How is DEF-Contamination destroying Aircraft Engines?

by Admin on June 13, 2022

Accidents can happen, and even the most seasoned specialists make mistakes now and again. Consider the introduction of DEF (Diesel Exhaust Fluid) into the engine, transmission, or hydraulic oils by mistake. While this is not as prevalent as DEF in diesel fuel, it has happened in our experience. If not addressed immediately, this mistake might cause substantial harm to your equipment.

iJET brings you all the details you need to know about DEF contamination.

What is Diesel Exhaust Fluid (DEF)?

DEF (Diesel Exhaust Fluid) is a water-based urea solution used in contemporary Tier 4 Final diesel engines to minimize emissions. This liquid is added to exhaust gases to neutralize hazardous nitrogen oxides (NOx) before they reach the atmosphere. DEF fluids have been utilized in on-highway vehicle engines for a long time, and in off-road mining and construction equipment more recently.


What happens when oils are contaminated with DEF?

DEF is a water-based fluid that reacts badly with oils. When DEF is added to the engine, transmission, or hydraulic oils, it can cause an emulsion or layer separation inside the reservoir. This can result in inefficient oil flow as well as damage to the oil pump and other system components. Under pressure and high temperatures, water-based fluids tend to flash off into steam, which means they provide poor lubrication and cause systems to operate ‘rough.’

This might cause deposits or excessive wear over time. DEF contamination will also increase corrosion rates, which will be most noticeable (and harmful) on soft metals like those found on gearbox clutch plates. Finally, the presence of water in any oil promotes oil oxidation, causing the oil to deteriorate more quickly than usual.

DEF contains a substance called urea in addition to water (DEF is approximately 67.5 percent purified water / 32.5 percent urea). This is a basic molecule that neutralizes acids (it’s comparable to urine). Oils polluted with a trace quantity of urea would presumably become a little more basic, but not enough to cause noticeable deterioration. If DEF was added over time, you could notice a shift in acidity levels, but most problems are caused by one-time mishaps.


How can you detect DEF contamination using oil analysis?

The appearance of high-water levels in your oil sample findings is the most evident evidence that DEF has polluted an oil system. The Karl Fischer test (more sensitive/accurate) or the Crackle test (more basic) can both be used to confirm water pollution.

Unfortunately, neither test can determine if the water comes from DEF contamination or another cause, such as humidity, damaged seals, prolonged idling, or running an engine too cold. However, if the oil sample contains two separate layers (for example, free-standing water at the bottom), a refractometer may be used to confirm the water/urea combination.


What should you do when oils are contaminated by DEF?

If you think that DEF fluid has polluted your engine, gearbox, or hydraulic oil, you have a few options:

  1. To get to the water layer, drain some oil from the bottom of the tank. This will eliminate part of the DEF.
  2. Collect an oil sample and send it in for testing this will aid in determining the severity of the problem.
  3. Examine when your next oil change is due and, if necessary, schedule one sooner.

Mistakes do happen, but with early discovery and adequate oil analysis testing, DEF contamination may be mitigated.


How can I prevent this from happening?

a variety of signage and educational documents that can be used to alert drivers to the fluid they are dispensing. Accidents happen but with clear signage and education, we may be able to reduce this problem at your facilities.


Federal Aviation Administration (FAA) has warned against jet fuel contamination by DEF

FAA had issued a warning for DEF contamination in Dec 2017, due to seven incidents of jet fuel containing diesel exhaust fluid (DEF) and jet fuel refueling done with equipment that was exposed to DEF, occurring between November 18 and November 21, 2017, in seven turbine-powered aircraft at Omaha’s Eppley Airfield. Read the full warning by FAA reported by Aero-News.

The rising number of jet fuel contamination accidents has pointed a finger toward aircraft operators’ responsibility worldwide to ensure that they address fuel contamination risk with adequate “Policies, Standards and Procedures” (PSPs). In addition to this, aviation professionals and aircraft operators globally must work with reliable fuel suppliers to refuel their aircraft. But with so many regional, international, and local fuel suppliers competing in the aviation world, who should you trust? The solution is simple, work with a reputable and dependable flight support provider.


Falcon has a close call with DEF-contaminated fuel.

Another incident with a Jet-A polluted with diesel exhaust fluid (DEF) happened on August 14, when a Fair Wind Air Charter Dassault Falcon 900EX was forced to return to Miami Opa-Locka Airport when two of its three engines failed. The use of DEF, a urea-based solution that reduces nitrogen oxide emissions in diesel exhaust, in aviation fuel is not permitted. Crystals occur when the two are unintentionally combined, producing potentially catastrophic blockages in airplane fuel systems.


What Does Fair Wind COO say?

According to Fair Wind COO (Chief Operating Officer) Alexander Beringer, the issue first surfaced shortly after takeoff, when the aircraft indicated a blockage in its number-two engine fuel filter, followed by the same signal in the number-three powerplant. When the number-two engine failed, the crew opted to return to base and reported an emergency. The number-three engine became unresponsive to throttle input at 8,000 feet on approach, but the crew landed safely using just the number-one engine, which also reported a filter blockage. “We were fortunate” he stated, noting that the entire affair took less than 12 minutes from beginning to end.


What are the losses?

While the extent of the damage is still being assessed, Beringer stated that all three engines will be removed and subjected to hot-section inspections; the APU (Auxiliary Power Unit) will be removed, inspected, and repaired; fuel pumps, filters, and control units will be replaced; and all the aircraft’s fuel tanks will be opened and thoroughly cleaned. According to estimates, there will be at least a month of downtime and a cost of more than $1 million.

Beringer feels that until all airport service cars are exempted from any DEF-usage rules, this blunder might happen again. He told AIN, “That removes the fluid off-airport properties and fixes it for good”. The industry has to urge federal and state regulators to come up with a long-term solution to this issue.”

But when you Are teaming up with a reliable flight support partner becomes crucial to ensure that the jet fuel used for your aircraft is pure and not polluted. iJET, your flight support partner of choice, understands this and helps you to choose the right fuel supplier, to ensure the quality of the jet fuel.  It acts as an independent third party with all-way round aircraft evaluation and offers an ultimate choice of fuel brand. 

Well-connected with local and international trusted fuel suppliers and working with aircraft operators globally, has equipped us with a network of trusted vendors so that you can rely on us for the fueling and refueling of your aircraft.

Find out the price of jet fuel – if you are overpaying or not. Read more

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