Finnish-modified F-18D Hornet crashes

[Finn47]

It took the local firm Patria some 100000 manhours to modify a badly damaged F-18 using one half of a Canadian Hornet, and all for nought as the finished product unfortunately crashed today. They were testing recovery from unusual attitudes and reportedly after a tail slide, the a/c entered a dive which was unrecoverable, so the pilots ejected and were found an hour later with minor injuries only. The aircraft, also called "Frankenhornet" however is a writeoff. The test pilots were "experienced", the local news say.

Fighter Jet Crashes in Forest | News | YLE Uutiset | yle.fi (http://www.yle.fi/uutiset/news/2010/01/fighter_jet_crashes_in_forest_1384722.html)

‘FrankenHornet’ flies!: Key.Aero, Military Aviation (http://www.key.aero/view_news.asp?ID=1224&thisSection=military)

[melmothtw]

How do you know that this was the 'FrankenHornet'? The report just says US-made F/A-18 Hornet.

[Double Zero]

Yes, Melmothw,

seems the description of ' FA18 on routine mission ' does not fit in, and if this 'FrankenHornet' is new, unusual attitudes & tailslides don't sound like early test procedures either...

[Finn47]

The English language news release was published several hours later than the original Finnish language breaking news, so I knew the reg (HN-468) and the details before posting. The pilots were on a test flight like I said, the broadcasting company have it wrong (it figures)... anyway, here are some pics of the crash site, published by the Air Force, also confirming the aircraft in question:

Puolustusvoimat - Frsvarsmakten - The Finnish Defence Forces (http://www.ilmavoimat.fi/index.php?id=1111)

The pilots have been operated due to fractures recieved, and are recovering OK. Nothing left of the aircraft except for a hole in the ground....

[Double Zero]

OK so maybe it was the FrankenHornet;

The question remains, why if a converted CF/A18, or attempted make of an F/A18E-F, no big intakes, just apparently big leading root extensions - LERX - so I presume no engines to match, and even the F/A18E has not really proven up to wondrous AofA & tailsldes, sadly given other displays.

I presume the F-18E/F etc ( inc. other aircraft - how about disbanded F-14's ? ) has been made available to Canada, but at at a silly price; if I were in the U.S. I might be thinking of assisting the protection of one of one's most important borders !

[ab33t]

What a pity , thank goodness the pilots are ok

[Finn47]

More details here, in English, though it´s not exactly certain in which order things actually happened:
The Air Force told reporters in Jyväskylä that the aircraft's crew had been practicing pulling out of a dive at a height of more than nine kilometres (29,500 feet) when the aeroplane suffered a tail slide.
The crew ejected at a height of about 4.5 kilometres after failing to restore manoeuvrability. The aircraft was flown during the test flight by a captain, 32, and a lieutenant-colonel, 44. The aircraft had been recently built at a cost of some 15 million euros from two airframes, one of which had been damaged in a mid-air collision in 2001. NewsRoom Finland (http://newsroom.finland.fi/public/default.aspx?app=803&newsid=23703)

[dead_pan]

The aircraft had been recently built at a cost of some 15 million euros from two airframes, one of which had been damaged in a mid-air collision in 2001.


Hmm, there's a garage down the road which does cut-and-shuts (allegedly). I didn't know you could do the same thing with fast jets - those crazy Finns.

Very glad the crew are okay.

[dat581]

OK so maybe it was the FrankenHornet;

The question remains, why if a converted CF/A18, or attempted make of an F/A18E-F, no big intakes, just apparently big leading root extensions - LERX - so I presume no engines to match, and even the F/A18E has not really proven up to wondrous AofA & tailsldes, sadly given other displays.

I presume the F-18E/F etc ( inc. other aircraft - how about disbanded F-14's ? ) has been made available to Canada, but at at a silly price; if I were in the U.S. I might be thinking of assisting the protection of one of one's most important borders !

WTF?

The CF-18 is the Canadian version of the F-18A and the only differences from a US F-18A is a few black boxes, a large spot light on the left side and some darker paint. The C&D versions are still the same size shape etc as the A&B and came off the same production line. They have updated systems and some have uprated engines. Also the one and two seat hornets are exactly the same from the rear end of the cockpit all the way to the rear of the aircraft.

The super hornet (the E&F) is a completely different aircraft with almost no parts in common with the A,B,C & D models. It is a much larger aircraft and it is not possible to mix parts between them. Have a look at a photo of them sitting side by side.

It would be like cutting the front off a 777 and stiching it onto a 747, it's just not possible.

:ugh::ugh::ugh:

[Moe Syzlak]

More tosh from 00. The F-18 is one of the best hi AOA machines-save vectored thrust designs. The are always limits however, as it usually incurrs a very high ROD! And, as you say, the A/B/C/D is very different to the E/F/G.

[NorthRider]

The ac in question was built by taking the back end of a damaged finnish c model Hornet and mating it with the front end of a damaged canadian b or d model. So they turned a single seater into a two seater and where very happy. The job took a couple of years and was finnsihed last september. Everybody involved in the project(Finnish air force, Patria and Boeing) reported it as a great success.

Local media reports that the flight was only the third testflight of the "new" a/c. Reports allso say that the plane was put into a tail slide at an altitude of 10km. It failed to recover properly and the crew ejected at about 4,5km. The plane was flown by a 32 year old captain and the other crew member was a 44 year old liutenant-colonel. They both suffered from fractures and where treated at Tampere university hospital.

Here is a link to a finnish newspaper... Text in finnis but some pictures of the crash site.Turma-Hornetin lentäjät joutuivat leikkaukseen - Suomi - Uutiset - Ilta-Sanomat (http://www.iltasanomat.fi/uutiset/kotimaa/uutinen.asp?id=1882795)

[dat581]

The ac in question was built by taking the back end of a damaged finnish c model Hornet and mating it with the front end of a damaged canadian b or d model. So they turned a single seater into a two seater and where very happy. The job took a couple of years and was finnsihed last september. Everybody involved in the project(Finnish air force, Patria and Boeing) reported it as a great success.


Must have been a B model. The Canadians don't have any Cs.

[Finn47]

The damaged Finnish Hornet was a single seater, so Patria bought the front end of a Canadian twin seater and thought they would gain a whole new twin seater and lots of unique know-how by combining the two frames. It almost worked, too.

[clunckdriver]

Just shows you that its not smart to pull too many G in "Fin Air", sorry, couldnt help myself!

[seppop]

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Reply with quote (http://forums.airshows.co.uk/posting.php?mode=quote&f=2&p=196153)The story, as what is publicly known as of now:

"Frankenhornet" (HN-468) left Patria's Halli airfield for a test flight to investigate aircraft behavior in "abnormal" flight modes followed by
an F/A-18C chase plane. The crew was a very experienced test pilot (Captain) and a flight test-engineer (Lt.Col.) with thousands of flight hours on them.

The final planned manoeuvre of the flight was to climb vertically to about 33000 ft, throttle the engines back and recover from the resulting tail slide.

As the nose dropped, the plane entered into a vertical dive. When the plane was at approximately 7000 m. (~23000 ft.) in vertical dive, the chase plane pilot radioed: "Do you have control?", to which the HN-468 pilot replied "Negative, Negative".

When the HN-468 was at an altitude of about 4500 m. (15000 ft.) in high speed vertical dive, the chase plane pilot commanded "Eject! Eject!", at which point the pilot and test-engineer ejected at an estimated speed of over 500 kt.

In the violent ejection, both crrew suffered broken limbs (not just bruises), as the M/B ejection seat installed in F/A-18D does not have arm restraints. In addition, one of the crew lost his helmet in the ejection and suffered severe facial trauma.

The plane crashed on a rocky piece of land, next to a farm field and disintegrated into very small fragments. The crew landed in a very thick forest, and even when they were located almost immediately after the crash, it took more than an hour to recover them in -22 C temperature. After recovery they were immediately transported to a hospital by a medevac helicopter, and surgically operated on thursday evening.

So, while the crew is "safe", they are not exactly quite "sound", but they're expected to survive and fully recover, which is the most important thing.

Obviously, there's a lot of speculation going on about possible causes to the loss of control, but I won't go into those...

The crash site is still being guarded by the military, citing danger of inhaling carbon-fibre fragments at the site, pretty much for the same
reason as when USN F/A-18 crashed at the approach of Miramar, San Diego last summer.

seppop (http://forums.airshows.co.uk/memberlist.php?mode=viewprofile&u=12426)

[Beancountercymru]

Hmm, there's a garage down the road which does cut-and-shuts (allegedly). I didn't know you could do the same thing with fast jets

Dead Pan

Oh yes you can - how about the Hawk Fuselage Replacement Programme:
Eighty Hawk T1/1A aircraft have been upgraded under the Fuselage Replacement Programme (FRP), which involves the replacement of the aft, centre and rear fuselage sections, using new build sections derived from the Mk. 60.
BAE Hawk - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/BAE_Hawk)

Or for rotorheads out there:

Dateline 23 November 1999: Soz, Oman, near the city of Muscat. Utilizing tailnumber ZA704, a British Mk II Chinook, a new and proven technique of rapidly removing the aft pylon is demonstratedDuring the Falklands War, Argentine Chinook AE-520 (http://www.chinook-helicopter.com/history/aircraft/argentina/argentina.html#AE-520) was captured intact and transported to the United Kingdom as a training aircraft. Upon arriving in the U.K., AE-520 was re-serialed as ZA-670. When ZA-704 experienced the accident it was evacuated to Fleetlands for repair. Fleetlands is a Royal Navy aircraft overhaul facility in Gosport, U.K., located on the English channel near Portsmouth. The RAF does aircraft overhaul and repair on part of the facility. The aft pylon (http://www.chinook-helicopter.com/standards/areas/aft_pylon.html) from ZA-670 was removed and modified from a C model to a D model. ZA-704s aft pylon was cannibalized for any usable parts to complete the conversion of ZA-670s pylon to the RAF HC Mk II standard. The pylon was then placed on ZA-704, returning it to flyable service. Any of the mechanical systems that were common to the RAF Chinooks were cannibalized from the remainder of ZA-670. The cockpit of ZA-670 was donated (http://www.chinook-helicopter.com/news/United_Kingdom/UK__Chinook_News.html#Cockpit) the the American POW/MIA search team in hopes of finding missing soldiers still in the Republic of Vietnam

Boeing's Mark 2 (HC2) Chinook helicopter. (http://www.chinook-helicopter.com/chinook/aft_pylon_removal.html)

[Easy Street]

It's my understanding that one RAF Tornado GR4 (ZA370?) comprises half a Tornado F2 mated with half a Tornado GR1... at least that was the banter from the engineers. Its tail letters were "DB" and it was known to the sqn as "Dirt Box"; I think it caused the gingers a fair bit of grief over the years.

[CarltonBrowne the FO]

Let's hope the join line runs laterally then... if it runs lengthwise I can see a real problem!

[Tester07]

seppop please check PMs.......

thanks

[Finn47]

The accident investigation board says in today´s press release that flight data recorder readout, as well as interviews with the pilots, have confirmed that for some as yet unknown reason, when the pilots were attempting to recover from the tail slide, the aircraft´s control systems switched over to mechanical backup steering and the ensuing straight-down dive proved impossible to control. The pilots were forced to eject when airspeed approached critical values.

Puolustusvoimat - Frsvarsmakten - The Finnish Defence Forces (http://www.ilmavoimat.fi/index.php?id=1118) (in Finnish only)

[seppop]

Tester07 wrote:

"seppop please check PMs.......

thanks"

All the Prime Ministers I checked concurred, or declined to comment... :)

[Dr Illitout]

Thank goodness "Maverick" and "Goose" got out. Nasty wounds though:(
My knowlage of the Hornets fly-by-wire system is nil but I have sat through lectures on the A320 and 777 systems. What strikes me as odd is that the system went straight to manual and missed out any degraded steps. Anybody know the Hornet's FBW system?
Also have they said if the engines were running after the tail slide?

Rgds Dr I

[Finn47]

No word yet about whether the engines were producing power. Literally translated, the press release says airspeed grew critical during "recovery attempts" (plural) which might include changes in power settings, of course. Efforts to find out the reason(s) for the control system reversion are expected to take weeks.

[dat581]

The Hornet FBW system consists of four computers that take the pilots comands and figure out the control surface deflections required to perform the required action. They each "vote" on the action and if one disagrees with the rest it is deemed to have failed. If all fail then the system reverts to direct electrical back up of all control surfaces. If that fails there is a cable back up to the horizontal tails only as a get home or out of danger device. Don't know if you could land the aircraft like this.

Anyone with a more detailed knowlage of the FBW system please correct me if i'm wrong!!!!

[Dr Illitout]

Thanks dat581. I Googled violently and couldn't see anything. I assume that there are multiple channels within each box as well as per Airbus and Boeing?

Rgds Cking

[dat581]

Thanks dat581. I Googled violently and couldn't see anything. I assume that there are multiple channels within each box as well as per Airbus and Boeing?

Rgds Cking

I don't think so, just one channel per computer. Can't check as i'm moving house in a week or two and all my Hornet infomation is packed up in boxes...

Any RAAF, CAF or USN blokes care to enlighten us?

[Finn47]

Plenty of info available on the net, here´s the basics:

FA-18 Hornet Flight Control System Review (http://safetycenter.navy.mil/MEDIA/approach/vault/articles/2004/0681.htm)

[Dr Illitout]

Thats an interesting webite!
So as I read it. Two computers each with two channels. So four channels BEFORE it goes to manual.
Oh for a schematic of the power sources!!!!

Rgds and thanks
Dr I

[dat581]

One gererator on each engine I don't know how many batteries plus one emergency battery which lasts about 20 minutes at best. The Super has I think nine diffferent power sources and no mechanical back up to the controls.

[Finn47]

The Air Force has published a shortish bulletin dated June 29 but in Finnish only, I´m afraid. Here are the findings so far: according to flight recorder data, either a mechanical or a hydraulic fault was discovered by the control system in the servo cylinder of the right stabilator. This finding led to the system shutting down the electrical control mechanism of both stabilators and switching over to mechanical backup (MECH-ON state). Attempts to regain electric control of the stabilators failed. All other control surfaces remained under normal control. The investigation continues.

That´s as accurate a translation as I´m able to make at this point.

[Finn47]

A press release has been published, confirming the above. During the tail slide, a fault occurred in the r/h stabilator servo cylinder valve which caused the stabilators to move in opposite directions. This again caused the system to revert to mech backup. There was not enough time nor ability to regain control using the mech backup system only so the command was given to eject. Full report only available for interim use by the Air Force and the press release can not be linked to, so you´ll have to take my word for it, I guess.

[Pompan nappi]

I can vouch that FINN47 has translated the Finnish text correctly.:ok:

I was actually working down the hall from the guy´s office who was in charge of the accident board for a few months last year - the other pilot was my classmate in the academy - and the other guy was a student on a course that I was in charge of in -05/06.

BTW, the plane hit the ground (hard), just a few clicks away from the church where I was married - longlongtimeago - a sign perhaps :ooh:

[Finn47]

Summary of events is available in English, here is the crucial part copied from the Air Force website:
As soon as the accident aircraft had entered a vertical dive the primary valve in the servocylinder that operates the right-hand stabilator failed; this resulted in differential stabilator deflection, and the flight control system reverted to the backup mechanical mode.
In normal operation inputs from the cockpit mounted flight controls are transmitted to the control surface servocylinders electrically. These inputs are processed by a flight control computer that commands the servocylinders for control surface deflection required for desired aircraft motion.
The backup mechanical mode uses cables and linkages to transmit control stick deflections to the two stabilator servocylinders for continued, albeit significantly degraded, stabilator control authority.
The other flight control surfaces remained under electrical control throughout the accident flight.
Attempts to Restore Normal Flight Control System Operation Failed
The reversion of the flight control system to the mechanical mode caused prolonged tailslide induced oscillations. Recovery from dive cannot be initiated until these oscillations have subsided; once this was achieved, the pilots initiated recovery and attempted to restore the electrical control of the stabilators, but this was precluded by the failure in the servocylinder.
During the recovery attempt, the aircraft failed to respond normally to the application of aft stick while speed was approaching the critical ejection speed. The crew ejected at approximately 875 km/h at the altitude of approximately five kilometers. The aircraft impacted terrain at 1147 hours and was completely destroyed.
The pilots sustained permanent injuries in the high-speed ejection. They are currently on convalescent leave and undergoing a medical rehabilitation program.