PERFORMANCE BASED NAVIGATION (PBN)

What is Performance Based Navigation(PBN) ?

Simply put, PBN means NO MORE GROUND AIDS based navigation.

PBN technology allows aircraft to fly precisely-defined flight paths without relying on ground-based radio-navigation signals. Required Navigation Performance (RNP) procedures, an advanced form of PBN technology, can be designed to shorten the distance an aircraft has to fly en-route, and to reduce fuel burn, exhaust emissions and noise pollution in communities near airports. Because of RNP's precision and reliability, the technology can help air traffic controllers reduce flight delays and alleviate air traffic congestion.

MITSUBISHI FLIGHT TEST

Mitsubishi Aircraft Corporation has completed the first flight test on Pratt & Whitney’s PurePower  PW1200G engine for the MRJ, just a week after it announced a delay to the programme

The PW1217G for the 90-seat MRJ90 flew on a specially designed stub wing aboard Pratt & Whitney’s Boeing 747SP flying test bed from Pratt &Whitney’s Mirabel Aerospace Centre in Canada.

Tests to validate the engine's fuel efficiency, durability and other performance metrics, will be conducted over roughly one year so they will be completed in time for the MRJ's maiden flight. In-flight testing will be done with the engine installed in an ultralarge aircraft.


The PW1217G engine uses geared turbofan technology, which the company says can reduce noise and fuel consumption by having the large fan rotate slower. This is expected to improve the MRJ's fuel efficiency by around 20% over rival jets in this class, which seat up to 100 passengers.

Mitsubishi Aircraft has announced a new schedule for the MRJ, delaying its launch by more than a year. Behind the pushed-back schedule were inadequate inspections of aircraft parts by parent Mitsubishi Heavy Industries Ltd. (7011).

The company will step up its sales campaign in such markets as the U.S. and Southeast Asia now that engine tests have begun.(adapted from Nikkei and Mitsubishi)

NEW GENERATION PURE POWER ENGINES: GEARED TURBOFAN

Today, the turbofan engine has found a home on practically all jet-propelled aircraft. However, the ambitious emission goals of ACARE 2020 cannot be fully met with the current turbofan concepts and industry majors need to look elsewhere to find a viable solution.

A high bypass engine is the key to reducing both fuel consumption and noise and developments are underfoot aimed to raise the bypass ratio above ten and optimize individual components for better aerodynamic efficiency.

BOEING WINGLET DESIGN FOR 737 MAX

B737 MAX

In continuation of our coverage on WINGLETS and FUEL SAVING A320 SHARKLETS, we bring the news about Boeing announcement and breakthrough on new winglet design concept for the 737 MAX. The new Advanced Technology winglet will provide MAX customers with up to an additional 1.5 percent fuel-burn improvement, depending on range, on top of the 10-12 percent improvement already offered on the new-engine variant.

FUEL SAVING A320 SHARKLETS

A320 NEO

Anew milestone has been achieved in Airbus’ application of “Sharklets” to its single-aisle product line with this week’s rollout of the company’s first new-build A320 fitted with the large wingtip devices, which will reduce fuel burn and enhance aircraft performance.

NEXT GENERATION ENGINE

PW1000G- Pure Power

PurePower PW1000G engine with Geared Turbofan™ technology is a state of the art gear system that separates the engine fan from the low pressure compressor and turbine, allowing each of the modules to operate at their optimum speeds. This enables the fan to rotate slower and while the low pressure compressor and turbine operate at a high speed, increasing engine efficiency and delivering significantly lower fuel consumption, emissions and noise. This increased efficiency also translates to fewer engine stages and parts for lower weight and reduced maintenance costs.

The PurePower PW1000G engine’s fan-drive gear system is just one component of this next-generation engine. The PurePower PW1000G engine also incorporates advances in aerodynamics, lightweight materials and other major technology improvements in the high-pressure spool, low-pressure turbine, combustor, controls, engine health monitoring and more.

WINGLETS

It’s a nearly vertical airfoil at an airplanes wingtip that reduces drag by inhibiting turbulence.

( Merriam-Webster dictionary)

First known use of winglet dates back to as early as 1611.

EVOLUTION OF WINGLET

NASA’s pioneering research in the 1970’s as part of energy efficiency program to conserve energy in aviation resulted in Winglets finding acceptance with airplane manufacturers and airlines alike.

Richard Whitcomb was instrumental in conducting test to explore hypothesis that a precisely designed vertical wingtip device could weaken wing tip vortices and thus diminish induced drag which translates into less fuel burn and better cruise efficiency.(NASA website)

American, Southwest, Ryanair, and others took advantage of fuel efficiency that comes with winglets and partnered with Boeing –Aviation Partners group(ABP) to have winglets installed.

Wing Tip fence

Wingtip fence is the preferred device of Airbus to tackle and reduce induced drag on wingtip.Airbus also has ambitious project in introducing Sharklets, akin winglets on its A320 neo and also an active proposal for the same to be introduced on A330.

AERODYNAMICS OF WINGLET

Winglets

Lift is the force that makes the aircraft fly. Lift is a result of unequal pressure in a wing as air flows around it with positive pressure underneath the wing and negative pressure above.

Drag is the resistance encountered while moving through the airflow. Considerable amount of drag is also generated from the high pressure under the wing, which causes air to flow up over the wing tip and spin off in a vortex.. These vortices produce what is called induced drag which hampers aircraft fuel consumption, range, speed and so on.

Sharklets

 Hence, the primary aim of winglet is to break the wing tip vortices and reduce the induced drag and increase aircraft performance. Fuel savings are estimated between 4-6% by employing winglets.  Initial results as released by airbus for A330 program indicate fuel saving in excess of 3.4% and increased take off weight. Also, the noise footprint will be reduced along with better carbon footprint in light of emissions being the centre stage of aviation policies.
(Acknowledgements: Airbus, NASA and Merriam-Webster)