Supplemental Type Certificate for the Cessna 208 Caravan

switch in the auxiliary pneumatic system and illuminates a blue light when the auxiliary pump is operating and creating a in the system. When the auxiliary pump is activated at high altitude, or if the system has developed air leaks, the AUX ON light may fail to illuminate. This indicates that the system vacuum is still below the AUX ON switch activation level, though the auxiliary pump is operating. The annunciator lights do not incorporate a press-to-test feature. Refer to SECTION VIII for lamp test and replacement. vacuum even System electrical protection is provided by a 15 amp circuit breaker in the pump motor circuit and a 2 amp circuit breaker in. the annunciator light circuit. The circuit breakers are located on the left side of the power box forward of the firewall. The auxiliary pump is mounted on the upper right forward side of the firewall. The auxiliary system connects to the primary system at a manifold downstream of the relief valve. Isolation of the primary and auxiliary systems from each other is accomplished by check valves on each side of the manifold. The primary system switch is located on the vacuum ejector side of the manifold and senses vacuum supplied to the gyros. The auxiliary system vacuum switch is located in the manifold downstream of the check valve and senses vacuum generated by the auxiliary pump. 43131 2404 Merrill Field Drive Anchorage, Alaska 99501 (907) 274-6166 In order to assure high reliability of the auxiliary air pump system, as a back-up power supply for the gyro instruments, the pump/motor assembly must be removed and replaced after 500 hours accumulated pump operating time or 10 years installed time, which-ever comes first. An elapsed time indicator (ETI) is incorporated into the auxiliary pump electrical system to show accumulated hours of operation. Refer to the Aero Twin Auxiliary Dry Air Pump Kit No. AP8100 Installation and Maintenance Instructions (Manual AP81M) for testing and servicing procedures. SECTION II-LIMITATIONS A. Operating Limits Flight in Instrument Meteorological Conditions (IMC) by reference to vacuum powered instruments is prohibited when vacuum gage indicator is not in the green arc range (4.5 to 5.5 inches mercury). B. Placards Above the switch/wire assembly, P/N AP8-40, on lower left side of the instrument panel: AUX VAC PUSH ON-OFF SECTION III -EMERGENCY PROCEDURES No change -Except: A. Engine Driven Vacuum Pump Failure 1. Vacuum Gage Registers Zero, VAC OFF Light Illuminated a. Turn on auxiliary air pump. FAA APPROVED Rev: A, Date: MAR 11 2003 FAA APPROVED Page 3 of 9 Rev: A, Date: MAR 11 2003 Page 4 of 9 2404 Merrill Field Drive Anchorage, Alaska 99501 (907) 274-6166 A. Engine Driven Vacuum Pump Failure (Continued) b. Verify that the vacuum gage registers in the green arc, the "AUX ON" light is illuminated, and the annunciator panel "VAC LOW" light is extinguished. NOTE The vacuum gage is the primary indicator of the system operational condition. Since the annunciator lights may have burned out bulbs they should not be relied on to indicate actual system condition. c. Verify that alternator capacity is not being exceeded as indicated by ammeter showing discharge and/or illumination of the voltage low light. Turn off non- essential electrical equipment. d. Continue normal operation. Have vacuum system serviced prior to next flight. 2. Auxiliary Pump On, Vacuum Gage Registers Below Green Arc May occur at high altitude or if system is leaking. a. b. C. Disengage the autopilot. Decrease altitude at a normal rate until the vacuum gage registers in the green arc. NOTE With the auxiliary pump on, even though the vacuum gage registers below the green arc, several minutes may be available before the attitude and directional indicators become unreliable. green arc until During descent, the is obtained, cross-check the attitude and directional indicators with the electrically powered turn coordinator or turn, bank indicator and magnetic compass. If reliability of the attitude gyro and directional gyro indicators is suspect, follow the procedures for Emergency Operation in Clouds in Section 3 (Vacuum System Failure) of the Basic Airplane Flight Manual. 2404 Merrill Field Drive Anchorage, Alaska 99501 (907) 274-6166 2. Auxiliary Pump On, Vacuum Gage Registers Below Green Arc (Continued) d. Re-engage the autopilot if desired and continue normal operation. Have vacuum system serviced prior to next flight. B. Auxiliary Air Pump System Failure (bleed air system previously failed) 1. Vacuum zero, "VAC OFF" light is registers gage the "AUX ON" light is extinguished and illuminated, the "VAC LOW" light is illuminated. a. Disengage the autopilot. b. If the failure occurs under IFR flight conditions follow Aircraft Flight Manual procedures for Emergency Operations in Clouds until reaching VFR flight conditions. c. Maintain VFR flight conditions until landing. d. Have primary and auxiliary vacuum system serviced prior to next flight. SECTION IV- NORMAL PROCEDURES described below, refer to If the system does not function as SECTION VIII of this Supplement for service information. A. Preflight The following functional check of the auxiliary air pump system is recommended prior to each instrument flight. 1. Turn on battery switch. Verify the "VAC OFF" and "VAC LOW" lights are illuminated. NOTE To prevent battery drain, operation of the auxiliary weather prior to in cold pump starting the engine is not recommended. 2. Start engine. Set power lever to 400 Ft.-Lbs. Verify "VAC OFF" and "VAC LOW" lights are extinguished and vacuum gage registers in the green arc. FAA APPROVED Rev: A, Date: MAR 11 ZUUS FAA APPROVED Page 5 of 9 Rev: A, Date: MAR 11 2003 Page 6 of 9 B. 2404 Merrill Field Drive Anchorage, Alaska 99501 (907) 274-6166 AERO TWIN, INC. 2404 Merrill Field Drive Anchorage, Alaska 99501 (907) 274-6166 SECTION VI- WEIGHT AND BALANCE/EQUIPMENT LIST A. Preflight (Continued) 3. Turn on auxiliary pump. illuminated. Verify "AUX ON" light is 4. Turn off auxiliary air pump. extinguished. Verify "AUX ON" light is NOTE In warm weather, with a fully charged battery, auxiliary pump operation may be checked prior to engine startup. Keep running time short to avoid excessive drain. Operation in Flight battery The auxiliary air pump system may be functionally checked in flight as follows: 1. Turn off non-essential electrical equipment as necessary to avoid exceeding the alternator capacity and draining the battery. 2. Turn on auxiliary air pump. Verify the "AUX ON" light is illuminated, and suction gage registers in the green arc. The suction gage should show a slight increase when the auxiliary pump is turned on. 3. Turn off auxiliary air pump. 4. Turn back on all desired electrical equipment. NOTE For maximum service life, avoid continuous non-emergency operation of the auxiliary air pump. SECTION V- PERFORMANCE No change. ITEM WT. (lbs.) Arm (inches) 99.1 Auxiliary Dry Air Pump, 13.6 Kit Number AP8-100 Refer to the Aero Twin Auxiliary Dry Air Pump Kit No. AP8-100 Installation and Maintenance Instructions (Manual AP8-1M) for detailed equipment list. SECTION VII-AIRPLANE AND SYSTEM DESCRIPTION Refer to Section I of this supplement and the instructions for continuing airworthiness. SECTION VIII-AIRPLANE HANDLING, SERVICE AND MAINTENANCE For other pneumatic and electrical system schematics, and test and service procedures, refer to the Aero Twin Auxiliary Dry Air Pump Kit No. AP8-100 Installation and Maintenance Instructions (Manual AP8-1M). A. Annuciator Lamp Test and Replacement Referring to SECTION IV NORMAL PROCEDURES, if the annunciator lights do not illuminate as expected, check for burned-out lamps, replace as required and retest the system. The annunciator lamps are sub-miniature T-13/4 wedge base (commercial type e5) bulbs. To replace the lamps, pull the legend button off the switch and eject the lamps by pulling on the release tabs. Reset the release tabs, insert new lamps and press the switch button back into place. NOTE The wedge base T-1 3/4 annunciator lamps are not interchangeable with the flange base MS25237-327 lamps used in other aircraft lights. It is recommended that spare lamps and fuses for the auxiliary pump system be carried in the aircraft. air FAA APPROVED Rev: A, Date: MAR 11 2003 Page 7 of 9 FAA APPROVED Rev: A, Date: MAR 11 2003 Page 8 of 9 AERO TWIN, INC. 2404 Merrill Field Drive Anchorage, Alaska 99501 (907) 274-6166 B. Pump Motor and Annunciator Circuit Replacement NOTE Blown circuit breakers may indicate electrical shorts or other problems. Inspect the auxiliary pump system for defects and repair as necessary. C. Auxiliary Pump Assembly Service Time Limit The auxiliary pump assembly P/N: AA4A2-1 must be removed and replaced at 500 hours accumulated operating or 10 years installed time, whichever occurs first. Accumulated operating time is established by the elapsed time indicator located under/behind the instrument panel. Refer to the Aero Twin Auxiliary Dry Air Pump Kit No. AP8-100 Instructions for Continued Airworthiness for details. D. Infrequent Use of Aircraft or Auxiliary Air Pump If the aircraft has been idle or the auxiliary vacuum pump has not been used for six months or more, refer to the Aero Twin Auxiliary Dry Air Pump Kit Instructions for Continued Airworthiness for special check-out procedures prior to IFR flight. SECTION IX- SUPPLEMENTS This supplement must be attached to the basic Pilots Operating Handbook and FAA Approved Flight Manual. FAA APPROVED Rev: A, Date: MAR 11 2003 Page 9 of 9 AERO TWIN, INC. Auxiliary Dry Air Pump Kit No. AP8-100 INSTALLATION INSTRUCTIONS Aero Twin, Inc. Document No. AP8-1M Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M NO. REVISIONS DATE LOG OF REVISIONS PAGES REVISED AND DESCRIPTION OF REVISIONS 04/20/90 Original Issue A 01/10/98 All pages revised and reissued per ECO AT-50. All pages dated January 10, 1998. B 06/08/01 All pages revised and reissued per ECO AT-68. All pages dated June 8, 2001. 0 10/15/02 D 05-22-03 APPROVAL SIGNATURE All pages revised and reissued per ECO AT-79. All pages dated October 15, 2002. All pages revised and reissued per ECO AT-91. All M. pages dated May 5, 2003. Page 2 of 13 Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 SEC TITLE Log of Revisions Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M Table of Contents Page 2 Table of Contents I. GENERAL INFORMATION A. Kit Description………………………….. B. Performance Specifications...... C. Ownership Registration and Document Revision Service..... INSTALLATION 4 .4 ..4 .4 5 II. A. General Notes...... B. Preparation to Begin Installation........ C. Vacuum Component Installation D. Electrical Component Installation III. A. General Notes......... SYSTEM ADJUSTMENT AND OPERATIONAL TESTS B. Vacuum Relief Valve Setting/Adjustment. .5 .5 .5 6 .7 C. Auxiliary Air Pump Functional Check (without Engine Power). .7 IV. D. Auxiliary Air Pump Functional Check - Engine running. E. Check aircraft total electrical load with Aux. Vacuum System on, engine running F. Check magnetic compass deviation. WEIGHT AND BALANCE .7 .8 .10 11 V. INSTALLATION PARTS LIST 12 Page 3 of 13 Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M SECTION I- GENERAL INFORMATION A. Kit Description: The auxiliary dry air pump system provides an independent backup vacuum source to operate the gyro flight instruments in the event that the bleed air vacuum system fails. The kit consists of a 28 VDC electrically driven dry air pump, connected to the primary pneumatic system through a manifold downstream of the vacuum relief valve. Isolation of the auxiliary from the primary system is provided by check valves in the manifold. The pump is controlled through a panel mounted switch, which incorporates annunciator lights to inform the pilot of the system operation status. Accumulated pump operation time (for compliance with in-service time limit) is recorded by an elapsed time indicator (ETI) that is attached to the pump-mounting bracket. For a complete operational description of the auxiliary pump system, refer to the AFM/POH Supplement supplied with the kit. B. Performance Specifications: The auxiliary pump system is designed to provide sufficient vacuum to power two gyroscopic flight instruments. In a normal installation, the auxiliary pump system can maintain a minimum of 4.6 in. Hg. vacuum across the gyros to an altitude of at least 24,000 feet. Note: Poor system installations and maintenance practices will reduce the maximum altitude at which a given vacuum can be obtained. The system electrical power requirement is 9.0 amperes at 28 VDC. In-service time for the AA4A2-1 auxiliary pump/motor assembly is limited to 500 hours actual pump operating time (established by the elapsed time indicator) or 10 years, whichever occurs first. Under normal usage, 500 hours of pump operating time is equivalent to 8000 or more aircraft operating hours. The vacuum pump must be running to read the accumulated time on the elapsed time indictor. C. Ownership Registration and Document Revision Service: FAR 21.50(b) and 23.1529 require that the manufacturer of a product establish a procedure to notify aircraft owners of changes to FAA approved maintenance documents. Aero Twin, Inc. is complying with these regulations by providing a Warranty Registration and Service Letter Program. A warranty registration card is included in each Kit Number AP8-100. This card must be filled out and returned to Aero Twin, Inc. so that the aircraft owner can be supplied with any important information related to the auxiliary air pump kit installed in his aircraft. Page 4 of 13 Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M SECTION II - INSTALLATION A. General Notes: 1. Certain parts of this installation can be difficult. We recommend that the most experienced mechanics available be assigned to the task. Wiring experience is particularly important. 2. Read all directions and review the complete installation drawing package prior to beginning. If there are any questions, contact Aero Twin at (907)274-6166. 3. The function and reliability of your auxiliary vacuum system will be directly related to the quality of the installation. 4. PRIOR TO DRILLING ANY HOLES, CONFIRM CLEARANCE ON THE BACK SIDE OF THE SURFACE TO BE DRILLED. This is particularly important when drilling through the firewall. B. Preparation to Begin Installation: 1. Remove cowlings 2. Disconnect battery 3. Remove pilot and copilot seats C. Vacuum Component Installation per Drawing AP8-21, sheets 1 through 6 of 6: 1. Sheet 1: Vacuum System Schematic. Review this prior to proceeding. 2. Sheet 2: Locate the position for the pump bracket and drill out six existing rivets in the firewall. Locate and drill three 7/8" diameter holes. 3. Sheet 3: With the bracket assembly held in position, match drill the bracket to the six mounting holes opened in the firewall. Drill two additional mounting holes through the bracket and the firewall, then install the bracket. 4. Sheet 4: Install the pump and contactor on the bracket. Make electrical connections to the pump and contactor. 5. Sheet 5: Install two fittings through the firewall; relocate the existing vacuum relief valve to the right-most fitting and reroute the instrument vacuum hoses as required. Install the supplied vacuum hose assembly between the bleed air ejector fitting and the second new fitting. 6. Sheet 6: Install the supplied fittings in the pump inlet and outlet ports. Install the vacuum manifold on the manifold bracket using two large cable ties (provided). Cut and install four hoses and one 180° tube bend as shown on the drawing. Note that the hose which loops from the pump inlet to the manifold is best routed around the engine mount tube as shown in the drawing; use the supplied Adel clamps to secure the hose to the upper mount tube. D. Electrical Component Installation per Drawing AP8-WI, sheets 1 though 5 of 5: 1. Sheet 1: Electrical System Schematic. Review this prior to proceeding. 2. Sheet 2: Locate an appropriate position on the panel for the system control switch. If the recommended position is used, it may be necessary to relocate one post light. Cut a rectangular hole as specified and install the switch can, placards*, and switch assembly. Install the ETI assembly to the pump-mounting bracket. Page 5 of 13 Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M *The load reduction caution placard will be installed only if needed, to be determined during system operational tests. At this point you should allow for sufficient panel space to install the placard if required. 3. Sheet 3: Install the four-pin receptacle in the third 7/8" diameter hole. Thread wires 372-37B, 372-35B, and 372-21B through the clamp crown/boot assembly, trim to length, and solder to the appropriate terminals of the receptacle. Secure the clamp crown/boot to the receptacle and secure all wires under the panel. 4. Sheet 4: Install the circuit breakers and doubler in the electrical box, and make all required electrical connections. Wire loom installed over the wires exiting the electrical box should extend into the box slightly - the box cover will retain the loom. 5. Sheet 5: Make electrical connections to the manifold. Complete the electrical installation by connecting the 4-pin firewall connector. Perform a thorough continuity check of all wiring, using the system schematic as a reference. When system continuity is verified, install loom over all exposed wiring forward of the firewall, to match existing engine wiring. Secure each end of loom and at 12 inch intervals using small cable ties supplied in kit. Recheck that all vacuum fittings are secure. Reconnect Battery. Reinstall Pilot's seat. When you are satisfied that the installation is complete and correct, proceed to system operational tests. SECTION III: SYSTEM ADJUSTMENT AND OPERATIONAL TESTS A. General Notes: The following items need to be done to confirm system functionality and potential effect on other aircraft systems (each is described in detail in the following paragraphs): Check/Adjust vacuum relief valve setting Check Aux. Vacuum System function with engine off • Check Aux. Vacuum System function with engine running • Check aircraft total electrical load with Aux. Vacuum System on, engine running • Check magnetic compass deviation Prior to proceeding, it is important to understand the function of the vacuum switches that are part of this installation. Both switches are mounted on the manifold. The "VAC-OFF" switch is a normally closed switch that activates the "VAC-OFF" annunciator on the aux system control switch. This switch senses vacuum condition in the instrument circuit. When bleed air powered ejector vacuum to the instruments is greater than 3 inches of mercury, the switch will open and the "VAC-OFF” light will turn off. This light can ‘flicker' if the vacuum level is near the 3 inch activation level (this can occur at low idle power settings). The "VAC-ON" switch is a normally open switch that activates the "VAC-ON" annunciator on the aux system control switch. This switch senses vacuum condition on the auxiliary pump side of the manifold. When the aux pump is supplying vacuum, the switch will close, illuminating the "VAC- ON" annunciator. Page 6 of 13 Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M B. Vacuum Relief Valve Setting/Adjustment: The aircraft vacuum relief valve should be set, with the engine operating at 68% Ng, so that the suction gauge reads 5.0 inches of mercury. Adjust the system as required, in accordance with the FAA Approved Maintenance Manual for the aircraft C. Auxiliary Air Pump Functional Check (without Engine Power) Note: If it is required to run auxiliary pump for more than a couple of minutes, it is recommended that the aircraft be connected to an APU. 1. Turn aircraft battery switch “ON”. 2. The "VAC OFF” side of auxiliary dry air pump switch should be illuminated (indicating that ejector vacuum is under 3 inches of mercury). This annunciator should remain illuminated when ever the engine is not running. If not, trace the system wiring to locate the problem. 3. Push the auxiliary dry air pump switch to cycle it to the “ON” position. Switch will stay partially depressed. Do not run the auxiliary pump for more than a couple of minutes unless an APU is connected. 4. Auxiliary pump “AUX ON” light should be illuminated (indicating that the auxiliary system is drawing vacuum). If the light does not illuminate, check that the pump is actually running. If not, trace the wiring to determine the problem. If the pump is running, check for vacuum leaks. 5. The annunciator panel “VAC LOW” light should cycle off shortly after pump is turned on (indicating that vacuum in the system is greater than 3 inches of mercury). 6. Check suction gauge for proper system vacuum- 4.5 to 5.5 inches of mercury. 7. Push the auxiliary vacuum switch to cycle to the "OFF" position. 8. The auxiliary pump “AUX ON" light should cycle off. 9. The "VAC OFF" light should remain illuminated. 10. Turn the aircraft battery switch “OFF”. D. Auxiliary Air Pump Functional Check - Engine running 1. Start Engine. 2. Set power lever to 400 Ft.-Lbs. 3. Check to see that the "VAC OFF" light in the auxiliary pump switch is not illuminated and that the vacuum gauge reads 4.5 to 5.5 inches of mercury. If not, repair the vacuum system. Page 7 of 13 Rev: D, Dated: May 22, 2003 Aero Twin, Inc. 2404 Merrill Field Drive Anchorage, Alaska 99501 Auxiliary Dry Air Pump Kit No. AP8-100 Installation Instructions Doc. No. AP8-1M 4. Turn the auxiliary vacuum pump on. 5. Check the "AUX ON" light for illumination. 6. Check to see that the "VAC OFF" light is still not illuminated and that the suction gauge still reads 4.5 to 5.5 inches of mercury. 7. Set power lever to idle. 8. Turn auxiliary pump off. 9. Shut engine down. E. Check aircraft total electrical load with Aux. Vacuum System on, engine running The ability of the aircraft electrical system to accept the additional load of the auxiliary pump must be checked as follows. 1. Start Engine 2. Turn on all electrical and avionics equipment that would normally be in continuous use the most critical flight condition (IFR, night, icing equipment): • Battery Switch - CHECK ON. • Avionics No. 1 and No. 2 Power switch - CHECK ON. • Radios ON. - • Navigational Lights, Strobe lights, and Flashing Beacon (if installed) - ON. • Panel Lights, Night - ON. • Seat Belt On and No Smoking Lights - ON. • Pitot static Heat - ON. • Stall Heat-ON. . Wing Light - ON. • Windshield Heat - ON. Propeller Heat - ON. Bleed Air Heat - ON. • Circuit Breakers - CHECK IN. Page 8 of 13 Rev: D, Dated: May 22, 2003