Boeing 757 Upgrade

The B757 Modification Programme has made significant progress since the first aircraft (NZ7571) was inducted into ST Mobile Aerospace Engineering (MAE), Mobile Alabama in March.   The aircraft initially received a major serving (C Check) which was overseen by an RNZAF Team from Fleet Planning Unit (FPU), Auckland Technical Support Unit (ATSU) and Directorate of Logistics Configuration (DLC).  In early April, final modification preparations were completed and MAE commenced the first phase of the extensive modifications.

WN07-0036-17.tn.jpg: Right image showing a Partially assembled DSS on assembly jig.

WN07-0036-18-tn.jpg: Left image showing SGT Munro inspects the completion of the Tear Strap removal.

Initially, the aircraft was jacked using special fuselage support jacks secured to critical structural sections of the fuselage.   An array of various shoring and support stands were then positioned under the complete length of the aircraft belly to ensure the aircraft was structurally supported during the Cargo Door modification.  This jacking and shoring process is a precise procedure with load cells fitted to all the jacks and readings balanced to fine tolerances. The load cells on the jacks are checked each day to ensure the load and balance is kept within tolerances. The load cell readings were sent to Boeing for analysis and approval before any structural members could be removed from the aircraft fuselage. This complicated and precise task was executed by a combined team from MAE and the parent company, Singapore Technologies Aerospace, over the span of a week.

WN07-0036-19-tn.jpg: Right image showing F/S Tony Fry discusses the work being carried out in the MEC area.

The aircraft is now prepared for what is the most visibly dramatic change where a significant section of the forward fuselage is removed in order for a replacement fuselage section known as the Door Surround Structure (DSS) to be fitted that will include provisions for the new cargo door.  The photos provide the most effective illustration of how this is achieved.   As this is the first aircraft MAE have modified with a cargo door for a number of years and therefore a significant number of aircraft lined up for the modification at MAE (FEDEX Programme), a very high level of interest was taken in the initial cut.  

WN07-0036-29.tn.jpg: Left image showing Lower DSS section being offered up to the assembly jig.

MAE has now progressed to the point where the required sections of aircraft skin, stringers and frames have been removed.   The Electrical & Electronic Equipment Bay and forward cargo pit have never been more accessible!  The remaining structure is now being prepared prior to the new DSS (refer photos) being offered up to the aircraft fuselage.   Additional alignment and datum checks are also required to ensure the aircraft hasn’t moved from it’s original pre-cut positions to ensure a seamless integration of the DSS to the aircraft fuselage. The tolerances required in the alignment check are so fine that any mismatch of more than .050 inches (roughly a pencil lead) will require rectification. 

Over the coming months, the aircraft will receive major modifications to enable a multi-role capability including the installation of a cargo handling system, air stairs, VIP section, new interior furnishings and new and upgraded communications and navigation equipment.    These will provide a leap in capability for the B757. However, it is agreed by all involved, there will be no point more memorable or dramatic in the programme than the day the first cut was made.

Read more on this subject see our Projects - Boeing 757 section.

WN07-0036-26/27-tn.jpg: Below Image showing view of the entire aircraft.

 

Below a sequence of images showing the various stages in the cutting process.

WN 07-0036-32-tn.jpg Left Image one.

WN 07-0036-35-tn.jpg Right Image two.

WN 07-0036-10-tn.jpg Below Image three.

WN 07-0036-12-tn.jpg Right Image four.