Jet nose cone caves in mid-flight [Archive]

mono

7th Jul 2008, 15:59

I actually saw very similar damage caused by (believe it or not) a lightning strike! I was doing a turnround inspection and there was an obliterated Radome. Initially I thought it was a birdstrike but the lack of blood and guts proved otherwise. It appeared that due to the position of the radar scanner (it was at 90 degs to the normal) the lightning bolt tracked straight through the radome and earthed at the scanner rather than along the diverter strips, taking the radome with it!. We needed a new radome and radar scanner.

boaclhryul

7th Jul 2008, 18:18

I see CNN have changed the headline. The original seemed to indicate that the crew overcame their initial inclination to keep the plane in the air forever:

Northwest flight lands despite mid-air damage (http://cnnwire.blogs.cnn.com/2008/07/06/northwest-flight-lands-despite-mid-air-damage/)

Michael

Sallyann1234

7th Jul 2008, 18:37

Northwest flight lands despite mid-air damage

Was there an alternative?

oceancrosser

7th Jul 2008, 21:34

We´we had similar damage on 757s, both due to birds and lightning. Aircraft landed ok, barely missing the usual schools, hospitals, seniors homes etc. on the way. It´s a big radome, and not very "pointy".

anartificialhorizon

8th Jul 2008, 08:46

Saw a bird go through the radome, miss the weather rx and puncture the pressure bulkhead on a 733 once.....

Good job it was not the windscreen me thinks....

stator vane

8th Jul 2008, 08:54

was he going counterclockwise on the M25 yesterday morning?

Airbubba

8th Jul 2008, 09:20

Oh well, at least it wasn't hit by a reggae truck...

July 7, 2008

A Concorde Is Disfigured While Parked in Brooklyn

By PATRICK McGEEHAN
The supersonic passenger jet known as Alpha Delta retired unscathed in 2003 after nearly 30 years of speeding back and forth over the Atlantic Ocean. But in less than two years in Brooklyn, it already has had its pointy nose knocked off.

In a multicultural crash in the middle of the night, the jet, a Concorde that is owned by a British airline, was hit by a truck that was hauling equipment from a Jamaican music and soccer festival. The truck clipped the distinctive nose cone off the parked Anglo-French jet about 3 a.m. last Monday, prompting an impassioned uproar among the jet’s band of enthusiasts.

To many admirers, the tapered nose, which could be lowered up to 12.5 degrees to clear the pilots’ field of vision during the jet’s steeply angled takeoffs and landings, was what made the Concorde the Concorde. Within 20 hours of the accident, photos of the damaged plane appeared on the Internet, and Concorde lovers were deploring the level of care it had received during its postretirement odyssey in New York.

Concorde Loses Its Nose Cone in an Accident in Brooklyn - NYTimes.com (http://www.nytimes.com/2008/07/07/nyregion/07concorde.html?em&ex=1215576000&en=e818d13ffa4dee1c&ei=5087%0A)

skywreck

8th Jul 2008, 09:54

Birdstrike? really.... have a careful look at the close up. You will notice
3 very visible indentations relating to some physical object striking
the nose cone. We are definitely not being told the truth about this
incident. Had "the object" striken further up, the windshield could have
been shattered with the subsequent possible loss of the aircraft.

http://img61.imageshack.us/my.php?image=fig2noseconevv1.jpg%5D

http://%5Bimg=http://img61.imageshack.us/img61/7096/fig2noseconevv1.th.jpg%5D%5B/url%5D
http://www.pprune.org/forums/%5BIMG%5Dhttp://img61.imageshack.us/img61/7096/fig2noseconevv1.th.jpg%5B/IMG%5D

skywreck

8th Jul 2008, 10:02

http://img61.imageshack.us/img61/7096/fig2noseconevv1.th.jpg

Sorry trying to link the image, if it doesn't work please follow link.

http://www.pprune.org/forums/%5Bimg=http://img61.imageshack.us/img61/7096/fig2noseconevv1.th.jpg%5D%5B/url%5D

Algy

8th Jul 2008, 10:15

This is real it appears. (http://www.flightglobal.com/blogs/unusual-attitude/2008/05/the-pelican-and-the-bombardier.html)

brakedwell

8th Jul 2008, 10:31

Did the bird on the steps do a turn in the cockpit? :cool:

oceancrosser

8th Jul 2008, 10:41

Fragman88

8th Jul 2008, 10:43

Actually had one of these. Dodging detween two building CB (Yes, I know better now, before you even start, 411A!), in clear air , they obviously decided a current path was there and connected via our F28 (F100 grandfather for the younger players).

Big Bang, flash, smell, some of it Ozone, usual scary strike stuff, Radar stops--`Antenna failure' message on new supersonic Colour Radar display. On arrival external OK except for pinhole damage but internal layers of the radome has popped in due to flash boiling of moisture in the laminations and physically obstructed the scanner's movement.

The one time I had severe damage to a radome was most unpleasant, not only for the Canadian Goose but for the vibration and handling of the A/C. Not to be underestimated

Sorry Vancouver about your Goose.

F88:ok:

skywreck

8th Jul 2008, 14:03

Oceancrosser

Granted I am not a pilot and generally visit this forums to learn about
real aviation from alleged professionals. Normally I don't comment on
matter outside my experience. However being a professional structural
engineer I know that whatever struck the cone of this aircraft was no
bird or lightning strike. Any structural engineer or anyone with experience
in impact assessment looking at the cone of this aircraft would readily
identify 3 specific points of impact which could only be made by a solid
rigid object. I supposse your total ignorance in these matters reflects
your useless reply.;)

lomapaseo

8th Jul 2008, 14:26

Granted I am not a pilot and generally visit this forums to learn about
real aviation from alleged professionals. Normally I don't comment on
matter outside my experience. However being a professional structural
engineer I know that whatever struck the cone of this aircraft was no
bird or lightning strike. Any structural engineer or anyone with experience
in impact assessment looking at the cone of this aircraft would readily
identify 3 specific points of impact which could only be made by a solid
rigid object. I supposse your total ignorance in these matters reflects
your useless reply.

people that live in glass houses shouldn't throw stones.

One has to consider the layup of the cloth used to make the cone shape as well as the structure immediately behind it (radar equipment).

While considering the possibilities of an inflight collision (birds, etc.) there are also air loads on the dome both of which have an effect of buckling the dome inward. Buckling deformations/fractures on such a dome shape result in a great deal of varriations so I wouldn't be too quick to assess 3 discrete points of impact.

MarkD

8th Jul 2008, 15:05

could be worse - could have been 20mm sparrows...

(sorry, was watching "Thirteen Days" last night - I'll get me coat)

skywreck

8th Jul 2008, 16:34

Three point of impact on a straight diagonal line....Ok - I've given you my opinion, Let's wait for the official explanation for this "rare" occurrence, assuming they'll ever give us one.:cool:

XPMorten

8th Jul 2008, 17:52

Since these nose cones usually are made of fiberglass or
similar, maybe it got hit by a vehicle on the ground before flight
weakening the structure - just a wild guess..

M

Airbubba

9th Jul 2008, 01:46

A P-3 from NAWC-23 at Dallas Love Field had a crushed nosed cone and did an emergency divert into Davis-Monthan AFB a couple of years ago, lightning was mentioned in more than one account but these guys don't give out much information when they fly:

Photos: Lockheed P-3C Orion Aircraft Pictures | Airliners.net (http://www.airliners.net/open.file/1098596/L/)

anartificialhorizon

9th Jul 2008, 01:55

I seem to recall some years ago at LHR, a truck drove into the radome of a BA 757 and then drove off.

The crew did not notice the damage and took off and only realised something was amiss when they could not pressurise the a/c and were getting cold feet !

The impact had damaged the pressure bulkhead as well as the radome.

The vehicle driver was subsequently fired.....

No organic remains visible on this particular radome. Ground damage me thinks or possibly pre existing delamination which then failed on the incident flight.

Flight Detent

9th Jul 2008, 02:44

Whilst I was flying P3B/Cs in the RAAF, we had two instances of nose radome damage, one where three pelicans (in formation) collided with the nose of the airplane, two into the radome, smashing it to pieces (worse than the P3C pic earlier), one of which penetrated the fwd pressure bulkhead and punched out several engine insts and splattered the pilot, similar to that RJ pic. The remaining bird hit the CPs windshield, very lucky, since thats the strongest part of the airplane, and just bounced off.

The other instance was during a very violent hailstorm inflight, miles downwind of the cloud source (I learned something there!), which resulted in the nose radome folding inward, very similar to the B757 pic shown.

Cheers...FD...:ooh:

toothpic

10th Jul 2008, 23:59

Maybe it hit a UFO???:rolleyes:

Eboy

11th Jul 2008, 01:56

UFO? This person thinks so . . .

"Most likely not another word will be heard about this incident. Government officials wouldn’t want to “alarm the public” by making them aware that unauthorized spacecraft could easily collide with any plane they fly on, and possibly completely destroy it."

Data4Science.net (http://data4science.net/essays.php?EssayID=807)

ICT_SLB

11th Jul 2008, 03:43

Algy,
It was real - I've seen it in BA service e-mails but it's on a CL604 (the displays on an RJ are portrait not near-square like the Challengers') and the CF34s are too close to the camera for a CRJ too. Just wish we had FSRs like the one in the picture!

HotDog

11th Jul 2008, 05:03

Not at all unusual. Sometimes you see an aircraft with a different coloured radome that has been borrowed as a pool spare from a pool partner airline. I can recall two instances of shattered or stoved in radomes due to lightning strikes or hail damage during my flying days.

aviate1138

11th Jul 2008, 07:14

Eboy said....

"UFO? This person thinks so . . .

"Most likely not another word will be heard about this incident. Government officials wouldn’t want to “alarm the public” by making them aware that unauthorized spacecraft could easily collide with any plane they fly on, and possibly completely destroy it."

Data4Science.net

Aviate adds.....

Ted Twietmeyer - Google that name! :rolleyes:

Bus429

11th Jul 2008, 08:14

Skywreck,
Are you suggesting some sort of conspiracy? Radomes fail occasionally, usually for the more rational reasons stated earlier on this thread. I've seen some rejected for excessive moisture content and lightning damage; it happens.

wilyflier

11th Jul 2008, 08:42

Like 40 years back on a Britannia out of Istambul to Bombay we entered cloud and picked up a load of static; blue lights on windscreen and props, increasing noise on the vhf, till BANG a lightning discharge off the nose. Radar stopped working as the dome partly collapsed. The really interesting thing was the rest of the trip our True airspeed increased by 5 knots.

Storminnorm

11th Jul 2008, 10:31

I blame it on Companies buying cheap Taiwanese radomes.:eek:

Let's face it, Wilyflier, any alteration to a Britannia airframe
would have been an improvement to it's aerodynamics!!!

Bring back the DC 8.

Speedpig

11th Jul 2008, 11:31

3 specific points of impact which could only be made by a solid
rigid object
Wing bone/beak/wing bone

My birdstrike post was only a suggestion for pete's sake :ugh:

Xeque

11th Jul 2008, 11:44

Algy??
That's a simpic!!
:=

GearDown&Locked

11th Jul 2008, 12:01

wilyflier:The really interesting thing was the rest of the trip our True airspeed increased by 5 knots.

Slippery when electrically (dis)charged! UFO stuff, no doubt about it...

GD&L:ok:

skywreck

11th Jul 2008, 13:04

Bus429

It is my considered opinion that the dome was hit by some rigid object
at three points, the central point created the deepest impact which
imploded the dome and the subsequent stress/tension cracked the
fuselage. The rigid object would in my opinion not be straight or
circular but rather triangular or of irregular shape.

As for bird strikes and the like, that would have caused a greater deal of
damage and left a great deal of evidence, as shown in some of the pictures
posted in this Forum of similar incidents. Considering how thin the fuselage
is I would say that in this case the impact wasn't head on and at high speed but rather a sideways strike which just grazed the surface.
A full impact would have removed the frontal cone in its entirety and left a gaping hole.

As for UFOs and the like, I couldn't say. Perhaps the event ocurred at some
point before take-off or after landing, and it's possible someone doesn't want to take responsibility, who knows. My initial post was meant to comment on the fact that it couldn't have been a bird/lightning/hailstone
strike as those tend to leave a different type of signature/damage.

CLEE

11th Jul 2008, 13:37

Was once called out to assay a mysterious "thump" that occurred 400' agl at each take-off on a Fokker 100.

Thought it might be oil canning of structure either due to dynamic pressure loads or aircraft internal pressurisation loads. Got the pilot to fly slow climb one sector, fast the next to see which.

Turns out it was related to dynamic pressure - went and looked at the nose radome (which several people had looked at before) and it was pristine, looked like it had just left the showroom.

Don't know what did the original damage, but it was wrecked on the inside - damage had likely been made worse by repeated indentation during flight (which caused the "thump" and went away on the ground) and moisture ingress (repeated freezing & thawing expanding an area(s) of delamination, causing more water ingress etc).

Fact is, any or all causes could have happened to the radome under discussion at various times - lightning, birdstrike, delamination, moisture ingress, ramp rash, inappropriate repair etc. - and it could have appeared to passed muster while being badly compromised. And any one of those events could have precipitated the final failure too, quite possible a long time later, where on a good radome perhaps they wouldn't.

An issue of concern to engineers like me is that lots of composites behave this way - they can look good from the outside (the direction from which they have been hit) while being trashed on the inside. If you've seen the number of dents on and around cargo doors you'll be wondering how we'll cope with carbon-plastic fuselages on the A350 & 787. I don't know the answer.

Capt Pit Bull

11th Jul 2008, 15:42

The really interesting thing was the rest of the trip our True airspeed increased by 5 knots.

I would think that would relate to instrument error rather than a reduction in drag.

pb

mnttech

12th Jul 2008, 19:44

From Aviation news net.

FAA Says Structural Defect Is Behind Dented 757 Radome
Wed, 09 Jul '08
Suspect Part Being Examined By NWA Technicians

A bird strike has been ruled out by the FAA as the cause of a mysterious dent in the nosecone of a Northwest Airlines Boeing 757.
As ANN reported (http://www.aero-news.net/news/commair.cfm?ContentBlockID=f27260a9-3a8e-45ee-9988-66751615747b&Dynamic=1), the crew reported hearing a bang descending through 18,000 feet Sunday near Tampa, and the plane's nose-mounted radar failed at the same moment... but no blood or feathers were found, and not many birds are found at flight level 180 anyway.
The plane landed without incident, and no one was injured.
Now, the FAA says the dent was a simple collapse caused by a structural defect in the radome itself. Spokeswoman Elizabeth Cory told the Twin Cities Pioneer Press an investigation is underway to determine why the structure failed

Pugilistic Animus

12th Jul 2008, 23:21

It's amazing that this lady got this ship down Business Jet Blog: Miracle Mid-Air Between NetJets Hawker and Glider (http://www.businessjet.com/blog/2006/08/miracle-mid-air-between-netjets-hawker.html)
Much respect to the injured skipper--:ok:---it's also amazing the glider pilot lived

Interesting fact for USA pilots ---sometimes ATC can release blocks of class alpha airspace [positively controlled IFR airspace abv 18000' msl for non-US pilots]---for high altitude /high speed glider events]
Mid-Air Collision of Glider and Jet near Reno: ASG-29 vs. Hawker XP800 (by Jeremy Zawodny) (http://jeremy.zawodny.com/blog/archives/007288.html)

Manley

13th Jul 2008, 08:40

OK "proffesional structural engineer" what in your expert opinion is this and probably all other a/c nose cones made from???

XPMorten

13th Jul 2008, 10:27

The really interesting thing was the rest of the trip our True airspeed increased by 5 knots.

Maybe airflow around the pitot changed/got turbulent giving a wrong (lower) indicated airspeed reading.. .

M

Storminnorm

13th Jul 2008, 14:37

A Court Line BAC 1-11 returning from PMI in '72 or'73
was directed into a rather nasty ball of cloud/hailstone.
I've mentioned this before on another thread page.
It totalled the radome, leaving what was left of it
draped over the Pilot and Co-Pilot's windscreens.
All leading edges were really hammered. Looked as
though they had been attacked by a demented
pewter maker.
The Captain, A Capt Hazeldene I believe, brought it
back to LTN in what remained of one peice, but had
to put on the Smoke Mask and look through the OPEN
D.V. window whilst landing. A Brilliant bit of airmanship
under the circumstances.:D

wilyflier

13th Jul 2008, 14:52

No,captain PB, I dont think so we had several hours of very careful cross check, Including another Brit on the same route for the winds.

ChristiaanJ

13th Jul 2008, 14:53

From that Data4Science site:
"What’s most interesting about this is that the highest air pressure on an aircraft is on the underside of the wings and fuselage which is the source of lift aerodynamically. Yet we can clearly see it is the upper area of the nose cone that was crushed."
Don't you love it when so-called 'experts' start out with the wrong data to try and "prove" their pseudo-science?
And when alleged 'professional structural engineers' demonstrate their total ignorance of radome structures and impact dynamics?

CJ

glhcarl

13th Jul 2008, 19:18

OK "proffesional structural engineer" what in your expert opinion is this and probably all other a/c nose cones made from???

Epoxy resin impregnated glass fabric.

At the forward end of the radome (nose) there is an fluted core (air gap) between the outer and inner surfaces. This gap closes torwards aft end aft end of the radome.

ChristiaanJ

13th Jul 2008, 21:35

Not instrument error
No, captain PB, I dont think so, we had several hours of very careful cross check, Including another Brit on the same route for the winds.Can you tell us some more?
After the radome collapse, both IAS and TAT (if there was a TAT sensor on the Brit) calibration would have gone out of the window, and IAS certainly by at least 5 kts, unless the Brit still had a pitot on the wingtip?

You're talking '60s. 'Professionally' I date from just after that, hence my question... How did you establish a TAS without a reliable CAS within a 5 kts error?

No scoffing or mocking, seriously interested, as another ancient.

CJ

Bus429

14th Jul 2008, 07:16

If I remember correctly, the Brit - the first commercial aircraft on which I worked- had its pitot probes (were they pitot/static probes?) on a stand-off on the forward fuselage.

Storminnorm

14th Jul 2008, 19:24

I've just dug the Britannia Vol 1 out of my loft.
Quote.
Britannia series 310. sect3,chap1,item3.
The radome fwd of frame F619, houses the radar scanner
unit, and comprises an inner and outer laminated
fibre-glass skin bonded to a honeycomb, (Dufaylite),
filler.
Radomes from Mod 2263, have a box section fluted core.
Mod 1708 embodies a replaceable nose cap bonded to the
radome as a protection against rain ingress.

There are two pitot probes, one each side of the fuselage,
and a total of four static vents also located on the fwd
fuselage.

Hope this helps, but I doubt it.:8

PS. There were no wing tip probes, at least I couldn't find
any in the Vol 1.

ChristiaanJ

14th Jul 2008, 19:57

There are two pitot probes, one each side of the fuselage, and a total of four static vents also located on the fwd
fuselage.
Hope this helps, but I doubt it.On the contrary, it very much substantiates what I remembered, but I had no doc to verify it.
Once the radome went, the airflow on the forward fuselage would have been disturbed so much, that even a mere 5 kts error seems, well ... lucky...

Which takes me back to wilyflier's post: how did you derive TAS?

PS. There were no wing tip probes, at least I couldn't find any in the Vol 1.I didn't really think there were any either. I think they went out with the Meteor....

CJ

Storminnorm

15th Jul 2008, 13:17

Oh dear Christiaan, NOT the Meatbox, How OLD
are you? That was when Pontious was at FTS!!!!!:sad:

Last flew in one of those in 1965, I think, with some
Sgt Pilot(!) who had been rejected by the Kamekaze
training programme for being TOO suicidal!!!!:\

ChristiaanJ

15th Jul 2008, 14:27

Oh dear Christiaan, NOT the Meatbox, How OLD are you? That was when Pontious was at FTS!!!!!Ah well.... I must have been between 10 and 12, when the RNethAF got their first Meteors. Those were the days where you not only could get on the base, but they even let you sit in the cockpits..... :)

Thinking about it, a nose or forward fuselage pitot static would not really have worked very well with four nose-mounted cannon in close proximity := . So there must have been others with the same arrangement.

CJ