Object strike at FL 262

[andrasz]

An Air China 757 departing Chengdu for Guangzhou reportedly struck an unidentfied object at about 8000 metres (~FL262) this morning and returned to the departure airport. The photos show a large dent in the radome. No news of whether bird or perhaps a weather balloon, to me the marks would rather suggest the latter.

http://m.cdn.blog.hu/pe/pekingikacsa/image/34.jpg

http://m.cdn.blog.hu/pe/pekingikacsa/image/19.jpg

[Basil]

Last item on checklist: Back for coffee and underwear change.
Loudest bang I've heard in an aeroplane was a lightning strike on the nose of a TriStar on finals. I'd guess theirs was worse.

[B Fraser]

The instrument packages on the weather balloons I have launched would have barely scuffed the paintwork, even at 500 kts. Whatever they hit was no ordinary weather balloon. The object appears to have been painted black, why paint part of a weather balloon that you will never see or use again ?

[Basil]

The instrument packages on the weather balloons I have launched would have barely scuffed the paintwork
What sort of date was that? ISTR that those in the 70s could have just about done that.

[B Fraser]

The 1980s however I doubt the gubbins inside the polystyrene box have become larger or heavier to any significant degree.

Here's a photo taken from the net of what looks like a more modern radio sonde. It is a tad smaller than those I was playing with. Other pictures suggest some are now packed in cardboard.

http://www.windows2universe.org/milagro/images/radiosonde_sm.jpg

[bzh]

Wonder if the us lost a drone the same day....

[RoyHudd]

Not at Fl 262

[toffeez]

A panda with wind.

[ShyTorque]

Strewth! Looks like a case of: "Hey Captain, what's that mountain goat doing up here in clou...? :eek: "

[Basil]

B Fraser, Looks quite wee esp if in shock casing.
Just remembered; we had a close encounter with one a long time ago. By the time we had visual contact it was too late to avoid. Did once take avoiding action on a para-glider :ooh:

Mods: sorry for the bad language in Chinese - isn't Gogle translate wonderful? ;)

[meekmok]

A 0.5 kg payload on a weather balloon hitting the radome at 500 knots would have roughly the same kinetic energy as a 200kg motorbike hitting it at 30 miles per hour.

I have no idea if a 0.5 kg (1 pound) payload on a weather balloon is typical.

[B Fraser]

A weight of 200g would be about right and they are frangible i.e. designed to deform and cause minimal injury should one land on the head of a member of the public. Either way, they will not leave a black mark on an aircraft in the event of a collision. Rocket sonde payloads are a different matter but that's for another day.

Basil, I assure you the chap on the paraglider wasn't me ;)

[framer]

I thought the black was just deformed fibreglass.

[lomapaseo]

I thought the black was just deformed fiberglass.

Some are, some aren't

either way the scuffs overall do not correlate to a spherical object even though the dent does.

[green granite]

I didn't realise that fibreglass deformed that much without shattering, or is it just the paint holding it together? :}

[Octane]

would that sort of impact penetrated the windscreen do you think?

[inducedrag]

In Capt. Johnny Sadiq's book 'Come Fly With Me - Jets', there's an incident described in which a PIA Trident was struck by a vulture in September 1969. The aircraft was operating Lahore to Rawalpindi flight under the command of Capt. Baakza with Safdar Nana as Co-pilot.

Shortly after take-off from Lahore, a vulture struck nose section of the Trident, penetrated aluminium skin of the aircraft, through pressure bulkhead, came out of instrument panel, glanced off the control column and struck the flight commander Baakza a severe blow on his inner thigh. The captain was now covered in blood and only semi-conscious on the aircraft which was rapidly depressurising with deafening wind blowing into the cockpit. Co-pilot Nana called Lahore for emergency landing, slowed down speed of the aircraft.

Nana asked Flight Engineer to remove semi-conscious captain from his seat to prevent disruption of flight controls during emergency landing. Nana also asked Flight Engineer to sit on captain's seat so that he had someone to select his slats, flaps, and landing gear while he concentrated on bringing the damaged Trident back on ground.

The Trident was safely landed by Nana at Lahore Airport.

[Basil]

Basil, I assure you the chap on the paraglider wasn't me

Just climbing out of Venice; given LT for shortcut; engaged autopilot; "What's that?!" JC! disengage a/p turn right and watch para pass down port side.
Since the parachutist would have seen and heard us on collision course before we saw him, I'm not sure if had already relieved himself before we passed. :}

[Weary]

The black is the colour of the composite material from which the nose cone is constructed, obviously under a coating of white paint.
Whatever has hit it has not left any trace of paint/blood/whatever on the nose - or penetrated the nose-cone directly, which is exactly what you would expect if that something was made of polystyrene foam, or encased in same.
A radiosonde sounds about right to me.

[First.officer]

Air birds hit flat nose great impact (Figure) - Page 2 - Shanghai Station News (http://www.newshome.us/news-4596193_2.html)

Mystery solved?

[lomapaseo]

would that sort of impact penetrated the windscreen do you think?

I doubt it. The nose cones break away long before the wind screen does.

For another poster

composite structures on aircraft don't break into small pieces on impact. They do give way and break along fracture lines and then may be finished off by the airstream or centrifugal forces in the case of engine nose spinners.

Whatever hit this one dented it but I don't see the typical crease and fracture at the bottom of a significant hit.

I'll allow that parts of a bird like bones may have left scuff marks directly in line with the flight path of the aircraft and not scattered.

[andrasz]

Mystery solved?

Dont't think so, the cited source does not appear to be too reliable.

I've seen the traces of several bird strikes (including a large seagull that hit the side window of a 73' on takeoff, managed to squeeze it open about 2-3 milimetres, and then proceeded to enter the cockpit through that gap, flesh, beak, bones, feathers & all...). A bird strike leaves quite a bit of a mess... Also 8000 metres is very high, have heard of vultures getting up that high, but a bird of that size hitting at 500mph would do more than a dent. Based on info from more knowledgable posters on this thread, I'd vouch for a balloon till proven otherwise.

[JW411]

Well, I would not discount a birdstrike. I posted on another forum recently that I hit a fair sized bird over Northern Germany at night between cloud layers on the descent into CGN at 19,000 ft.

I am also sure that I have read of geese being up at 30,000 ft (without filing a flight plan).

[J.O.]

Indeed. UPS hit a goose on the windscreen at FL310 over Colorado Springs a few years back. It was in the dark of night - must have scared the stuffing out of that crew.

[topdog1]

Several years ago saw a similar failure due to delamination of the radome over time.The weakened structure had imploded under the air loads.
New radome please

[bcgallacher]

I removed feathers jammed in a lap joint aft of the radome on an Iranair 727 that had a bird strike at 23000 feet over the Gulf at night - seemed to belong to some kind of raptor.

[ATC Watcher]

The birds going up above 20.000 ft are not that many (i.e. Condors, Vultures, Canadian Geese ) all fairly big an heavy ( Vultures around 4-5 Kg , Geese 5-9 Kgs and condors up to 15 Kg ) .
These kind of weights at 900 Km/h hitting the ( plastic) radome would end up on the knees of the crew I think.
I would also normally leaves some blood traces.

[ironbutt57]

The radome probably just collapsed due internal structural failure..

[training wheels]

Blood stains are usually evident on the airframe after a bird strike ...??

[ATC Watcher]

Blood stains are usually evident on the airframe after a bird strike ...??
You bet.
just type " bird strike" on google images.

[worrab]

Amongst all the gore is this one:

Sutherland Shire Squadron - Photo Gallery - Bird Strike (http://sutherlandshire.airleague.com.au/bird_strike.htm)

Which bears some similarity, lacks gizzards and appears to be a confirmed bird strike.

[FlightPathOBN]

China has plenty of UAV's, the Guizhou Soar Eagle ceiling is 59,000 feet.

The service ceiling on a Global Hawk is 60,000 feet, and routinely fly at 45,000.

[Jn14:6]

B Fraser,
I don't know about the weather balloons which you are used to, but the one I had an encounter with over southern China a few years back was MANY times the size of the one pictured!:eek:

[Nemrytter]

Jn14:6: The balloons expand as they climb (due to the low atmospheric pressure). At typical aircraft cruising altitudes they will be 50-100% larger than at sea level.

[FlightPathOBN]

The typical National Weather Service radiosonde instrument looks like it would cause the damage...seems reasonable China would use something very similar..

http://www.examiner.com/images/blog/EXID219/images/2009-09-16_135538.jpg

[B Fraser]

It was the type where the hydrogen obeys the laws P1V1/T1 = P2V2/T2. The balloons did leak a bit and hydrogen does behave slightly oddly but the equation is a good enough analogy to show what happens when P reduces by a lot and T reduces by a little (in terms of Kelvin).

If you added a bit too much gas then the balloon would burst at a lower altitude so you could bunk off home sooner. Not that I ever did such a thing :E

[Jn14:6]

Nemrytter:
Not just the balloon, but the VERY large object dangling beneath it!

[crewmeal]

No no no you have it all wrong it's a UFO:

Did Chinese plane have mid-air crash with UFO? | The Sun |News (http://www.thesun.co.uk/sol/homepage/news/4962798/did-chinese-plane-have-mid-air-crash-with-UFO.html)

[El Grifo]

Currently of course, for once, The Sun is 100% correct :D

[Herod]

Absolutely. It was an object, it was flying (after a fashion at least), and it's unidentified. Ergo UFO.

[Dimitrii]

It says right on it that it is Harmless.

[pattern_is_full]

The radome probably just collapsed due internal structural failure.

Possible. When a dome undergoes an inversion under stress, as this radome did, the process is called "snap-through", and can produce a substantial "thump" even if there is no collision with a specific object, just failure under a continuous load (airstream.) The thump can easily give the impression of an actual impact.

Just making an engineering point - I have no opinion yet as to what happened here.

[lomapaseo]

The air loads are miniscule compared to object strikes and handling, including leaning on it.

I'm afraid that it had some help other just going poof in the night

[ChrisJ800]

There are other items carried by ballons than just Met packages, eg Google Loons for airborne wifi: Project Loon | Google Balloons Offer Free Wi-Fi, Internet | Photos (http://www.theage.com.au/digital-life/digital-life-news/google-floats-balloons-for-free-wifi-20130615-2oamm.html)

[atakacs]

was there ever an official report on this one ?