Aircraft Specifications and Flight Planning: Part 1 – Keeping Specs/Weights Updated

PT 3 M minute read
Aircraft Specifications and Flight Planning: Part 1 – Keeping Specs/Weights Updated

This business aviation blog post is part of a series on aircraft specifications and flight planning.

Aircraft specs differ depending on aircraft model as well as the particular aircraft. For instance if you have three similar models of aircraft in your fleet, each is likely to have different specs/weights to consider. Being that each aircraft and operator is different, providing the most current and accurate aircraft specifications and weights to your 3rd-party provider helps ensure flight plans and planned flight endurance can be calculated correctly.

The following is an overview of what you need to know about keeping your specs current and the impact if you do not:

1. Changes in aircraft specs over time

Aircraft Basic Operating Weight (BOW) is a critical number as variations in it can significantly change fuel burn and alter operating costs. Correct BOW is particularly important for long-haul/max-endurance flights. BOW changes over time, so it’s important for operators to weigh aircraft when items are added or removed. If you’ve added flight deck equipment, refurbished the interior, added an onboard shower, or repainted your aircraft, the BOW will have changed. The most recent aircraft weights should be forwarded to your 3rd-party provider to ensure correct flight plan fuel consumption data. For example if you’ve retrofitted winglets, the change will have altered aerodynamic efficiency/range. Keep in mind that no two aircraft of the same type will have the same BOW/specifications.

2. Updating specs regularly

Aircraft specs and BOW should always be updated to ensure accurate flight planning. While generic aircraft specs/weights may be used for ballpark estimates, such estimates should never be used for actual flight plan purposes. There are also “biases” to consider, depending on the make and model of aircraft. For example with Gulfstream aircraft, our flight planning experts typically add a 16% bias for flights of less than three hours. However, biases depend on the age of the aircraft, how the operator flies it, planned flight level, and speed. Buffers are also added to an aircraft based on operator feedback. So, it’s best practice for operators to compare actual fuel burns with flight plan burns to confirm accuracy. Be aware that even small changes in altitude or payload can greatly impact range performance of a filed flight plan.

3. Top issues with operating specs

Aircraft weight and navigational equipment specifications are the top items we see in terms of missing and/or incorrect information. It’s imperative that this information be correct to ensure the best and most efficient outcomes for your flight. Routinely updating specs makes a difference, especially for long-haul flight legs when tech stops are required or when en-route weather issues are likely.

4. Keeping your 3rd-party provider updated

In addition to updating aircraft specs regularly and providing that information to your 3rd-party provider, it’s also a good idea to give the 3rd-party provider your most recent Letters of Authorization (LOAs). That way, if you’re ramp-checked overseas and do not have LOAs with you, your 3rd-party provider can forward them upon request.

5. Tracking fuel burn

Best practice, to maximize accuracy of flight planning, is to track fuel burn and compare the results against flight plans. If there’s a fuel burn discrepancy, let your 3rd-party provider know so that biases can be added as needed to ensure future flight plans are correct. The more information your 3rd-party provider has, the more accurate your flight plans will be.


Best practice is to make a point of tracking and updating aircraft specs/weights with your 3rd-party providers on a regular basis. Waiting until the last minute to provide aircraft spec updates has the potential to cause issues and operational delays.


If you have any questions about this article or need assistance with anything related to flight planning, contact me at

Stay tuned for Part 2, which covers planning considerations pertaining to your aircraft specifications.

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