I want to give our savvy DT readers a collective pat on the back for your excellent discussions on the recent F-15 grounding.
Though I absorb quite a few barbs from you at times and deservedly so, in very few cases (sarcasm) it is one of the greatest pleasures editing this blog to see how smart, involved and dialed in our readers are. The issue with grounding the F-15s is a perfect case in point.
Our boy Byron Skinner pegged it right off the bat when he spoke of known structural problems with the F-15:
Welcome to the original air frame structural design flaw discovered in the F-15 in the late 90’s. In short the tail section wants to fall off. The F-15E’s had already gone into production and the AF didn’t want to invest any money in an aircraft designed in the 1970’s so it was let go.
Without 9/11 they may have gotten away with it but with the Homeland Security over flights and the wars in Afghanistan and Iraq missions putting excessive hours on the flawed F-15 airframes it’s only a matter of time before more fall out of the sky and an aircrew is lost…
…The design defect is in the aft part of the air frame where the tail fins connect to the fuselage. If it’s a material problem or a structural design failure it still being debated. It was estimated that since it appeared that the F-15’s were good for about 20 years before the airframes via fatigue and other stresses would be come an issue that with the restrictions the F-15 was serviceable with in the operational environment before 9/11.
The AF decided to roll the dice and not correct the problem and made permanent the operational restrictions on the F-15’s…
Then our friends at Aviation Week (I wonder if they were tipped off by our comments) put together a story on the problem. Heres what they found:
F-15 operations were suspended pending review of a Nov. 2 crash. A possible structural failure was involved in the Missouri Air National Guard F-15C crash, which could have larger implications about the integrity of the entire F-15 fleet, say USAF officials.
Aerospace industry and USAF officials say the fuselage broke in two immediately behind the cockpit during a 2.5–3.5g maneuver. The aircraft had been delivered to USAF in 1982.
In a statement, the pilot said his first warnings were smoke and fumes in the cockpit. Almost immediately he was in the aircrafts slipstream. He ejected and suffered flailing injuries.
Our boy Byron also brought up the BRAC issue…
Let us not forget that they were facing declining budgets, the Soviets were gone, the public was EXPECTING a PEACE DIVIDEND, BRAC and an administration who never really understood the military.
And Av Week, found something similar:
Also, investigators are looking at maintenance practices to see if problems could have been generated by closing down the unit as part of the base-realignment process. An initial USAF analysis found that it was a unique problem with a single aircraft, not a fleet-wide problem.
But worries me most is the idea that the Air Force is using this grounding to push Congress for more F-22 funding. Im not a huge proponent of conspiracy theories, but it seems so tempting to me that the Air Force cant help but use the grounding to say see, we told you the F-15s are old and need replacing. And they know that brining up BRAC issues have particular resonance among lawmakers starved for Pentagon pork in their districts no matter how antiquated the base may be.
Again, Av Week:
USAF and industry officials say fleet groundings sometimes occur every few months for various safety issues. They say senior USAF leadership is using this grounding to push for a larger F-22 force. And while USAF was grounding its F-15s, military officials briefing an international fighter conference in London said that the F-15Cs wouldnt be retired until 2025–30, and that the F-15E will serve beyond 2035.
The accident in Missouri could be unique to that [one] aircraft, a veteran F-15 squadron commander says. And if its not, there are lots of fixes you can make to keep them flying. The pitch for more F-22s is whats going on.
And this was not lost on our DT readers either.
What worries me most is that at some institutional level, in E-Ring Air Force offices in the Pentagon, the decision was made to make a bigger issue of these seemingly isolated crashes than should have been so that a better case for F-22s could be made. Again, I dont want to think this, but when a service makes a decision to define its future with one piece of very expensive hardware like the F-22, its almost too tempting a Devils Bargain to avoid.
But if Byrons right, and there is a long-term structural problem with the F-15, its our duty as a nation to fix the problem or replace the planes as soon as possible. I just dont know enough about the engineering side of this debate. Thats what Ive got our readers for.
Thanks to everyone for your input. And keep up the good work.
(Av Week gouge from NC)
– Christian
Yeah,but they have found a way for B-52s to keep flying for almost 50 years.But thats most likely because they don’t have a highly touted replacement for the B-52 like the F-15 does in the F-22.Does the Air Force want the F-22 so badly that they’d allow F-15s to disintegrate in mid air so they can claim it “unsafe” & open up the F-22 shops to build more F-22s? When the F-35 is finally ready,will the F-16s start falling out of the skies in massive numbers & a “design flaw” be found in them too? In the case of the Marine Corps,how can the AV-8B Harrier be found to be [more] unsafe? But then,I’d expect the Marine Corps to have more honor than the Air Force in resorting to trickery like that.
I realize that doc75, but we have no verification from official AF sources for a failure at either location on the aircraft. My reasoning was to point out that soon after our post, readers pinged on a structural failure — one that has existed for years. Maybe Av Week’s location is more accurate, but Byron was onto it early.
The Air Force is as unscrupulous today as it was back in the 50’s & 60’s when it fought against the Navy having nuclear bombing capability with the A-3 Skywarrior & the A-5 Vigilante bombers.These two planes could have only complemented our nuclear bombing capabilities & was no threat whatsoever to the Air Force’s B-47 & B-52 bombers.Using Air Force logic,we shouldn’t have had boomer submarines either because that also stepped into the Air Force’s domain concerning nuclear missiles.I don’t see any of our other armed services making deals with the devil to the extent that the Air Force seems to be making,both in the past & in the present.
Roy, the B-52 experiences nowhere near the g loading that a fighter does. BUFFs spent years sitting on the ground pulling alerts during the Cold War. There’s not a lot of load on the jet when its at zero AGL and zero airspeed. Apples-to-oranges.
Hard choice to make. An 30 year old airframe, verses one that is state of the art and able to take on anything in the world for the next 20+ years. Why do people so appose something that is new and better? The F-15 was state of the art in its day and we bought it, who was saying that the F-4 was the way to go. Why do people so hate the F-22 the best in the world. There is a valid reason to start phasing the F-15 out of the front line role, and put F-22s in.
I just don’t understand why some people really don’t like the F-22 even though it is the best in the world. Can someone help me out, am I missing something here. The Army has to have the latest body Armour, and MRAPs. Yet the Airforce is expected to fight with old outdated airplanes. Am I the only one who sees a double standard.
About the USMC having more honor than the USAF. Im sorry but we are fighting the same war here, and when was the last time a USAF person said the USMC was a bunch of retards because they want a new airplane. Im sorry but who is it that really wants the new F-35? Why does the USAF have to fly old airplanes when everyone else gets new stuff?
Doc75,
When you consider the coveting of new weapons,there’s not much difference in wanting a new F-22 over the other fighters we have & coveting a new bomber over the B-52,B-1,& B-2 bombers.You watch,as soon as they have a viable new bomber ready to be tested,there will be a loud voice calling the three bombers I mentioned unsafe & we’ll probably started seeing “design flaws” in the B-52s,B-1s,& B-2s.
Also,going back to my gripe about the Air Force killing the Navy’s A-3 Skywarrior & A-5 Vigilante bombers,we don’t seem to be having very many bombers today,how much would having these naval bombers have helped our strategic needs(seeing that they probably would also still be flying today)? When new toys come along,like a spoiled brat,the Air Force destroys their old ones to justify the buying of the new shiny ones(with more bells & whistles).
By the way,those Russians are so “bright.” According to Strategypage.com,the “design flaw” affecting our F-15s also affect their Su-30s.I read this in an article about India replacing their MiG-25s with the Su-30.They only gave that a one sentence mention though.
Who is to say though that the same “design flaw” is not in the F-22? To the untrained,uneducated eye like mine,the F-22 looks like a glorified,“stealth” F-15 & a logical evolution of the F-15 at that.
If you’re worried you’ve seen the last of the F-15, don’t be. Once upon a time the U-2 couldn’t keep it’s tail attached during takeoff and it accelerated the development of successors such as Global Hawk but the U-2 got fixed and it’s still around. And then the A-10 had tail problems that accelerated the development of successors such as the JSF and the A-10 subsequently got fixed and upgraded and it’s still going strong. The moral of the story is the successor aircraft are important and need to be developed and fielded but if the original is a useful workhorse it’ll stay around and continue to fuel these debates about “why develop and buy new stuff when you can fix the old stuff?”. You can rest assured the E-ring has no intention of retiring the F-15 early. Even if we wanted to replace F-15’s immediately with F-22’s it simply can’t be done — insufficient manufacturing capacity, too much money, not enough currently fielded F-22 capability. Relax.…
It looks like structural/fatigue have plagued a 30 year old airframe but I wonder how many more unexpected “international date line” incidents will catch the F22 fleet by surprise
I’m still waiting to see some links to reports on how the F-22 matches up with the F-15 in a guns only engagement, in one on one, two on one, and five on one. I think a lot of us here are skeptical that the F-22 will be up to the task in a all out MK one eyeball furball, or that it will have enough advantage to make up for the all to few airframes being purchased in such a situation. Sure it might work well in a limited engagement, but what about a all out war over China, NK, Russia, or India? And don’t say it can’t happen. Look out 30 years and anything can happen.
And for the record, I think we should be buying F-22s and F-15s. We should be expanding our fighter fleet, not just replacing the current airframes.
This whole story reminded me of that F-14 stabiliser found washed up on the beach in Ireland
http://content.hamptonroads.com/story.cfm?story=104179&ran=157482
Same problem?
What about super hornets?
Roy,
As doc siad the stresses on the airframe of a Buff and a F-15 are not the same. The Buff’s dont have the strain of airial manuever that the F-15’s do. While the Buff’s ran low level flights in the 70’s and 80’s they only operate at high altitude today, Thus metal fatigiue is not an issue.
Also there have been a number of highly touted replacements for the Buff, you even mentioned them in another post. So it seem the point is lost.
Oh and deals with the devil??? please… You might want to look at the A-12 program some time.
“I just don’t understand why some people really don’t like the F-22 even though it is the best in the world. Can someone help me out, am I missing something here. The Army has to have the latest body Armour, and MRAPs. Yet the Airforce is expected to fight with old outdated airplanes. Am I the only one who sees a double standard.“
John, the main prejudice to the F-22 and F-35 seem to be cost. While the F-15 was a $30 million plane and about 1,000 were built, the F-22 is somewhere around $130 million a copy for 200 aircraft. Give the Army $1 billion, and they can buy new body armor for every Soldier in the Active, Guard, and Reserve. Give the Air Force $1 billion, and they can buy 10 planes. It may not be a valid comparison, but to someone concerned with tightening budgets, that’s how it looks. The Air Force also has a reputation for spending money on frills and comforts that the other services do without either because of budgets or traditional lifestyle (ie: At my base in Texas, the Air Force personnel are given extra pay for living in army housing because its not up to Air Force standards).
I agree with Sam Adams, even though I don’t like his beer so much.
We should be purchasing more F-22s, the Air Force wants double what they are going to be getting. And to supplement that we need to purchase F-15s with AESA radar, thrust vectoring, and even candards. These have been put on front line F-15s (AESA) and on experimental F-15s.
I’ve said this before on another blog entry here (and was shot down in a blaze of glory), but the JSF is a waste of money. The Navy does not necessarily want them anymore with the Super Hornet doing very well, and I’m sure the Air Force would want more F-22s and new F-15s/F-16s in lieu of the JSF. The only people that need this plane are the British and the Marines to replace the very unsafe Harrier.
Don’t get me wrong, the JSF is a great airplane. But we already have a 5th generation fighter in the F-22. Let’s get new airframes to do the things F-15s and F-16s currently do now which don’t require stealth.
DC2
NTV
The only thing I remember about the A-12 program was that then Sec.Def. Cheney killed it before it even got off the ground,so to speak,along with his killing off further production & upgrading of the the F-14 Tomcat,& his “I wish I could keep them” retiring of the Iowa Class Battleships.
Response to Roy Smith’s comment:
” But then,I’d expect the Marine Corps to have more honor than the Air Force in resorting to trickery like that.“
Does the name Odin Lieberman ring a bell?
Sorry,had to look up the name Odin Lieberman,yeah a lot of money was invested in the V-22 Osprey.Well,it looks like we have three services invested in questionable aircraft,the Air Force with the F-22,the Army with the UH-72 Lakota(they dumped the Comanche,may be close to dumping the ARH,but they want to keep this “turkey?” The “logic” fails me here),& finally the Marine Corps with the V-22 Osprey.
In response to whoever said that the Super Hornet was enough for the Navy & they didn’t need the F-35 Carrier Version,the navy still hasn’t adequately replaced the A-6 Intruder,the Super Hornet cannot do what the F-14 Tomcat was able to do with long range air-to-air missiles protecting the fleet from enemy bombers,& I’d hope that that Chinese sub popping up in the middle of a naval sea exercise would show that retiring the S-3 Vikings was a huge STUPID mistake.Arming an Airship for anti-submarine warfare would offer more protection than our navy has now.
So the Bushies were right on Iraq, budget deficits, global warming, and the number of F-22s; except that the experts all agree that they are wrong? Huh?
180+ F-22s are not enough when confronting the Air Forces of India, Russia, or China. I just don’t agree with that philosophy. You need overwhelming force just like Colin Powell has always preached. Having just enough certainly has not worked in Afghanistan or Iraq. Maybe if we had tried the surge in the beginning we would not be where we are today. And maybe if we had done the same thing in Afghanistan Osama’s head would be mounted on the wall in the Oval Office.
The F-18 is a tremendous platform for the Navy and with AESA does a far superior job than the F-14. Purchasing the JSF would do nothing to replace the loss of the Phoenix long range AAM that the Tomcat carried.
I’m not a big proponent of the V-22, even though it is really a cool aircraft. And in my opinion, the Marines can only have one expensive toy just like the Air Force. With Marine aviation now launching from carriers it is time we took a look at killing VSTOL. Sorry jar heads.
DC2
Being a Aircraft structural engineer working on an aging fleet, this is a subject I know plenty of things about such problems.
It’s most likely a fatigue issue (an obvious statement).
But the problem is that during design and testing nothing ever reflects reality!
Fatigue loads are very difficult to predict, often a very small percentage load increase will reduce overall life severely (S-N curves quite simply illustrate this). Also high strength materials usually have a high fatigue life (ie. a good S-N curve) but poor cracking resistance. So what you find is that while no cracking will occur, there will be a sudden surge of failures as aircraft reach a certain life limit.
The no of cycles for the crack to grow to failure is likely to be less than the inspection interval as prior calculations would have not considered the number of flights the aircraft are reaching wasn’t calculated in the initial design.
Ie. there is no design flaw as such, the flaw is that these aircraft were never meant to reach this number flight cycles, so they were never designed as it is termed to “age gracefully”. You want an aircraft that is light and high performance, yet age gracefully — you cant!
Maybe with all composite aircraft we will eventually achieve this, but even so the material is likely to degrade over time.
Older designed aircraft tend to age more gracefully as they were designed with a higher RF (reserve factor) and all the calcs done would have been much more pessimistic. So hence the stress in the structure as a whole would have been much lower. (This isn’t a rule though — cracking can occur very low.)
Roy, Yes the A-12 was cut before it got off the ground. Rightfully so, It was one of the worst procurment mistakes in thelast 40 years. Way behind schedule, way above cost, way above wieght, and most likely considerably non-stealthy.
The point being, that many around here seem to attack the AF for procurment problems, when its clear that ALL 4 services have had mistakes in the past 30+ years. While I am in no way excuseing these mistakes, people need to take an objective view of all of them and not focus unevenly on one service.
Funny, the Air Force gets called “dishonorable” for supporting the F-22 (which is NOT a turkey despite your obvious dislike for it) But when a Marine Corps squadron commander tells his subordinates he needs to lie to keep the airplane going they get a pass?
No branch is perfect, and no one can call another branch dishonorable with out saying they all are. I get sick when some Jarhead says the USMC is the definition of honor, or when a flyboy says the same thing. No branch is better than another. And to say the USAF is dishonorable for wanting a new airplane is BS. Who bought the expensive V-22? whose LUH program is going downhill fast?
For what its worth,I just read(& thus must be the last to know) that Iran has AIM-54 Phoenix Missiles. I don’t know if they are operational,but it would seem like any bombing mission would first have to take out their F-14s before non-stealth aircraft like the B-52 & B-1 bombers can take part in the attack.The idea of Iran having Phoenix missiles may be poo pooed with descriptions of how the Phoenix wasn’t & isn’t such a great missile,but it still has to be something taken into account.This is where one hopes that stealth REALLY works.
Okay,forget the AIM-54 Phoenix,they should not have canceled the AIM-155 Advanced Air-to-Air Missile because that could be fired by the Super Hornet & the F-15,which means that it could have been fired by the F-22 also.I want to be careful not to introduce profanity to this blog,but it is freakin’ insane the [il]logic that the suits had & have in canceling systems left & right.All of that money diverted from these programs has sure made my life better.
Davids, I take offense to the remark that “In the f-15 case, I be willing to bet it was half ass preventive Matenance by the guard unit” and “irst that F-15 was a guard plane so there might be some doubt if the preventive work was done properly.” I have spent 23 years now in the Air Force, 10 years active duty and 13 years Air National Guard. I perform Non Destrutive Testing on F-16 aircraft, with 6+ years on the F-15 (A thru E models), C-130, E-3, and many other airframes. I’ve worked as a guard maintainer alongside Air Force troops in Iraq, Saudi, Quater, and other locations. And as of right now I say with extreme confidance that Guard aircraft maintence is much better than active duty for several reasons:
1. The age and experience level of Guard maintenance personnel is older and most have more years “turning wrenches” than the comparable active duty force. Last year the oldest active duty troop was 25 and she only had 6 years experience in this career field. Many of our crew chiefs and other maintainers are well over 30, and many are in their 40s with 15+ years experience. Along with this is a maintainince maturity level, a higher level of discipline with performing maintance tasks and inspections.
2. Guard personnel are not “assigned” to their unit. They are recuited into the unit from the local community and tend to have a higher sense of loyalty and dedication to the unit and it’s mission. They are many times recruited by neighbors, friends and families, so it’s very common to seen generations pass thru the gates. On a guard base you have a sense of “ownership” within the unit and it’s aircraft that is missing from an active duty unit. Active duty units have sometimes people assigned that can’t wait to get off of the base, and it shows in how they do their job.
3. Along the recruting lines, an active duty recruit can put in a request for a specific job if they want, but it’s more common for them to make a selection of 8 or so jobs, and then the Air Force based on test scores places them in the spot that fills the Air Force needs. With a Guard Unit, the recruiters bring the potential recruits to the shops where they can spend time, see first hand what the job entails, what the job tasks are so they can better select what they want to do withing the guard, plus allows the shop chiefs to determine if the recruit is the one they want for the job, or if he/she would be better off somewhere else. So in the guard the troops are better matched into the job positions which increases the quality of the job performance.
4. During Air Force Inspections (Operational Readiness, Unit Compliance, etc) there is NO Air Force standard vs Guard standard. All units regardless of being Active Duty or Air National Guard are evaulated and graded on the same standard.
5. During my deployments to the Middle East, our unit has taken pride in having a higher mission capable rate (percentage of deployed aircraft that are fully mission ready and not downgraded for maintance issues) than our active duty counterparts, and our unit has twice set records for having a 100 percent mission capable rate for multiple days in a row, something that I’ve never personally seen occur with an active duty unit.
6. In my 13 years with the Guard, when there has been an issue with the F-16 airframe or engine and an inspection technique has to be developed to address the problem, the Air Force engineers go to Guard units to work with guard troops becuase of what I said in point number one. Once a troop in the Active Duty side of the house hits, 15+ years he/she tends to be in the office, not on the flightline. On the guard side of the house, not only is that troop in the office as shop chief, section chief, but because the workforce in the guard is smaller, he/she is a working supervisor, with a lot of experience, and an intimate knowledge of the airframe that the engineers rely on.
This is not to put down my brothers and sisters in the active duty force, there are a lot of dedicated troops here in the states and overseas, who keep the engines burning and the airframes in the air. But to say that the guard dosn’t know how to fix and fly airplanes is an insult and an erronous assumption.
Give me a 40 year old guard troop to fix my jet with 20 years experience who wrote the tech data, over a 21 year old new troop no matter how good he is any day
Scott-ANGNDI
I have been involved with the F-15 for twenty seven years. Never havr I heared such uninformed, speculative untrue comments. The F-15 has a remarkable reliability record. These pepole should get their facts straight before BLOGGING. But I guess for a fantisy trip it fills the bill.
estetik cerrahi
Actually I practice the level by myself to be much quicker than together, and I need not buy cronous gold for , but it was very amusing that two people played in together.
Although I already buy dofus kamas to you, and you will not put this in your heart.
2.5–3.5g is nothing for an Eagle, so a failure of this magnitude is pretty significant. It would be interesting to know if the BRAC involving MOANG did lead to a failure to perform required maintenance or inspections.
Master, I am really very think of you, what a pity that we as if already parted forever. Now, I buy Habbo gold for your come back.
Finally, I gained have sufficed the LOTRO Gold, had the family. We were in together finally.
Because each people is not so rich, you have Hellgate London gold and you might save much time that practice the level.
But you every time always were left after you took my imvu money. You will also be not giving me a smile.
To buy NosTale Gold win you must not only use your strength as a team, with the new features they plan to add cheap NosTale gold late. So no player will have to worry about ever losing their NosTale money account.