Aerodynamics & performance

It is well known that contamination on the runway may be a contributing factor to a runway excursion. In Sweden, known for warm and dry summers, the contamination mostly consists of snow and ice in the winter...

Southwest engineer gives operator perspective on blended winglet.

This document will help you to increase your knowledge in a better understanding of contaminated and slippery runways

Airplane tires are designed to withstand a wide range of operating conditions, including carrying very high loads and operating at very high speeds. It is common for a jet airplane tire to carry loads as heavy as 60,000 pounds while operating at ground speeds up to 235 miles per hour. To accommodate these operational conditions, each tire has specific load and speed ratings. Tires are carefully designed and tested to withstand operation up to, but not necessarily beyond, these ratings.

Aircraft braking coefficient is affected by liquid water in frozen runway contamination.

Pilot braking action reports that are based on reliable assessment procedures and that use the proper terminology are potentially valuable supplements to other runway condition information. The limitations of pilot braking action reports should be understood.

One of the very best documents published on a very sensitive operational topic.

The maximum altitude at which an airplane can be flown is limited by three factors: 1) the maximum certified altitude 2) the buffet-limited maximum altitude 3) the thrust-limited maximum altitude. The most limiting of these three altitudes defines the maximum operating altitude...

Among the various environmental concerns, the aircraft noise item has been constantly growing in importance over the past years. Indeed, unlike a Mozart’s symphony, airplane noise is one of those sounds which are undesirable to most of the observers. Its various effects on man, especially on the people living in the vicinity of civilian and military airfields must be studied to be better accounted for. This shall allow the determination and continuous refinement of indices reflecting noise impact, in order to develop an appropriate noise policy. The latter has the difficult mission to conciliate both the noise reduction around airfields while not penalizing too much the airlines operations, that is to say the air transport industry as a whole.

This document reviews the philosophy of Fuel Conservation

Wingtip Devices: what they do and how they do it. A Boeing aerodynamist explains in very simple words what is hidden between "induced drag reduction", "vortex", "winglets" and so on.

Today’s portable sensors and data-analysis techniques enable scientists worldwide to visualize dimensions, measure velocities and track positions of wake vortices generated by specific variants of large commercial jets.

This Boeing document reviews the importance of V1, statistics of past Rejected Takeoff (RTO) accidents and incidents and tries to provide an appropriate education for a better

This Boeing article deals again with Angle of attack (AOA) which is an aerodynamic parameter that is key to understanding the limits of airplane performance. Recent accidents and incidents have resulted in new flight crew training programs, which in turn have raised interest in AOA in commercial aviation. Awareness of AOA is vitally important as the airplane nears stall. It is less useful to the flight crew in the normal operational range. On most Boeing models currently in production, AOA information is presented in several ways: stick shaker, airspeed tape, and pitch limit indicator. Boeing has also developed a dedicated AOA indicator integral to the flight crew’s primary flight displays.

Since the early days of flight, angle of attack (AOA) has been a key aeronauticalengineering parameter and is fundamental to understanding many aspects of airplane performance, stability, and control. Virtually any book on these subjects, as well as basic texts and instructional material written for flight crews, defines AOA and discusses its many attributes...

This well-illustrated document to help pilots to understand different takoff thrust setting techniques.

The objective of this Briefing is to provide, from an operational perspective, an overall review of takeoff speeds, and of the factors that affect the calculation and use of V speeds.

What is Improved Climb? How is Improved Climb used? Explore in this Boeing document all the operational considerations of "improving" climb performance

Takeoff Thrust Setting Review for Airbus Operators.

Reminders on Airbus recommendations.

Most current performance requirements for the certification and operation of transport category airplanes were established at the beginning of the jet age. Today, operating experience and data provide the most accurate means to further improve the performance requirements of modern transport airplanes.

This SAS Braathens document has been published by Boeing during one of its latest symposiums. Once again it is well illustrated and quite interesting to read.

Topics of discussion are numerous: benefits of using Reduced Thrust, Methods for Reduced Takeoff Thrust, Regulatory requirements, thrust effect on takeoff performance, assumed temperature method. This is an exhaustive brochure.

Recommendations For De-Icing and Anti-Icing published by the AEA (Association Of European Airlines). The AEA De-icing/Anti-icing Working Group is the European focal point for the continuous development of safe, economical and environmentally friendly standards and procedures for the deicing/anti-icing of aircraft on the ground in conjunction with related international standards

Boeing goes well beyond the idea that V1 is the speed at which the takeoff should be continued unless the stopping maneuver has already been initiated.

ow to optimize Takeoff performance? This document has been published by Airbus for the 14th Performance & Operations Conference.

When an aircraft is dispatched in accordance with certification and operational regulations, there are some inherent margins included in the calculated takeoff and landing performance. Although it is not permitted to take advantage of these margins in order to increase the aircraft performance limit weight, it is of interest to be aware of the magnitude of these margins.

Operators typically purchase twin-aisle airplanes for long-distance flights. However, when market conditions dictate, operators may use some of these airplanes on shorter flights. In such instances, appropriate action by the flight crew can reduce the likelihood of brake overheating and concomitant departure delays.

Basics, principles of operations and a new software tool for operational predictions

This document provides a brief introduction to aviation fuel definitions and characteristics, familiarizes you with terminology and industry jargon,addresses operational concerns related to fuel, and exchanges some insight into the energy of flight.

This Airbus document provides reminders on aerodynamics, flight mechanics, altimetry, influence of external parameters on aircraft performance, flight optimization concepts, etc. Great information...

This material describes the cargo loading areas on Airbus aircraft and the systems related to cargo holds.

Today's tough competitive environment forces airlines to consider operational costs in every facet of their business. All ways and means to achieve this goal have to be rationally envisaged, safety being of course the prime factor in any airline operation. A wide spectrum of considerations intervene in this process stemming from airline economics, marketing management, crew scheduling, flight operations, engineering and maintenance management, technical condition of aircraft. The idea behind this document is to revisit the cost index concept with a view towards balancing both fuel- and time-related costs.

The purpose of this brochure is to provide airline flight operations with some recommendations on the way to regularly monitor their aircraft performance. This brochure was designed to provide guidelines for aircraft performance monitoring based on the feedback obtained from many operators and on the knowledge of Airbus aircraft and systems.

There is nothing to add: everything is the main title!

The purpose of this document is to provide Airbus operators with an understanding of Airbus aircraft operations in cold weather conditions, and address such aspects as aircraft contamination, performance on contaminated runways, fuel freezing limitations and altimeter corrections.

This brochure provides an overview of the flying techniques and operational aspects involved in approach-and-landing accidents.

Today's tough competitive environment forces airlines to reduce their operational costs in every facet of their business. All ways and means to achieve this goal have to be rationally envisaged, safety being of course the prime factor in any airline operation. A wide variety of different aspects have to be taken into consideration in this process, such as airline economics, airline management, flight operations, maintenance management, technical condition of aircraft. The purpose of this document is to examine the influence of the latter with respect to aerodynamic deterioration.

Boeing publication reviewing during the 2006 Operators Symposium all the possible solutions to manage fuel consumption.

A very interesting document published by All Nippon Airways and dealing with different possibilities to optimize the reserve fuel.

Flex/Derate, Engine bump and derated climb specific to Airbus aircraft.

Operators have reported the use of excessively low takeoff reference speeds that have resulted in tail strike, high-speed rejected takeoffs (RTO), and other instances of degraded performance. These incidents were caused by a variety of human errors that typically resulted from using an erroneously low value for gross weight or an incorrect flap reference setting when determining takeoff speeds. This document is published by Boeing and it is well illustrated.

Airbus presents New Derated and Flexible Takeoff Thrust for up to 40% thrust reduction.

The Effect of ZFW / ZFWCG on Airbus Operations.

The determination of Dispatch Takeoff Weight seems to be quite easy: start with the empty weight of the airplane and add the weight. But is it always that straightforward? Is everything actually wihed prior to the flight? How is the airplane empty weight determined? This Boeing document is a very well done brochure.

This Rolls Royce document answers to frequent asked questions on Derated Climb Performance:

This Boeing document is an excellent briefing on deicing/anti-icing fluids. A must to know...

A perspective to get started with dignified Cost Index Values...

A UPS captain explains the operational aspects of CDAs or Continuous Descent Arrivals

Barometric altimeters on modern aircraft with digital Air Data Computers are very accurate most of the time and we rely on these altimeters in every aspect of today’s air travel. We diligently set the local altimeter settings prior to each takeoff and each approach but we do not routinely make any corrections for non-standard temperatures. This FSF document explains the chilling result of cold temperatures on barometric altimeters.

This Boeing document will help you to understand better the Center Of Gravity Limitations.

Blended winglets on the Boeing Business Jet and the B737-800 commercial airplane offer operational benefits to customers. Besides giving the airplanes a distinctive appearance, the winglets create more efficient flight characteristics in cruise and during takeoff and climbout, which translate into additional range with the same fuel and payload.

When discussing landing distance, two categories must be considered: 'actual landing distance' is the distance used in landing and braking to a complete stop (on a dry runway) after crossing the runway threshold at 50 feet; and 'Required landing distance' that is the distance derived by applying a factor to the actual landing distance. Actual landing distances are determined during certification flight tests without the use of thrust reversers. Required landing distances are used for dispatch purposes (i.e., for selecting the destination airport and alternate airports).

With the start of the winter season in the northern hemisphere, it is a timely reminder to re-publish this Airbus article, initially written in 2018. Ice ridges on the lower nose fuselage can cause Computed Airspeed (CAS) values delivered by the ADRs to be lower than the actual airspeed which may lead to unreliable airspeed events. This article describes the potential effect on the aircraft’s systems from the takeoff phase and how to prevent such a situation.

All Brakes are subject to wear. Some brakes may also experience oxidation which can lead to brake rupture. In the case of a brake rupture or if brakes are too worn, the aircraft braking performance is reduced. This can result in a runway overrun if the full braking capacity is required such as during a rejected takeoff with an aircraft weight at or close to the maximum takeoff weight. Brake rupture can also lead to damage that can cause a brake fire due to hydraulic fluid coming into contact with hot parts.
This article describes carbon wear and oxidation phenomena. It recalls the maintenance procedures used to identify worn or oxidized brakes, flight crew procedures, and good practices to prevent brake wear and oxidation.

The conditions and factors associated with landing on a wet runway or a runway contaminated by standing water, snow, slush or ice should be assessed carefully before beginning the approach. The Flight Safety Foundation team found that wet runways and runways contaminated by standing water, snow, slush or ice were involved in 96 percent of the runway-excursion accidents, in which runway condition was known.