Today we would like to stand back and take a 50K foot view of the business aircraft maintenance cycle and discover the points within that cycle that play a role in efficiently performing maintenance.

The maintenance cycle

Aircraft go through a repeatable and predictable series of events we refer to as the maintenance cycle. The maintenance cycle is made up of four basic components or segments: flight, inspection, corrective action, and modification. Let's look at each segment in series to help us understand how they affect each other as well as the importance of each.

Flight — Once the aircraft is delivered to the owner for use (either new from the factory or fresh out of maintenance or modification), the flight segment of the maintenance cycle begins. The flight segment is the only time in which the aircraft is making money. Even aircraft that are not used commercially should be considered to be costing the operator when the aircraft is not flying. In all cases, the aircraft was purchased to fly.

The length of the flight segment is limited by two primary factors: 1) scheduled maintenance and 2) component failure. It is important to keep in mind that the scheduled inspection program, which is made up of several scheduled maintenance events, is purposely designed to minimize component failure as well as downtime. As the aircraft is operating in this flight segment, it is accumulating hours, cycles, and calendar time and as such is constantly moving closer to its next scheduled maintenance event.

Inspection — The next segment of the maintenance cycle is the inspection segment. Recurring inspections performed on a scheduled basis help to identify potentially unsafe conditions. Correction of these unsafe conditions ensures continued safe operation of the aircraft. The inspection segment describes the physical action taken by qualified persons trained to isolate the unsafe conditions which developed as a result of the use of the aircraft during the flight segment(s).

Prior to beginning the inspection phase, it is important to examine the maintenance records (logbook) and/or computerized maintenance status to determine the current status of the aircraft's inspection and maintenance program and identify possible deficiencies in the aircraft's maintenance records.

An aircraft inspection is required to be performed using a checklist. The obvious purpose of the checklist is to avoid forgetting any portion of the inspection as well as allow the inspection program to be divided up into a logical and efficient schedule. Any discrepancies found while inspecting the aircraft are recorded and, with few exceptions, must be corrected prior to returning the aircraft to service.

Maintenance/corrective action — The next segment in the maintenance cycle is the corrective action segment. The corrective action segment consists of the performance of hands-on maintenance in order to correct any physical defects found as well as any records deficiencies identified within the records. Proper correction of the discrepancies found will determine the airworthiness of the aircraft. Once each item has been corrected, a second inspection should be conducted to verify complete and safe correction of the discrepancy. If all discrepancies that affect "airworthiness" have been corrected, the aircraft may then be approved for return to service. The approval for return to service is a written certification (by a properly certificated person or agency) that specifies the aircraft meets all regulatory airworthiness requirements and is safe for continued operation.

If any of the defects found by the inspection, that impact the airworthiness of the aircraft are left undone, the inspection performed must still be recorded as accomplished, however in such case, "a list of uncorrected discrepancies" must be provided to the aircraft owner-operator and the aircraft may not be operated until those items are corrected. With FAA approval, the aircraft may be flown to another location to have the corrective action performed.

Modification — The last segment in our definition of a maintenance cycle is the modification segment. Often, an aircraft owner will decide that the aircraft would better fit their needs if it was modified. Modifications can be at the discretion of the owner-operator, or in some cases, new regulations may require a modification be performed in order to continue operations.

Modifications are either major or minor in nature. One reason I choose to include the modification segment in the maintenance cycle is the significance that modifications can have on the inspection segment. All major modifications should come with Instructions for Continued Airworthiness or ICAs. These instructions may include new inspection and/or maintenance requirements that must be blended into the current inspection program for the aircraft. The two basic methods the FAA uses for approving aircraft modifications are STCs (Supplemental Type Certificates) and FAA Field Approvals, the latter of which is getting to be less and less common.

So, we return to the flight segment and continue the maintenance cycle for the life of the aircraft. Having complete and accurate maintenance records made possible by a simple, easy to use maintenance tracking system will make the maintenance cycle more predictable and, as a result, much less expensive. Following are some ways that maintenance records can make a difference in the cost of the operation of your aircraft.

The invisible costs 

One of the most costly, though intangible, expenses incurred by an aircraft owner-operator is downtime. Because the aircraft is an asset to the company, it usually has ongoing costs regardless of its availability for use. Add to that, the cost of alternative transportation, and the possibility of lost business from the company's inability to act quickly (one of the reasons it bought the aircraft in the first place) and you can see how unplanned downtime must be avoided. The only way to manage downtime is to get your arms around the maintenance requirements and the utilization of the aircraft and effectively plan the maintenance to be accomplished. It is best to accomplish every scheduled maintenance item that will come due before the next scheduled inspection. If possible, plan aircraft modifications to be accomplished in conjunction with a scheduled maintenance event. With the maintenance shops bulging at the seams with work, scheduling for the inspection well ahead of time is essential to being sure of when the aircraft will be out of service.

Duplication of work

Duplication of work is another expense for aircraft owners-operators and is not only unnecessary but causes wear and tear on the aircraft. If the scheduled inspection or maintenance item that has been accomplished is not properly recorded in the aircraft maintenance records, the maintenance will either be duplicated or time will be spent chasing down a revised maintenance record, reinforcing the old saying that, "No job is finished until the paperwork is finished." The regulations clearly require the owner-operator to examine the maintenance records prior to returning the aircraft to service. This is not only to ensure the aircraft has been approved for return to service properly, but just as important, to ensure that all required maintenance entries have been made. Paperwork is never as much fun as working on the aircraft and is many times completed in a rush and with half the effort.

As maintenance providers, we need to encourage the owner-operator to look over the entries (second set of eyes); and as owner-operators, we should understand the importance of making sure record entries are complete and accurate and take the time to look them over in detail.

Most maintenance providers would much rather make needed corrections up front than get a call in six months asking for a new entry. And, we are all susceptible to making mistakes. Our logbook auditors commonly find omissions, inaccurate times/cycles, wrong dates, etc., all of which cost more to correct after the fact.

The sale of the aircraft

Not only does the accurate and complete recording of maintenance have a significant impact on the ongoing operational cost of an aircraft, the overall value of the aircraft is impacted as well.

Arguably, the most revealing pre-buy inspection is a good audit of the aircraft records. A complete audit will identify the current status of the aircraft as required by 14 CFR 91.417, uncover time frames of no maintenance, identify inaccurate engine cycle tracking as well as aircraft time tracking, and reveal aircraft damage history. Once an aircraft has been damaged, it is difficult to establish a value that is as high as the identical aircraft with no damage.

Complete records pay off

Incomplete or missing records will greatly impact the value and ability to sell the aircraft. The completeness and accuracy of the aircraft's maintenance records is something we can control with very little effort.

We have seen missing blocks of time or missing logbooks impact the value of a used aircraft as much as 25 percent. For a $15 million aircraft that figure is $3,750,000. Hard to believe isn't it? Well, think about it this way; if your particular aircraft is one of several available at the time you are ready to sell and you are missing a large block of maintenance records for some reason, the aircraft with complete and accurate records will sell first, no doubt. And, when you are faced with a must-sell situation, you will be forced to reduce the price significantly in order to move the aircraft.

So, you can see how important complete and accurate aircraft records are. The regulations set up the framework for maintenance recording. They dictate what must be recorded, by who, and when, as well as what records must be transferred with the aircraft.

I hope that as a result of reading this article you have a new or reinforced appreciation for the impact that maintenance record keeping has on the cost of maintenance and the overall value of an aircraft.  

Joe Hertzler is the CEO and co-founder of Avtrak Inc., provider of the industry's first Internet-based and compliance-focused maintenance tracking service — Avtrak GlobalNet. Avtrak has announced, within the past two years, alliances with Gulfstream, Raytheon, and Sikorsky that have each selected Avtrak's GlobalNet technology for the next generation of their factory-provided maintenance tracking services, Gulfstream, Raytheon FACTS, and Sikorsky Helotrac II.