From the Boston Globe website

Costly flaws found in Navy's top jet
Wing mechanism wear could halve flight hours
By Bryan Bender, Globe Staff | May 17, 2007

WASHINGTON -- Engineers have uncovered a flaw in the Navy's top fighter jet that could reduce by half the aircraft's advertised service life and potentially cost taxpayers hundreds of millions of dollars in repairs, according to Pentagon documents and military and industry officials.

A mechanism inside the wings of the F/A-18 Super Hornet, manufactured by Boeing Co. , is wearing out prematurely, prompting the Navy to order the company to make changes in the plane's production as well as retrofit several hundred planes already operating off the decks of Navy aircraft carriers, according to a Navy official.

Officials stressed that they are not considering whether to ground the workhorse jet, because the problem does not affect its operation. Still, the "fatigue life issue," if uncorrected, would drastically shorten the $50 million aircraft's life span from 6,000 flight hours to 3,000 hours, the documents warn.

Through testing of Super Hornets they discovered there is a fatigue issue on part of the inside of one of the wings," a Navy official confirmed in a statement yesterday. "From here on out every aircraft will be made so they don't have the problem." The official said at least 193 planes now in service will be retrofitted beginning in 2010. The plane was introduced in 1999.

But the wing is apparently not the only thing that needs to be retrofitted, according to the Navy official, who asked not to be named because he is not authorized to speak for the program. The Navy did not comment officially about the problem despite numerous requests.

The current fleet of Super Hornets is slated to receive a total of 40 modifications, both major and minor; additionally, a separate problem with the aircraft's wing flaps could limit even further the plane's ability to fly safely, the documents show. Special fatigue tests now underway to identify a fix for the second wing problem are set to be completed in July.

Navy officials said they will not know the price tag for retrofitting the wings until an "engineering change proposal" outlining solutions is completed in the coming months.

Loren Thompson, a defense analyst at the Lexington Institute, a defense and public policy think tank, said any structural problem in the jet's wing "is a much bigger problem" that will require expensive, time-consuming repairs.

"It would be very costly to go back and refit" the jets, Thompson said. "Usually, if there is fatigue or corrosion problems [on aircraft wings], it is [on] the outside part that is exposed to the elements. When you develop a fatigue problem inside the wing, the challenge of fixing it grows.

"The cost, the man hours, the time the aircraft are out of service: No matter how you want to measure it, it is not minor."
The Navy plans to build 210 Super Hornets over the next five years. Ninety of the planes will be outfitted with advanced radar and high-tech sensors to jam enemy electronics. That version, known as the Growler, is awaiting approval to begin initial production next year.

Australia recently signed a $2.4 billion deal to purchase 24 Super Hornets, the first sale in what Boeing hopes will be a growing foreign market for the aircraft.

The structural problem in the wings has emerged at a time when Boeing has proposed selling the Navy at least 100 more Super Hornets in case the F-35 Joint Strike Fighter -- the Pentagon's next-generation attack jet now under development -- is delayed further, according to news reports. The F-35, produced by Boeing rival Lockheed Martin, is not expected to enter service for eight years.

The Super Hornet is 25 percent larger than its predecessor, which was first widely introduced in the 1980s. Considered one of the Pentagon's most complex aircraft, the Super Hornet became the Navy's mainstay jet after the infamous A-12 stealth aircraft project -- launched to replace the aging, earlier-model Hornets -- collapsed.

Some critics argue that the design changes and upgrades in the latest generation Hornets were so significant that the Super Hornet project should have been scrutinized as though it were an entirely new aircraft line -- rather than the more cursory look reserved for modifications of earlier-model aircraft.

They never built a prototype," said James P. Stevenson , a military aircraft specialist and author of "The Pentagon Paradox," which reserves a chapter for the F/A-18 program. "After 25 years of development they still haven't got it right."

Indeed, the F/A-18 program has had a series of aerodynamic and structural problems over the years. As far back as the early 1980s, the first versions of the Hornets also had problems with premature wear and tear on the airframe, requiring significant retrofitting.

Those structural issues have been more pronounced with the Super Hornet.

For example, testing of the Super Hornet in the late 1990s revealed that the plane would "flutter" during certain maneuvers -- a flaw that nearly brought the program to a standstill. It required the Navy and Boeing to make substantial changes to the wings and pylons.

Yet while those adjustments made the flutter "manageable," according to the new documents, it produced a new problem: accelerated wear on some of the missiles carried under the wings, according to the documents.

Now, the Navy and Boeing are scrambling to come up with a solution for the Super Hornet's wing fatigue, which first showed up in tests in 2005, the Navy official said.

The prediction that the flaw could drastically cut the jet's anticipated life pan amazed some defense analysts .

"That would be a significant decrease," said Richard Aboulafia , a defense analyst at the Teal Group in Fairfax, V a.

Still, the documents indicate the Navy and Boeing are confident they know how to fix the problem. A proposal "that will address the inter-wing retro fit" is expected within a few months, according to a document prepared by Naval Air Systems Command and provided to the Globe. "Not until 2008 will aircraft roll off the line with full life" if Boeing makes the necessary adjustments to its production, according to the document.

Serves them right as far as I am concerned!

There's a superior aircraft out in the desert that would make a suitable replacement for them.

I'm actually surprised the top two posts weren't made in a "light red" font!! :wink
In the interests of fairness is this article, taken from the Navy Times website.


Navy, Boeing downplay alleged F/A-18 problems

By Christopher P. Cavas
Posted : Friday May 18, 2007 10:31:07 EDT

U.S. Navy and Boeing officials were quick to respond to a Boston Globe story May 17 that alleged “costly flaws” in Super Hornet strike fighters could cut their lifetime flight hours in half.

“The Boston Globe article has many misstatements,” said Patricia Frost, a spokeswoman for Boeing Naval Systems in St. Louis. “Boeing and the U.S. Navy expect the Super Hornet and the EA-18G to meet or exceed their 6,000-hour design life.”

The Globe story reported that “a mechanism inside the wings of the F/A-18 [E and F] Super Hornet Â&褽 is wearing out prematurely” — a problem that, if uncorrected, “would drastically shorten the $50 million aircraft’s life span from 6,000 hours to 3,000 hours.”

Boeing and the Navy acknowledged that problems have been found with the aircraft, but said the situation described in the Globe story dates from four years ago. Fixes already have been incorporated into new aircraft and will be retrofitted into older planes, Boeing and the Navy said.

“The U.S. Navy has identified a pylon fitting in the wing of the F/A-18 E and F model Super Hornet where fatigue could potentially shorten the wing’s expected service life and is implementing a corrective measure,” said Chuck Wagner, a spokesman with Naval Air Systems Command in Patuxent River, Md. “The fitting is part of the lower wing spar and is used to reinforce the area where stores attach to the wing. The potential problem was identified through an engineering analysis in 2003 and subsequent testing in 2005, which are part of our routine risk-mitigation processes for the aircraft’s development. The Navy and Boeing worked together, a fully-funded project is underway, and today every aircraft coming off the production line is being delivered with the solution that corrects for the potential future fatigue. A retrofit solution on those aircraft already in the fleet is planned for 2009 and will correct the identified wing area prior to those aircraft reaching the flight-hour threshold in which fatigue could potentially be experienced. The Navy is confident it has selected the optimal proactive response which in no way compromises the readiness or performance of the aircraft’s mission.”

Asked whether the situation affected new EA-18G Growler electronic countermeasures aircraft — which are all converted on the production line from two-seat F models — Wagner said the problem did “not influence them at all, because the solution is already incorporated into aircraft coming off the production line. The solutions were incorporated before the first G was delivered.”

Fixes and modifications to aircraft in series production are not unusual, Frost said.

“They’re part of the normal life of an aircraft,” she said. “If something comes up you go out and fix it in a timely fashion before it becomes a serious issue.”

It'll all be OK when they get the F-35s as, rather than having to shift their own fleet(s) about, they'll just "borrow" them off some other country! :wink


I'll see if I can find the said article about the Cs to A+s.

Chad,

The smiley at the end of the "highlight it more" comment was there for a reason, the comment itself was more in answer to something Rob had said to me to be fair.(It was a light hearted comment)

I am well aware of the Tomcats problems during its service life in the Navy and the maintenance issues in the types latter part of service, old aircraft get tired, fact, and thats just what happened with the Tomcat, and yes the aircraft had a very troublesome service life and by all accounts was a bitch to keep in the air, but the points you have made about various upgrades to the Tomcat during its service, although true are comments that could be made about most fast jets in military service today, most if not all jets go through various upgrades and design changes throughout their service lives, indeed the Legacy Hornet has had various upgrades and mods inc engines and radar and the Super Hornet has already been through a series of mods/upgrades, the jets coming off the line now are far better then the initial batch.

An increase of around 1200 hours is quite a significate one, has the Legacy Hornet had that kind of increase on its service life? The Legacy Hornet has been a great jet for the Navy down the years but they are starting to show the strain of carrier cycles with a few starting to get close to their hours limit.

Even with its high hours/cost maintenance can you honestly say that the decison to retire the Tomcat even earlier then was originally planned was the correct one?, I am not convinced.

With the high tempo of ops being carried out in recent years the Legacy Hornets are wearing out faster then anticipated, Super Hornets cannot come off the production line fast enough and JSF is some way off entering service, the short term solution of saving money by retiring the Cat early could and probably will lead a short fall in aircraft in the long term. The exact same thing is happening here in the UK with our government hell bent on retiring our assets and not replacing them (But that's another thread)

Cheers
John

I know, I know, it's digging up an old thread but... it's all the Marine Corps' fault.