Performance Tool Features

Allow us to walk you through what we have to offer.

Table of contents

Performance Tool Why Do I Need a Performance Tool? Introduction Virtual Performance Tool Installation Data Aircraft Airport Database Engine Failure Procedures Performance Calculations Takeoff Dispatch Landing Dispatch Landing Enroute Weather (METAR - TAF)
Non-Normal Checklist
VPT PRO only

*Complimentary / Experimental Features Virtual Dispatcher and Weight & Balance Introduction Weight & Balance

Performance Tool

Why Do I Need a Performance Tool?

Any airplane operated in the public transport role must adhere to the operational requirements set out by the regulatory agency. These regulations prescribe a minimum performance level for each stage of flight. The certification and operational regulations collectively aim to achieve a high standard of safety that has kept air travel as the safest form of transportation. To meet the required safety standard, aviation authorities have incorporated a safety margin into the airplane's performance data. The application of these safety margins is achieved through the use of a performance tool prior to each takeoff and landing.



Virtual Performance Tool

Our Virtual Performance Tool includes all the functionalities to accomplish the most accurate calculation for your flight.

In the aviation industry, ensuring the safety, economic efficiency, and compliance of aircraft operations is paramount. Traditionally, airlines have grappled with gathering essential performance data dispersed across hard copy manuals provided by aircraft manufacturers, including the Aircraft Flight Manual (AFM), Operations Manual, and Performance Engineer's Manual.

Virtual Performance Tool revolutionize this process, providing a comprehensive solution for all virtual pilots and virtual airlines. Now, navigating the complexities of aircraft systems and data interfacing becomes a seamless journey. Enhance the efficiency of each takeoff and landing without compromising safety standards!

Wondering how we achieve this? Keep reading to explore all that the Virtual Performance Tool has in store for you!



Option 1: Online Version

The online version of our tool is the most complete and requires no installation. Simply access it through your web browser on a large screen (tablet or laptop) for the best experience. Please note that using a mobile phone may not provide optimal functionality.


For iOS users, the latest version of iOS is required. Please note that some older devices may not be compatible due to Apple policy and restrictions. We recommend trying the demo before purchasing to ensure compatibility.

Option 2: Mobile Version (iOS & Android)

We're excited to announce the upcoming release of our mobile version for both iOS and Android.

ZFTT Training (2023)



We offer a wide range of aircraft, each meticulously added using official data from its manufacturer. Our advanced calculation system ensures accurate results, enhancing realism and safety in your virtual operations.

We're all about accuracy. Each aircraft in our collection is meticulously detailed with specific configurations for winglets, engines, and brakes. No generic data here – just the real deal.

Due to the individuality of each model, you have the opportunity to discover a diverse array of aircraft specifications. From underpowered planes with performance-limited takeoff weight, like the B737-800 with CFM56-7B24 engines, to highly overpowered options with Vmcg limitations, such as the B737-700BBJ with CFM56-7B27-B3 engines, our collection offers a diverse array of experiences. This will allow you to better understand your aircraft and the importance of performing accurate calculations.

0 Aircraft Families
0 Aircraft Models
0 Aircraft Variants

Brake Type

Brakes are a critical component of an aircraft's landing gear system, responsible for slowing down the aircraft during landing and taxiing. The two most common types of brakes are steel and carbon. Each type has its own set of characteristics, advantages, and disadvantages.

Steel Brakes
  • Performance: Reliable, but less efficient heat dissipation.
  • Cost: Less expensive to purchase and maintain.
  • Weight: Heavier, potentially impacting fuel efficiency.
  • Wear: Faster wear, more frequent maintenance.
Carbon Brakes
  • Performance: Better heat dissipation and stopping power.
  • Cost: More expensive to purchase and maintain.
  • Weight: Lighter, contributing to fuel savings.
  • Wear: Carbon brakes typically experience slow wear, resulting in longer maintenance intervals. However, improper usage of carbon brakes can lead to accelerated wear, necessitating more frequent maintenance.

To optimize the performance and longevity of carbon brakes, it's recommended to apply a single, constant brake input rather than multiple applications. This approach helps reduce brake wear by maintaining a consistent level of pressure. In some cases, allowing the aircraft to build up speed before applying a single brake input can be more effective than using multiple applications.


Aircraft performance calculation plays a pivotal role in ensuring safe and efficient flight operations. However, variations exist in how performance calculations are conducted between different regulatory authorities.

The Joint Aviation Authorities (JAA) was an organization that developed common safety regulatory standards for member states in Europe. In 2002, it was succeeded by the European Aviation Safety Agency (EASA), which is responsible for regulating civil aviation safety in the European Union (EU) and other associated countries.

In the United States, the Federal Aviation Administration (FAA) is the national aviation authority.

Differences in aircraft performance calculation between JAA/EASA and FAA arise from distinct regulatory frameworks and operational priorities. JAA/EASA follows standardized methodologies in line with European regulations, incorporating factors like noise abatement and terrain considerations specific to European airspace. Conversely, the FAA's approach is tailored to U.S. operational needs, focusing on compliance with Title 14 of the Code of Federal Regulations (14 CFR) and considerations such as runway length requirements and obstacle avoidance. These variations reflect regional nuances in regulatory practices within the global aviation industry.


Airport Database

Our performance database is meticulously designed to meet diverse requirements, distinguishing itself from reliance on fixed AIRAC cycles. It encompasses critical data, incorporating temporary obstacles documented by NOTAM, SUP, and any alterations to takeoff and landing distances. The airport database undergoes daily monitoring and updates, ensuring that you have access to the most recent information, promoting a secure flight experience.

We actively monitor our airports for:

  • Adjustments for TERPS/PAN-OPS operations
  • Dynamic runway closures with permanent or daily schedules
  • Magnetic variation (WMM-2023)
  • NOTAM (including obstacles and runway shortening)
  • SUP (Supplements)
  • Timezones

We also enlarge our airport databases by adding customized information such as:

  • Non-Standard Missed Approach Climb Gradient (MACG)
  • Runway Exits (calculated + handcrafted)
04/02/2024 15:11:04 UTC Active NOTAM monitoring with daily updates
0 Number of Airports Last updated: 04/02/2024 15:11:04 UTC
0 Runway(s) Closed by NOTAM Last updated: 04/02/2024 15:11:04 UTC
0 Non-Standard Handcrafted Missed Approach Climb Gradient (MACG)
60 Handcrafted Runway Exits and over 10,000 calculated

Every aircraft type has its own dedicated airport database designed to meet the specific requirements of that variant. This includes meticulously crafted Engine Failure Procedures, uniquely designed to ensure optimal performance and safety. Therefore, it is typical for larger aircraft, such as a B747 or A380, to have a more limited list of available airports compared to smaller jets like the B737 or the A320.


Engine Failure Procedures

The primary purpose of an engine-out procedure is to ensure the safety and continued control of the aircraft. The standard guidance suggests a straightforward ascent to the Minimum Safe Altitude (MSA) with the instruction "Climb straight ahead to MSA". However, certain airports situated in mountainous areas or areas with obstacles may necessitate a different path to meet the safety requirements and increase the maximum allowable payload. In these situations, we offer a comprehensive description of the optimal flight path to navigate safely and avoid obstacles in the event of an engine failure.

Engine Failure Procedure - Obstacle Clearance Obstacle Clearance Calculation

Beneath the text's surface, a smart algorithm is at work. It considers things like lift reduction during turns, wing span for low-wing obstacle clearance, speed, turn radius, and best and worst-case scenarios for the failed side and its impact on the turn. This algorithm crafts a path width that covers all obstacles along the Engine Failure Procedure. These obstacles then play a key role in figuring out your takeoff performance.

Visual Representation of Different Engine Failure Procedures at TNCM Visual Representation of Different Engine Failure Procedures at TNCM. CLB STRAIGHT AHEAD. TO D1.2 "PJM" VORDME, RT(15BA) TRK150. *MAX SPEED 150 KTS ALL TURNS*

Visual Representation of Obstacles Analysis at LOWS Visual Representation of Obstacles Analysis at LOWS.

Ready to go beyond routine flights from A to B?

Master the engine failure procedures and practice them at the most challenging airports.
Our tool gives you the best Engine Failure Procedures to minimize obstacle limitations.

Performance Calculation

Takeoff Dispatch

The takeoff calculation is arguably the most complex type of computation, involving numerous considerations. We meticulously examine each step to deliver the most precise result available for your flight simulation experience. The take-off phase spans from brake release to either the point where the airplane reaches 1500 feet or the height necessary to clear the last take-off obstacle if it's higher.

  • Field Length:
    Ensures adequate runway for safe continuation or rejection of takeoff in the event of an engine failure, and sufficient runway for a normal, all-engines takeoff.

    Take-off distance is determined between the start of the take-off roll and the point when the airplane reaches 35 ft (15 ft on wet).

    The engine failure is considered to take place at VEF and to be recognized (action taken) at V1.

    If decision at V1 is to continue, a take-off distance is defined by the airplane having reached a height of 35 ft (15 ft on wet).

    If decision at V1 is to stop, an accelerate-stop distance (ASD) is then defined.

    The safety margin consists in adding 15 % to the distance demonstrated by flight test.

  • Minimum Climb Requirement (One Engine Inoperative):
    Ensures the aircraft has sufficient climb capability throughout takeoff.

    Includes the required limitations to the take-off weight in order to achieve minimum climb performance. It is worth noting that, at this stage, those minimum performances have nothing to do with the obstacle clearance criteria. The obstacle clearance will be treated separately and may, of course, lead to higher performance penalties.

    The minimum climb gradient criteria correspond to still air conditions, while the obstacle clearance takes the wind into account.

    The takeoff is divided into four sections, each with a minimum climb gradient required for certification, up to an altitude of 1500 feet. This gradient is solely dependent on the number of engines the aircraft is equipped with.

  • Obstacle Clearance Requirement:
    Ensures the aircraft can clear all obstacles with the required margin, and this is precisely where the Engine Failure Procedure can have a significant impact.
  • For obstacle clearance, a NET flight path must be taken into account. This trajectory is virtual, achieved by reducing the gross trajectories with a safety margin determined based on the number of engines the aircraft possesses.

    Furthermore, the winds used in the obstacle clearance computation represent 50 % of the actual HW and 150 % of the actual TW (airport wind).

    Finally, the so computed net flight path must overfly the obstacles by at least 35 ft.

  • Maximum Certified Tire Speed:
    Limits the maximum ground speed before liftoff.
  • Tires are designed for a maximum ground speed. Its limiting effect will be applicable for all T/O speeds up to VLOF.

    Tire speed requirements have been checked and are not limiting for normal conditions. However, these limits could be exceeded at certain conditions where improved climb is used in conjunction with downhill slope, tailwind, and/or high altitudes and temperatures.

  • Brake Energy Requirement:
    Sets the maximum amount of energy the brakes can absorb in the event of a rejected takeoff.

    Maximum brake energy absorption is limited by design and certification.

    VMBE (Maximum Brake Energy Speed) is the speed giving a kinetic energy which is equal to the maximum brake energy.

    V1 must never exceed VMBE. Should V1 exceed VMBE, weight must be reduced, or the analysis must be done again with another flap setting or a lower V1/VR.

Optimum V1

V1 is the latest speed at which you can safely abort a takeoff, and it's also the earliest speed at which you can proceed with the departure.

However, fewer virtual pilots are aware that V1 actually represents a range of speeds, typically set between:

Vmcg ≤ V1 ≤ VR

The operator has the flexibility to configure their performance tool according to their procedures. This includes selecting the preferred value of V1 to be used.

  • Minimum V1: the minimum permissible V1 speed for the referenced conditions from which the takeoff can be safely completed after the critical engine has failed at the designated speed (VEF). This option prioritizes shorter ASDR (Accelerate-Stop Distance Required) but results in a longer Engine-Out Go distance. Due to the smaller V1, it is typically more inclined towards a "go" decision during takeoff.
  • Maximum V1: the maximum possible V1 for the referenced conditions at which a rejected takeoff can be initiated and the aircraft stopped within the remaining runway (or runway plus stopway where available). This option prioritizes a shorter Engine-Out Go distance but results in a longer ASDR (Accelerate-Stop Distance Required). Due to the larger V1, it is typically more inclined towards a "stop" decision during takeoff. This is usually the closest one to the CDU speeds.
  • Optimum V1: a flexible and optimized V1 that balances the requirements of Takeoff Distance Required (TODR) and Accelerate-Stop Distance Required (ASDR). It considers factors such as wind, slope, and obstacle clearances to deliver the most effective performance available.
Takeoff Calculation Takeoff Brake Cooling Takeoff Airport Details Takeoff Details Takeoff Brake Cooling Takeoff Bug Card

Our tool is set to provide you with the Optimum V1 for your conditions, which may differ from the generic values given by your CDU/MCDU. Understanding the theory will help you to maximize your performances.

Improved Climb

The "Improved Climb" technique uses the excess runway available to accelerate to higher takeoff speeds thereby achieving higher gradient capability.

The excess gradient is achieved by using a heigher V2. To increase V2:

  • VR (rotation speed) must be increased
  • V1 must be increased to ensure sufficient speed is available to continue the takeoff in case of engine failure

The excess speed must be cautiously managed, especially on very long runways and at high weights, as your Performance-Limited Takeoff Weight (PLTOW) could be restricted by tire limits. A rejected takeoff at such speed and weight may lead to fuse plug melting. This limitation can be realistically assessed using our performance tool.

Extended Second Segment

Typically, a standard Acceleration Height is determined in accordance with operator procedures, with a legal minimum starting point as low as 400 ft AGL. However, opting for too low an acceleration height may pose conflicts with certain obstacles, limiting your maximum takeoff weight. Conversely, selecting an excessively high acceleration height may clash with engine limitations.

The Maximum Takeoff Thrust (TOGA) is certified for use within a maximum window of 5 minutes, extendable to 10 minutes with manufacturer authorization. While this enhanced feature requires additional maintenance considerations, it can significantly boost performance, especially in scenarios with high obstacles surounding the airport of departure.

Our premium package provides diverse profiles with various engine certifications, allowing you to tailor your choice to specific needs and optimize performance. This process is automatically reflected in your Engine Out Acceleration Height / Minimum Flaps Retraction Altitude.

Loss of Runway Length due to Alignment

Airplanes typically enter the takeoff runway from an intersecting taxiway. The airplane must be turned so that it is pointed down the runway in the direction for takeoff. FAA regulations do not explicitly require airplane operators to take into account the runway distance used to align the airplane on the runway for takeoff. On the contrary, EASA regulations require such a distance to be considered.

At Virtual Performance Tool, we conduct lineup corrections as part of our takeoff performance calculations whenever the runway configuration prevents positioning the airplane at the threshold. This adjustment is typically necessary for a 90° taxiway entry or a 180° turnaround on the runway. Detailed adjustments, as outlined in published tables, guide this correction process.

Slippery vs Friction

Here's a fun fact you can explore with our precise tool: A shallow layer of dry snow can actually create a slippery runway surface, leading to an increase in the Accelerate-Stop Distance Required (ASDR). However, once the snow depth reaches a certain threshold, the accumulated contaminant will induce friction, thereby reducing the ASDR. Consequently, it's common to observe a lower Performance-Limited Takeoff Weight (PLTOW) on runways with shallow snow depths compared to those with deeper accumulations.

Takeoff Result

Performance Calculation

Landing Dispatch

The landing calculation, often underestimated by virtual pilots, remains a critical performance assessment. Regulatory standards mandate its completion before each flight.

The landing mass of the aeroplane shall not exceed the maximum landing mass specified for the altitude and the ambient temperature expected for the estimated time of landing at the destination aerodrome and alternate aerodrome.

The Maximum Landing Weight is the most restrictive of:

  • Field length limited weight
  • Landing climb limited weight
  • Approach climb limited weight
  • Tyre speed limited weight
  • Brake energy limited weight
  • Missed approach climb gradients limited weight
  • Maximum certified (structural) weight
  • Most favourable runway limited weight

Prior to dispatch or in the event of in-flight re-planning, crews must determine the maximum weight at which the airplane can land at destination, alternate or fuel en-route alternate (when required) is within available landing distance in expected conditions. LDR must be less than LDA.

    Landing Dispatch Landing Calculation Detail

Normal and Ice calculations

Max Landing Weight is calculated as “Normal” and “With Ice”. With Ice MLW applies when operating in icing conditions during any part of the flight with forecast landing temperature below 10° C. At temperatures above 10°C, our tool will not display With Ice MLW.

Quick Turnaround Weight and Time

We conduct thorough Quick Turnaround Weight and Time calculations for compatible models. The Maximum Quick Turnaround Weight (MQTW) is defined as the maximum weight permissible for the aircraft, considering the allotted time specified in your Aircraft Flight Manual (AFM) for the particular aircraft type and brake category installed. This weight ensures that under the given waiting time, the occurrence of fuse melt is prevented or avoided. For instance, the 737NG AFM specifies time ranges of 48-67 minutes, contingent upon the brake type and aircraft model. This is different from the "Recommended Brake Cooling Schedule" explained in Landing Enroute.

Autoland Safety Increments

We provide autoland safety increments for models supporting this feature. The landing distance at a given weight is greater for an autoland than a manual landing due to a possible longer flare. A standard value for the 737-800 with Flap 30 configuration is typically set at 185 meters (please note that a different, more precise value may be utilized by our tool).

Missed Approach Climb Gradient

The Missed Approach Climb Gradient refers to the minimum rate at which an aircraft must climb during a missed approach procedure.

The Missed Approach Climb Gradient is typically expressed as a percentage or in feet per nautical mile (ft/NM). It represents the vertical distance the aircraft must climb over a given horizontal distance (usually one nautical mile) during the missed approach procedure.

The minimum gradient stands at 2.5% for PANS-OPS airports and 200 FT/NM (equivalent to 3.3%) for TERPS airports. However, certain airports may impose a more stringent climb gradient due to obstacles or terrain along the missed approach path. By ensuring the aircraft can achieve a higher Missed Approach Climb Gradient (MACG), pilots gain the flexibility to opt for a lower minimum as indicated on the corresponding airport chart.

Here is an example with the ILS 16 in Thessaloniki (LGTS). The ILS approach has two set of minima. One for standard missed approach with a 2.5% climb gradient and one for a 4% climb gradient. Note the differences in the minimas for an ILS CAT I. Those are due to the terrain clearance in the runway axis.

ILS 16 in Thessaloniki (LGTS) - Jepp Chart ILS 16 in Thessaloniki (LGTS)

The community has the opportunity to propose non-standard Missed Approach Climb Gradient (MACG) values, which are then subject to review by our performance department. Frequently, a single request prompts the inclusion of additional gradients specific to the requested airport.

ILS 16 in Thessaloniki (LGTS) - VPT form Custom MACG for LGTS 16
0 Non-Standard Handcrafted Missed Approach Climb Gradient (MACG)

Performance Calculation

Landing Enroute

The Landing-Enroute calculation mirrors the Landing-Dispatch procedure but is intended for use in-flight, prior to reaching the Top of Descent, utilizing the most current weather data. In addition to previous calculations, the Landing-Enroute includes the computation of:

  • Landing distances (both factored and unfactored) for specified autobrake settings.
  • Brake cooling schedule (if applicable to the selected model).
Landing - Textual Results Landing - Graphic Results Landing - Details Landing - Recommended Brake Cooling


Larger airliners have an autobrake system which is designed to only use the amount of wheel braking required to achieve the target deceleration commanded for the selected auto brake setting. Upon touchdown, automatic wheel braking is initiated with main gear spin up and brake pressure increases until deceleration rate commanded by the selected Autobrake setting is attained. Brake pressure will modulate to maintain the selected deceleration rate until the auto brake is disconnected or the airplane is stopped. The system will respond to changes in reverse thrust, aerodynamic forces and runway slope to maintain the selected deceleration rate.

Choosing an autobrake setting is either dictated by the performance criteria or by our plans on how to vacate the runway. Sometimes the terminal is at the end of the runway and we can use the minimum braking available. Sometimes it’s the other way around and we prefer to vacate as soon as practical to reduce the taxi time.

Using a performance tool will help you to choose which autobrake setting is most suited for your needs.

Recommended Brake Cooling Schedule

The brake cooling schedule information is provided to assist in avoiding the problems associated with hot brakes. For normal operation, most landings are at weights below the AFM quick turnaround limit weight. However, some conditions, some restrictions and quick turnaround time could affect the performance of the brakes. This situation could be avoided by taking into consideration the brake cooling schedule.

Our tool provides you with both ground and air cooling times, along with the anticipated Brake Temperature Monitoring System (BTMS) value following your landing.

Aerodynamic Drag

Some of our models, like the 737, include an aerodynamic drag feature which improves the Recommended Brake Cooling Schedule.

Indeed, the tables found in the FCOM/FPPM/QRH are accounted for the least aerodynamic drag landing flap (F15 on the B737). For a higher flap setting, the additional aerodynamic drag helps the braking therefore reduces the BCS. When available, our algorithms take this into consideration to get closer to the manufacturer values.

Runway Exits

As outlined in our Airport Data section, our tool introduces an unprecedented feature: displaying available exits on each runway.

To achieve this, we calculate these exits based on the takeoff intersection of the current runway and its opposite counterpart. While not flawless, this ensures extensive global coverage.

Moreover, we offer the option to incorporate manually crafted exits for specific runways. This innovative feature comes with a continually expanding list of exits.

6 Handcrafted Runway Exits
Landing Result

Performance Calculation

Weather (METAR - TAF)

In reality, we utilize ATIS (or D-ATIS) data to populate our performance tool. Understandably, this isn't always feasible in Flight Simulation. Hence, we furnish you with alternative weather information sources.

  • Raw METAR / Decoded METAR
  • Raw TAF / Decoded TAF
    Weather EIDW - Decoded EHAM - D-ATIS - IVAO


We analyze weather data and flag any significant conditions that warrant your attention. Our monitoring includes gusty winds, cumulonimbus clouds, low visibility, precipitations, and more!

NOTAM fetching ZLLL - Highlighted Weather


The METAR2VPT feature is a proprietary algorithm that automatically analyzes METAR data and populates your performance tool. It assesses runway conditions, temperature, dew point, and other variables to determine the optimal runway condition, anti-ice requirements, as well as worst-case wind scenarios, magnetic variation correction, and more.

Multiple Sources

We also fetch our weather data from multiple sources to always maximize the availability of the data.

  • Aviation Weather Center
  • Avinor Norway
  • NOAA

Performance Calculation


Daily Monitoring

As detailed in our Airport Data section, our airport database receives daily updates containing the latest NOTAMs (Notices to Airmen), SUPs (Supplemental Notices), and more. You can directly observe this in our performance tool when selecting your runway, as you'll be presented with the choice between a runway with NOTAMs or without NOTAMs.

    NOTAM example 1 NOTAM example 2 NOTAM example 3 NOTAM example 4

Manual modifications

In addition to daily airport updates, manual modifications may be required for the active runway. This feature not only relies on published NOTAMs but also allows users to manually adjust the runway as needed. Whether it's adding a takeoff intersection or accommodating obstacles, users have the flexibility to make necessary changes.

  • Missing NOTAM:
    In cases where a NOTAM (Notice to Airmen) is missing, users have the option to manually adjust the runway length to accurately represent the current conditions.
  • Remove a clearway or stopway:
    Users are able to eliminate a clearway or stopway by reducing the overall runway length by 1 meter or 1 foot.
  • Shorten a contaminated runway: When faced with a contaminated runway, users can adjust the runway length manually. Given that the contamination report divides the runway into three equal sections and applies the lowest coefficient to the entire length, users can improve performance by removing the last section if it is the most affected. This adjustment can be particularly beneficial on longer runways.
  • Create a runway intersection: Users can create a takeoff intersection by shortening the runway length from the threshold.
  • Introduce or Assess Additional Obstacles: Users have the capability to introduce a previously unaccounted obstacle onto the runway. Evaluating this can be challenging since NOTAMs typically describe obstacles using coordinates or relative to a navigation station. However, this feature proves highly beneficial for training purposes, enabling users to gauge the influence of obstacles on overall performance.
NOTAM fetching Add a Custom NOTAM

NOTAM fetching

We also provide access to the latest NOTAMs (Notice to Airmen) for your selected airport directly from our FAA source. This allows you to quickly check for any runway closures, obstacles, ongoing construction, and other pertinent information.

NOTAM fetching Automatic NOTAM fetching

Performance Calculation

Non-Normal Checklist (NNC)

The Non-Normal Checklist is indeed the first step toward a more realistic flight experience. Initially intimidating for virtual pilots, but soon you'll be glad you jumped into it. You'll master the QRH and gain a deeper understanding of your aircraft systems.

The Quick Reference Handbook (QRH) is a manufacturer-made manual containing checklists to handle any non-normal situation, such as electric failure, loss of hydraulic pressure, or even engine failure.

Certain non-normal situations directly affect your aircraft's performance. Understanding the fundamental principles of aircraft systems makes it clear that a hydraulic failure, for example, can impact your brakes, flaps, or overall aircraft controllability, which can significantly impact your landing performances.


Virtual Performance Tool provides you with an exhaustive list of Non-Normal Checklist, allowing you to factor in any penalties resulting from failures.

NOTAM fetching 737NG - List of NNC

Getting Started with the QRH

The following recommendations apply to Boeing aircraft only. Some titles or sections may differ for aircraft equipped with EICAS.

  1. Get a QRH for your aircraft
    Some addon manufacturers provide you with the QRH. If not, you can search online, for example, "QRH 737-800," to try to find one. Ensure that you have the correct QRH for your aircraft model.
  2. Understanding the layout of your QRH
    The QRH is divided into sections:
    • Quick Action Index: The first page of the QRH contains a list and index of all urgent/important non-normal checklists (NNC) for faster access.
    • Lights Index: Lists NNC sorted by the annunciated light.
    • Unannunciated Index: Lists NNC that are not annunciated.
    • Alphabetical Index: Lists NNC sorted alphabetically.
    • Normal Checklist: Contains normal checklists such as "Before Takeoff," "Landing," etc. These may vary per operator.
    • Non-Normal Checklist: This section houses all NNCs, divided into aircraft systems. The index is based on the FCOM Volume 2 System Description order.
    • Performance Inflight: Contains various tables for inflight use, such as Engine Inoperative Ceiling, recommended brake cooling schedule, airspeed unreliable pitch and thrust settings, and more. A useful resource during cruises.
    • Maneuvers: Contains schematic or textual descriptions of different maneuvers, from normal takeoff and landing to terrain escape maneuvers, TCAS RA, or windshear recovery procedures.
    • Checklist Instructions: This section provides instructions on how to use both Normal and Non-Normal checklists.
    • Evacuation: Located at the back of the QRH for easy access, this contains the evacuation checklist.
  3. Checklist Instructions
    The initial section to review is the 'Checklist Instructions'. Here, you'll find fundamental guidance on utilizing the QRH and understanding its symbols, applicable in both Normal and Non-Normal scenarios.
  4. Practice Locating the Appropriate NNC
    Quickly finding the correct NNC is crucial. Practice locating the NNC for various failures. Some NNCs may be similar; verify the "conditions" to ensure you're using the correct one.
  5. Execute the NNC
    With the exception of Memory items, which are to be executed immediately, the NNC is to be executed systematically (Read & Do). The QRH provides a clear structure to follow, ensuring you don't miss any steps.
  6. Apply the Performance Penalty
    If necessary, the QRH will direct you to the Performance Chapter Inflight (QRH or Virtual Performance Tool). Apply the appropriate NNC to your performance tool to account for performance penalties. Caution: some NNCs might offer different flap configurations. Ensure you select the correct one.

We're here to help you become the ultimate virtual pilot.

Performance Calculation

MEL (Minimum Equipment List)
CDL (Configuration Deviation List)

Minimum Equipment List (MEL)

In aviation, the Minimum Equipment List (MEL) is a document approved by the aviation authority that outlines the specific equipment that must be operational for an aircraft to be dispatched for flight. It allows operators to legally operate an aircraft with certain non-essential equipment temporarily inoperative, provided that specific conditions and limitations are met.

Elevate your flight sim experience by dispatching your aircraft with some failed items! Configure the aircraft according to the MEL, and take it into account in your performance calculations.

MEL example Example of a MEL item selected

Configuration Deviation List (CDL)

On the other hand, the Configuration Deviation List (CDL) is a list of approved aircraft configurations that deviate from the standard aircraft configuration specified in the aircraft type certificate. It documents deviations such as interior reconfigurations, optional equipment installations, missing or damaged external panels, or modifications that do not affect the aircraft's airworthiness or safety.

Although addon manufacturers do not include any visual or performance penalties for any CDL item, it remains a very good practice for virtual pilots to fully understand our job.

CDL example Example of a CDL item selected
Real MEL 73-21-02 (2024)

Virtual Dispatcher and Weight & Balance


Regulations mandate that during any phase of operation the loading, mass and centre of gravity of the aeroplane complies with the limitations specified in the approved Aeroplane Flight Manual (AFM), or the Operations Manual if more restrictive. It is the responsibility of the commander of the aircraft to ensure that this requirement is met.

While our primary focus revolves around performance, we offer complimentary access to an advanced weight and balance system with every performance subscription. It's important to note that this sophisticated system may not always align with third-party tools featuring less advanced capabilities.

Contrary to common assumptions, weight and balance are not directly intertwined with performance calculations. An aircraft's center of gravity can, however, influence performance in scenarios involving advanced features like alternate CG, trim setting calculations, or VMCA assessment. The performance tool, in all instances, exclusively considers the center of gravity value expressed as a percentage of the Mean Aerodynamic Chord (MAC). Typically, weight and balance procedures are handled by dispatchers in most airlines, and the results are then communicated to the flight crew.

We present you with two remarkable features: a conventional manual weight and balance system, and a seamlessly automated process facilitated by our Virtual Dispatcher. The tool generates professional-looking documents, striving to bring you as close as possible to reality in your virtual aviation operations.

Virtual Dispatcher and Weight & Balance

Weight & Balance

The weight and balance system serves to confirm limitations in two crucial aspects:

  • Mass limitations are set to ensure adequate margins of strength and performance. The total weight of the aircraft shall not be greater than the maximum weight allowed by the EASA/FAA for the make and model of the aircraft.
  • Center of Gravity (CG) position limitations are set to ensure adequate stability and control of the aircraft in flight. The center of gravity (CG) must be maintained within the allowable range for the operational weight of the aircraft.

At Virtual Performance Tool, we employ the authentic weight and balance formula in our calculations. The aircraft is divided into stations, measured from a Reference Datum. This measurement is referred to as the "arm," typically expressed in inches. On this arm, we apply a mass, resulting in a moment. The sum of all moments divided by the total mass yields the average arm. This average arm can then be converted to %MAC using the LEMAC (Leading Edge Mean Aerodynamic Chord) and MAC (Mean Aerodynamic Chord) length. This algorithm typically differs from the one used in Flight Simulators.

Weight & Balance Formula

\( \text{MOMENT} = \text{WEIGHT} \times \text{ARM} \)

\( \text{CENTER OF GRAVITY} = \frac{\text{MOMENT}}{\text{GROSS WEIGHT}} \)

\( \text{CG % MAC} = \frac{\text{CENTER OF GRAVITY} - \text{(LEMAC)}}{\text{TOTAL LENGTH MAC}} \)

The weight and balance are subdivided into multiple sections, each of which will be elaborated upon below.


The SETUP section enables you to choose your weight and balance profile, providing your aircraft's empty weight and facilitating the addition of loads to determine your Operating Empty Weight (OEW).

The Operating Empty Weight refers to the weight of an aircraft when it is in a standard operating condition, including the weight of the aircraft's structure, systems, and fixed equipment. It excludes the weight of fuel, passengers, cargo, and any other variable items.

  • Placard Weight:
    Customizable placard weight allows for a more restrictive Maximum Takeoff Weight (TOW). Some airlines utilize this option to set a maximum takeoff weight lower than the maximum structural takeoff weight.
  • Flight Crew:
    While the standard flight crew number is typically two, there are instances where a non-standard member of the flight crew might be present in the flight deck. This could include a relief pilot, Aviation Administration Inspection personnel, or the presence of a Safety Pilot during Line Training, an Observer, and so forth.
  • Cabin Crew:
    The cabin crew is responsible for the safety of the passengers and the aircraft cabin. The number of cabin crew members is determined by the number of passengers and the type of aircraft. There are situations where a higher-than-standard number of cabin crew members might be present in the cabin, such as during a line check, observation flight, and other scenarios. Conversely, a lower-than-standard number may occur in extreme circumstances. In such cases, our tool outlines special procedures and limitations to address these unique situations.

Virtual Performance Tool

Ready to step out of your comfort zone and plan a flight like a real pilot?

Still not convinced? Try our free demo!

Our demo showcases the VPT Pro subscription, granting access to our entire fleet. However, please note that availability of airports is highly limited in this version.

Rest assured, we offer a full refund within one week of your initial payment if our tool doesn't meet your expectations.