9.4 Flight Planning in the Real World

Student Pilots: Learning the Old School Way

When learning to fly, students learn how to make flight plans manually. Even at the initial stages of training, flight planning is a big component of the written and practical exams. And even today, despite the widespread proliferation of smartphones and tablets running capable flight planning apps like Foreflight, it is still common and useful to teach basic flight planning skills "on paper". 

Here are some of the old-school tools of the trade:

The planning process goes something like this:

Overall this approach is an excellent way of developing flight planning skill. Manually constructing a flight plan from scratch forces you to think about what you are doing, and quickly highlights where there are gaps in your knowledge. 

Operationally, there are some drawbacks to the approach. Most drawbacks stem from the time-consuming nature of paper planning:

• it is difficult to evaluate variations of your initial plan, and therefore difficult to achieve the best performance out of your plane

• many students have the painful experience of spending an hour or two building a flight plan only to find that as they finish, an updated winds forecast has been released 

• fatigue from number crunching can reduce your situational awareness 

Commercial Flight Planning

There are around 100,000 commercial flights operating per day globally. Creating flight plans manually is a great way to learn, but for the scale of commercial operations, more power is needed. Money and lives are on the line. We can say that flight planning at the global scale is powered by two key things:

1. Standardization

2. Computers

To explain this, consider how we might abstract the "paper planning" tools and process into a diagram:

In this diagram I am cheating a bit by using catch-all terms "Other preferences" and "Other info" to bury a ton of complex details in the inputs and outputs. I am doing this deliberately to keep the focus on the essential elements. 

Standardization

The above layout is generally what you will find in flight planning systems used all around the world. The fact that these systems can support flight planning for flights that traverse multiple countries and continents owes to the fact that a massive effort of international standardization has been performed since the end of World War 2. Some of the key organizations involved in this effort are:

• ICAO (International Civil Aviation Organization), which consists of 193 member states 

• IATA (International Air Transport Association) 

• FAA (Federal Aviation Administration)

• EASA (European Union Aviation Safety Agency) 

• Eurocontrol 

The ICAO in particular plays a big role in formalizing standards and recommended practices, and delivers this information to users in two comprehensive lines of publications:

• ICAO Annexes (examples:  Annex 2  — Rules of the Air, Annex 6  — Operation of Aircraft)

• ICAO Document Series (example: Doc 4444  — Procedures for Air Navigation Services — Air Traffic Management)

From our system layout, we can pick out some examples of international standardization at work: 

•  Flight Plan output: ICAO standards and recommended practices describe in comprehensive detail what content should be in an operational flight plan, and prescribe formats used to transmit such plans to air traffic control for approval 

• Navigation data: Each ICAO member country agrees to publish its navigation data in a bundle called the Aeronautical Information Publication (AIP), which includes detailed information about the country's airports, runways, navaids, waypoints, airways, airspace, and much more. The countries also agree to a common 28-day update schedule called the AIRAC cycle. 

• Aircraft data: Here in particular I would refer to aircraft performance data, which is a term that encompasses all the major performance characteristics of an aircraft model including takeoff and landing distances, payload, climb capability, endurance, range, speed, fuel consumption and more. If you were to ever buy an aircraft from a manufacturer, you would find an operating handbook included, part of which contains a detailed Aircraft Performance Section. This manual may be paper or digital. IATA took this a step further for airlines by creating a standardized set of specifications for digital aircraft performance data called Standard Computerized Airplane Performance (SCAP). This performance data is obviously essential to flight planning and its standardization allows airlines to use a single flight planning system even if their fleets include a mix of aircraft manufacturers and models. 

Computerization

The second key to flight planning at the global scale is computerization. Here, we are referring to the algorithms running on computer systems that make it possible to rapidly generate a comprehensive, accurate and optimized flight plan. There are several companies around the world which provide flight planning information systems. 

As you can imagine, the algorithms each company uses to perform the flight plan computation are closely guarded. As mentioned in the intro to this project, flight planning involves the creative combination of these fields:

• Computer science 

• Navigation

• Aircraft Performance

• Weather

I think this makes flight planning a bit of a niche topic. I am actually not aware of any textbooks on the topic, referring specifically to the problem of building flight planning computer systems. That can make this subject difficult to study without going to an aerospace engineering graduate school or working in the flight planning niche of the aviation industry. Knowledgeable readers take note: could writing a textbook on computerized flight planning be a lucrative business opportunity?