Aircraft Cruise Speed vs. Maintainance Ratio

Does changing the cruising speed manually within the acceptable limits for the aircraft affect maintainance ratio?

No, calculation of maintenance is based on kilometres only.

Yes it does. If you are at 99.7 a simple speed override to maximum will save you a few minutes off flight plan, frequently bringing maintenance ratio to positive 100.1 etc.

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Only when those saved minutes are used to extend a maintenance window, you will see this perceived effect. The requirements for maintenance (ergo the “damage points” obtained by an aircraft during flight) are still the same.

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So you’re both right :wink:

Learned something new. Thanks for framing that in a way I could really understand.

Is there a way/formula/guidelines to adjust cruise speed to offset maintenance needs?

I have a flight with about 90% maintenance ratio. Over a few weeks, the maintenance value has fallen to 53% before the overnight maintenance I set. I’m sure it will slowly drift lower. But if I set the cruise speed higher, there will be more time for the nightly maintenance. I’m wondering if this will adversely affect the maintenance.

I’m trying to work out how to tweak this. It’s such a distance that there are only return 2 flights per day, over 20 hrs, leaving 4 hrs for maint. And… it’s my best earner. Maybe I should do only one flight on Sundays? Or make each day subsequently later?

Maintenance ratio must be over 100%. Otherwise, your plane soon will be grounded.
If you have very long flights, I would suggest that you use 7 planes. Add one flight to those 7 planes on every day. Then you won’t have any problems.

I can see how that would work, but I don’t have the cash to do that yet.
Thanks for the tip… sounds like a plan.

I had one where the maintenance ratio was about 85%.
Eventually the condition dropped to about 55%.
I was panicked. :frowning:

It was a full schedule, so I thought, what if I just delete one return flight. I deleted the scheduled flights for Saturday night. That brought the maintenance ratio up to about 108%. Been working nicely since then. :upside_down_face: