I would like some technical info, please

[capnflyright]

What does "r and r" mean in regards to engine maintenance? Is there a website that can explain maintenance intervals(i.e. 300,600,1200 etc.) and what has to be performed? Does this depend on the program the aircraft is inspected by(i.e. CAMP, MSP, ESP etc.)?

 

[LR25]

RR usually means "removed and replaced" on maintenance logs.

LR25

 

[328dude]

You might get worried or start asking questions if there is just one "R" followed by "Could not Duplicate, Ops Check Good".

 

[DairyAir]

discrepancies

This is my favorite write up made by what I assume to have been a very hungover captain.

Discrepancy read: Nav Lights inop.
Corrective action: Turned on NAv Lights ops check good.

We photocopied that one and hung on the wall of the crew room. The captains new name is "Switch"

 

[~~~^~~~]

Generally R&R means removed and replaced. Inspections will be noted and parts will be specified, if new / overhauled.

There are many sources for the information you seek. Begin with the product manufacturers web sites and technical representatives.

Yes, it does matter which maintenance plan the aircraft is on. Aerial applicators, military and experimental can run stuff till it breaks (on condition). Part 91 has both mandatory items and some items that can be run on condition. Part 121 and 135 must follow manufacturer's guidelins, be under a more conservative periodic maintenance program, or have an FAA approved periodic maintenance program.

For example the airline I fly for gets much more than the scheduled time between hot sections out of their PW engines. They achieved this by running the engines significantly below the manufacturer's published limitations and by tearing down sample engines at specific intervals to give an indication of what the entire fleet is experiencing.

Rolls Royce had a RB211 go 25,000 hours between overhauls at Delta using such a program.

So, there are a lot of variables...

 

[avbug]

"Aerial applicators, military and experimental can run stuff till it breaks (on condition). "

The military operates under an entirely different set of regulations, but in every case (including aerial application and experimental categories), the maintenance intervals established by the manufacturer must be observed, as outlined in FAR 91.403(c).

In the case of experimental aircraft, which are generally exempted from the requirements of FAR 43 (Maintenance, preventative maintenance, rebuilding, and alteration) by 43.1(b), the maintenance schedule is still limited by certificated components which are intended to continue as approved components, and in general by any specific intervals called for by the manufacturer (to include the builder). A common example is the engine and avionics, which many builders intend to keep certificated and legal. All applicable replacement intervals, AD's, etc, still apply to that equipment in order to comply with the type certificate, TSO, etc. (However, if the operator elects not to perform the inspections, this is legal, but the equipment no longer conforms to approved data, and becomes experimental in nature, and the data plate should be removed).

"R&R" is a common use term which is discouraged by the FAA for it's ambiguity. It's also discouraged by professional organizations, such as PAMA. This includes terms such as IAW, RIR, etc. The reason is that such terms are widely recognized, but ambiguous and not precise. Interpretation is required. Plain english entries are best.

CAMP isn't an inspection program, but a paperwork and tracking program. The CAMP system incorporates the manufacturers programs, and also takes into account AD's, service bulletins, and other pertinent maintenance issues. Reports are filed by the operator for each item of maintenance performed. CAMP tracks the maintenance, and provides alerts when intervals or required items are due, or aren't met. It's a pricey system, but a recognized tracking system. Adherence to CAMPs doesn't ensure compliance, however. It's still up to the individual operator to ensure that all requirements are met.

 

[~~~^~~~]

The military operates under an entirely different set of regulations, but in every case (including aerial application and experimental categories), the maintenance intervals established by the manufacturer must be observed, as outlined in FAR 91.403(c).

§ 137.29 General.

(c) The holder of an agricultural aircraft operator certificate may deviate from the provisions of part 91 of this chapter....

I'm not saying that an Agricultural operator does not have to have an annual. However, they do not have follow manufacturer's reccommended time between overhauls. The military sure doesn't follow TBO guidance. This is a particular problem on military turbine helicopters that hit the civillian market because the Army does not typically log the engine cycles. Even if somebody wanted to follow the regs under 91 it would be impossible because you would not know where to start unless you installed a civillian engine, or overhauled every rotable.

Basically the overhaul plan for any Agricultural, or Military, aircraft is inspect the engine, if it looks OK it is good until the next inspection regardless of how many hours are on it.

 

[avbug]

FAR 137.29(b) exempts operators in general from the operational regulation extended by FAR 91. It does not excuse the requirement to meet all conformity requirements with approved data, however.

TBO is a recommendation, not a manufacturers mandatory replacement time. Therefore, even under FAR 91, it is not mandatory, and has no bearing on the subject. Any Part 91 operation may continue beyond TBO, and many do, as do many 135 operators and 121 operators (yes, they do).

I have flown for several certificate operators who extended engine TBO's. One operator in particular single handedly extended a well known engine TBO by 400 hours, incrementally, and we were working on 100 more when I left. Again, TBO is not a mandatory time specified by a manufacturer, and is not applicable as given under 91.403(c).

For operations under 121 and 135, TBO is limiting, but may be extended in accordance with the maintenance program for each operator, and it frequently is. In fact, this is often the way in which TBO's for particular powerplants are proven out, and extended, generally. The documentation provided by certificate holders in conjunction with an approved inspection program (and tear down program, as appropriate) is often the basis for increases in TBO for a particular engine type.

Ag operators still conform to annual inspections, and to applicable airworthiness directives, and other requirements provided by the FAR, and by the manufacturer. Individual rotables and components are still subject to mandatory inspection, replacement, service, etc. Each operator for whom I've flown and worked has complied in detail, just as much as any 121 or 135 operator. I've had experience in a variety of different operations under FAR 137, including specific schooling, as both pilot and mechanic. I've never worked with an operator, or for an operator, who didn't shoot for the highest degree of maintenance in these operations. Those of us who do it, know our lives depend upon it.

The military observes specific proceedures and limitations in accordance with the regulations provided (Technical Orders, etc) for each aircraft, and branch.

"This is a particular problem on military turbine helicopters that hit the civillian market because the Army does not typically log the engine cycles. Even if somebody wanted to follow the regs under 91 it would be impossible because you would not know where to start unless you installed a civillian engine, or overhauled every rotable. "

This is the case with all military equipment transferred to the civil sector. I've flown a number of aircraft transferred out of military service into civillian use, and public use. Very often obtaining type certificate data, or achieving conformance with certification requirements, is difficult or impossible. This applies to rotables as well as airframes, powerplants, etc. I've operated enough of that equipment under FAR 137, in fact, that I'm quite familiar with the difficulties, restrictions, and hazards. Most of the time, military equipment transferred to civillian use cannot meet the specific category certification that civillian certificated aircraft can, and the subsequent use of that equipment is very limited. It isn't just helicopters.

However, the issue isn't one of prior documentation. A more basic issue arises as to the origional certification of the product, which is seldom in conformity with the applicable type certification regulations. In order to obtain primary, standard, utility, transport, etc category certification, a complete testing and certification process must be done to bring those aircraft into conformity. With much of this data unavailable or unperformed, the cost of certifying most military aircraft is entirely prohibitive, and the aircraft remain in restricted category, exhibition category, etc.

In the case of several military aircraft I've flown, we've completely recertificated the aircraft as a new type, in accordance with the modifications we have performed for the specific mission, and achieved a unique certification status. This is done on a limited and individual basis with a particular set of serial numbers, and not in general. It's difficult, but possible.