Chapter 21 Air Conditioning - Extra Aircraft · 2015-05-27 · Maintenance Manual and Illustrated Parts Catalogue Extra EA-400 Air Conditioning Page Date: 13. July 2001 21 Page 5

Maintenance Manual and Illustrated Parts Catalogue

Extra EA -400

Page Date: 8. December 1999 21 Page 1

Chapter 21 Air Conditioning


Extra EA -400 Air Conditioning

Page 2 21 Page Date: 13. July 2001

Table of Contents

21-00-00 GENERAL .........................................................................................................5 Description ..........................................................................................................5 Troubleshooting...................................................................................................6 Service and Maintenance.....................................................................................8 Removal / Installation..........................................................................................8

21-20-00 DISTRIBUTION................................................................................................9 Description ..........................................................................................................9

21-20-01 Panel Vent Fans .................................................................................................9 Removal (Pilot’s Side) ........................................................................................9 Installation (Pilot’s Side) ...................................................................................10 Removal (Copilot’s Side)..................................................................................12 Installation (Copilot’s Side) ..............................................................................13

21-30-00 PRESSURIZATION CONTROL ..................................................................15 Description ........................................................................................................15 Handling ............................................................................................................16 Removal / Installation........................................................................................18

21-30-01 Cabin Outflow Control Valve Filter..............................................................18 Replacement ......................................................................................................18

21-30-02 Cabin Outflow Control Valve.........................................................................18 Removal / Installation........................................................................................18

21-30-03 Safety Valve......................................................................................................19 Removal / Installation........................................................................................19

21-60-00 TEMPERATURE CONTROL.......................................................................20 Description ........................................................................................................20



Page Date: 13. July 2001 21 Page 3

Figure 21-01a Cabin Air Condition and Pressurization Scheme (SN 03 to 19)




Figure 21 – 01b

Cabin Air Condition and Pressurization Scheme (from SN 20 foll.)




21-00-00 GENERAL

Description

Refer to Figure 21-01a/b. For ventilation either pressurized or ram air is available. The air source can be selected by the cabin air selection knob located on the middle console controlling the cabin air selection valve.

If pressurized air is selected, air is guided from the combustion air intake through an air filter, the turbocharger, the intercooler, a sonic venturi and then either through the cabin cooler or directly through the cabin inflow check valve into the cabin. At the same time ram air is guided from the ventilation air ram intake to the vacuum pumps for cooling.

Note If maximum air flow for ventilating is desired it is advisable to select pressurized air.

If ram air is selected, air is guided from the ventilation air ram intake through the cabin inflow check valve into the cabin, while pressurized air now feeds the vacuum pumps.

SN 03 through 19

Inside the cabin air can be guided to the windshield dispensers for defogging and defrosting and to the legroom dispenser or through the RH armrest channel to the rear, which depends on the position of the windshield defrost flap controlled by the respective knob on the middle console. In the pressure dome area an electric heater and the evaporators of the air conditioning system are installed. The evaporators also work as cabin fans. The air conditioning system including a compressor condenser module located in the tail cone sucks cabin air and blows cool air through hoses to the eyeball vents and the leg room dispenser in the front cockpit area and to the adjustable nozzles in the overhead air channel of the passenger compartment ceiling.

SN 20 through 25 From SN 20, the ventilation system has been modified. Instead of the rear overhead air channel, the cooled air is now routed through the LH arm rest duct to the lower LH cockpit section as well as through the RH arm rest duct to the RH cockpit section. The overhead air channel is furnished with a vent fan to feed the adjustable air deflectors with ventilated cabin air.

The eyeball vents have been replaced by two independent adjustable air outlets, which are combined with two panel vent fans to re-circulate the cockpit air. Finally, the leg room dispenser has been removed.

When the evaporator blowers are operating, either cooled (air condition on) or ventilated (air condition off) air is pressed through both side armrest channels. From the RH evaporator blower, air is led into a duct in the RH armrest to the right cockpit section. From the LH evaporator blower, air is ducted first through the electrical heater in the LH armrest duct. This duct leads through the

5. July 2002




cabin door where it is sealed with two oval rubber seals, and finally is routed into the lower LH cockpit section. When the electrical heater is engaged the compressor module is disengaged, and vice versa.

From SN 20, operation of the heating, ventilating and air conditioning system implies the following characteristics: (Refer to Section 7, Pilot’s Operating Handbook, figures 7-3, 4, 6, 13)

1 The cabin ventilation system, including both evaporator blowers and the overhead air channel vent fan, is controlled by the VENT HI / LO switch in the CABIN area of the left side panel. Both evaporator blowers work with different power settings in low or high mode, whereas overhead air channel fan operation features only one power rate for both switch positions LO / HI.

2 Heating and air conditioning system work exclusively. For either operating the heating or the air conditioning, the ventilation system must run in high mode simultaneously (VENT switch to position HI).

SN 26 following

The LH duct ends in the LH armrest behind the switch/breaker panel. The other system components remain unchanged.

Troubleshooting

Complaint Possible Cause Remedy

Excessive cabin leakage Identify and seal

Excessive door seal leakage Replace door seal

Excessive emergency exit seal leakage

Replace emergency exit seal

Dump solenoid energized Check dump switch and squat switch

Controller failure Replace controller

Pressurization system inactive Switch pressurization system ON

Control valve failure Replace control valve

No or inadequate pressurization

Safety valve failure Replace safety valve


Control valve static reference blocked

Clean static reference connection

Control valve filter blocked Replace filter

Incorrect pressurization or pressurization rate control

Controller defective Replace controller

5. July 2002




Complaint Possible Cause Remedy

Incorrect pressurization or pressurization rate control

Control valve defective Replace control valve

Control valve static reference blocked


Pressure differential exceeding 5.5 psi

Control valve differential failure

Replace control valve


Squat switch setting incorrect Correct squat switch setting

Safety valve static reference blocked


Dump switch defective Replace dump switch

Squat switch defective Replace squat switch

Safety valve solenoid failure Replace safety valve

No dump

Safety valve blind plug at vacuum port not installed

Install blind plug

Differential pressure switch (5.65 psig) defective

Replace differential pressure switch

Erroneous CAB PRESS warning

Absolute pressure switch (10,000 ft) defective

Replace absolute pressure switch

5. July 2002




Service and Maintenance

Servicing of the air-conditioning unit shall be performed by an approved air-conditioning service station, only R-134a type refrigerant must be used.

The air-conditioning compressor condenser module is equipped with conventional evacuating and charging connections.

After new system plumbing installation, component replacement or line or hose rupture, a leak check is required, see General Operating, Servicing and Maintenance Manual for Airborne R-134a Air-conditioning Systems for leak check and general charging procedures.

Refer to General Operating, Servicing and Maintenance Manual for Airborne R-134a Air-conditioning Systems for component maintenance procedures..

Access to the compressor condenser module is gained through the tailcone access hatch.

Charging quantity of the installation is 1.050 kg +/- 0.050 kg, proper charging can be verified at the sight glass on the receiver dryer. With the system fully charged and operating, observe the suction and discharge pressures. Typical values at various ambient temperatures, with hot cabins are shown below:

OAT (°C)

Suction pressure (psig)

Discharge pressure (psig)

20 28 112

25 30 133

30 31 156

35 32 180

Removal / Installation

For removal and installation of air-conditioning, heating or temperature control system components, contact EXTRA Flugzeugbau GmbH.




21-20-00 DISTRIBUTION

Description

Valid for Serial - No. 20 following For better ventilation in the forward cabin section two vent fans (Micronel type D603L-024KA-3) are installed in the LH and RH side of the instrument panel. Each vent fan sucks air through a composite tube from the lower side of the panel shelf. On the blow side each vent fan is connected to a vent grid, which can be adjusted to either direct or shut off the air flow. Two jiggle switches (marked 0/1), placed on the instrument panel near the resp. air outlet, control the vent fans. The electric fan motors are protected by a 1A - fuse each.

21-20-01 Panel Vent Fans Valid for Serial - No. 20 following

CAUTION With some installations, it might not be required to remove the main panel completely, depending on individual wire and hose length. Take care not to damage instrument wiring and gyro air hoses.

Removal (Pilot’s Side)

Detail Steps/Work Items Key Items

Main Panel Removal

1 Remove 8 Phillips screws around left main panel

2 Remove 4 Phillips screws securing EHSI ED - 461 to panel

3 Remove 4 Phillips screws securing EADI ED - 462 to panel

4 Slightly swivel down left main panel Take care not to damage flexible hoses and electrical wiring

5 Disconnect illumination wires on instru-ments without D-Sub-Connections

6 Disconnect D-Sub-Connection on Warning Panel

7 Disconnect D-Sub-Connection on Fuel Flow Indicator

8 Disconnect electrical wiring on OAT Indicator

9 Disconnect DME Hold Switch





10 Disconnect electrical wiring on Turn Coordinator

11 Disconnect electrical wiring on Slaving Control KA - 51 B

12 Disconnect wiring from Amperemeter (prop de- ice)

Molex plug

13 Unscrew flexible hose on Manifold / Fuel Pressure Gauge

14 Pull off pitot and static hoses from Airspeed Indicator

15 Pull off static hose to Altimeter at T-fitting next to Altimeter

16 Pull off static hose to Vertical Speed Indicator at T-fitting next to Vertical Speed Indicator

17 Remove main panel completely

Vent Fan Removal

18 Carefully remove vent grid from panel Use a lever to pull out four guide lugs at the edges

19 Remove composite tube from vent fan back side

Loosen clamp

20 Cut off two electrical wires about 5…10 inches from fan connection or de-solder wires from fan connection

Sign connection

21 Loosen 4 Allen bolts and nuts securing fan to LH panel corner

22 Remove vent fan inclined backwards

Installation (Pilot’s Side)


Vent Fan Installation

1 Move fan to back side of LH panel corner

2 Install 4 Allen bolts and nuts securing fan to panel

3 Re-solder electrical wires to fan connection





4 Lead composite tube from underside of instrument shelf to vent fan back side. Install tube with clamp.

5 Snap vent grid into panel

Main Panel Installation

6 Move left main panel in reach of connections

7 Connect D-Sub-Connections on Warning Panel

8 Connect D-Sub-Connections on Fuel Flow Indicator

9 Connect electrical wiring to OAT Indicator

10 Connect DME Hold Switch

11 Connect electrical wiring to Turn Coor-dinator

12 Connect electrical wiring to Slaving Control KA - 51 B

13 Connect Molex - plug to Amperemeter (prop de- ice)

14 Connect illumination wires to instruments without D-Sub-Connections

15 Connect flexible hose to Manifold / Fuel Pressure Gauge

16 Connect pitot and static hoses to Airspeed Indicator

17 Connect Altimeter static hose to T-fitting

18 Connect Vertical Speed Indicator static hose to T-fitting

19 Insert panel into instrument shelf Take care not to damage flexible hoses and electrical wiring

20 Re- install Phillips screws to panel

21 Re- install Phillips screws to ED - 461

22 Re- install Phillips screws to ED - 462




Removal (Copilot’s Side)


1 Remove 8 Phillips screws around right main panel

2 Slightly swivel down right main panel Take care not to damage flexible hoses and electrical wiring

3 Remove two 37-pin-connections from Annunciator Panel

4 Remove 30-pin-connection from KNI-204 VOR/LOC and Glide Slope Indicator

5 Pull off static and pitot hoses from Airspeed Indicator

6 Disconnect wiring from Airspeed Indicator Molex plug

7 Pull off static hose from Altimeter

8 Disconnect wiring from Altimeter Molex plug

9 Remove Vac., Gage and Air Inlet hoses from Sigma Tek 5000 Vacuum Horizon

10 Disconnect wiring from Sigma Tek 5000 Vacuum Horizon

Molex plug

11 Remove Vac., Gage and Air Inlet hoses from Sigma Tek 4000 Directional Gyro

12 Disconnect wiring from Sigma Tek 4000 Directional Gyro

Molex plug

13 Remove 3 single pin connections from Coolant Temperature Gage

14 Remove 4 single pin connections from CHT/EGT Gage

15 Remove 5 single pin connections from Oil Temperature / Oil Pressure Gage

16 Remove 2 single pin connections from TIT Gage

17 Remove 2 single plugs and 1 triple plug from LH Fuel Quantity Gage

18 Remove 2 single plugs and 1 triple plug from RH Fuel Quantity Gage





19 Remove 2 screwed cable clamps (+, -) from Ammeter

20 Remove 2 screwed cable clamps (+, -) from Voltmeter

21 Remove 4 air hoses Vent, Vac, R, L from Dual Suction Gage

22 Remove main panel completely

Vent Fan Removal

23 Carefully remove vent grid from panel Use a lever to pull out four guide lugs at the edges

24 Remove composite tube from vent fan back side

Loosen clamp

25 Cut off two electrical wires about 5…10 inches from fan connection or de-solder wires from fan connection

Sign connection

26 Loosen 4 Allen bolts and nuts securing fan to LH panel corner

27 Remove vent fan inclined backwards

Installation (Copilot’s Side)


Vent Fan Installation

1 Position fan to back side of RH panel corner

2 Install 4 Allen bolts and nuts securing fan to panel

3 Re-solder electrical wires to fan connection

4 Lead composite tube from underside of instrument shelf to vent fan back side. Install tube with clamp.

5 Snap vent grid into panel

Main Panel Installation

6 Move right main panel in reach of instrument connections

7 Screw cable clamps (+,-) to Voltmeter

8 Screw cable clamps (+,-) to Ammeter





9 Install single plugs and triple plug to LH Fuel Quantity Gage

10 Install single plugs and triple plug to RH Fuel Quantity Gage

11 Install 2 single pin connections to TIT Gage

12 Install 5 single pin connections to Oil Temperature / Oil Pressure Gage

13 Install 4 single pin connections to CHT / EGT Gage

14 Install 3 single pin connections to Coolant Temperature Gage

15 Connect Molex plug to Sigma Tek 4000 Directional Gyro

16 Install Vac., Gage and Air Inlet hoses to Sigma Tek 4000 Directional Gyro

17 Connect Molex plug to Sigma Tek 5000 Vacuum Horizon

18 Install Vac., Gage and Air Inlet hoses to Sigma Tek 5000 Vacuum Horizon

19 Install 4 air hoses Vent, Vac, R, L to Dual Suction Gage

20 Connect static hose with Altimeter

21 Connect Molex plug to Altimeter

22 Connect static and pitot hoses with Airspeed Indicator

23 Connect Molex plug to Airspeed Indicator

24 Install 30-pin-connection to KNI-204 VOR/LOC and Glide Slope Indicator

25 Install two 37-pin-connections to Annunciator Panel

26 Insert panel into instrument shelf Take care not to damage flexible hoses and electrical wiring

27 Re- install Phillips screws to panel




21-30-00 PRESSURIZATION CONTROL

Description

The system consists of the engine turbocharger, a sonic venturi (flow limiter), a cabin control outflow valve, an unregulated safety valve, the cabin pressurization switch, the cabin pressure controller, a dump safety switch, the landing gear squat switch, and two indicators, one for cabin altitude and differential pressure and one for cabin rate-of-climb.

Pressurization air is supplied from the engine turbocharger through the sonic venturi and then through a check valve into the cabin. Adequate flow to maintain pressurization up to the maximum differential pressure of 5.5 PSI is provided by the engine at normal power setting. Power changes should be made smoothly to prevent sudden changes in pressurization air inflow resulting in cabin pressure transients.

The airplane may be operated in either the pressurized or depressurized mode. The mode selection is made with the cabin pressurization switch, which either opens the safety valve for depressurized mode, or closes the safety valve and thus activating the cabin control outflow valve for pressurized mode, on condition that pressurized air is selected on the cabin air knob and the dump safety switch is in OFF-position. Mode operation should be selected prior to takeoff. If a change from pressurized to depressurized mode must be made while airborne, depressurize the cabin following the procedure given below before turning the dump switch as otherwise a rapid decompression occurs, which would cause discomfort to the passengers. When changing from unpressurized to pressurized mode, the cabin altitude rate of change will be limited by the pressurization controller. The valves are also opened by the landing gear squat switch assuring depressurized mode when aircraft is on ground to avoid bursting the cabin door due to cabin pressure when opening. However this is only a safety device: landing in pressurized mode is prohibited !

In the pressurized mode cabin pressure is regulated by the cabin control outflow valve allowing air to exhaust either to the pressure level preselected by the cabin pressure controller or to maximum differential pressure level. Setting the center dial (identified as “Flight Level”) of the cabin pressure controller will suggest the system being at a certain flight altitude. So the system will maintain the corresponding cabin altitude (about 5.5 PSI above static pressure of flight level) or reach it with the rate set by the rate control knob located on the lower left corner of the pressurization controller. Only in case of maximum differential pressure is reached or flight level is below the selected cabin altitude, cabin altitude changes with the same rate the flight altitude does.

In case of failure of the cabin outflow control valve the safety valve will open at a differential pressure of slightly above 5.5 PSI to avoid structure damage.




Handling

Use the cabin pressure controller as follows. Also refer to the sample chart (Figure 21-02).

1 Activate the pressurization controller by turning on the cabin pressurization switch. Make sure that the dump switch is off and the pressurized cabin air is selected.

2 Set the published official airport altitude (such as shown on flight charts) under the index arrow by turning the center control knob.

3 Turn the index arrow of the rate control knob (lower left corner of the control) to the 12 o’clock position (approx. 500 fpm). These steps set the system to pressurize at approximately 700 feet above the runway after takeoff. The system will hold this cabin altitude until the maximum differential altitude is reached (see “Cabin Altitude with minimum Flight Level Setting” line of Figure 21-02) or a different cabin pressure is selected.

4 After having cleared the airport area and established the climb and being on course to the destination (see “a” on Figure 21-02), select the flight level corresponding to the intended cruise altitude in the center dial and align that with the index arrow. This alignment also indicates the approximate cabin altitude (within approx. 700 feet) at the index on the larger numbers marked “Airport Alt.”.

5 Increase or decrease the rate at which the cabin changes altitude for the best comfort level from normally 500 fpm by turning the rate knob counter clockwise for decreasing or clockwise for increasing the rate. Usually it is the best method to set the rate to reach the changed cabin pressure (referenced from the “Airport Alt.”) slightly ahead of reaching the cruising altitude (550 fpm in the sample of Figure 21-02). This selected altitude will be maintained until the aircraft changes altitude sufficiently to reach the max. differential pressure or descends sufficiently to go below the selected airport altitude.

6 When the aircraft reaches the proximity of the destination and starts to descent (see “b” on Figure 21-02), set the selector knob to the published airport altitude.

7 Set the rate so that the selected airport altitude is reached in the cabin prior to descending to that altitude (650 fpm in the sample of Figure 21-02). When approaching the runway, the pressurization will cease approximately 700 feet above the landing prior to landing. Should any slight pressure remain, the remainder will dump when the squat switch closes. However, this is an additionally safety device, because landing with cabin pressurized is not allowed.

CAUTION If pressurization mode shall be finished during flight, follow the procedure above, setting the airport altitude equal to the momentary flight altitude. Switch to the depressurized mode not before the selected airport altitude is reached.




Figure 21-02 Cabin Pressurization Sample Chart





For removal and installation of pressurization system components, contact EXTRA Flugzeugbau GmbH.

21-30-01 Cabin Outflow Control Valve Filter Replacement


1 Gain access to the inner side of the rear pressure bulkhead by removing the aft cabin liner

2 Loosen the filter retention screw on the control outflow valve housing until the filter flange is free to rotate. It is not necessary to remove the screw entirely.

3 Rotate the filter until the flat on the filter clears the screw head.

4 Remove the filter cartridge and replace with new one.

5 Rotate the filter so filter flange is captured by the screw head.

6 Tighten filter retaining screw.

21-30-02 Cabin Outflow Control Valve The valve is attached to the LH side of the pressure dome.



Removal

1 Remove upper half of rear baggage compartment wall

Machine screws AN 526 10-32

2 Remove tail cone access panel on LH fuselage side

3 Remove valve flange from pressure dome 8 stop nuts MS 21044 AN3 with washers AN960 – 10L (3/8 inch.)





4 Remove 2 overflow tubes 9/16 fitting; retain with 11/16 wrench at pressure dome fitting

5 Lift up valve from pressure dome

Installation

Install in reverse sequence of removal

21-30-03 Safety Valve The valve is attached to the RH side of the pressure dome.



Removal

1 Remove upper half of rear baggage compartment wall

Machine screws AN 526 10-32

2 Remove tail cone access panel on LH fuselage side

3 Remove battery Refer to Ch. 24-30-01

3 Remove valve flange from pressure dome 8 stop nuts MS 21044 AN3 with washers AN960 – 10L (3/8 inch.)

4 Remove 2 overflow tubes 9/16 fitting; retain with 11/16 wrench at pressure dome fitting

5 Lift up valve from pressure dome

Installation

Install in reverse sequence of removal

NOTE Verify that blind plug at vacuum port is installed correctly. With installed valve, the vacuum port is accessible behind the rear baggage compartment wall.




21-60-00 TEMPERATURE CONTROL

Description

If pressurized air is selected the temperature mainly can be regulated by means of the cabin cooler bypass valve controlled by the cabin temperature knob located on the middle console. Additional regulating is possible by either activating the electric heater or by switching on or off the air conditioning system and changing the operation mode of the cabin ventilation.

Note The heater and the air conditioning system operate only if cabin ventilation is running at least in low mode.

If ram air is selected the cabin temperature knob has no function.

Documents

Chapter 21 Air Conditioning - Extra Aircraft · 2015-05-27 · Maintenance Manual and Illustrated Parts Catalogue Extra EA-400 Air Conditioning Page Date: 13. July 2001 21 Page 5