Incorrect Aircraft Specifications and Flight Planning: Part 2 – Areas to Watch for

PT 4 M minute read
Incorrect Aircraft Specifications and Flight Planning: Part 2 – Areas to Watch for

This business aviation blog post continues from our article last week, titled "Aircraft Specification and Flight Planning: Part 1 – Keeping Specs/Weights Updated."

Having accurate and updated aircraft specs on file with your 3rd-party provider not only establishes more efficient routings and flight legs but also helps operators maintain regulatory compliance. More information is required today than ever before for worldwide general aviation operations, and regulations differ country to country. For example China requires you to operate on a pre-approved routing, and this will depend on the navigational equipment your aircraft has.

The following is an overview of what you need to know:

1. Regulatory requirements impact aircraft specs

Over the past few years, more and more regulatory requirements have come into play worldwide. For example International Civil Aviation Organization (ICAO) 2012 flight plan requirements have altered the flight planning process. If your flight plan does not contain information compliant with ICAO 2012 requirements, air traffic control will likely reject it. Navigation equipment and authorizations, such as Automatic Dependent Surveillance-Broadcast (ADS-B) and Performance-Based Navigation (PBN), often determine permitted Flight Levels (FLs), and this will impact fuel consumption. Operators traveling in certain parts of Asia, who are not ADS-B compliant, may be faced with lower operating altitudes, increased fuel burns, and higher travel costs.

2. There are some top considerations

  • Basic Operating Weight (BOW) and zero fuel weight are the most relevant weights in terms of aircraft specs. These items impact how fast and how far an aircraft can fly a particular flight leg.
  • Fuel reserve policies differ among operators. Some specify 45-minute landing reserves, while others require landing reserves of 10% or more. However, a reserve policy isn’t necessarily a "one size fits all" input, so it’s recommended that you speak to your 3rd-party provider.
  • PBN and Reduced Vertical Separation Minimum (RVSM) certifications often impact routing, FL, and access to special airways (including North Atlantic tracks). In some cases routing may be limited to below FL 290 if RVSM or ADS-B certification is missing. This significantly impacts fuel burn and range. Keep in mind that, in addition to specified onboard navigation equipment, you’ll also require Letters of Authorization (LOAs), from your regulatory authority, in order to take advantage of operational benefits.
  • Minimum Navigation Performance System (MNPS) certification covers FL 280- 410 over much of the North Atlantic. If your aircraft isn’t MNPS-certified, along with an LOA, when you cross the North Atlantic, your FL will usually be restricted, and you will not benefit from preferred en-route handling from Gander Oceanic and Shanwick centers.
  • High-Frequency (HF) radios are required for operation in most MNPS airspace. If you don’t have HF radio, on a North Atlantic flight for example, you’ll have to remain in airspace which provides VHF radio coverage, known as the "blue spruce" routes. This adds additional distance and fuel burn to your flight as the routes takes you further north where this coverage is available. This is often the case with aircraft that are on experimental certificates and some demo aircraft.
  • 8.33 kHz radio spacing matters in Europe. If you don’t have 8.33 spacing, when entering European Union airspace, you’ll need to drop down to FL 195 or below. (At one time 8.33 radio spacing waivers were available, but that is no longer the case.)
  • Extended-Range Twin Operations (ETOPs) certification may be required for preferred routes based on regulatory requirements from the state of registry of the aircraft, type of flight, and a company’s particular operations specifications. ETOPs requirements usually impact charter (non-scheduled commercial) rather than private non-revenue operations with authorizations for 60-, 90-, 120-, and 180-minute single-engine diversion range to alternate airports.
  • PBN has to do with what approaches/departures an aircraft may fly and may determine your eligibility to use certain restricted airways. If you don’t have the mandated PBN requirements loaded for your aircraft, your flight plan may be rejected, resulting in operational delays.
  • ADS-B is becoming a more widespread requirement worldwide. In certain parts of the world – including the corridor between Singapore and Hong Kong – operators without ADS-B certification do not have access to preferred airways and/or FLs.

3. Operator-driven items impact flight plans

  • Operator-driven specifications frequently impact the flight planning process. In some cases operators choose to refrain from overflying certain countries due to security issues.
  • In order to avoid turbulence for passengers, there may also be added restrictions for particular operators, in terms of routing/FLs. In the flight-planning process, 3rd-party provider flight planning specialists and meteorologists work closely to meet clients’ specific requirements regarding turbulence along the route.
  • Individual passenger restrictions can also impact routing and flight efficiency. There may be cases where passengers specify that they do not want to fly above FL 350 for medical reasons.
  • Sanctioned country restrictions impact operations in different ways. While overflight permits can be obtained for Iran and Cuba for example, certain operators may choose not to overfly those regions based on the operators’ own internal operations specifications.
  • Last-minute operations may not allow sufficient lead time to organize all required overflight permits. In such cases you may need to consider alternate, longer, non-optimal routings to reach your destinations.

4. Revising flight plans may be necessary

There are times when you’ll need to alter a flight plan based on schedule changes or meeting delays. This could require revisions to airport slots, prior permissions required, and permits. You may be stuck on a ground stop due to weather issues, or you may be forced to divert if a particular airport is closing, and airport overtime is not possible. Or you may need to alter a flight plan due to time-sensitive routes. For example India has many timed and one-way airways, and delays may result in the need to revise a permit that’s route-specific.


Missing or inaccurate aircraft specifications can negatively impact flight planning efficiency in many ways. If on-file information is not accurate, there’s potential for operational delays, diversions, unplanned tech stops, being stuck at an airport during a closure, crew duty day issues, and even having to cancel a trip. Updating aircraft specifications and weights with your 3rd-party provider should always be a top checklist item.


If you have any questions about this article or need assistance with your future flight planning needs, contact me at

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