Article
The Controversy Around Engine Borescope Inspections
By Denise Wilson, CAM
I recently attended the Corporate Jet Investor conference in London, a premier global event drawing over 500 senior aviation leaders focused on jet transactions.
Among the most debated sessions was a panel titled: “Rethinking Engine PPIs—a Deep Dive into the Evolving Role of Pre-Purchase Inspections.”
The panel’s premise was that engine borescope inspections aren’t needed to determine a jet engine’s airworthiness during a pre-purchase inspection.
Interestingly, engine program reps urged aircraft brokers, aviation attorneys and others regularly involved in aircraft due diligence to convince their buyers to forgo doing borescope inspections during pre-purchase inspections.
The speakers claimed that borescope inspections pose risk to sellers by finding issues that would normally not be discovered in between major periodic inspections. Thus, they’re not covered under engine programs.
Of course, it’s in the engine program administrator’s interest to discourage unscheduled borescope inspections. Their program pricing is based on the replacement of certain components at scheduled intervals, making unexpected findings costly.
Understanding ENGine Program Coverage AND BORESCOPE INSPECTIONS
Those of us that regularly represent buyers and sellers during pre-purchase inspections collectively took issue with this messaging.
There was general agreement that an engine maintained under Chapter 5 of the aircraft’s maintenance manual, that exhibits no issues during ground engine runs and no squawks during flight, is airworthy.
That said, certain situations complicate this decision. Sellers must decide whether to allow a borescope inspection, while buyers must weigh the risks of skipping one.
Here are four such situations:
- A buyer’s legal team proposes language in the Aircraft Purchase Agreement that the engines must be “within all manufacturer’s specifications and tolerances.”
If a seller permits the inclusion of this language, the condition can only be determined by taking a deeper look into the engine. Which, as we all know, an airworthy engine that is 500 hours away from overhaul looks a lot different than a brand new engine.
As one engine program representative stated in the session, “If a buyer wants [an engine] 100% within tolerances, he[/she] needs to go buy a new aircraft or new engine.”
- A buyer forgoes a borescope inspection on an engine with less-than-robust program coverage, then experiences a post-sale engine event.
Now, any issue that arises is now the new owner’s responsibility, even if it was a pre-existing condition.
Additional costs may include engine removal and installation, shipping, loss of use, replacement aircraft costs, and so on. This can lead to lengthy downtimes, as loaner engines under some programs are not always immediately available.
A buyer forgoes a borescope inspection on an engine covered by a program that excludes foreign object damage (FOD). After assuming ownership, it’s discovered that there was a FOD event.
The insurance company requests evidence showing the FOD is a new issue and occurred during the current owner’s operations. A borescope report is a clear-cut way to prove the FOD did not exist when ownership changed.
Completing an engine ground run on a cool day, at sea level, may mask issues that would be apparent on a hot day at a high elevation airport.
Balancing Due Diligence and Risk in Engine Inspections
So how can a buyer conduct enough due diligence on the engines to ensure safe, trouble-free engine operation until the next major inspection?
And how can they avoid exposure to unexpected costs after taking delivery?
At the same time, how can a seller with engines on a program avoid the risk of paying for costly component replacements due to allowing a buyer to complete a borescope inspection during a pre purchase inspection?
The answer depends on which engine powers your aircraft, and which program you have.
Citation Engine Programs
It’s important to note that most engine programs will not cover findings from a borescope inspection that is accomplished as an unscheduled inspection.
For example, completing ground engine runs to determine whether the engines produce charted power per current ambient conditions through ground engine runs, reviewing FADEC downloads, accomplishing an operational check flight, and completing a visual inspection of the front/cold section are all tasks that provide results.
These results could lead to further decision-making on whether a borescope inspection should be accomplished.
Williams TAP Blue
For a TAP Blue-covered engine, this process confirms airworthiness and helps prevent unexpected repair costs for the new owner. Should an anomaly appear during any of these steps, Williams will likely then request additional investigation, which could lead to a possible borescope inspection of the hot section. Once Williams suggests the borescope inspection, any potential repairs are now covered by TAP Blue.
At The Jet Agent, a majority of the aircraft we sell are equipped with Williams engines, and most are covered under either TAP Blue or TAP Elite.
TAP Blue is an extremely robust engine program, covering both foreign object damage and corrosion, minimizing risk to both sellers and buyers.
For owners of a Williams-equipped Citation with TAP Blue program coverage, you’re in the best possible position to minimize your exposure to unexpected costs during a pre-purchase inspection.
Williams TAP Elite
If your engines are covered by TAP Elite and you’re thinking about selling your aircraft, consider upgrading to TAP Blue. It’s a good idea especially if you’re interested in reducing your exposure to the costs of remediation for FOD or corrosion found during a borescope inspection that Williams approves, as repairs due to FOD or corrosion are both exclusions under TAP Elite.
Pratt & Whitney
If you own a Citation with Pratt & Whitney engines, a borescope inspection during a pre-purchase inspection increases the seller’s risk.
And risk is even higher if the inspection is done without prior approval. That said, the extent of this risk depends on your specific engine program (e.g., ESP, ESP Gold, ESP Platinum, or JSSI).
But none offer the same level of protection as Williams’ TAP Blue program.
Expert Guidance for a Smooth Jet Transaction
If you’re considering selling your jet or transitioning to your next one, engaging a professional team to oversee the process is the best way to mitigate risk.
At The Jet Agent, our Maintenance Technical Advisor recommends the appropriate level of due diligence based on a thorough review of the aircraft’s condition, maintenance history and operating environment.
We provide buyers with an acceptable level of access for due diligence while minimizing your risk of unexpected costs and downtime. Likewise, when acquiring your next jet, we’ll guide you through the best path to ensure a well-informed purchase.
As former Citation fleet operators and owners of a Part 145 repair station specializing in Citation maintenance, we have the expertise to navigate the transaction process and help you avoid common pitfalls.
ABOUT THE AUTHOR
Denise Wilson, CAM, is the founder and President of The Jet Agent. Wilson has more than 25 years of experience in all facets of the aviation industry. This includes 20+ years of flying Citations and other jets in both business aviation and commercial operations, and 18 years assisting clients in the acquisition and sales of jet aircraft.
She previously served as founder & CEO of Desert Jet, collectively consisting of an aircraft acquisitions and sales division, a jet charter and management company, a jet maintenance business, and a popular FBO featuring a newly built private terminal, Desert Jet Center. Under her leadership, the company grew exponentially, ranking on the Inc. 500 list of the nation’s fastest growing, privately-owned companies five consecutive years.
As a jet aircraft broker and acquisition consultant, Wilson provides concierge-level acquisition representation, aircraft sales, and coaching to clients. She authored the Amazon #1 Bestseller “The Insider’s Guide to Buying and Selling Jets.”
ABOUT THE JET AGENT
The Jet Agent helps clients navigate the complex world of jet acquisitions and sales with confidence. The Jet Agent is in the top 5% of aircraft brokers worldwide by transaction volume and ranks as the #1 seller of Citation M2s and CJ3s. Headquartered in Scottsdale, Arizona, with offices in Denver, Dallas and Sacramento, The Jet Agent is dedicated to elevating the aircraft brokerage experience with expert guidance and concierge-level service
