Understanding how well an aircraft supports your mission requires more than simply knowing whether it takes off on time. While dispatch reliability often gets the spotlight, it tells only part of the story about an aircraft’s true operational health. Aircraft availability—how often the aircraft is actually ready to fly—reveals deeper insights that many flight departments overlook. As maintenance demands grow with age and usage, tracking availability becomes essential for anticipating problems before they disrupt the business. In this post, we’ll explore why monitoring both reliability and availability is critical for informed decision-making and long-term fleet planning.
The NBAA Forum for Enhanced Reliability and Maintainability Standards (FERMS) offers the following criteria: A delay of more than 30 minutes, or a delay that results in a cancelation due to the aircraft systems not being able to dispatch would constitute a reliability issue.
The above definition includes any taxi back or air returns but excludes delays caused by a ground incident or other factors outside the aircraft systems being able to perform the mission.
Such occurrences can lead you to recognize that an aircraft has issues. If dispatch reliability issues become more frequent, they could cause you to question whether the aircraft is still up to the mission requirements it was acquired to perform.
So, it should come as little surprise that many flight departments – when asked – can tell you what their dispatch reliability is. Most flight departments can – and do – track their aircraft dispatch reliability. A lengthy delay or cancellation owing to the aircraft’s systems is, after all, a high visibility event in which passengers are inconvenienced.
Dispatch Reliability & Availability: What’s the Difference?
Dispatch reliability is only one tool for telling the story about the health of the aircraft. Aircraft availability is the other tool that, combined with reliability, will provide you with a fuller picture.
Aircraft availability tends to be less visible, but for flight operations that track it, this tool can reveal deeper insights into your aircraft’s health.
As a matter of fact, there are many within the industry who believe aircraft availability is just as important – and, in some cases, more important – than dispatch reliability in aircraft health monitoring.
Availability is also described in the FERMS, and is considered important enough to have the full explanation in FERMS documentation. But just how many flight departments are using this tool? Why, exactly, is tracking your aircraft’s availability important?
Ideally, your aircraft should be available on-demand as a business tool 24/7 365 days annually. As such, it needs to be available to fly those ‘pop-up’ missions and emergency missions that arise with little or no notice.
The assumption of 24/7 availability is very different than dispatch reliability, since dispatch reliability assumes the aircraft is ready, and can perform the mission with the systems in working order. In contrast, availability calculates the hours of downtime that are required to make that aircraft available for it to dispatch.
Reasons All Flight Operations Should Track Availability
Let’s illustrate with the example of an aircraft that returns from a trip on Monday night with discrepancies that need to be rectified before the next trip which is scheduled for Friday morning. The discrepancies are expected to take three full days to rectify, therefore the aircraft is unavailable in the interim.
During that time, the executives get an important call on Wednesday afternoon requiring them to visit one of the company’s plants. They need to fly on Thursday morning, so call the flight department only to learn that the plane is unavailable due to the maintenance work it is undergoing.
An alternative solution must be found to facilitate the travel need, and the executives are suddenly aware – to their frustration – of there being an issue with the reliability of the plane.
Now let’s assume an alternative scenario where the Flight Operation has been tracking the aircraft’s availability over a long period of time and noticed the trend for a growing amount of maintenance being required by the aircraft.
Recognizing that the aircraft’s lower availability will impact on the executives’ need to fly eventually, the flight department has the empirical (as opposed to anecdotal) evidence to head off the problem before it develops and put the case forward to the executives for the airplane to be replaced.
Taking a proactive approach to show the executives the evidence for a growing lack of availability for the aircraft, the executives are already aware that the aircraft is potentially less able to meet the demands of last minute travel, but plans are in place for last minute supplemental lift to be sourced if needed while an ideal replacement aircraft is being found.
For as long as the executives make their trips unhindered, it will be hard without empirical evidence to convince them that the time to upgrade is approaching. But with all the evidence to hand the process will be far easier, and a timely upgrade will be found before availability becomes a major problem to the aircraft owner.
Another reason why it’s important for flight departments to forecast aircraft availability is because it’s helpful to understand and explain downtime for upcoming major maintenance events.
Typically, newer aircraft do not have the major inspections older aircraft have since they have amassed lower times on engines, parts and airframe. While this tends to be easier to document, using the availability tool set will show empirically how much additional downtime is going to be due in a set period of time, along with the overall effect on the flight operations.
How to Know When to Upgrade the Airplane
Tracking aircraft availability can be used to help know and justify the sweet spot of when to upgrade your airplane(s). It can also be used when considering what age aircraft to buy if you’re shopping the pre-owned market for its replacement.
Knowing that one aircraft will be down for 2-3 months in two years’ time versus another plane that is already having that same maintenance undertaken might be the justification needed in buying an airplane that is either a year or two older or newer.
In Summary…
Hopefully it’s clear to see that tracking aircraft availability is something that should be on your ‘Must Do’ list as a progressive, proactive flight operation.
It is essential for flight departments to have good data to be able to keep the executives informed and make good decisions. Far too many flight departments just ‘wing’ this very important data set when, by spending just five minutes per week, they could have critical data to support their decision making…
Original article published on avbuyer.com
