For those who might haven't heard about it yet, the german Bundeswehr has announced in public that a manufacture fault has been discovered in the rear fuselage of the Typhoon aircraft, in a part produced by BAE Systems, and that has a consequence, while solutions are sought and the full danger to safety is determined, they are not going to accept the 6 aircraft on delivery this year. Flying hours across the fleet will also be kept under control and possibly reduced as the safe, guaranteed flying life of the airframes has been cut precautionally from 3000 to 1500 hours.
The official Bundeswehr statement is available here. Its content has been reaffirmed by officers interviewed by the German press.
Defense News reports that the problem was first detected by the Royal Air Force, which launched the alarm and also cut flying hours to comply with a 1500 hours safe life, without announcing anything in public. Eurofighter has released a statement to the press that acknowledges the issue but basically says that all is fine and we should not worry:
Munich 1st October, 2014
MEDIA STATEMENT FROM ALBERTO GUTIERREZ, CEO EUROFIGHTER GmbH
‘Eurofighter GmbH is aware of and actively managing a recently discovered quality issue concerning one of the manufacturing processes used during the assembly of the Eurofighter Typhoon rear fuselage.
We would like to make clear that this issue does not affect flight safety, neither does it impact ongoing fleet flying or limit fleet operations.
Eurofighter GmbH is currently working together with NETMA and its Customers taking all measures necessary to ensure that this issue is successfully resolved without any flight life limitations to the operating air forces.‘
We can expect to hear more about this matter going ahead, for obvious reasons, even if so far there has not been a particular outcry on the press.
The manufacturing issue does rise the questions about what the effective danger is, and how the problem can be solved and, importantly, who is going to pay for the solution. If BAE screwed up, it would be very desirable that BAE pays, because the defence budget really has no need for a new funding crisis due to a big unplanned expenditure showing up like this.
The Bundeswehr laying the blame squarely on BAE tells us that the problem is localized in the STAGE 1 block of the rear fuselage, a part that BAE builds on behalf of Italy's Alenia, which builds the STAGE 2 and 3 and assembles them together.
What caught my eye the most, however, is the astonishingly low certification of 3000 flying hours for the airframe. This value is far, far lower than anything we normally expect from a combat aircraft: Tornado has a 7000 hours life, extended to 7500 in some cases across the RAF fleet as of 5 July 2011 information released to Parliament by minister Peter Luff and quoted by DESIDER. An extension to 8000 hours was being tested to meet the OSD in 2021, and testing was possibly completed despite the advancing of OSD to March 2019; F-35 is due to be certified for 8000 hours. Some USMC Hornets are being life extended to a scary 10.000 hours to hold the line until the F-35B is available in numbers. And so along.
Typhoon is meant, by design, to eventually be certified for a 6000 hours life, with a growth potential to be eventually measured afterwards.
The certification of a safe flying hours life cycle comes after a long, complex stress simulation test conducted on land using airframes which never go into the air but are mechanically stressed to reproduce the effects of flying on the structure. Indicatively, three hours of simulated stress are representative of one hour of real flying, so that test airframes are stress-tested to the equivalent of three life cycles in order to certify one single actual-flying life.
The Typhoon is being stress-tested at the BAE Systems facilities in Brough, UK. 18.000 hours campaigns of tests were carried out earlier on prototype and developmental airframes, but for the final certification, due to the widespread differences between development examples and production aircraft (and the fact that the development airframe was stressed empty of internal systems), a new campaign had to be started. A twin-seater taken directly from the Warton production line is used for the campaign, known as Production Major Aircraft Fatigue Tests - PMAFT Twin Seat. In paralel, due to the extensive differences between twin seat and one seater, there is also a one seat airframe undergoing the same treatment under the Single Seater Fatigue Test (SIFT) campaign. The SIFT uses a dummy rear fuselage, but an actual centre and front fuselage for realism of the testing.
Some components, finally, are stressed separately, such as landing gear, foreplanes, flaps and slats.
In March 2012, the airframe had been stressed to the equivalent of 11.000 hours out of a planned 18.000 needed to certify the intended 6k hours life.
The completition of 12.000 test hours, and the extension of certification from 3000 to 4000 hours as a consequence, were described as being "weeks away".
The stress test campaign would last a full three years still, by what BAE says. Indicatively, the activity should conclude by March 2015, if what BAE said holds true and current.
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| The Typhoon stress test installation in Brough |
Do you see the problem?
More than two years after that news release and not many months away from the expected completition date, german official sources are revealing that the certification for Typhoon is still at just 3000 hours, when, by now, we should be well above 4000 at the minimum, and indeed close to reaching the final 6000 hours point.
If what the germans are saying is true, something certainly feels very wrong. Dates, plans and numbers being given most evidently do not match: if the sources i've posted are all telling the truth, i can only think that something has been imposing grave delays to the certification activity from soon after that BAE article was posted. Might it be that the test airframe has been developing grave cracks in the rear, and investigations on the root cause have, in quite a long time, revealed the quality issue now being denounced? Or is there some other problem we are not yet being informed about? I really can't say. But answers will have to be found quickly.
6000 hours are expected to be representative of a 25 years service life with an average of 240 hours flown per year. It is evident that a 3000 hours airframe life means the aircraft will be viable for a much shorter time, and a 1500 hours life is just ridiculous. The Germans, which fly considerably less than the RAF, assess that they will have 1500 hours old airframes by 2018. The RAF is going to hit that value much sooner: consider that the british Typhoon fleet celebrated the 100.000 cumulative flying hours earlier this year, which equates, over a fleet of some 100, to airframes 1000 hours old as of last year. Of course, airframes were not delivered all together and have not used in the same way, so some will actually be "older" in hours terms than many others. For some, the 1500 hours point might be very close indeed, if not already reached and passed.
UPDATE: thanks to Topman for reminding me of the fact that, indeed, some RAF Typhoons (no idea how many) have indeed well passed the 1500 hours mark. The first of them underwent major maintenance in 2012 after completing 1600 hours.
When the Typhoon fleet celebrated the worldwide 250.000 flying hours milestone back in July this year, it became even more evident how much the RAF weights in the Typhoon world: more than 100.000 hours versus some 20.000 for Saudi Arabia and 130.000 for the combined Germany, Italy, Spain and Austria. This makes evident why any delay in clearing the doubts on the airframe life will hit the RAF hardest.
I look forwards to greater clarity on this issue and on its effective consequences, while hoping that the problem can be fixed quickly and without Typhoon draining the defence budget even more.
UPDATE: new
Defense News article confirms “temporary” reduction to 1500 hours of fatigue
life. Eurofighter expects it will take until mid-2015 to test and ensure that
requirements are met in the component affected, and that it does not expect
significant fleet readiness problems in the meanwhile. Britain and Saudi Arabia
are continuing to accept deliveries, while Germany, Italy and Spain are
rejecting the new aircraft for now.
UPDATE 2: the other well known problem of Typhoon is always very clear and very annoying. David Cameron has visited the II Squadron RAF in Akrotiri and announced that the UK will deploy a further two Tornado GR4. Moreover, the premier announced the decision to delay by one year the disbandment of II Squadron, which was due to lower its flag in Marham on 31 March 2015 to stand up on 1 April 2015 as the fifth and last Typhoon squadron, at RAF Lossiemouth.
The passage of II Sqn colors to the Typhoon has been delayed by one year (at least), out to April 2016, due to the Typhoon being, despite all efforts, still substantially incapable to conduct complex air to ground work. The old Tornado soldiers on in its place.
It is not yet clear what kind of impact will be felt by the schedule for the standing up of the 5th Typhoon squadron: personnel from the ex 617 and 12 Sqns should have already been directed to Lossiemouth to work on forming this last unit, but the extension of II Sqn as a Tornado formation might delay the completition of the process.
No real way to tell if the Typhoon structural issues have had any weight of their own in the decision. Most likely no, but, in the facts, the new Typhoons being delivered will not fly for a while, and the build up process for the whole fleet is going to be slowed down significantly.
UPDATE 3: Airbus is optimist that the manufacturing quality problem will not have grave consequences, and that the safe hours cap at 1500 hours will be removed before airframes have to be parked on the ground having reached that limit. We will see.
UPDATE 4: Commander No 1 Group RAF said on October 6 that despite the extension to II Sqn's life as a Tornado GR4 unit, the 5th Typhoon squadron is still expected to stand up in early 2015, and that an adjusted plan is being worked out.
NOTES:
Data on early Eurofighter airframe durability testing from "Eurofighter, a safe life aircraft in the age of damage tolerance" by Robert Dilger, Dr. Holger Hickethier (EADS) and Michael D. Greenhalgh (BAE Systems), 2007
