I continue to be amazed at the oceans of acronyms that abound in aviation. My wife is a Registered Nurse, and I think that the medical industry, followed by the IT world rank closely in their affinity for, and use of acronyms. A web site I continue to recommend highly is www.acronymfinder.com. They claim to have nearly a half million acronym entries, and I have yet to stump them. For example, I tried “MRB” and it returned 18 results, but for this blog we’re going to be looking at the three used in our industry.

The three types are:

• Maintenance Review Board: Convened during a new aircraft’s Type Certification process
• Material (or Manufacturing) Review Board: Convened during the manufacturing process
• Maintenance Review Board: Used by an airline for aircraft in service

During a new aircraft’s design process, part of the Type Certification effort involves the manufacturer defining what will be the maintenance program for the aircraft. To do this, an MRB is convened. It assigns a Chairman, and the board, which is usually made up of “invited” aircraft professionals with backgrounds or jobs in Engineering, Airline Maintenance, Reliability, and the applicable Civil Aviation Authorities. After the MRB has defined, and had approved the maintenance program for the aircraft, the details reflective of the MRB are usually published in a document called the Maintenance Planning Document (MPD). It is the MPD which an airline would use as the basis to establish their own maintenance program peculiar to their operations, and to have the same approved by their respective Civil Aviation Authorities. The following is an excerpt from an EASA document outlining their MRB process:

Article 10 – interface with other activities

1. For the development of initial minimum scheduled maintenance requirements for derivative or newly type certificated aircraft, the Agency shall set up, as appropriate, a maintenance review board (MRB). It shall therefore appoint a chairperson and define the terms of reference of that board. A maintenance review board shall include persons with relevant maintenance, certification and operational expertise. The product manufacturer and representative operators shall be invited to present to the board proposals for a maintenance programme. The Chairperson shall ensure that there is appropriate co-ordination with the operations evaluation board (OEB).

After an aircraft has been in operation for a period of time, an MRB may be reconvened to make adjustments in the maintenance program. For example, an MRB just recently decided to extend the time between the B Checks for the 777; this based on operational statistics demonstrating that extending the time would not have an adverse effect on the airworthiness of the aircraft.

Note that the “M” here stands for either Manufacturing or Material. This MRB is in fact used in industries outside of aviation. A simple example follows: An aircraft is in the process of being assembled. During a drilling operation on the aircraft structure for the installation of a fastener, the drill is not perfectly aligned, resulting in a hole that is elongated and not centered. The non-conforming hole is documented, and an MRB determines that a larger hole can be drilled, and a larger fastener used without compromising the structural integrity of the area or part. Such deviations are mapped and documented, and form part of the documents given to the customer at delivery. Sometimes an MRB may determine that the non-conformance is not acceptable, and the part has to be scrapped. This MRB is usually made up of engineers, production, and quality representatives who must approve the deviation in accordance with their written procedures. The individuals that can serve on this MRB are typically designated and approved by the manufacturer for this activity.

Like a Manufacturing MRB, an airline’s MRB is convened to address some non-conformity or maintenance exceedence. For example, you have a plane in the hangar for scheduled maintenance. An inspection reveals some corrosion underneath the lavatory stalls (sigh, some things never change). A technician then uses mechanical means to blend or remove the offending blemish. After the corrosion has been removed, a measurement must be taken to assure there still remains sufficient structural thickness. The measurement shows that the remaining thickness does not meet the minimums established in the Structure Repair Manual. An MRB is then convened to establish one of three things:

• Is the exceedence acceptable as-is based on engineering calculations?
• Will additional repairs, such as structurally beefing up the effected area be required? If so, what will be the requirement?
• Will a part have to be scrapped and replaced?

The processes and procedures of this MRB have to be documented in the airline’s manual system, and only designated individuals can participate in the approval process. I was once on such an MRB at a major airline.

Now back to acronyms. How many of us have Googled our names? Well, out of curiosity, I went to the acronymfinder web site and searched on Roy. There were sixteen results, which by the way, are ranked in terms of popularity of use. Republic Of Yemen and Rookie Of the Year were the top two. No, there were no entries for Resto. How about those acronyms that are actual words that complement the thing being described? For example, Airbus publishes a technical magazine for its customers called FAST, for Flight Airworthiness Support Technology, or ATLAS, for Automated Test Language for Aircraft Systems (cool huh?). You know someone expended some serious gray matter or marketing dollars to come up with those.

A common slang term I’ve heard young adults use when departing each others company is “word”, so I’ll use it here:

(Wishing Our Reading is Desirous) Just made that up...