Boeing is set to start deliveries of 737s equipped with the low-drag nozzle and plug engine configuration as it approaches the completion of the performance improvement package (PIP) upgrade.
The first part of the upgrade was rolled out in a block part change on the line in March when aerodynamic clean-up features were introduced. These include reduced drag anti-collision light fairings, low drag wheel well enclosures and improvements to slat and spoiler trailing edges.
A second block introduced the upgraded CFM56-7BE engine in July, with initial delivery to China Southern that month.
The next phase adds an improved, and frankly stylish-looking, shorter primary nozzle and plug set.
KLM will be the first to take an aircraft, a 737-700, with all these features.
A final change, due for introduction in January 2012, will be an improved environmental control system exhaust vent controlled by a ‘smart’ actuator. The combined package, which Boeing began testing in November 2010, is aimed at reducing fuel consumption by 2%.
Plug and nozzle - before
...and after PIP update