In 2018, Gulfstream Aerospace Corporation ("Gulfstream") issued a customer bulletin a horizontal stabilizer lower bonded skin inspection applicable to G-V and G550 aircraft. Since then, the customer bulletins have been revised.

Customer Bulletin 228B ("CB228B") is currently applicable to G-V aircraft, serial numbers 501 through 699. Customer Bulletin 190B ("CB190") is currently applicable to G550 aircraft, serial numbers 5001 through 5158 (except 5093, 5132, 5143 and 5156). G550 aircraft with serial numbers higher than 5158 (i.e., in service less than 11 years) must comply with the MAUS inspection during its initial 144 month scheduled inspection.

The customer bulletins incorporate a Fokker-issued service bulletin and require that the affected G-V and G550 aircraft undergo one of two Mobile Automated Scanner (MAUS) horizontal stabilizer NDT inspections not later than (i) the next scheduled 144 month inspection or (ii) October 31, 2021, whichever occurs first. The compliance option may be dependent upon the availability of equipment so an owner, operator and/or prospective purchaser must ensure the availability of equipment for their preferred option.

The customer bulletins have three (3) parts:

  1. Part I allows a scan of only the "critical areas" (10 labor hours) to extend the deadline for compliance with the more extensive Part II inspection. Part I provides for certain Allowable Damage Limits ("ADL"), ranging from none to minimal.
  2. Part II requires a scan of the entire affected area (80 labor hours) and requires "permanent" repair if corrosion/disbonding in excess of the Part II ADL criteria is detected. The "hard stop" deadline for. t II inspection is October 31, 2024 (except in the case of the G550s with serial numbers higher than 5158).
  3. Part III provides for temporary, time-limited treatment of corrosion/disbonding that is greater than the Part I ADL and less than the Part II ADL by application of Corrosion Inhibiting Compound ("CIC") (+/- 40 labor hours) pursuant to an engineering report.

Part I Inspection and Results Consequences

If a Part I limited scan of the "critical areas" detects corrosion/disbonding less than the Part I ADL, the aircraft can return to service. However, Part I inspections must be repeated every twelve (12) months until the Part II inspection is completed (not later than October 31, 2024) and permanent repairs accomplished.

If Part I scan findings exceed the Part I ADL but do not exceed the Part II ADL, the area is mapped and the aircraft can return to service after application of CIC pursuant to Part III. In this event, the Part II scan must be performed not later than (i) forty-eight (48) months after CIC application, or (ii) October 31, 2024, whichever occurs first, and permanent repairs made at that time.

If Part I scan findings are beyond the Part II ADL, a Part II inspection must be accomplished and permanent repairs made. In this case, the next Part II inspection is due ninety-six (96) months after return to service following completion of the permanent repairs.

Part II Inspection and Results Consequences

If the aircraft has not undergone a Part I inspection, the deadline for. t II "full" scan is October 31, 2021. If Part II scan detects corrosion/disbonding less than the Part I ADL (and this does occur from time to time), the next Part II scan is due ninety-six (96) months later.

If the Part II scan findings exceed the Part I ADL, but do not exceed the Part II ADL, the aircraft can be returned to service after CIC application pursuant to Part III. In this event, the next Part II inspection must be performed not later than (i) forty-eight (48) months after CIC application, or (ii) October 31, 2024, whichever occurs first, and permanent repairs made at that time. The next Part II inspection is due ninety-six (96) months after permanent repairs are accomplished.

If the Part II scan findings exceed the Part II ADL, the aircraft must undergo permanent repairs before it can be returned to service. In this case, the next Part II inspection is due ninety-six (96) months following return to service after completion of the permanent repairs.

Warranty Coverage

Gulfstream states that, if corrosion/disbonding is detected through compliance with a Part I scan or a Part II scan prior to expiration of the Primary and Secondary Structure warranty, and Part III temporary treatment (i.e., application of CIC) is accomplished, then the warranty will pay the cost of compliance with the first subsequent Part II inspection (the "full" scan and permanent repairs), even if the Primary and Secondary Structure warranty expires after the Part III time-limited repair (CIC application) during the forty-eight (48) month period before the subsequent Part II inspection is due. I have not yet received any confirmation that Gulfstream will consent to transfer of this "extended" warranty to subsequent purchasers. You should require that Gulfstream confirm the available warranty coverage in writing for each aircraft.

Summary

  1. Before October 31, 2021, an affected G-V or G550 must undergo a Part I MAUS inspection or Part II MAUS inspection.
  2. If a scan detects corrosion/disbonding that does not exceed the Part I ADL, the aircraft can be returned to service. However:
    1. If a Part II "full" scan was conducted, the next Part II inspection is due ninety-six (96) months later.
    2. If the scan was conducted pursuant to Part I, then the operator must comply with the Part II inspection not later than October 31, 2024, and comply with Part I scans every 12 months during the interim:
      1. If all subsequent Part I scans do not detect corrosion/disbonding in excess of the Part I ADL, the Part I scans can be repeated every 12 months until the Part II inspection is complied with not later than October 31, 2024.
      2. If a subsequent Part I scan detects corrosion/disbonding in excess of the Part I ADL, but within the Part II ADL, the aircraft can be returned to service following Part III repair (CIC application) for 48 months, but compliance with the Part II inspection must be accomplished not later than (i) expiration of the 48 months or (ii) October 31, 2024, whichever is earlier.
      3. If a subsequent Part I scan detects corrosion/disbonding in excess of the Part II ADL, a Part II scan and permanent repairs must be accomplished before the aircraft can be returned to service. The next Part II inspection is due ninety-six (96) months later.
  3. If a scan detects damage in excess of the Part I ADL, but not in excess of the Part II ADL, then:
    1. If a Part II "full" scan was conducted, then:
      1. The permanent repairs can be accomplished, in which case the next Part II inspection is due ninety-six (96) months later.
      2. The operator can elect to comply with the time-limited Part III repair (CIC application), in which case the next Part II inspection is due forty-eight (48) months later, and permanent repairs must be accomplished at that time.
    2. If a Part I "critical area" scan was conducted, the aircraft can be returned to service following Part III repair (CIC application) for forty-eight (48) months, but compliance with the Part II inspection must be accomplished not later than (i) expiration of the forty-eight (48) months or (ii) October 31, 2024, whichever is earlier. However, if a subsequent Part I scan detects corrosion/disbonding in excess of the Part II ADL, permanent repairs must be accomplished before the aircraft can be returned to service (in which case the next Part II inspection is due 96 months later).
  4. If a scan detects damage beyond the Part II ADL:
    1. If a Part II scan revealed the findings, permanent repairs must be accomplished before the aircraft can be returned to service. In this event, the next Part II inspection is due ninety-six (96) months later.
    2. If a Part I "critical area" scan was conducted, the aircraft can be returned to service following Part III repair (CIC application) for forty-eight (48) months, but compliance with the Part II inspection must be accomplished not later than (i) expiration of the forty-eight (48) months or (ii) October 31, 2024, whichever is earlier. However, if a subsequent Part I scan detects corrosion/disbonding in excess of the Part II ADL, permanent repairs must be accomplished before the aircraft can be returned to service (in which case the next Part II inspection is due 96 months later).

Please feel free to contact Scott Burgess if we can be of assistance in drafting the terms of a sale or purchase agreement for any aircraft, but especially G-V and G550 aircraft that have not complied with the applicable customer bulletin.