Servicing

 

TTP	B1-L1	ATA12
Beech 90 Series	B2-L1	Servicing

               
Tires When inflating the tires, inspect for cuts, cracks, breaks, and tread wear. The pressure of a serviceable tire that is fully inflated should not drop more than 5% over a 24-hour period.

Check the tires daily for proper inflation on aircraft performing more than one flight a day. Other aircraft should be checked before each flight and  at  least  once  a  week. Tire  pressure should be checked only when the tires are cool; consequently, wait at least two hours (three hours in hot weather) after a flight before checking tire pressure.
Main landing gear - 8-ply at 55 ± 3 psi, 10-ply at 70 ± 3 psi
Nose landing gear - 53 ± 2 psi

External Power Use only an auxiliary power source that is negatively grounded.

Before connecting the external power unit, turn off all radio equipment and generator switches, but leave the battery on to protect transistorized equipment against transient voltage spikes.

If the battery voltage indicates less than 20-VDC, the battery must be recharged or replaced with a battery indicating 20-VDC or greater before using auxiliary power.

Compressor Washing

There are two types of compressor washing; desalination wash and performance recovery wash.

The desalination wash is used to remove salt deposits while the performance recovery wash is used to remove baked-on deposits. 

  1.     Install cleaning equipment.

  

2.     Motor engine for 30 seconds while injecting wash mixture.

 

3.     Allow starter-generator to cool down for 15 minutes.

 

4.     Motor engine for 30 seconds.

 

5.     Allow starter-generator to cool down for 30 minutes.

 

6.     Remove cleaning equipment and reconnect compressor bleed air and the P3 air filter.

 

7.     Start engine.

CAUTION

 

Any time the engine compressor is washed,  both  the  compressor  bleed air line and the P3 air line to the fuel control unit must be capped off. 

Performance Recovery Wash Procedures

1.     Install cleaning equipment.

 

2.     Motor engine for 30 seconds while injecting wash mixture.

 

3.     Allow starter-generator to cool down and the cleaning solution to soak for 30 minutes.

 

4.     Motor engine for 30 seconds while injecting rinse mixture.

 

5.     Allow starter-generator to cool down for 15 minutes.

 

6.     Motor engine for 30 seconds while injecting rinse mixture.

 

7.     Allow starter-generator to cool down for 30 minutes.

 

8.     Motor engine for 30 seconds.

 

9.     Allow starter-generator to cool down for 15 minutes.

10.   Remove cleaning equipment and reconnect compressor bleed air and the P3 air filter.

 

11.   Start engine.

Before any external  engine washing, cover or protect all electrical components and plugs on the engine or in the engine compartment. Do not allow water to enter the engine air inlet or exhaust. High pressure water or solvent should not be directed on electrical components or mechanical parts having air vent holes. After washing the engine, blow dry the components with dry shop air.

Aircraft Exterior Prior to washing, attach the pitot cover securely and plug or mask off all other openings. Be particularly careful to mask off all static air buttons before washing or waxing. Use special care to avoid washing away grease from any lubricated area.  Prior  to  cleaning,  cover  such  areas  as wheels, brakes, etc., and lubricate as necessary after cleaning.To reduce the possibility of corrosion and to prolong battery service life, cover battery vents when washing the aircraft.

Always be sure all maskings and coverings are removed before returning the air- craft to service.

The urethane finish undergoes a curing process for a period of time after application. During the first month after paint application, some special care is required.

Clean the aircraft with mild detergents and water only.

Use only soft clean rags, keeping the rag free from dirt and grime. Rinse the rag often using clear water.

Remove stubborn oil or soot deposits from the cowlings, wheel wells etc. by gently using an automotive tar remover.

Normally, waxing is not necessary. However, the surface may be kept waxed as a means of protecting against acid rain and ultraviolet damage if exposure to these elements is unavoidable.

Pressurization System

Fluctuation  of  cabin  pressure  often  indicates dirty  outflow  and/or  safety  valve  poppet  and seat or safety valve filter. Inspect and clean the seats of the valves at the specified intervals or more  frequently  as  needed.  

Use a suitable liquid dispenser filled with Joy® detergent and water or with isopropyl alcohol, and flush the valve poppet, seat, and noise suppression screen. It may be necessary to remove the noise suppression screen and wipe the poppet and seat with a clean rag dampened with Joy® detergent and water or with isopropyl alcohol. When the filter is cleaned regularly and is not subjected to severe residue deposits, the filter can be cleaned without disassembling. Rinse in cleaning solvent and dry with shop air. Ensure that the orifice of the filter housing is free of foreign material. If the filter has not been cleaned regularly, or if there is considerable residue deposit, disassemble the filter and clean.

Deicer and Vacuum System

Centralized  filters for the vacuum- driven instruments are on the aft side of the pressure bulkhead immediately behind the instrument panel on early aircraft and in the nose compartment on later aircraft. Effective LJ-502 and subsequent and LW-1 and subsequent, only one centralized instrument filter is installed. Remove these filters and replace at the interval specified.

The only servicing required is for the vacuum regulator valve, which prevents the vacuum system from exceeding operating limits by allowing the proper amount of air to enter the vacuum lines. On aircraft LJ-1 through LJ-5, the vacuum regulator valve is in the left wheel well. On LJ-6 through LJ-75, it is on the left side of the fuselage immediately aft of fuselage station 177, where access is gained through a panel under the seat. On aircraft LJ-76 and subsequent and LW-1 and subsequent, the vacuum regulator valve is on the forward side of the pressure bulkhead in the nose compartment.

Pitot and Static System

On LJ-626 and subsequent and LW-1 and subsequent, the pitot mast is the lowest point in the pitot line and the resultant natural drainage eliminates the need for drain cocks. On LJ-1 through LJ-625, the pitot system drain cocks should be checked for moisture collection following each washdown and each flight in atmosphere of high humidity.

Engine Control Cables

Engine control cables are lubricated by the manufacturer with a special lubricant  compounded for effective lubrication  in the excessively low temperatures  encountered during flight at high altitudes. The cables may be periodically purged with dry nitrogen to prevent moisture condensation and subsequent freezing.

Under no circumstances should any lubricants be introduced into sealed or unsealed cables.

If the control cable has already been contaminated with a lubricant that congeals at low temperatures, the nitrogen purge  is  ineffective and  the  affected control cable must be replaced

Windshields Glass windshields with  an  anti-static  coating should be cleaned as follows:

 

1.     Wash excessive dirt and other substances from the glass with clean water.

 

2.     Wash the windshield clean with mild soap and water or with a 50/50 solution of iso- propyl alcohol  and water. Wipe the glass surface in a straight rubbing motion with a soft cloth or sponge. Never use any abrasive materials or any string acids or acid base material to clean the glass.

 

3.         Rinse the glass thoroughly and dry, but do not apply wax.

Plastic Windows The plastic windows should be kept clean and waxed at all times. Any nonacid, nonabrasive material may be used for this purpose. Windex® and similar commercial window cleaners may be safely used. Use automotive cleaners and waxes on plastic windows only if they are nonacrylic. To prevent scratches and crazing, wash the windows carefully with plenty of soap and water, using the palm of the hand to feel and dislodge dirt and mud. A soft cloth, chamois, or sponge may be used, but only to carry water to the surface. Rinse the window thoroughly, then dry it with a clean, moist chamois. Rubbing the surface of the plastic with a dry cloth builds up an electrostatic charge that attracts dust.

Remove oil and grease with a cloth moistened by kerosene. Never use gasoline, benzine, alcohol, acetone, carbon tetrachloride, fire extinguisher or anti-ice fluid, lacquer thinner, or glass cleaner, for such materials soften the plastic and may cause crazing.

After removing dirt and grease from the window, wax with a good grade of commercial wax. The wax fills in minor scratches and help prevent further scratches. Apply a thin, even coat of wax and bring it to a high polish by rubbing lightly with a clean, dry, soft, flannel cloth. Never use a power buffer; the heat generated by the buffing pad may soften the plastic.

Landing Gear Wash the landing gear (both nose and main) with low pressure water and mild detergent as soon as practical following operation on salty or muddy runways. Blow all wash off with low pressure air before flight or storage of the aircraft.

 Landing Gear Shock Absorbers

To check the fluid level in the landing gear shock absorbers, place the aircraft on jacks and raise the wheels off the ground, deflate the strut by releasing the air through the valve and compress the strut, then remove the filler valve adapter.

The fluid level should be at the bottom of the valve standpipe with the struts fully compressed. If the level is low, add hydraulic fluid to reach the standpipe, work the strut slightly to eliminate any trapped air, then add more fluid as necessary.

Remove the aircraft from the jacks and with the aircraft empty except for full fuel and normal oil level, inflate the nose strut until the piston is extended  3–3-1/2  inches,  and  inflate the  main strut until the piston is extended 3 inches.

Landing Gear Shimmy Damper

 

To check the fluid level in the shimmy damper, insert a wire approximately 1/16 inch in diameter through the hole in the washer at the aft end of the aft floating piston rod until the wire touches the bottom of the hole in the floating piston.

Mark the wire, remove it, and measure the depth of insertion. Inserting the wire in the hole of the floating piston, rather than letting it rest against the face of the piston, gives a more accurate check. The wire can be inserted approximately 5 1/4 inches when the reservoir is empty.

When the shimmy damper is full, the distance from the end of the piston rod to the bottom of the hole in the aft floating piston is 2 5/8–2 7/8 inches. When the distance is from 3 1/8–3 1/4 inches, the shimmy damper should have hydraulic fluid added.

Shimmy Damper Fluid Servicing

1.     Perform the Landing Gear Shimmy Damper

Removal procedure.

 

2.     Remove the piston rod end fitting and secure the shimmy damper in a fixed position with the fitting end of the piston rod down.

3.     Remove the snap ring, washer, and spring from the aft end of the piston rod.

 

4.     Remove the aft floating piston from the pis- ton rod by screwing a long 10–32 bolt into the piston and pulling it out.

5.     Fill the piston rod with hydraulic fluid.

NOTE

Trapped air in the piston rod prevents proper functioning of the shimmy damper. While pulling the forward floating piston toward the fitting end of the piston rod with the bolt, ascertain that the aft floating piston follows directly behind the fluid without trapped air.

6.     Insert  the  10-32  bolt  through  the  fitting end of the piston rod and engage the for- ward floating piston. Pull the floating piston toward the fitting end of the piston rod; at the same time, insert the aft floating piston and spring, and install the washer and snap ring.

 

7.     Remove the bolt from the forward floating piston and install the piston rod end fitting.

8.     Perform the Landing Gear Shimmy Damper Installation procedure.

Landing Gear Hydraulic System Servicing Servicing the hydraulic landing gear system consists  of  maintaining  the  correct  fluid level and maintaining the correct accumulator precharge check it in accordance with the Servicing Schedule.

Charge the accumulator just inboard of the left nacelle and forward of the main spar, to 800 ± 50 psig using dry compressed air or bottled nitrogen. A charging gauge is on the accumulator. A fill reservoir is on the inboard side of the accumulator and has a dipstick marked HOT/FILL and COLD/FILL attached to the cap. Prior to removing the fill reservoir cap, the lever on the cap must be lifted to relieve any air pressure. Add hydraulic fluid as required to fill the system.

NOSE LANDING GEAR LUBRICATION

ITEM	LUBRICANT	INTERVAL
Door hinges and retract linkage	MIL-PRF-7870 (Supersedes MIL-L-7870) oil	200 Hours
Grease fittings	Aeroshell® Grease No. 17****	200 Hours
Wheel bearings	Mobil Aviation Grease SHC 100*	200 Hours
Nose wheel steering mechanism	Aeroshell® Grease No. 17****	200 Hours
Hinge bolts and bushings**	LPS® No. 3 Metal Protector	200 Hours
Grease fittings  ***	Aeroshell® Grease No. 17****	200 Hours
Drag leg bolts and bushings **	LPS® No. 3 Metal Protector	200 Hours
Grease fittings  ***	Aeroshell® Grease No. 17****	200 Hours
Drag leg stop bolts grease tting  **	Aeroshell® Grease No. 17****	200 Hours
Top brace upper and lower bearings	Aeroshell® Grease No. 17****	200 Hours

MAIN LANDING GEAR LUBRICATION

 

ITEM	LUBRICANT	INTERVAL
Grease fittings	Aeroshell® Grease No. 17	200 Hours
Wheel bearings (4) *	Mobil Aviation Grease SHC 100	200 Hours
Retract grease fittings  (10)	Aeroshell® Grease No. 17	200 Hours
Door hinges and retract linkage (12)	MIL-PRF-7870 (supersedes MIL-L-7870) oil	200 Hours
Grease fittings  (10)	Aeroshell® Grease No. 17	200 Hours
Yoke assembly, drag brace (2)	MIL-PRF-7870 oil	200 Hours

ENGINE LUBRICATION

 

ITEM	LUBRICANT	INTERVAL
Control rod ends	MIL-PRF-23827 (supersedes MIL-G-23827) grease	200 Hours
Starter-generator drive shaft spline on LJ-1–LJ-1110, and LW-1 and after. (Aircraft LJ-1111 and after have wet spline drive shafts which are lubricated by the engine oil system and do not require periodic lubrication.)	Molykote® M77 or Plastilube® No. 3	400 Hours or any time the generator is removed. (Some, upon inspection, may require more frequent spline lube intervals.)
Cam plates and pins	Lubriplate No. 130AA	200 Hours

ENGINE CONTROLS, TRIM TAB CONTROLS AND PROPELLER LUBRICATION

 

ITEM	LUBRICANT	INTERVAL
ENGINE CONTROLS
Linkage (all moving parts)	MIL-G-21164 grease	As required for proper operation
Throttle switch actuator	Door-Ease®	As required for proper operation
Prop detent spring	Door-Ease®	As required for proper operation
TRIM TAB CONTROLS
Tab control linkage (all moving parts)	MIL-PFR-7870 (supersedes MIL-L-7870) oil	As required
PROPELLER
*Propeller hub (Hartzell)	Aeroshell® Grease No. 5, Aeroshell® Grease No. 6, Aeroshell® Grease No. 7, Aeroshell® Grease No. 22, Exxon 5114EP, Royco 22C	200 Hours
**Propeller hub (McCauley)
Low pitch stop rods (reversing propeller)	Marvel Mystery Oil®	200 Hours

.   CONTROL COLUMN, RUDDER PEDALS, AND BELLCRANKS LUBRICATION

 

ITEM	LUBRICANT	INTERVAL
CONTROL COLUMN
Linkage	SAE 30 oil	400 Hours
RUDDER PEDALS AND BELLCRANKS
Tab control linkage (all moving parts)	MIL-PFR-7870 (supersedes MIL-L-7870) oil	400 Hours

AILERON AND FLAP CONTROL SYSTEMS AND WING BOLTS LUBRICATION

ITEM	LUBRICANT	INTERVAL
AILERON CONTROL SYSTEM
Aileron quadrant	MIL-PRF-7870 (supersedes MIL-L-7870) oil	400 Hours
Aileron bell cranks	MIL-PRF-7870 oil	400 Hours
Aileron push rod ends	MIL-PRF-7870 oil	400 Hours
FLAP CONTROL SYSTEM
Flap actuator piston	SAE-J2360 (supersedes MIL-L-2105 and MIL-L-10324) oil	1,200 Hours
Flap tracks	Dry spray lubricant	200 Hours
Flap actuator drive shafts with keyway style ends on aircraft LJ-1– LJ-526 without Beech Kit No. 99-4017	MIL-PRF-23827 (supersedes MIL-G-23827) grease	1,200 Hours
Flap motor gearbox	MIL-PRF-10924 (supersedes MIL-G-10924) grease	200 Hours
WING BOLTS
Barrel nuts (lower, LJ-1 – LJ-1087 except LJ-1085, and LW-1 and after with Beech Kit No. 90-4077-1; upper on LJ-1085 and LJ-1088 and after)	* MIL-PRF-16173 (supersedes MIL-C-16173), grade 2 corrosion preventive compound	At the rst scheduled inspection, anytime the wing bolt has been loosened or retorqued, and annually thereafter.

DOORS AND STROBE LIGHTS LUBRICATION

 

ITEM	LUBRICANT	INTERVAL
DOORS
Emergency exit door mechanism	Mix Molykote® Z with naptha into a paste and apply with brush	800 Hours
Cabin door latching mechanism	MIL-PRF-7870 (supersedes MIL-L-7870) oil	400 Hours
Hinge	MIL-PRF-32033 (supersedes VV-L-800) oil preferred; CRC 3-36, LPS-1® or WD-40® alternate	200 Hours
STROBE LIGHTS
Timer motor (cams and bearings)	Aeroshell® No. 12 oil	800 Hours

Snow Removal

The best way to remove snow is to brush it off with a squeegee, soft brush, or mop. Be careful not to damage any components that may be attached to the outside of the aircraft, such as antennas, vents, stall warning devices, etc. Remove loose snow from the aircraft before heating the aircraft interior; otherwise, at low temperatures, the snow may melt and refreeze to build up a considerable depth of ice. Never attempt to chip or break fro- zen snow from the aircraft. If the aircraft has been hangared and snow is falling, coat the aircraft surfaces with an anti-icing solution; snow falling on the warm surface has a tendency to melt, then refreeze.

After snow is removed from the aircraft, inspect it for evidence of residual snow, particularly in the control surface gaps and hinge areas. Carefully inspect the static ports for evidence of obstruction.

Frost Removal

Remove heavy frost that cannot be removed by wiping with a gloved hand or soft towel by placing the aircraft in a warm hangar or with a deicing fluid.

After removal of all frost from the aircraft exterior, check all external components for damage that may have occurred during frost removal.

Ice Removal

Moderate or heavy ice and residual snow deposits should be removed with a deicing fluid. No attempt should be made to remove ice deposits or break an ice bond by force.

Control surfaces should be moved to ensure that they have full and free movement. Check the landing gear mechanism, doors, wheel wells, uplocks, and microswitches for ice deposits that may impair function.

Following ice removal, should freezing precipitation continue, the aircraft surface should be treated for anti-icing.

 

•  SAE type I anti-icing fluids (unthickened-type fluids)—Mainly provide protection against refreez- ing when there is no precipitation.

 

•  SAE type II anti-icing fluids (thickened- type fluids)—Provide protection against refreezing when precipitation occurs.

 

•  SAE type IV anti-icing fluids (thickened- type fluids)—Provide protection against refreezing when precipitation occurs.

All approved type I, type II, and type IV fluids may be used for either deicing or anti-icing at any dilution as allowed by the fluid manufacturer’s recommendations.

Deicing Precautions

Take all reasonable precautions to minimize the entry of fluid into engines, intakes, and control surface cavities.

 

•  Do not direct  deicing/anti-icing  into the orifices of pitot heads or static vents; do not apply these fluids directly onto airstream direction detectors, probes, angle-of-attack airflow sensors, or on windows.

 

• The engines must be shut down during deicing/anti-icing.

 

•  Both  wings  and  the  tail  section  must receive the same complete treatment.

 

• Remove any traces of deicing/anti-icing fluid on cockpit windows prior to departure. Pay particular attention to windows fitted with wipers. In addition, any forward area from which the fluid may flow back onto windscreens during taxi and takeoff must be clean prior to departure.

 

•  After prolonged periods of deicing/ anti- icing, check for residues of thickened deicing/anti-icing fluids in aerodynamic cove areas and cavities like balance bays and rear spars of the wing and stabilizers.

Deicing Fluid Handling Precautions

Take the following precautions when using deicing and anti-icing fluids:

 

•  Do not permit glycol solution to come in contact with the skin. It may cause serious frostbite.

 

• If the solution is spilled on gloves or clothing,    remove    immediately.    Rapid evaporation of the solution can lower the temperature of material and destroy insulating qualities.

•  Avoid contact with skin or eyes.

 

•  Stay on the windward side during application. Avoid prolonged exposure to heavy concentrations of glycol vapors.

 

•  Do not let the solution contact bearings. It may dilute the grease.

 

•  Avoid applying the solution on windows because it may reduce visibility.

 

•  Take care when walking on surfaces that are coated with glycol. The mixture leaves a slippery film that is hazardous to walk upon.

 

•  Take precautions to keep the solution from entering air ducts or cabin heater and ventilator ducts, because of toxic fumes entering the cabin or cockpit during taxi or takeoff.

Fuel Tanks. : Each wing contains an integral fuel bay, located between the front and rear spars. Fuel bays should be filled immediately after each flight to lessen condensation in the tanks and lines. A fuel filler cap is located on top of each wing and provides a fueling/defueling point for each fuel bay.

              Fuel Drains. " Fuel drains are located at various places on the underside of each integral fuel bay and throughout the fuel system. These drains are utilized to collect fuel samples for analysis. This sampling is accomplished by placing the fuel sample cup up to the drain valve, and depressing the valve with rod protruding from the cup.

Safety Precaution:

1. Ground airplane first.
2. Ground vehicle  to the same ground as the airplane.
3. Bond vehicle  to airplane.
4. Bond refuel nozzle to airplane.
5. Ensure fire fighting equipment is positioned and immediately available.
6. Do not wear clothing that has a tendency to generate static electricity such as nylon or synthetic fabrics.
7. Do not wear metal taps on shoes.
8. The airplane should be in a designated fuel loading/unloading area.
9.  High wattage, pulse transmitting avionics equipment shall not be operated in the vicinity of the fueling/defueling operation.
10. Use designated equipment for fuel loading/unloading to prevent contamination.
11. During defueling, ensure anti-ice additive blended fuel and unblended fuel are not mixed.

PTP  Beech 90 Series	B1	LOC		SGH
	B2	LOC		SGH

243001 Main Battery - Examine the general condition and security. Complete the applicable
main battery servicing procedure. Refer to Chapter 12, Battery - Servicing. B 05-12-02 120

Fueling Procedures.

(1) Ground airplane and vehicle.

(2) Ensure battery switch is turned OFF.

(3) Place protective mat around fuel filler area and remove fuel filler caps.

(4) Fuel airplane. Ensure correct grade of aviation fuel is used.

(5) Replace filler caps. Wipe up excess fuel from wing area.

(6) Remove grounding equipment.

 Defueling Procedures.

(1) Ground airplane and vehicle.

(2) Ensure battery switch is turned OFF.

(3) Remove fuel filler caps.

(4) Insert defueling nozzle into fuel bay and begin defueling.

(5) Remove as much fuel as possible with defueling nozzle.

(6) Drain fuel from drains located on underside of fuselage.

(7) Remove drain valves from bottom of fuel tank and drain remaining fuel.

(8) Remove grounding equipment.