Structural repair of Piper Aerostar PA60-601P

At the beginning of 2019, a Piper Aerostar PA60-601P aircraft got significant damages after a runway overshoot during a landing in Carpi-Budrione airport (Italy).

 

DESCRIPTION

The Piper Aerostar PA60-601P is a twin piston engine pressurized aircraft with a full metal structure. It is certified with FAA TC A17WE, FAR 23, normal category and included in the EASA product list. 

The Contracted MOA, Officine Aeronautiche Ghidotti (OAG), based in Carpi (MO) airport, provided a damage assessment report, that reportED as follow: 

  • Several components of the left MLG and the NLG are damaged and need to be replaced
  • Attachment points of the left MLG and the NLG are damaged and need to be replaced
  • Damages have been detected on both nose of the aircraft and the lower left wing section, immediately after the left MLG
  • No damage to wing main spars occurred 

The damaged areas and the actions that have been taken to restore them are listed as follows. IPC parts have been purchased from Aerostar when possible. When spare parts were not available, a repair has been designed.

Spare parts available from Aerostar

Spare parts available from Aerostar

Spare parts available from Aerostar

No spare parts available. In any case the procedure to change the bulkhead is too invasive

Spare parts available from Aerostar

Spare parts not available from Aerostar

The repair focused on the forward cabin bulkhead and nose area and on the left wing skin, lower part, immediately at the rear of left MLG.

Piper Aerostar PA60-601P Aircraft damaged parts to be repaired

FUSELAGE and NOSE DAMAGE

The picture illustrates the damage to the forward bulkhead, at STA 54.25, caused by the rear deformation of the NLG. Part of the forward Bulkhead has been removed by OAG for necessary inspection.
Here is visible only the left part of the forward bulkhead but le LH part is in the same conditions.
The lower part of the rib at STA 54.25 is available by the TCH with installation instructions. For this reason the repair only covered the Aluminium sheet of the forward bulkhead.

Structural repair of Piper Aerostar PA60-601P nose - fuselage
Nose damage – detail of under fuselage skin seen from front (red lines) – damaged part has been removed in the picture

This is the view from the front nose area of the panel that is placed on the center of the lower fuselage, between STA 54.25 and 83.00, symmetrically with respect to the symmetry plane of the fuselage itself.
The panel needed to be replaced with another equivalent panel, no instruction or spare parts from Aerostar were available.

LOWER LEFT WING DAMAGE

damaged lower portion of the left wing , included in the red lines– rivets damaged have been circled by a marking pen in black ink
 

Damaged lower portion of the left wing , included in the red lines. Damaged rivets have been circled by a marking pen in black ink

damaged lower portion of the left wing (red circle), seen from FW; the other panel has been only opened for inspection purpose

Damaged lower portion of the left wing (red circle), seen from FWD; the other panel has been only opened for inspection purpose

STRUCTURAL REPAIR DESCRIPTION

Repair were designed in compliance with the requirement of the FAR 23 subp. D. with these criteria: 

23.603 – Material: the material used to restore metal sheets is the same of the original parts
23.603 – Workmanship: a suitable qualified MOA will implement the repair in the damaged aircraft 
23.605 – Fabrication methods: the new designed parts are designed to use the same technology of the original structures they need to restore 
23.607 – Self-Locking nuts: All parts are riveted, no bolts are used and no self-locking nuts 
23.609 – Protection on the structure: the structure is protected by using the original protection products and the original paint 
23.611 – Inspection provision: there is no change in the inspection provision, the original inspection caps are not modified 

FUSOLAGE AND NOSE

Front pressurized cabin bulkhead: Since the lower part of the rib at STA 54.25 was available by the TCH with installation instructions, the repair covered the Aluminium sheet of the forward bulkhead. 

Nose area: Minor repairs on the Al Alloy sheets not related to the primary structure. 

Panel under central part of the fuselage: The panel needed to be replaced with another equivalent panel, no instruction or spare parts from Aerostar were available.

LOWER LEFT WING

Panel and ribs immediately after the left MLG bay: The repair covered the Aluminium sheet and related ribs of this panel.
The original one needed to be cut in correspondence with the main wing ribs and spars, and substituted with one that ensured equivalent structural stiffness. 

WORK CONCLUSION

Structural repair of Piper Aerostar PA60-601P