December 13, 2023 - No. 051


In This Issue 

: New FAA rule would see non-US aircraft mechanics tested for drugs and alcohol

: Ospreys had history of safety issues long before they were grounded 

: GPS: The birth of the commercial GPS industry and how it changed the world

: Air Force looks to create single ‘Frankenplane’ from 2 damaged F-35s 

: Air Guardsmen Keep Aging F-15Cs Flying With Spare Parts Made In-House 

: Epic turboprop receives FIKI certification

: Successful Remote-Piloted Flight For Cessna Caravan

: Van’s Files For Chapter 11 Protection

: Should I pre-oil these Lycoming engines?

: Pratt & Whitney engines achieve 100% SAF flight in AW139 helicopter 

 

 


New FAA rule would see non-US aircraft mechanics tested for drugs and alcohol
BY IAN MOLYNEAUX
2023-12-08

A union in the United States (US) has thrown its weight behind a new rule proposed by the Federal Aviation Administration (FAA) to test overseas aircraft mechanics for drugs and alcohol.  

Under the new rule, certificated repair stations located outside the US, whose staff carry out ‘safety-sensitive maintenance functions’ on certain air carrier aircraft, would be required to implement a drug and alcohol testing program. 

According to the FAA, few countries require testing of aviation or maintenance personnel. 

“This rule would ensure these employees are held to the same high level of safety standards regardless of where they are physically located,” the FAA said.  

The International Brotherhood of Teamsters union said that it “applauded” the rule, which would see overseas technicians face the “same drug and alcohol screening as safety-sensitive aircraft mechanics” as in the US.  

Joe Ferreira, Teamsters Airline Division Director, said: “This is a critical step forward in ending our two-tiered aviation safety system, whereby mechanics in countries like China, El Salvador, Brazil, and Singapore don’t have to abide by the same rules as American aircraft technicians, who are among the most talented and knowledgeable in the world.”  

Ferreira added: “There’s a huge segment of the flying public that doesn’t know that the airplane they are flying on might be repaired by someone who isn’t subject to the same substance abuse screening as a technician in this country. When passengers find out about this, they are usually outraged and horrified.” 

Teamsters said that the move would protect US airlines, small and large, that are sending maintenance work to overseas facilities without any scrutiny regarding the drug and alcohol use of employees. 

Bob Fisher, Teamsters Airline Division Deputy Director, said: “This will go a long way towards onshoring aviation maintenance jobs by ending an economic incentive that puts the flying public at risk. We will continue to oppose the outsourcing of the work in our craft and demand additional regulatory and statutory requirements to ensure airlines can’t cut corners to save money overseas. We look forward to providing the FAA with our insights during the rulemaking process, and to the expeditious implementation of the mandate once it’s finalized.”  

If the rule is finalized, the repair stations in question would need to ensure that their employees receive all necessary anti-drug and alcohol training. 

The facilities would then be responsible for sending staff testing data electronically to the Department of Transportation in the US. 

The FAA estimated that the proposed rule would impact approximately 977 repair stations in 65 countries.  


 


 

 


 

A V-22 Osprey aircraft from the "Thunder Chickens" of Marine Medium Tiltrotor Squadron 263 conducts landing qualifications aboard the multi-purpose amphibious assault ship USS Bataan, July 8, 2008. (Petty Officer 3rd Class Patrick Gearhiser/Navy)

Ospreys had history of safety issues long before they were grounded
By Tara Copp, AP
Air Force Times Editor Rachel S. Cohen contributed to this story.

Thursday, Dec 7

A V-22 Osprey aircraft from the "Thunder Chickens" of Marine Medium Tiltrotor Squadron 263 conducts landing qualifications aboard the multi-purpose amphibious assault ship USS Bataan, July 8, 2008. (Petty Officer 3rd Class Patrick Gearhiser/Navy)

When the U.S. military took the extraordinary step of grounding its entire fleet of V-22 Ospreys this week, it wasn’t reacting just to the recent deadly crash of the aircraft off the coast of Japan. The aircraft has had a long list of problems in its short history.

The Osprey takes off and lands like a helicopter but can tilt its propellers horizontally to fly like an airplane. That unique and complex design has allowed the Osprey to speed troops to the battlefield. The U.S. Marine Corps, which operates the vast majority of the hundreds of Ospreys in service, calls it a “game-changing assault support platform.”

But on Wednesday, the Air Force, Navy and Marine Corps grounded all Ospreys after a preliminary investigation of last week’s crash indicated that a materiel failure — that something went wrong with the aircraft — led to the deaths of all eight Air Force Special Operations Command airmen on board.

And it’s not the first time. There have been persistent questions about a mechanical problem with the clutch that has troubled the program for more than a decade. 

There also have been questions as to whether all parts of the Osprey have been manufactured according to safety specifications and, as those parts age, whether they remain strong enough to withstand the significant forces created by the Osprey’s unique structure and dynamics of tiltrotor flight.

The government of Japan, which is the only international partner flying the Osprey, had already grounded its aircraft after the Nov. 29 crash.

“It’s good they grounded the fleet,” said Rex Rivolo, a retired Air Force pilot who analyzed the Osprey for the Pentagon’s test and evaluation office from 1992 to 2007 as an analyst at the Institute for Defense Analyses, and who previously warned military officials that the aircraft wasn’t safe. “At this point, they had no choice.”

The Osprey has become a workhorse for the Marine Corps and Air Force Special Operations Command and was in the process of being adopted by the Navy to replace its C-2 Greyhound propeller planes, which transport personnel on and off at-sea aircraft carriers.

Marine Corps Ospreys also have been used to transport White House staff, press and security personnel accompanying the president. White House National Security Council spokesman John Kirby said they also are subject to the standdown.

While the Ospreys are grounded, Air Force Special Operations Command said it will work to mitigate the impact to operations, training and readiness. The command will continue to fly other aircraft and Osprey crews will continue to train on simulators, spokeswoman Lt. Col. Becky Heyse said.

It was not immediately clear how the other services will adapt their missions.

Questions about the clutch
The first Ospreys only became operational in 2007 after decades of testing. But more than 50 troops have died either flight testing the Osprey or conducting training flights over the program’s lifespan, including 20 deaths in four crashes over the past 20 months.

In July, the Marine Corps for the first time blamed one of the fatal Osprey crashes on a fleet-wide problem that has been known for years but for which there’s still no good fix. It’s known as hard clutch engagement, or HCE.

The Osprey’s two engines are linked by an interconnected drive shaft that runs inside the length of the wings. On each tip, by the engines, a component called a sprag clutch transfers torque, or power, from one proprotor to the other to make sure both rotors are spinning at the same speed. That keeps the Osprey’s flight in balance. If one of the two engines fails, the sprag clutch is also a safety feature: It will transfer power from the working side to the failing engine’s side to keep both rotors going.

But sprag clutches have also become a worrying element. As the Air Force, Navy and Marine Corps began looking at HCE events following incidents in 2022, they determined that the clutches may be wearing out faster than anticipated.

Since 2010, Osprey clutches have slipped at least 15 times. As the system re-engages, hard clutch engagement occurs. In just fractions of a second, an HCE event creates a power spike that surges power to the other engine, which can throw the Osprey into an uncontrolled roll or slide. A power spike can also destroy a sprag clutch, essentially severing the interconnected drive shaft. That could result in the complete loss of aircraft control with little or no time for the pilots to react and save their Osprey or crew, Rivolo said.

In the 2022 crash of a Marine Corps MV-22 in California that killed five Marines, hard clutch engagement created an “unrecoverable, catastrophic mechanical failure,” the investigation found. The fire was so intense it destroyed the Osprey’s flight data recorder — another issue the Marines have pushed to fix, by requiring new flight data recorders to be better able to survive a crash.

Ospreys have been grounded before
After Air Force Special Operations Command experienced two hard clutch engagement incidents within six weeks in 2022, the commander, Lt. Gen. James Slife, grounded all of its Ospreys for two weeks. An undisclosed number of Ospreys across the military were grounded again in February 2023 as work began on clutch replacements.

But getting replacements to all the aircraft at the time depended on their availability, Slife said in 2022.

And even that replacement may not be the fix. Neither the services nor defense contractors Bell Textron or Boeing, which jointly produce the Osprey, have found a root cause. The clutch “may be the manifestation of the problem,” but not the root cause, Slife said.

In last week’s crash, Japanese media outlet NHK reported that an eyewitness saw the Osprey inverted with an engine on fire before it went down in the sea. If eyewitness accounts are correct, Rivolo said, clutch failure and a catastrophic failure of the interconnected drive shaft should be investigated as a potential cause.

After its investigation of the 2022 crash, the Marine Corps made several recommendations, including designing a new quill assembly, which is a component that mitigates clutch slippage and hard clutch engagement, and requiring that all drivetrain component materiel be strengthened.

That work is ongoing, according to the V-22 Joint Program Office, which is responsible for the development and production of the aircraft. A new quill assembly design is being finalized and testing of a prototype should begin early next year, it said.

When asked what inspections the JPO will conduct on the fleet while they are grounded, the office told Military Times that’s still unknown.

“The mishap investigation will ensure a thorough look into the casual factors, which will help identify recommendations to address any issues uncovered,” Marcia Hart, a spokesperson for Naval Air Systems Command, said Thursday.

Whistleblower questions
Materiel strength was the subject of a whistleblower lawsuit that Boeing settled with the Justice Department in September for $8.1 million. Two former Boeing V-22 composites fabricators had come forward with allegations that Boeing was falsifying records certifying that it had performed the testing necessary to ensure it maintained uniform temperatures required to ensure the Osprey’s composite parts were strengthened according to DOD specifications.

A certain temperature was needed for uniform molecular bonding of the composite surface. Without that bond, “the components will contain resin voids, linear porosity, and other defects that are not visible to the eye; which compromise the strength and other characteristics of the material, and which can cause catastrophic structural failures,” the lawsuit alleged.

In its settlement, the Justice Department contended Boeing did not meet the Pentagon’s manufacturing standards from 2007 to 2018; the whistleblowers contended in their lawsuit that this affected more than 80 Ospreys that were delivered in that time frame.

In a statement to The Associated Press, Boeing said it entered into the settlement agreement with the Justice Department and Navy “to resolve certain False Claims Act allegations, without admission of liability.”

Boeing said while composites are used throughout the V-22, the parts that were questioned in the lawsuit were “all non-critical parts that do not implicate flight safety.”
“Boeing is in compliance with its curing processes for composite parts,” the company said. “Additionally, we would stress that the cause of the accident in Japan is currently unknown. We are standing by to provide any requested support.”

Ongoing fixes
The V-22 Joint Program Office said that since the 2022 incidents, significant progress has been made toward identifying the cause of the hard clutch engagement.

“While the definitive root cause has not yet been determined, the joint government and industry team has narrowed down the scope of the investigation to a leading theory,” it said in a statement to the AP. “The leading theory involves a partial engagement of some clutches which have been installed for a lengthy period of time. This has not yet been definitively proven, but the data acquired thus far support this theory.”

Bell assembles the Osprey in a partnership with Boeing in its facilities in Amarillo, Texas. Bell would not comment on last week’s crash, but said it works with the services when an accident occurs. “The level of support is determined by the service branch safety center in charge of the investigation,” Bell spokesman Jay Hernandez said.

In its report on the fatal 2022 crash, the Marine Corps forewarned that more accidents were possible because neither the military nor manufacturers have been able to isolate a root cause. It said future incidents were “impossible to prevent without improvements to flight control system software, drivetrain component material strength, and robust inspection requirements.”

 

 
Charlie Trimble provides the 4000A GPS Locator to the Smithsonian Museum. Introduced in 1984, it was the first commercial GPS positioning product. (Image: Smithsonian)

GPS: The birth of the commercial GPS industry and how it changed the world
December 4, 2023  
By Charles R. Trimble

Trimble Navigation, which had started out making Loran receivers, was looking for its next marine project when HP decided to cancel its GPS project. Budget problems in Washington put completion of GPS in doubt. However, encouraging words from Brad Parkinson were enough for Trimble Navigation to buy the canceled project.

The purchase included a stack 14-ft high of unclassified reading material and a breadboard that fit on the table of a mobile home. It was a working GPS receiver that had recorded the mobile home’s position as it was driven around freeways in the San Francisco area. It took 12 months for a team of two engineers and 15 consultants to come up with the seven breakthroughs needed for the block diagram. Trimble was to iterate this block diagram on an 18-month cycle to follow Moore’s Law cost curve to the $100 required for car navigation. It took another year to build six rack-mounted multichannel receivers.

In October 1984, Trimble sold the first receiver for $100,000. Then came the sale of 20 OEM single channel timing receivers. The oil service industry was an important early market. At the time there were only seven GPS satellites in the sky and applications were limited to 3-4 hrs/day of accurate position measurement. 

Accuracy was a market driver, which led to the development of differential systems. These provided meter accuracies over wide areas. The next and far more difficult step was enabling a 1st order survey — which required accuracies of 1 cm/km.

Meanwhile, next gen GPS was added to Trimble’s marine Loran-C receiver and the company produced aviation receivers for the commercial markets. In January 1986, Trimble licensed its GPS technology for the Japanese car navigation market to Pioneer.

Then came the Shuttle disaster, and a new rocket had to be designed to launch more satellites. With only seven satellites in the sky and an unknowable time for rocket development, GPS use for navigation was off the table. Getting carrier phase 1st order products to work became critical for Trimble’s survival. In May of 1986, Trimble shipped an order of seven survey systems to the California Department of Transportation (Caltrans). Earthquake monitoring was a niche market add-on. Another “bet your company” deal was a Japanese order of 25 dual frequency systems.

During this time Trimble started to realize GPS was more than a device — that time-stamping events and geo-tagging things made it a valuable information technology component. The real value was in the information. By 2000, the Hong Kong price of the GPS function in quantities of a million devices a month was $1. GPS became ubiquitous and a fundamental component of a thriving information technology market.

GPS started out as a real-time worldwide system for navigation. It is now an indispensable part of modern life. GPS has truly changed our world.


 


Air Force looks to create single ‘Frankenplane’ from 2 damaged F-35s
By Zamone Perez
 Wednesday, Dec 6

A scene from the reconstruction process of two wrecked F-35s. (U.S Air Force)
Just as Dr. Frankenstein created a patchwork human from the parts of various cadavers, maintenance experts at Utah’s Hill Air Force Base are attempting to give life to an entirely new F-35A Lightning II from the parts of two mishap-damaged aircraft, according to a statement from the 75th Air Base Wing.

To do so, the F-35 program opted to reconstruct one aircraft, dubbed “AF-211,” that was damaged when its nose landing gear failed in June 2020. The aircraft’s nose section will be replaced with the undamaged nose from another jet, called “AF-27,″ that suffered a severe engine fire at Eglin Air Force Base, Florida, in 2014.

AF-27 currently serves as a model that lets airmen practice repairing battle damage.
Experts from the F-35 Joint Program Office, the 388th Fighter Wing, the Ogden Air Logistics Complex and Lockheed Martin are working on the project, the release said. (Frankenstein’s assistant Igor, however, will noticeably be absent.)

“It takes a team to make these types of endeavors successful,” Dan Santos, F-35 JPO heavy maintenance manager, said in the statement. “I am very impressed with the collaborative efforts from the various agencies across Hill AFB, working together to make this happen.”

While other F-35s have been repurposed, this particular aircraft takes previous Air Force recycling efforts a step further. The jet merging effort is a first — and these processes are being documented for possible repurpose initiatives in the future.
RELATED

The project is currently several months ahead of schedule and on track to be finished in March 2025, even without the expertise of an Ingolstadt-based doctor.
“The F-35 program is still young compared to all legacy airframes,” Dave Myers, F-35 JPO Lightning Support Team lead engineer, said in the statement. “We are doing this for the first time, and organizationally for the future, we are creating a process we can move forward with.”

 


 

Staff Sgt. Christopher Robinson, a jet engine mechanic with the 142nd Maintenance Group, inspects an F-15 Eagle upon its return from a flying mission, February 14, 2019, Portland Air National Guard Base, Ore. (U.S. Air National Guard photo by Master Sgt. Steph Sawyer)

Nov. 30, 2023 

The average age for America’s fleet of F-15C Eagles is about 38 years old, and many of the aircraft’s spare parts are no longer produced or can take days to order from a manufacturer. Luckily, the Oregon Air National Guard’s 142nd Wing has a metals technology shop at Portland Air National Guard Base where Airmen fabricate parts in-house to keep the wing’s elder Eagles flying.

“We have the ability as a unit to say, ‘Hey, stop what you are doing. We need to have this part made,’ and then have that part made in hours or even minutes,” Staff Sgt. Nathan Carssow, an aircraft metals technology craftsman with the 142nd Maintenance Squadron, said in a Nov. 29 news release about the shop.

Some of the parts help hold the plane together. Recently, the craftsmen made an aluminum stringer for the F-15C’s tail cone. The stringer is one of three stiffeners that provide a framework for the tail cone assembly that airframe skins and smaller parts attach to, Master Sgt. Steph Sawyer, a spokesperson for the 142nd Wing, told Air & Space Forces Magazine. 

Tech. Sgt. Nate Brown, a 142nd Maintenance Squadron metals technology craftsman, observes a CNC (Computer Numerical Control) mill as it carves a piece of solid aluminum into a stringer, an essential aircraft part, Nov. 4, 2023, Portland Air National Guard Base, Oregon. U.S. Air National Guard photo by Staff Sgt. Sean Campbell

Another type of key part are bushings, which often look like small thin tubes that reinforce functional holes in the aircraft which have weakened with wear.

“In the more intricate parts of our job, if an aircraft is in need of something, like the bushings, it’s not going to fly until our shop finishes the project,” Tech. Sgt. Nate Brown, a 142nd Maintenance Squadron metals technology craftsman, said in the release. “ … When a job is serious enough to need metals tech, it’s not going to fly until we finish the project that’s been given to us.”

Turning metal into a part ready for the demands of military aviation requires special tools, including manual lathes, CNC (Computer Numerical Control) mills, 3D printers, and welding tools. Other tasks are less demanding but just as important, like removing screws stuck in removable panels or skins.

“Stuck screws can cause a work stoppage due to the maintainers being unable to access those areas to accomplish maintenance or inspections,” Sawyer said.

Staff Sgt. Nathan Carssow, a 142nd Maintenance Squadron aircraft metals technology craftsman, machines a stringer for a tail cone, a part that has become un-procurable, November 4, 2023, Portland Air National Guard Base, Oregon. U.S. Air National Guard photo by Staff Sgt. Sean Campbell

Despite fewer than 10 Airmen working there, the shop has made quite a dent, saving $1.2 million in Air Force Repair Enhancement Program (AFREP) funds in fiscal year 2023 alone. When Airmen fix a part through AFREP, the unit can take the money that would have gone towards a replacement part and instead use it on capital improvements or new equipment. The same goes for non-aircraft parts, such as those used by aerospace ground equipment, ammunition, or other shops that keep the service running.

Metal shops can be especially helpful for older aircraft like the F-15 or the RC/WC-135, but even younger jets sometimes need creative in-house fabrication. For example, the Air Force’s fleet of F-35 fighters is just four years old on average, but AFREP Airmen at Hill Air Force Base, Utah saved the base thousands of dollars by designing better F-35 sensor covers and better diagnostic tools for the stealth jet. 

That means when the Oregon Air National Guard starts flying brand-new F-15EX Eagle IIs in fiscal year 2025, the Airmen at the metals shop will probably still have plenty opportunities to test their mettle.

Air Guardsmen Keep Aging F-15Cs Flying With Spare Parts Made In-House

 


Epic turboprop receives FIKI certification
By General Aviation News Staff
December 7, 2023 t

The FAA has granted Flight Into Known Icing (FIKI) certification for the Epic Aircraft E1000 GX turboprop.

“This certification process is one of the most challenging,” said Doug King, CEO of Epic Aircraft. “We began testing several years ago, flying the E1000 GX in all of the FAA-specified natural icing conditions.”

“This FAA certification establishes that the E1000 GX can withstand known icing conditions in a real-world operating environment with minimal changes required of the airplane,” he added.

The first test flight began with artificial ice shapes which were 3D printed at the Epic factory in Bend, Oregon. Since that time, more than 450 flight hours on three test aircraft have been recorded, many of which were conducted in natural icing conditions in several locations in the United States.

Epic Aircraft also performed extensive tests with the E1000 GX in normal operation and ice protection system failure conditions in icing tunnels and with artificial ice shapes to simulate ice build-up attached to the airfoils.

More than 18 different icing configurations in two different icing wind tunnels were executed, for a total of 280 hours of icing wind tunnel test, company officials report.
The E1000 GX’s de-icing system includes an optical ice detector, de-ice boots on the wings, horizontal stabilizer leading edges, engine inlet, as well as bleed air heated windshield and electrically heated propeller, air data probes, and AOA sensors.

“Beginning with our first aircraft delivery in 2024, the E1000 GX will incorporate the minimal changes required for FIKI. Previously delivered certified airplanes, including the E1000, will require modifications and will be retrofitted at our factory service center in Bend, Oregon,” said King. “Our goal is to have the existing fleet completed no later than early 2025.”


 


Successful Remote-Piloted Flight For Cessna Caravan
By Mark Phelps 
Published: December 6, 2023

California-based Reliable Robotics announced today (Dec. 6) it has completed an FAA-sanctioned uncrewed flight of a Cessna 208B Caravan at Hollister Airport (KCVH) just south of San Jose, with a remote pilot in control from the company headquarters in Mountain View, California, 50 miles away. The Caravan took off from Runway 31 and entered a closed traffic pattern for landing. Designed for autonomous flight, the company’s technology enables remote operation through all phases of flight, including taxi, takeoff and landing.

Reliable Robotics said its technology is “aircraft agnostic” and has multiple layers of systems redundancy. The system incorporates “advanced navigation technology” and is also designed to prevent controlled flight into terrain (CFIT) and loss of control inflight (LOC-I).

One target market is enabling cargo flights to remote areas. The announcement noted, “The Caravan, and other regional cargo aircraft like it, serve an essential role connecting communities and businesses across the United States and around the globe.” Chris Hearne, Textron Senior VP of Engineering and Programs, said, “Reliable’s successful flight of an uncrewed Cessna 208 Caravan represents a milestone for the industry in bringing new technology to aviation.”

Last August, Reliable Robotics announced it had completed simulations and flight tests as part of the FAA’s Urban Air Mobility Airspace Management Demonstration. The simulations involved integrating remotely piloted aircraft into congested airspace, according to Reliable. The flight trials took place over the course of a week in northern California.

Today’s announcement also revealed that Reliable has been working under multiple contracts with the U.S. Air Force since 2021 “to leverage the significant progress on remote piloting for the Cessna Caravan to jointly examine how this commercially derived technology can be applied to large multi-engine aircraft for cargo logistics, aerial refueling and other missions.”


 

Van’s Files For Chapter 11 Protection
By Russ Niles 
Published: December 5, 2023

Van’s Aircraft has filed for Chapter 11 protection while it reorganizes with the goal of maintaining existing services and emerging as a solvent company again. In a statement posted late Monday, Van’s tried to assure owners of 10,000 finished aircraft, builders and future customers the company has a future. “During this period of reorganization, we will continue to source, produce, and provide parts, service, and support to our customers. We will also be crating and shipping kit orders,” the company said.

The company blamed a maelstrom of issues for the decision, which was made about a month after company founder Dick Van Grunsven announced the company was pausing certain functions while it addressed a serious cash flow crisis. Two separate quality control issues, along with an imbalance of orders and deliveries due to COVID, led to the crisis. “The purpose of the Chapter 11 filing is to allow Van’s to continue to provide ongoing support for its customers, suppliers, and employees for many years to come,” the statement, which is copied in full below, says.

Statement By Van’s Aircraft On Chapter 11 Filing
On December 4, 2023, Van’s Aircraft filed for protection under Chapter 11 of the federal bankruptcy code, a key step in the reorganization of our company. During this period of reorganization, we will continue to source, produce, and provide parts, service, and support to our customers. We will also be crating and shipping kit orders.

Over the past few years, the company has faced a handful of complex issues, including unprecedented supply chain challenges throughout COVID, faulty primer that led to corrosion problems on quick build kits, and problems with laser-cut parts that were manufactured in response to high demand. As a result of this combination of issues, the company experienced serious cash-flow problems from which it could not recover through the normal course of business.

During that time, Van’s built up a significant and high-value parts inventory. As we manufacture the additional parts needed to balance this inventory, we will leverage it to fulfill orders for kits and parts over the next 12 to 18 months.

The purpose of the Chapter 11 filing is to allow Van’s to continue to provide ongoing support for its customers, suppliers, and employees for many years to come. We understand that this situation creates a hardship for everyone involved. However, without these changes we do not see a viable path forward that would allow Van’s Aircraft to remain in business and support its customers.


 


Should I pre-oil these Lycoming engines?
By Paul McBride
December 11, 2023 

Question for Paul McBride, the General Aviation News engines expert: I am looking at pre-oiling Lycoming engines, such as the O-320-E3D, O-320-E2D, D2J, etc., installed in Piper Warriors and Cessna 172s.

I was planning on removing the oil line coming out of the engine going into the oil cooler, installing a fitting, and pre-oiling with about 25 to 35 psi through the oil cooler. While camping the fitting on the engine, this should flow the oil cooler and the rest of the engine, bypassing the Vernatherm and back flow into the filter and oil pump.

Originally, I was looking at tapping into the center post of the oil filter adapter, but this would not let oil flow through the oil cooler, which for a fresh engine would not be a problem, but for an engine that has been sitting, it would be good to flush out the oil cooler at the same time.
What are your thoughts?
Glenn Ingle

Answer from Paul McBride: Glenn, the first question I’d have to ask is what you are attempting to do?

If you’re thinking is to lubricate the entire internal components of the engine, I hate to tell you that it’s not going to work.

Sorry for being so blunt, but pre-oiling Lycoming engines with, let’s say 25 to 30 psi from an external source, would only pre-oil the main, connecting rod, and cam bearings, or any area that is serviced by a direct oil pressure point.

If your thought is to pre-oil the cam and tappet faces by using this procedure, it’s not going to work. The cam and tappet areas are only oiled by splash oil and have no direct pressure oil points.

While this design has been questioned over many years, it is what it is and has served Lycoming engines relativity well since the 1930s when the first flat opposed Lycoming was certified.

Please don’t confuse my statement with this being a perfect design, but in most all situations, it has worked fine.

We all know of some situations in the past where cam and tappet spalling was a problem on certain engine models. The problems were addressed on those specific engine models and engineering redesign corrected the issues.

Again, my guess is that you want to eliminate any possibility of internal lack of lubrication during engine start-up.

As I mentioned previously, since the cam and tappet area are only served by splash oil, if you really want to focus on that area and keeping it in the best of health, here are a few suggestions.

First, the worst thing that you can do for an engine is allow it to have extended periods of inactivity. Couple that with infrequent oil and filter changes, and you’ve opened the barn door for internal engine corrosion, especially in the area of the cam and tappet interface.

If you can picture the tappet body face being a vertical surface and can imagine what happens to the oil on that surface as time passes when the engine is sitting inactive, the natural occurrence is that the oil drains off of the surface.
What has a tendency to remain are the by-products of combustion and they are acidic in nature. These remnants of what was once a lubricated service are now contaminated and the corrosion process begins. The process is aggravated by extended periods of inactivity, as you can imagine.

On the next engine start-up when the cam lobe swipes across the face of the tappet, metal is displaced, and the spalling process begins. Unfortunately, that condition will never get any better and will, over time, continue to displace metal. At some point, you’ll become aware of this when you cut the oil filter open for inspection during a routine oil and filter change.

If you operate these engines frequently and change the oil and filter frequently, you shouldn’t have to worry about pre-oiling. I’d also suggest you read the latest version of Lycoming Service Bulletin 480.

If it’s a question regarding the aircraft not being flown during the winter months, the best thing to do is change the oil and filter before storing the aircraft for any period of time so those acidic properties in the engine oil don’t get a chance to begin the corrosion process.

Also, do not turn the prop and put a sign on the prop stating that. That’s always a good idea.


I hope I’ve addressed your question and hopefully given you some insight as to how to deal with this type of situation.


 


Pratt & Whitney engines achieve 100% SAF flight in AW139 helicopter
Comprehensive series of flight and ground tests spanning 75 minutes was conducted at Leonardo's facility in Cascina Costa di Samarate.

Jijo Malayil
Published: Dec 10, 2023 05:39 AM EST

Leonardo's AW139 running on 100 percent SAF.
Pratt & Whitney  
Comprehensive series of flight and ground tests spanning 75 minutes was conducted at Leonardo's facility in Cascina Costa di Samarate.

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In the pursuit of emissions reduction in the aviation sector and the attainment of net-zero targets, aircraft equipment manufacturers are actively exploring enabling technologies that necessitate minimal alterations to existing aircraft designs. 

At the forefront of this transition is Pratt & Whitney Canada, a prominent aircraft engine manufacturer. Their recent milestone achievement involves the successful completion of the inaugural flight for a helicopter, powered by the firm's PT6C-67C engine in a Leonardo AW139 helicopter and fueled entirely by Sustainable Aviation Fuel (SAF). This marks a significant stride in the industry's commitment to sustainable aviation practices.

Last month, the firm also achieved the milestone of completing a transatlantic flight exclusively utilizing SAF in a Gulfstream jet. A GS600 business jet had utilized Pratt & Whitney's modified PW800 engines to complete the journey. Furthermore, November also saw Virgin Atlantic using a Boeing 787 powered by Rolls-Royce Trent 1000 engines, to complete the world's first 100 percent SAF-fueled transatlantic flight with a commercial aircraft. 


 


Curt Lewis