-selected or AC power has been lost (aircraft with ASC 295) or depressurization rate limiting has been initiated. MAN HOLD knob controls outflow valve. J 25862C01 Gulfstream IV OPERATING MANUAL CABIN PRESSURE CONTROL Panel Figure 3 2A-21-00 It: EFTA01105889 Cult:stream IV OPERATING MANUAL FLIGHT • Flight plan's maximum aircraft altitude set in AIRCRAFT portion of window. • Corresponding cabin altitude is shown in CABIN window • Scale is in thousands of feet BARD CORR • Barometric pressure correction window • Scale in Inches of ' Mercury (In Hg). • Range is 28.00 to I,. 31.00 In Hg. A FLIGHT A `' BARO CORR LANDING RATE C> 0 R r I 1 E :Nt. r o I 0 T 1000 FT IN MG 100FT 100 FT MIN iLDG • Landing Field Elevation (LFE) setting window • Scale is in hundreds of feet. • Range is -1,000 to +15,000 feet RATE • Cabin altitude rate•of- change for climb or descent • Desired value is set: corresponding opposite direction value is shown • Scale is in hundreds of feet per minute (FPM). • Range (Minimum): •• UP: 50 FPM • • DOWN: 30FPM • Range (Maximum): •• UP: 2,000 FPM •• DOWN: 2,000FPM 25861C00 Cabin Pressurization Selector Panel Figure 4 PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 17 !Aay 2C C2 1 EFTA01105890 Gull:stream IV OPERATING MANUAL - 1 0 fin n 0 Li LI RC FPM 'DERN PRESS • Displays cabin differential pressure in pounds per square inch (psi). • Readings above 9.6 psi will cause the amber indicator to illuminate above the display. • Readings above 9.8 psi will cause the red indicator 10 illuminate above the display. innni t i0Ou 'CABIN ALT • Displays cabin altitude in feet (FT). RC • Displays cabin rate of change for climb conditions (+) and descent conditions (-) in Feet Per Minute (FPM). Cabin Differential Pressure / Altimeter / Rate•cit•Climb Indicator Figure 5 25863C00 2A-91-30: Airflow and Temperature Control Sy,stem 1. General Description: The airflow and temperature control system for the Gulfstream IV provides for comfortable cabin and cockpit temperatures throughout the operating envelope of the aircraft by enabling the flight crew to perform the following functions: • Select and control bleed air entering and exiting two Environmental Control System (ECS) refrigeration pack assemblies, referred to as the Left and Right ECS Packs. This dual pack concept provides redundancy in the event one pack should fail. Source air into the ECS packs is provided to a bleed air manifold by either an approved external air source or APU air (while on the ground), or by High Pressure (HP) turbine bleed air from 2A-21-00 Page 18 May 30+02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105891 Gulfstream IV OPERATING MANUAL either or both of the aircraft's engines (on ground or in flight). Through use of an isolation valve, air from the bleed air manifold can be directed to either ECS pack. This results in a constant mass of conditioned air for all areas within the pressure vessel. • Control the temperature of conditioned air delivered to the cockpit and cabin areas (referred to as zones) within the pressure vessel. This is done using the two ECS packs to cool incoming air and deliver it to a conditioned air manifold. Valves mix hot bleed air with cold conditioned air to modulate the temperature of the air coming from the manifold into the pressure vessel. Water separation. for humidity reduction. is also provided. During normal inflight operation. temperature controlled and pressure.controllecl HP bleed air from either or both engines is supplied to the bleed air manifold. Air from the manifold is provided to the ECS packs, where cooling takes place. Each pack consists of a primary heat exchanger. secondary heat exchanger and an air cycle machine (ACM). (The term -air cycle' means that cooling is produced by a thermodynamic cycle, using only air as a medium, as opposed to a vapor cycle. which employs Freon TM or other similar gases.) The ECS packs then reduce air temperature to values above freezing. Humidity reduction is accomplished by a mechanical water separator. Temperature control of the zones within the pressure vessel is accomplished by varying the amount of hot bleed air which bypasses the cooling equipment. Separate temperature control is provided for the cockpit and cabin zones using a control panel located on the overhead panel in the cockpit. Provisions for manual control of the system are included in the event of a failure rendering electronic control inoperative. An advantage of the GIV airflow and temperature control system is that it is capable of functioning independently while on the ground. With the engines not operating, the bleed air manifold can be supplied with air from either the APU or from an approved external air cart. System operation on the ground is virtually the same as in flight. the difference being that ram air flow across the heat exchangers is provided by a cooling fan. Should either or both engines be operating. the flight crew may select either or both engines to supply bleed air to the manifold through use of the ISOLATION valve switch. During certain emergency procedures. the flight crew may induce ram air ventilation into the airflow and temperature control system. Ram air is supplied from a dorsal fin duct and controlled by a RAM AIR switch located on the overhead panel in the cockpit. For the purposes of this description. the airflow and temperature control system is divided into the following subsystems: • Air Control System • Temperature Control System • Distribution System • Refrigeration System • Ram Air Ventilation System • Temperature Indication System • Equipment Cooling System PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 19 May 30;02 Revision 7 EFTA01105892 Gulfstream IV OPERATING MANUAL 2. Description of Subsystems, Units and Components: A. Air Control System: (See Figure 6 and Figure 7.) (1) Bleed Air Manifold: The bleed air manifold is used as the source of bleed air for the air conditioning system. Air to the manifold is supplied by either an approved external air source or APU air (while on the ground). or by HP turbine bleed air from the aircraft's engines (on ground or in flight). The bleed air manifold delivers air to using systems. one being the air conditioning system. Delivered air is approximately 400° F at a maximum pressure of 40 psig. For the air conditioning system. air is delivered to the air conditioning shutoff and flow regulating valves in the tail compartment. (2) Air Conditioning Shutoff and Flow Regulating Valves: The air conditioning shutoff and flow regulating valves perform two functions in the air conditioning system: • Act as shutoff valve when system operation is terminated. • Act as a flow regulator when the system is operating. The air conditioning shutoff and flow regulating valve is pneumatically operated butterfly valve. using upstream duct pressure as the operating force. An internal electrical solenoid is installed and. when energized. pressurizes the valve to close it. This prevents air entry. ending system operation. When de.energized. upstream duct pressure opens the butterfly valve and airflow starts again. Airflow through the valve is regulated to a maximum of 42.1 (±1.5) pounds per minute (ppm) of flow. There are several ways to energize the solenoid and close the valve: • Selection of the RAM AIR switch to RAM. • Selection of the L PACK or R PACK switch to OFF. • ACM compressor discharge temperature reaching 450° F (on ground). For aircraft 1000 through 1155 (excluding 1034) having ASC 135. aircraft 1034. and aircraft 1156 and subsequent, the following additional functions exist: • Selection of the MASTER CRANK or MASTER START switch closes the LEFT ECS PACK valve (on ground). The valve will automatically reopen when the MASTER CRANK or MASTER START switch is deselected. • Selection of the L ENG START or R ENG START switch closes the RIGHT ECS PACK valve (on ground). The valve will automatically reopen when the start valve closes. Exiting the air conditioning shutoff and flow regulating valve. air flows through an ozone filter that reduces concentration to a maximum of 0.1 pan per million. The air is then delivered to the temperature control system and split into two paths. One path is 2A-21-00 Page 20 May 3W02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105893 Cu!Stream IV OPERATING MANUAL routed to the primary heat exchangers (for primary cooling) and the other path is routed to the cabin and cockpit temperature control valves (bypass air). B. Temperature Control System: (See Figure 8.) Air leaving the ozone filter is delivered to the temperature control system and can take two paths: either through the refrigeration unit or through the cabin and cockpit temperature control valves. The amount of air that can pass through the temperature control valves is dependent upon valve butterfly position. The remaining bleed air is delivered to the refrigeration unit to be cooled. This now cold air then rejoins the hot bleed air from the temperature control valves, thereby becoming temperaturecontrolled (conditioned) air. The position of the temperature control valve determines the compartment temperature by mixing the hot and cold air to maintain the desired temperature. All temperature control devices in this system are directed toward control of the appropriate temperature control valve. (1) Cabin/Cockpit TEMP CONTROL Panel: The Cabin/Cockpit TEMP CONTROL panel. located on the cockpit overhead panel. is used to automatically or manually set a desired cabin or cockpit temperature. Each portion of the panel (CABIN and CKPT) is isolated and independent of the other. The selector knob provides automatic and manual temperature control selection based upon knob position. In the OFF position. no signal is applied to the temperature control valve from either the manual selector knob or the temperature controller. Clockwise rotation of the knob from OFF places the system in the automatic mode of operation (the normal mode of operation). with the temperature controller providing electrical signals to the temperature control valve. Range of the automatic mode of operation is COLD (60° F) to HOT (80° F). Counterclockwise rotation of the knob from OFF places the system in the manual mode of operation, with the manual selector knob providing electrical signals to the temperature control valve. Range of the manual mode of operation is COLD (temperature control valve fully closed) to HOT (temperature control valve fully open). Returning the knob to OFF defaults the system to full cold operation. NOTE: Some aircraft are outfitted with additional manual temperature controls located aft of the baggage compartment door. These controls, however, are pneumatic. not electric and are dependent upon a minimum 3 psid cabin pressure to manipulate the temperature control valves. (2) Cabin/Cockpit Temperature Control Valves: The cabinlcockpit temperature control valve is a pneumatic modulating butterfly valve. Pneumatic pressure is required to open the butterfly and the amount of opening is controlled by. and proportional to. the amount of pneumatic pressure applied to an PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 21 May M(02 Revision 7 EFTA01105894 Gulfstream IV OPERATING MANUAL internal diaphragm chamber. With no pneumatic pressure applied to the diaphragm chamber. an internal mechanism maintains the butterfly in the closed position. The pneumatic opening pressure, referred to as servo pressure. originates from pressure ducted from upstream of the valve. The ducted pressure is routed to a servo air pressure regulator and torque motor. (3) Servo Air Pressure Regulator and Torque Motors: The servo air pressure regulator and torque motor controls the pressure to the temperature control valve using an electrical signal received from the cabin/cockpit temperature controller. The electrical signal is converted into a pneumatic signal and the pneumatic signal positions the temperature control valve accordingly. (4) Cabin/Cockpit Temperature Controllers: The cabin/cockpit temperature controller receives and interprets various inputs in order to derive an output signal. These inputs are: • Two cabin/cockpit temperature sensors. for ambient temperature • One cockpit temperature sensor, for ambient temperature • Two cabin/cockpit duct temperature anticipators. for duct temperature and exhausted air temperature These inputs are compared to the desired ambient temperature commanded by the TEMP CONTROL panel knob and an output signal is then sent to the servo air pressure regulator and torque motor to position the temperature control valve. The cabin/cockpit temperature controller receives power from the 28V Right Main DC bus (aircraft 1000 through 1143. excluding 1034) or the Essential DC bus (aircraft 1034. and aircraft 1144 and subsequent). (5) Cabin/Cockpit Temperature Sensors: The cabin/cockpit temperature sensors are dual elements consisting of two separate sections. One section provides temperature information to the cabin temperature controllers, while the other element is actually a temperature bulb for the digital cabin air temperature indicator located on the cockpit overhead panel. On airplanes SN 1437 and subsequent and SN 1000 through 1436 having ASC 162A, a second cabin temperature sensor is also installed. It is used for temperature indication only. (6) Cockpit Temperature Sensor: The cockpit temperature sensor is a single thermistor sensing element. It is used with the compartment thermostat to provide temperature information to the cockpit temperature controller. (7) Crossover Function: Airflow and temperature control capability is maintained in the event of failure of either engine or either ECS pack. In the event of an engine failure. the BLEED AIR switch for the 2A-21-00 Page 22 May 303)2 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105895 Gulfstream IV OPERATING MANUAL operative engine is left ON while the BLEED AIR switch for the inoperative engine is selected OFF. The ISOLATION valve would be opened to allow operative engine bleed air to both ECS packs. Both PACK switches are left ON for full airflow and temperature control capability. In the event of an ECS pack failure. the PACK switch for the operative pack is left ON while the PACK switch for the inoperative pack is selected OFF. The BLEED AIR svritch for the operative paclis engine is left ON for full airflow and temperature control capability. Depending on flight conditions and mission requirements. problem ECS packs should be managed as necessary. Airplane Flight Manual limitations should be consulted if an ECS pack is to be shut down in flight. NOTE: Do not select both ECS packs OFF at altitude. C. Distribution System: (See Figure 6 and Figure 7.) Exiting the temperature control valves. the hot bleed air is joined with the cooled air from the refrigeration unit to become temperature-controlled air. This air is then introduced into the cabin and cockpit distribution systems. each having separate temperature control valves and ductwork. The cockpit distribution system consists of ducting from the cockpit temperature control valve. the refrigerated air duct, an air duct check valve and a silencer. Final distribution is from four outlets in the cockpit: a controllable side (or shoulder) outlet and a non-adjustable foot outlet, for each pilot. The cabin distribution system consists of ducting from the cabin temperature control valve, a air duct check valve and a silencer. Final distribution is through two louvered baseboard ducts running most of the cabin's length, one on each side. Cabin and cockpit check valves are installed in the compartment ducting allowing air to flow only in a forward direction. Should the air attempt to reverse flow. the check valve closes to prevent backflow. Cabin and cockpit silencers are installed in the ducting under the floor to silence air noise from the bleed air ducts. D. Refrigeration System: (See Figure 7.) Bleed air which does not bypass the cabin and cockpit temperature control valves is routed into the refrigeration unit (ECS pack). The ECS pack consists of the following major components: • Primary Heat Exchanger • ACM and ACM Overtemperature Thermal Switch • Secondary Heat Exchanger • Water Separator System PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 23 May 30;02 Revision 7 EFTA01105896 Gulfstream IV OPERATING MANUAL • Water Separator Anti-Ice System • Cooling Fan • Cooling Air Distribution (1) Primary Heat Exchanger: The primary heat exchanger is the first stage of the refrigeration process. Ram air from the dorsal fin inlet is used as a coolant. The heat exchanger is a "single pass' type exchanger and is located in the tail compartment. Air exiting the heat exchanger is split into two ducts. One duct routes air into the eye of the compressor section of the ACM. The other duct routes air through the water separator anti-ice valve into the anti-ice muff assembly. bypassing the ACM and secondary heat exchanger. (2) Air Cycle Machine (ACM) and ACM Overtemperature Thermal Switch: The ACM is an expansion turbine which reduces air temperature by causing the air to perform useful work. resulting in lower air pressure and thus. lower air temperature. The work extracted from the airstream in the turbine section is absorbed a compressor wheel directly shafted to the turbine wheel and located in a separate chamber on the upstream side of the unit. A large percentage of the work extracted from the airstream by the turbine wheel is used by the compressor wheel. As the compressor wheel is performing work on the upstream air, its pressure and temperature are increased. This work arrangement is called a pressure recovery system or *bootstrap' system. With the ACM in full operation (no airflow to the anti-ice valve). airflow moves through the compressor section to the secondary heat exchanger. then to the turbine section nozzle. exiting out the eye of the turbine section into the mixing muff. A 450° F thermal switch is incorporated into the discharge side of the bootstrap compressor to monitor discharge air temperature. If a malfunction causes low or no airflow across the heat exchangers. the compressor discharge temperature Ml rise accordingly. At 450° F. the svritch causes an amber L-R COOL TURB HOT message to be displayed on CAS. Additionally, when on the ground. the ECS pack will be automatically shut off due to a protection circuit passing through the ground configuration of the nutcracker system. An amber L-R COOL TURB HOT CAS message in flight may be the result of either an excessive air supply to the ACM. resulting in an overspeed/overtemperature condition. or an air bearing failure in the ACM. Excessive airflow from 12th stage compensation can be the result of operating cowl anti-ice and/or wing anti-ice at high altitudes. (3) Secondary Heat Exchangers: Secondary heat exchangers are installed adjacent to the primary heat exchangers. Ram air from the dorsal fin inlet is used as a coolant. (4) Water Separator System: 2A-21-00 Page 24 May 3W02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105897 Gulfstream IV OPERATING MANUAL Air expansion inside the cooling turbine and resultant discharge temperatures below ambient forces moisture into the air where it condenses. A two-section water separator provides a means for removing the water. The first section consists of a coalescer which transforms the many small droplets into a few large drops by forcing the water through a coarse mesh cloth bag. In the second section. the airstream is forced to swirl by means of a series of vanes so that the large drops are spun to the outside walls. Water extracted from the air is also sprayed into the secondary heat exchanger cooling air inlet to assist in cooling. The water separator is capable of removing approximately 80% of all liquid state water passing through it but it cannot, however. remove water vapor. The water separator also contains a relief valve which. if the coalescer becomes clogged. bypasses the air through the unit. In this case. dehumidification would not take place. (5) Water Separator Anti-Ice System: During cool, moist conditions. cooling turbine discharge temperatures can fall low enough that condensed water freezes. To prevent the coalescer from becoming clogged with ice crystals and restricting airflow, a water separator anti-ice system is installed in the tail compartment. The system consists of a water separator anti- ice valve. a sensor and a bypass duct mixing muff assembly. The water separator anti-ice valve is a butterfly-type shutoff and modulating valve. It controls the refrigeration unit cold air outlet temperature to a minimum of 37° F (nominal) by modulating the flow of compressor inlet air to the anti•ice muff at the turbine discharge. Valve position is controlled by a torque motor in response to signals received from the water separator anti-ice sensor/controller. The water separator anti-ice sensoacontroller is a pneumatic thermostat. installed on the discharge side of the water separator. The thermostat is set to maintain anti-ice valve position so that air moving through the water separator is held at a temperature of approximately 37° F. The sensor/controller remains function throughout all altitude. temperature and humidity ranges. One cockpit indication that a water separator may be frozen is an absence of cool air in all modes of operation. To determine whether the water separator is merely frozen or the ACM is faulty. the affected PACK switch is selected OFF and a ten minute time period is allowed to elapse. The affected PACK switch is then selected ON and the air temperature is checked. If cool air returns, the water separator was most likely frozen, thus a warmer temperature should be selected. If warm or hot air returns. the ACM is most likely faulty. (6) Cooling Fan: Ground cooling places additional requirements on the air conditioning system. As there is no ram air flow, the possibility exists that the air conditioning equipment would overheat unless a source of cooling air is supplied. A turbofan is installed downstream of the ACM in the dorsal fin ram PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 25 May M.(02 Revision 7 EFTA01105898 Gull:stream IV OPERATING MANUAL air duct. The fan assembly provides airflow across the primary and secondary heat exchangers whenever the air conditioning system is in operation on the ground. Fan air leaving the heat exchangers is then exhausted overboard. (7) Cooling Air Distribution: Dehumidified, refrigerated air from the discharge side of the water separator is ducted forward, joining that portion of the hot bleed air having passed through the cabin/cockpit temperature control valves to become temperature•controlled air. Also. dehumidified. refrigerated air from the ECS pack Is ducted into one line which supplies cabin and cockpit eyeball ducts installed by the operators completion agency. A check valve Is installed in each line to prevent backflow. E. Ram Air Ventilation System: In the event of an emergency, the flight crew can ventilate the aircraft with ram air from the ram air dorsal fin Inlet. A line is installed in the ram air duct just upstream of the primary heat exchanger. The line is routed to the ram air check valve and then to the downstream side of the left water separator refrigerated air duct. II ram air duct pressure is greater than refrigerated air duct pressure, the ram air check valve opens. allowing ram air into the refrigerated air line. The ram air then moves forward through the cabin duct check valve, into the distribution system. The ram air check valve allows airflow to move only from the ram air duct into the air conditioning system ducting. During normal operations with the air conditioning system running, system pressure is always greater than ram air pressure, thus the ram air check valve is held closed. Selection of ram air ventilation is accomplished using the RAM AIR switch located on the cockpit overhead panel. Selection of the switch to RAM supplies 28V Essential DC bus power to close both air conditioning shutoff and flow regulating valves, shutting off the air conditioning system. As air conditioning system duct pressure falls below ram air duct pressure, the ram air check valve opens. allowing ram air into the distribution system. Conversely, selection of the RAM AIR switch to OFF allows both air conditioning shutoff and flow regulating valves to open, restoring the air conditioning system. As air conditioning system duct pressure rises above ram air duct pressure, the ram air check valve closes, allowing air conditioning system air Into the distribution system. NOTE: Selection of the RAM AIR switch to RAM results in the cabin altitude climbing, eventually causing the pressurization system outflow valve to close. Consideration should be given to manually opening the outflow valve to ensure adequate airflow for radio rack cooling. NOTE: During use of ram air ventilation, the flight crew has no control of cabin air pressure or temperature. 2A-21-00 Page 26 May 30+02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105899 Gulfstream IV OPERATING MANUAL F. Temperature Indication System: (See Figure 8.) A digital cabinrcockpit air temperature indicator is installed on the TEMP CONTROL panel on the cockpit overhead panel. The CABIN temperature display is provided ambient temperature information from the cabin temperature sensor. The CKPT temperature display is provided ambient temperature information from the cockpit temperature sensor. Both sensors also provide temperature information to their respective temperature controller. Location of the sensors is determined by the operator's completion agency. Power for the indicator is furnished by the 28V Essential DC bus through the CKPT/CABIN TEMP IND circuit breaker. The indicator is calibrated in degrees Fahrenheit. with a maximum display value of 199° F. G. Equipment Cooling System: (See Figure 9.) Electric cooling fans are installed to force cooling air to the display unit cathode ray tubes (CRTs). center pedestal equipment, radio racks and nose compartment. With electrical power applied. operation of most fans is automatic and is transparent to the flight crew. For aircraft 1000 through 1155 (excluding 1034) having ASC 87. and aircraft 1034. 1156 and subsequent. selection of the PILOT. EICAS or COPILOT DISPLAY switch while on the ground energizes both CRT cooling fans. In flight. the fans operate continuously. regardless of switch position. Supplemental cooling air for center pedestal equipment is provided by a fan mounted in the aft right side of the pedestal. The fan is not thermostatically controlled and operates whenever 28V Right Main DC bus power is available. With electrical power applied and the main entrance door open. the right- hand radio rack cooling fan operates. On aircraft 1156 and subsequent, a RH RR FAN MAN ON switch is installed on the copilot's side console to provide additional manual control of the right-hand radio rack fan. Additionally. blue RH RR FAN AUTO. RH RR FAN FAIL and LH RR FAN FAIL annunciators are installed on the copilot's side console to show radio rack fan status. With the aircraft on the ground and nose compartment temperature above 90° F. a thermal switch opens the nose compartment cooling valve. This energizes a fan and illuminates an amber N COOL VALVE OPEN annunciator on each side of the flight panel. Once airborne. a nutcracker relay closes the valve. Should the valve fail to close in flight. the N COOL VALVE OPEN annunciators will illuminate. 3. Controls and Indications: (See Figure 8 and Figure 9.) A. Circuit Breakers (CBs): The airflow and temperature control system is protected by the following CBs: PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 27 May 30;02 Revision 7 EFTA01105900 Gull:stream IV OPERATING MANUAL Circuit Breaker Name: CB Panel: Location: Power Source: L AIR COND PO C-13 ESS DC Bus R AIR COND PO D-13 ESS DC Bus CABIN PRESS 115V PO D-11 ESS AC Bus, 0A CABIN PRESS 28V PO B-11 ESS DC Bus CABIN PRESS IND PO A-12 ESS DC Bus CABIN TEMP CONT PO D-14 ESS DC Bus CKPT/CABIN TEMP IND PO A-11 ESS DC Bus CKPT TEMP CONT PO 8.13 ESS DC Bus DISPLAYS FAN WI CP D-5 ESS DC Bus (1) DISPLAYS FAN #2 CP D-6 R MAIN DC Bus (2) NOSE COMPT COOL FAN CP M-1 R MAIN DC Bus (3) NOSE COMPT COOL VLV CP L-1 R MAIN DC Bus PED COOL FAN CP J-1 R MAIN DC Bus LH RR COOL FAN CP K-1 ESS DC Bus RH RR FAN CON CP I.1 ESS DC Bus RH RR COOL FAN CP H-2 ESS DC Bus SGL PACK PO C-14 ESS DC Bus L TEMP CONT AC P H-11 ESS AC Bus, 0A R TEMP CONT AC P I.11 ESS AC Bus. $A NOTE(S): (1) ESS AC bus. oA, on aircraft 1000, 1002 through 1095 (excluding 1034) not having ASC 49/49A. (2) R MAIN AC bus, 0B, on aircraft 1000, 1002 through 1095 (excluding 1034) not having ASC 49/49A. (3) R MAIN AC bus, oB, on aircraft 1000 and 1002 through 1095, excluding 1034. B. Caution (Amber) CAS Messages: CAS Message: Cause or Meaning: L-R COOL TURB HOT Cooling turbine discharge air above 450° F (232° C). DU FAN 1.2 FAIL Respective DU cooling fan has failed. FWD RADIO RACK HOT Inside radome. left or tight equipment bay temperature has exceeded 200° F (93° C). C. Other Indications: I I Indication: Cause or Meaning: Amber N COOL VALVE OPEN Annunciator (Pilot's/Copilot's Right Panel) Nose compartment cooling valve is open. Blue LH RR FAN FAIL Annunciator (Copilot's Side Console) (1) Left-hand ratio rack cooling fan has failed. Blue RH RR FAN FAIL Annunciator (Copilot's Side Console) (1) Right-hand radio rack cooing fan has failed. 2A-21-00 Page 28 May 30+02 PRODUCTION AIRCRAFT SYSTEMS Revision 7 EFTA01105901 Gulfstream IV OPERATING MANUAL I I I Indication: Cause or Meaning: Blue RH RR FAN AUTO Annunciator (Copilot's Side Console) (1) Right-hand radio rack cooling fan operating automatically. Blue RH RR FAN MAN ON Annunciator (Copilot's Side Console) (1) Right-hand radio rack cooling fan operating manually. NOTE(S): (1) Aircraft 1156 and subsequent 4. Limitations: There are no limitations for the airflow and temperature control system at the time of this revision. PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 Page 29 May 30/02 Revision 7 EFTA01105902 Gulfstream IV OPERATING MANUAL THIS PAGE IS INTENTIONALLY LEFT BLANK. 2A-21-00 Page 30 May 30,P2 PRODUCTION AIRCRAFT SYSTEMS EFTA01105903 (;udfstreann IV OPERATING MANUAL CABIN PRESS SAFTEY VALVE MANUAL CABIN PRESS CABIN PRESS CONTROLLER CABIN PRESS TRANS- DUCER CABIN PRESS CONTROL EMI FILTER COCKPIT TEMP SELECTOR SILENCER TEMP CONTROL 44. I ♦ CABIN / COCKPIT TEMP CONTROLER COCKPIT TEMP CONTROL SENSOR • OVERBOARD Ik oft CABIN / COCKPIT TEMP CONTROLER CABIN TEMP CONTROL SENSOR 4, I CABIN AIR OUTFLOW VALVE EMERG CABIN PRESS RATE SWITCH COCKPIT DUCT OVERTEMP SENSOR COCKPIT DUCT TEMP ANTICIPATOR SENSOR OVERTEN ABIN na lg SILENCtR I CABIN DUCT TEMP ANTICIPATOR SENSOR PRESSURIZED AREA CABIN / COCKPIT FACE AIR CHECK VALVE CONDITIONED AIR CONDITIONED AND MANIFOLD AIR MIXED RAM AIR CABIN 7 COCKPIT FACE REFRIGERATION UNIT AIR CHECK VALVE (A) PRIMARY / SECONDARY HEAT SERVO AIR PRESS EXCHANGER REG VALVE (B) AIR CYCLE MACHINE (ACM) COCKPIT AIR COCKPIT TEMP (C) ANTI-ICE AIR MODULATING VALVE CHECK VALVE CONTROL VALVE (D) OVERTEMPERATURE SWITCH (E) ACM BYPASS CHECK VALVE (F) ACM BYPASS SHUTOFF VALVE (G) COOLING FAN FROM RH SERVO CONTROL SYSTEM TO DADC #2 TO_ DADC #1 RAM AIR allo RAM AIR CHECK 4. = VALVE ♦ .... . .. . .. . . . . . . . . . . .. OVERBOARD * 'IT 4 WATER SPRAY ASPIRATOR ; • OVERBOARD CABIN AIR WATER CHECK VALVE SEPARATOR NI SENSOR REFRIGERATION UNIT COMPRESSOR OUTLET AIR PRESSURIZED AREA TEMP CONTROL L PACK RAW ORS A PAO.0 OFF RIM Orr OZONE FILTER AIR • CORD ••• • OZONE SOV FILTER te • . . REFRIGERATION UNIT FROM LH SERVO CONTROL SYSTEM CABIN TEMP CONTROL VALVE SERVO AIR PRESS REG VALVE ACM AIR I MANIFOLD AIR PRIMARY CONDITIONED AIR EICAS COOL TLRSHOT NOTE: • • WATER SEPARATOR 25864C00 Airflow And Temperature Control System Block Diagram Figure 6 2A-21-00 Page 31 / 32 May 30/02 EFTA01105904 COCKPIT PNEUMATIC OVERTEMP SENSOR TO COCKPIT ORIFICE CABIN SILENCER CABIN DUCT TEMPERATURE SENSOR LEGEND MI WARM AIR COLD MR Eig RAM AIR HOT BLEED AIR CONDITIONED AIR PRIMARY HEAT EXCHANGER SECONDARY HEAT EXCHANGER TEMPERATURE CONTROL VALVE TORQUE MOTOR WATER --------- SEPARATOR MIXING MUFF SECONDARY HEAT EXCHANGER STATIC =_- PRESSURE VENT ASPIRATOR RAM-AIR CHECK VALVE TEMPERATURE CONTROL VALVE TEMPERATURE CONTROL VALVE TORQUE MOTOR LI REAR PRESSURE BULKHEAD TEMPERATURE CONTROL VALVE SUPPLY AIR , FROM RIGHT SERVO -"/ CONTROL SYSTEM ANTI-ICE VALVE COMPRESSOR OVERBOARD BYPASS DOOR BYPASS CHECK VALVE BYPASS DOORS PRIMARY HEAT EXCHANGER SUPPLY AIR FROM LEFT SERVO CONTROL SYSTEM OVERBOARD TO OVER- TEMPERATURE LIGHT (ON AT 450 F) SWITCH a 25865C01 Gulfstre-am IV OPERATING MANUAL Refrigeration System Block Diagram Figure 7 2A-21-00 Page 33 / 34 May 30/02 EFTA01105905 Gulfstream IV OPERATING MANUAL TRAM AIR • OFF (Normal position, RAM legend distinguished): Ram air is inhibited due to ECS pack airflow. • RAM (Amber): Both ECS packs are shut off. Ram air from dorsal fin duct enters air conditioning system through ram air check valve. CABIN / CKPT Temperature • Display cabin and cockpit temperatures obtained from respective temperature sensor. • Display in degrees Fahrenheit with a maximum of 199 F. (CABIN / CKPT AUTO / MAN • OFF: No signal is sent to respective temperature control valve. • AUTO: Temperature cont- roller provides signal to temperature control valve. Range is COLD (6ff F) to HOT (60' F). • MAN: Manual selector knob provides signal to temper- ature control valve. Range is COLD (temperature control valve fully dosed) to HOT (temperature control valve fully open). ISOLATION TEMP CONTROL L PACK RAM AIR R PACK OFF ••• CABIN RAM OFF N, CKPT ISOLATION When selected open (on ground): • White bar in switch capsule illuminates. • Left and right bleed air manifolds are combined. • Crossbleed air from opposite engine is available. • APU air is available for ECS packs and engine starting. When selected open (in air): • Same conditions listed above are present except APU air is available for engine starting only. When selected to OFF: • White bar in switch capsule extinguishes. • Left and right bleed air manifolds are isolated. • Crossbleed air from opposite engine is inhibited. • APU air is available for R ENG bleed air manifold only. L PACK / R PACK • ON (Normal position; OFF legend extinguished): Air conditioning shutoff and flow regulating valve is de- energized, allowing air conditioning air flow. • OFF (Amber): Air conditioning shutoff and flow regulating valve is energized closed; air conditioning airflow ceases. 25$68C00 Cabin / Cockpit TEMP CONTROL Panel Figure 8 2A-21-00 Page 35 / 36 May 30/02 EFTA01105906 Cult:stream IV OPERATING MANUAL N COOL VALVE OPEN • Illuminates amber when nose compartment cooling valve is open. neax If yr susp 1 vai,v,.,„. ----- .? RADIO RACK FAN TORS (Aircraft SN 1156 & subs.) Illuminate blue corresponding to fan activity: • RH RR FAN MAN ON: Right- hand radio rack fan manually selected on. • RR RH FAN AUTO: Right-hand radio rack fan under automatic control. Fan operates anytime main entrance door is open. • RH l LH FAN FAIL: Respective fan has failed. 25867C00 Cockpit Annunciators Figure 9 PRODUCTION AIRCRAFT SYSTEMS 2A-21-00 3? MI, 2C C2 EFTA01105907 Gulfstream IV OPERATING MANUAL THIS PAGE IS INTENTIONALLY LEFT BLANK. 2A-21-00 Page 38 May 30,02 PRODUCTION AIRCRAFT SYSTEMS EFTA01105908