Aircraft have a variety of inspection and maintenance requirements that are completed at certain intervals to ensure an aircraft’s airworthiness. From King Air’s phased inspections to Twin Commander’s scheduled inspections, each aircraft has its own set of guidelines that owners and operators need to follow. Cessna Citation inspections are no different.
An Inspection Document 10—often referred to as a “Doc 10” or Phase 5 inspection (for 550 models) —is performed on Cessna Citation 525s every 36 calendar months, or every 1,200 flight hours, whichever comes first. The Cessna Citation Doc 10 inspection is one of the most in-depth inspections done on Cessnas and covers all airframe areas, from tip to tail.
What the Cessna Citation Doc 10 Covers
For Cessna 525 owners, the Document 10 inspection requires a higher level of expert attention as compared to other inspections. During this inspection, aircraft technicians thoroughly inspect the aircraft’s systems and components, and the inspection involves disassembling the aircraft’s interior to check the wiring harnesses and flight control cables and pulleys. Additionally, technicians will inspect the engines and interior of the fuel bays.
The Doc 10 inspection includes a list of almost 50 tasks, ranging from landing gear wheel well inspection to aircraft system filters. Included in that set of tasks are:
Inspect all components and related structures for security of installation, cracks, corrosion, and damaged electrical components
Anti-skid system motor/pump filter
Replace the filter element
Anti-skid electrical control box
Inspect for security of installation, corrosion, and damaged electrical components
Anti-skid system components
Inspect for security of installation and hydraulic leaks. Check for security, damage, and indication on the pressure gauge. Check for security and damage of the air filler valve.
Stringers and Bulkheads (under the nose compartment floor)
Inspect for security of installation, corrosion, failed fasteners, and evidence of structural damage. If any corrosion is found, your MRO should talk with you about expanding the inspection to include the remaining portion of the stringers and bulkheads above the compartment floor as well.
Forward pressure bulkhead
Inspect for cracks, loose or failed fasteners, corrosion, and evidence of structural damage
Standby gyro with battery pack
Inspect battery pack and mount for security of installation, cleanliness, and evidence of damage
Flight guidance computers and mounts
Inspect for security of installation, evidence of damage, and condition of electrical components
General nose compartment inspection
Inspect all components for security of installation and evidence of damage
Relay junction box
Check for cleanliness and damaged electrical components, Inspect relay contracts and socket bases for corrosion.
Windshield bleed air manual control values, tube assemblies, and fittings
Check for air leaks and the operation of the valve
Brake reservoir air filter
Replace the filter element
Windshield alcohol pump
Inspect for security of installation and evidence of damage and clean or replace the filter as necessary
Windshield alcohol reservoir
Inspect for security of installation
Windshield defog manifold
Inspect the outlets and ducts for security of installation
Inspect the emergency battery box and batteries for corrosion, and check for any damaged electrical components
Windshield bleed air nozzle and augmentor door
Check for evidence of damage or any obstruction to the nozzle outlets
Check for any cracks, loose or failed fasteners, or evidence of structural damage
Check the emergency brake control valve for security of installation
Visually inspect the interior and exterior surfaces of the cabin door for cracks or failing fasteners. Visually inspect the locking indicator linkages and door handles for proper adjustment and lubrication
Emergency exit seal
Check for any signs of deterioration or evidence of damage
Perform a self test procedure, along with a landing gear extended test, and a squat switch logic test
During the Cessna Citation Doc 10 inspection, a lot of attention is given to inspecting under the aircraft floorboards throughout the length of the cockpit and cabin. In addition, several critical operational inspections are performed as well as:
- Functional check of the flap system
- Check of the fuel indication system
- Functional check of the passenger oxygen system
- Functional check of the landing gear and systems
The entire Cessna Citation Doc 10 inspection takes approximately 200 to 250 labor hours to complete.
Other Cessna Citation 525 Inspections To Keep In Mind
In addition to the Doc 10 inspection, there are other Cessna Citation inspections to keep in mind, including:
- Doc 1 Inspection (every 300 hours): Vapor Cycle, Engine Fire Extinguisher Inspection
- Doc 2 Inspection (every 12 months): Emergency equipment, O2 masks, emergency power supply, and landing gear lube
- Doc 3 Inspection (every 24 months): CVR and directional gyro
- Doc 4 Inspection (every 36 months): N2 Hydrostatic test
- Doc 5 Inspection (every 60 months): Engine fire bottle hydrostatic test
- Doc 6 Inspection (every 72 months): Portable fire extinguisher inspection
- Doc 7 Inspection (every 144 months): Portable fire extinguisher hydrostatic test
- Doc 8 Inspection (every 300 hours, or 24 months): Airframe inspection
- Doc 9 Inspection (every 600 hours/12 months, or 200 hours/4 months): Battery capacity check
- Doc 11 Inspection (every 2400 hours/72 months, then 1200 hours/36 months): Flight compartment window prism inspection and fuselage skin joint NDT
- Doc 12 Inspection (every 12 months): ELT inspection
- Doc 13 Inspection (every 24 months): A/S, Alt, ADC and static
- Doc 17 Inspection (every 100 hours/12 months): NiCad Battery Check
- Doc 18 Inspection (every 150 hours): Pylon firewall inspection
- Doc 21 Inspection (every 600 hours/24 months): Windshield bleed check
- Doc 22 Inspection (1200 hours, then every 300 hours): Precooler check
- Doc 29 Inspection (7200 hours, then every 5000 hours): Cockpit and cabin zonal inspection
- Doc 33 Inspection (every 300 hours, or 12 months): Door seal inspection
- Doc 35 Inspection (every 6 months): Corrosion inspection
Always Consult A Trusted Aircraft Maintenance Technician
Always consult a trusted aircraft maintenance technician when navigating the ins and outs of your aircraft’s inspection and maintenance needs. At Winner Aviation, our maintenance technicians have decades of experience and can help you follow inspection guidelines for your aircraft. We’ll work with you to combine service when possible, so you can reduce downtime and save on labor costs.
Request a quote for maintenance or inspections with us today, or talk with our maintenance team about your upcoming Cessna Citation inspection.