No one wants to buy an aircraft riddled with corrosion, but some will be unavoidable, argues Jet Tolbert. What are the different causes and remedies, and how much should be deemed too much by the aircraft buyer?
Almost anything will cause corrosion on a metal airplane if it’s not cared for appropriately. Air that comes into contact with bare metal can expose it to moisture and oxidization.
The blue fluids used in the various aircraft systems (such as the lavatory) can cause serious structural corrosion if they leak into the belly of the aircraft.
The de-icing fluids used by ground crew can seep into certain aircraft parts, causing deep corrosion. Even the environment the aircraft is based in if particularly humid, sandy or saline can cause varying degrees of corrosion.
Any of these situations could necessitate high-dollar repairs that have the potential to exceed the value of the aircraft, and a prospective buyer needs to be aware of them.
The aircraft OEMs are also aware of most scenarios causing corrosion, and have developed preventative procedures.
Most require bare metal to be treated. Aircraft are inspected around the lavatory (for example) to ensure that any leaks are caught quickly before corrosion takes hold. Procedures have been developed to perform deep washes of aircraft exposed to anti-ice/de-ice fluids, and similarly for airplanes that operate in more corrosive environments.
Most times the corrosion is found during the inspection process and treated quickly with very little impact on the aircraft’s structure. On occasion, though, the inspection process reveals corrosion that requires a high-dollar repair.
Corrosion doesn’t just go away. It is essential that it is quickly cleaned and any affected areas are treated for prevention of future corrosion.
Effects of Corrosion on Aircraft Marketability
Light Corrosion:Nearly all aircraft will have some history of light surface corrosion that has been treated and maintained. This type of superficial corrosion is not very costly to keep on top of, and should not unduly concern a potential buyer.
Contained Corrosion: Let’s imagine, however, that an aircraft had a leaking window or lavatory that was not detected in time to prevent corrosion impacting the aircraft structure… This type of corrosion has the potential to go much deeper, requiring structural repairs involving engineering and special re-inspection requirements after the repairs have been made.
In such instances a reputable maintenance facility will eradicate any signs of corrosion with no need for special inspections in the future.
Yet, following the repairs, although the aircraft can operate just the same as any other aircraft, an experienced aircraft acquisition broker may advise a prospective buyer that the corrosion history should impact the value of the airplane. The extent of the impact on value will be more pronounced in a buyer’s market than in a seller’s market, however.
Extensive Corrosion:Now let’s imagine an aircraft based in a tropical climate or excessively exposed to de-icing fluid is being considered for purchase. It may have undergone significant corrosion-related repairs due to a lack of deep washes and inspections, and could carry a high repair bill to rectify all of the identified corrosion.
This aircraft could also be liable to detection of additional corrosion at later inspections, having been removed from the previous corrosive environment to operate in a more moderate one.
Needless to say that in this scenario the impact of higher maintenance bills (not to mention the stigma that comes with the aircraft’s prior operations in a corrosive environment) will have a much greater potential impact on the new owner, and a prospective buyer should be very thorough in their understanding of this aircraft, its maintenance-record, and its value in this context.
Identifying Corrosion or Potential Corrosion
Though an aircraft’s base location can say much about what it’s exposed to on a regular basis, the maintenance history will provide the deepest understanding of compliance with corrosion prevention, revealing any history of corrosion and its associated repairs.
First impressions can sometimes be misleading, but walking up to an airplane that has extensive surface corrosion will indicate that the aircraft has not been treated properly during a recent repaint, or that the aircraft is getting significant exposure to corrosive conditions. These should cause a buyer to be wary of what might be found by a deeper inspection.
While some corrosion is common, having the right professional team around you should minimize the risk of an aircraft being acquired that will require substantial investment to rectify its previous owner’s mistreatment or mishandling.