Cessna maintenance

[172510]

In the Cessna maintenance manual, maintenance is required at intervals expressed in terms of "hours of operation"
I've been through the manual and the FARs, but could not find any official definition of "hours of operation".
Is it block time? Airborne time? Hour meter time?
My CAMO says it is block time.

[172510]

If the manufacturer of the aircraft recommends every 50 hours airborne time, the I have the choice between airborne time and bloc time.
If the manufacturer recommends every 50 hours bloc time, then I don't have the choice, as every 50 hours airborne time would be less often than what the manufacturer recommends.
So I'm looking for the official definition of the phrase "hours of operation" used by Cessna.

[obgraham]

Hobbs meter time?

[172510]

If the manufacturer of the aircraft recommends every 50 hours airborne time, the I have the choice between airborne time and bloc time.
If the manufacturer recommends every 50 hours bloc time, then I don't have the choice, as every 50 hours airborne time would be less often than what the manufacturer recommends.
So I'm looking for the official definition of the phrase "hours of operation" used by Cessna.

[A and C]

I'm going to guess you are in France, the rest of Europe uses flying time to calculate maintenance requirements ( as do the French for airliners ).

[ericferret]

In the UK most light aircraft are maintained on the Light Aircraft Maintenance Programme (LAMP). It specifies that maintenance is calculated on the basis of flying hours. Every commercial aircraft I have worked on over 40 years used flying time.

Block time or chock to chock as another variation has been used for charging customers for the time they have the aircraft.
Always thought it a bit of a rip of myself but there are arguments both ways.

I would say it does make a difference.

If every flight has a 10 min pre flight checks, taxi and warm up plus a 5 minute taxi and shut down that is an extra 15 minutes non flying time per flight (based on a one hour training flight). If your engine for example has a 2000 TBO you are loosing 500 hrs!!!!!!!
All your maintenance will be done 25% early and your bills will roll in more frequently. Nice little earner for the maintenance organisation. More downtime, more component changes and more maintenance interventions during the life of the aircraft.

Get another CAMO those guys are going to cost you a lot of money. Ask them where it specifies you have to use block time. I have never come across an operator or for that matter a private owner who used block time.

[172510]

I'm not asking what you do with your aircraft, I'm just asking what is Cessna's definition of "Hours of operation". What other people do won't help any when I want to have a maintenance programme approved. What will help is the ability to demonstrate that the phrase "hours of operation" in the maintenance manual published by Cessna refers to airborne time and not to flight time.
Apparently nobody knows, which is surprising.
The phrase "hours of operation" is not defined in the FAR's, at least I could not find any definition, nor could I in Cessna documents, nor in ATA Spec 100 about maintenance manuals.
I'll ask Cessna, and hope to get an answer in writing.

[ericferret]

As Cessna are an American company they are bound by American regulations.

(1) Section 91.417(a)(2)(i). Requires a record of total time-in-service to be kept for the
airframe, each engine, and each propeller. Part 1, section 1.1, Definitions, defines time in service, with respect to maintenance time records, as that time from the moment an aircraft leaves the surface of the earth until it touches down at the next point of landing.

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC43-9C.pdf

[172510]

Thank you ericferret, but I do know what time in service means, and it's not relevant here.
I'm looking for the definition of "Hours of operation".


It isn't nearly as rigid as you think. It is down to the agreed maintenance schedule. Cessna do not have a 'must be this way or else your plane will fall out the sky' version of operating hours. My authority, the French DGAC via its contractor OSAC is definitely rigid. The long time custom in France is to construe "hours of operations" as "Block time". And I do need OSAC's approval of my maintenance programme if I want to use my aircraft for flight lessons.
I got an Email from Cessna telling me that in their maintenance manual, "Hours in service" means the value given by the G1000.
That value is usually between airborne time and block time.
Although I've not found any Cessna document to substantiate my surmise, I think that the total hours of operation value given by the G1000 is 1/60 of the ratio of the number of revolutions of the crankshaft over a given RPM value

[Intruder]

Are you the only Cessna operator in France? If not, the DGAC and OSAC have already dealt with Cessna aircraft, and know how they want to define the terms. Ask them how they define it for other operators.

[m39462]

Thank you ericferret, but I do know what time in service means, and it's not relevant here.The FARs sections concerning an approved inspection program (§91.1109,§125.247,§135.419 take your pick) agree it must include

(2) A schedule for the performance of inspections that must be performed under the program, expressed in terms of the time in service, calendar time, number of system operations, or any combination of these.

So if "hours of operation" is going to be a factor in an approved program it must be equivalent to one of the above.

[NutLoose]

FAA Federal Aviation Regulations (CFR 14 Part 1)

Time in service, with respect to maintenance time records, means the time from the moment an aircraft leaves the surface of the earth until it touches it at the next point of landing.

See

eCFR ? Code of Federal Regulations (http://www.ecfr.gov/cgi-bin/text-idx?rgn=div8&node=14:1.0.1.1.1.0.1.1)


They are mixing it up with


Flight time means:

(1) Pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing; or

(2) For a glider without self-launch capability, pilot time that commences when the glider is towed for the purpose of flight and ends when the glider comes to rest after landing.

MODEL 152 SERIES SERVICE MANUAL
2-46. INSPECTION REQUIREMENTS: As required by Federal Aviation Regulations, all aircraft
must undergo a 100 hour and/or annual inspection or may be inspected in accordance with
FAA approved Progressive Inspection.
2-47. 100 HOUR AND/OR ANNUAL INSPECTIONS: (Refer to the Inspection Charts. Column 1.)
This inspection ~equires each item marked with a symbol to be inspected at each 100 hours
of flight time and/ or each 12th month following the last inspection recorded for the aircraft.
2-48. SPECIAL INSPECTIONS: (Refer to the Inspection Charts. Column 2.) This inspection
requires each item that has a numeral inserted in the column be inspected m accordance
with the corresponding numeral listed in the back of the Inspection Charts.
2-49. PROGRESSIVE INSPECTIONS: (Refer to the Inspection Charts, Column 3.) In lieu of the
conventional 100 hourl annual inspection as covered in Part 91.169 of the Federal Avlatlon
Regulations, an aircraft may be inspected m accordance with 8 progressive mspectlon.
Progressive inspection allows the inspect~on work load to be divided into smaller operations
that can be accomplished in 8 shorter time period and offers mcreased safety
reliability. and utility while decreasing downtime, Aircraft on this program do not require
the 100 hour/annual inspection. "Cessna Progressive Care" has been designed for th~s
purpose. It is highly recommended for aircraft being flown 200 hours or more per year

[172510]

Are you the only Cessna operator in France? If not, the DGAC and OSAC have already dealt with Cessna aircraft, and know how they want to define the terms. Ask them how they define it for other operators.
I know what they want, they want "block time".
If I want them to accept airborne time, I need a document from Cessna saying that their MM refers too airborne time.
In the meanwhile I got an email from Cessna saying that it refers to G1000 time, which is not far from airborne time.

[NutLoose]

From the SIDS for the Cessna 152

CESSNA AIRCRAFT COMPANY MODEL 152 SERIES SERVICE MANUAL
INSPECTION COMPLIANCE (Refer to Note 1)
DETAILS FOUND IN SECTION 2-14-XX
SUPPLEMENTAL INSPECTION NUMBER
TITLE
INITIAL REPEAT
INSPECTION OPERATION
MILD/ MODERATE 20 Years
MILD/ MODERATE 10 Years 112A-14-20 57-53-01 Flap Tracks Corrosion Inspection SEVERE 10 Years SEVERE 5 Years 13
2A-14-21 71-20-01 Engine Mount Inspection 5,000 Hours or 20 Years
At Engine Overhaul
10
2A-14-22 55-11-03 VerticalFinAttachBracket 100 Hours or 1 Year
100 Hours or 1 Year
22
NOTE1: Time limits for the INITIAL inspections are set by either flight hours or calendar time, whichever occurs first. Except for Section 2A-14-21, Supplemental Inspection 71-20-01, corresponding calendar inspection times are per REPEAT flight hour or calendar time specified, whichever occurs first. Corrosion Prevention and Control Program (CPCP) remain calendar time based. If the INITIAL inspection has been completed, and a CPCP is in effect, then REPEAT inspections are based entirely on flight hours.

[NutLoose]

CESSNA AIRCRAFT COMPANY MODEL 100 SERIES (1963 - 1968) SERVICE MANUAL
INSPECTION TIME LIMITS - STRUCTURE
1. Scope A. This provides the mandatory times and inspection time intervals for components and airplane structures. This section also gives the required details to monitor them using scheduled inspections. This section applies to items such as fatigue components and structures, which are part of the certificationprocedures. Refertothedescriptionparagraphbelowfordetailedinformationcon cerning each of these sections. NOTE: The time limits and maintenance checks listed in this section are the minimum requirements for airplanes operated under normal conditions. For airplanes operated in areas where adverse operating conditions may be encountered, such as high salt coastal environments, areas of high heat and humidity, areas where industrial or other airborne pollutants are present, extreme cold, unimproved surfaces, etc., the time limits should be modified accordingly. NOTE: The inspection guidelines contained in this section are not intended to be all-inclusive, for no such charts can replace the good judgment of certified airframe and power plant mechanics in performance of their duties. As the one primarily responsible for the airworthiness of the airplane, the owner or operator should select only qualified personnel to maintain the airplane. 2. Inspection Requirements A. Twotypesofinspectionrequirementsareavailablebasedonoperating usageandtwoadditionaltypes of inspections are available based on operating environment. (1) Operating Usage (a) Severe Usage Environment 1 If the average flight length is less than 30 minutes, then you must use the SEVERE inspection time limits. 2 If the airplane has been engaged in operations at low altitudes such as pipeline patrol, fish or game spotting, aerial applications, police patrol, sightseeing, livestock management, etc. more than 30% of its life you must use the SEVERE inspection time limits. 3 Airplanes which are equipped with floats or skis must use the SEVERE inspection time limits. (b) Typical Usage Environment 1 If neither 2(A)(1)(a)(1) or 2(A)(1)(a)(2) or 2(A)(1)(a)(3) above applies, the TYPICAL usage environment applies. (2) Operating Environment (a) Severe Corrosion Environment 1 If the airplane is operating more than 30% of the time in a zone shown as severe on the corrosion severity maps in Section 2A-30-01, then the SEVERE CORROSION environment time limits apply. (b) Mild or Moderate Corrosion Environment 1 If 2(A)(2)(a)(1) does not apply, then the MILD/MODERATE CORROSION environment time limits apply. B. After the operating usage and the operating environment are determined, make a logbook entry that stateswhichinspectionschedules(TYPICALorSEVEREoperatingusage andMILD/MODERATEor SEVERE operating environment) are being used.

That infers airborne as the hours