China Airlines 747F damages two engines at ORD

[DaveReidUK]

With a dozen or more containers as collateral damage ...

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/640x480/china_airlines_ord_half_size_c9b4e63956c3e283cd87a431acda612 e85497c24.jpg

ADS-B track would suggest it diverged by about 45 m from the taxiway across the SE Cargo Ramp at O'Hare on arrival.

https://wgntv.com/news/chicago-news/cargo-truck-collides-with-plane-at-ohare/

[Chiefttp]

If the video is normal speed, that crew was taxiing way too fast given the conditions…notice the cargo can getting injested into the #1 Engine. Wow
https://youtu.be/i9o59T14ukg

[Pilot DAR]

I suspect that the video is showing the event very "speeded up". The time between the two flashes of the top and bottom red flashing beacons is 12.3 seconds in the video, where other videos I find of B747 beacons appear to show the beacon flash period to be just over a second. So the video is maybe ten times actual speed?

[DaveReidUK]

Approx 16 kts at the point where it left the twy centreline, 13 kts at impact, per ADS-B.

[Chiefttp]

There is a time stamp in the upper left corner and the seconds counter seems normal.

[Pilot DAR]

There is a time stamp in the upper left corner and the seconds counter seems normal.

Yes, I agree. I also note that although the flash rate of the 747 beacons seems unusually slow on the video, the flash rate of the ramp vehicles seems normal. My mind is open about the speed of the video, and thus the speed of the 747....

[andrasz]

My mind is open about the speed of the video, and thus the speed of the 747....
This is a video (taken probably on a phone) of the display screen showing a replay of a timestamped security camera video with a frame rate of probably around 10 fps, which is then adjusted for real time playback (normal video is 30 fps). The aircraft appears stopped at the beginning because the replay is paused. The short beacon flashes are not captured with the original slow frame rate, but the relative motion paths are real. You can see it on the motion of the reversing tug at the end. There was also a snow plough right ahead which also starts reversing before disappearing behind the aircraft. Agree with the initial assessment, way too fast for the given conditions, though I'd argue it was not the speed that mattered in his case. Doubt that tea and biscuits will be offered...

[metalboi69]

Taxiing like a rally driver. Expensive mistake

[offa]

There is a considerable upslope off S2 into the ramp (see video) and he appeared to be nose high staring into the lights with little or no visibility under the nose and snow covered taxiway markings. Probably had a handful of thrust to get up the slope and the aircraft ran away with them .... if it was 12 knots it would be way too fast under these conditions. Nose wheel might have had little traction with snow and coming off slope and abrupt or excessive tiller would easily have lost any traction that it did have. Body gear activation would have made it worse. Park brake set and tow truck might have been a good option. Easy to say after the event.

[Magplug]

Taking all into account it looks normal speed to me. There is significant 'barreling' of the image due to a rather wide angle lens hence the horizon appears to drop away the further you go way from the centre.

[andrasz]

...looks normal speed to me.

Normal for a dry taxiway on a clear day...

[hans brinker]

Taking all into account it looks normal speed to me. There is significant 'barreling' of the image due to a rather wide angle lens hence the horizon appears to drop away the further you go way from the centre.

Normal for a dry taxiway on a clear day...


I think he was talking about the video speed, not the aircraft speed....

[RatherBeFlying]

The last frames show a service vehicle rapidly reversing and hitting some containers. Hard to blame the rampie in urgent survival mode.

[compressor stall]

Looking at the liked news article “Cargo truck collided with plane”

huh? That’s like saying tree collided with car wrt to this incident.

[punkalouver]

My guess……..it was not the snow that was particularly slippery. I suspect that there was smooth ice that had formed at the gate at some point, perhaps very recently. Then snow fell on top of it. Meanwhile, the taxiways were mostly snow over pavement. Therefore, minimal issues while taxiing on a route with several turns leading to a false sense of security and the assumption that the parking area was the same.

[Chiefttp]

Reports here in The States are saying the pilot mistook the taxiway edge lines for the taxiway centerline.

[andrasz]

Reports here in The States are saying the pilot mistook the taxiway edge lines for the taxiway centerline.
Looking at the crime scene, I find that rather unlikely. For one, no edge lights only centerline lighting for twy crossing the apron...

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/800x465/__8d874558ef6a9ccd2d3b9c2427e6259d1d223178.jpg

[By George]

The 747 is one of the few widebodies where you can see your wingtips from the cockpit window. In fact if you plonk your cheek on the glass you can see number one engine too. In a tight spot you can always use that secret look out the window technique. Coupled with slowing down there is no need to vacuum up half the airport.

[vilas]

The 747 is one of the few widebodies where you can see your wingtips from the cockpit window. In fact if you plonk your cheek on the glass you can see number one engine too. In a tight spot you can always use that secret look out the window technique. Coupled with slowing down there is no need to vacuum up half the airport.
In a big aircraft like the 747 there's no way pilot can judge his position accurately by putting his cheek to the window. All that is necessary is to be at safe speed to avoid skid and correctly positioned on the centre line. For a sharp turn, with landing gear 95ft behind pilot has to go well past the centre line before turning, may be he went too far ahead and got on the edge instead the centre line.

[Chiefttp]

Here is a plot of the path the 747 took on the taxiway. Obviously he was confused, and coupled with snow covering most of the taxiway markings you can see what may have caused this accident.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1971x1182/4c957f2f_8892_4e06_ae90_ce6e28651e70_f110ebb001864cb34657895 0976768a4e21be1bf.jpeg

[punkalouver]

My guess……..it was not the snow that was particularly slippery. I suspect that there was smooth ice that had formed at the gate at some point, perhaps very recently. Then snow fell on top of it. Meanwhile, the taxiways were mostly snow over pavement. Therefore, minimal issues while taxiing on a route with several turns leading to a false sense of security and the assumption that the parking area was the same.

I have to admit, I thought they were turning into the gate when this happened, not on a taxiway. It still could have been smooth ice under the snow as the aircraft does appear to slide sideways at the end. Taxi speed does appear to be an issue.

[Sailvi767]

I have to admit, I thought they were turning into the gate when this happened, not on a taxiway. It still could have been smooth ice under the snow as the aircraft does appear to slide sideways at the end. Taxi speed does appear to be an issue.

I would not agree on taxi speed. Runways are usually predictable in frozen precipitation events. Taxiways and ramps are all over the place and can vary wildly at different points on a airport. I once watched a SWA 737 come into the ramp in Kansas City at a good clip. Taxiways were pretty good. Ramp was horrible. When he realized he had no braking he yanked both engines into reverse. Sadly one did not spool up right away and he did a beautiful almost 360 degree pirouette. Even the Russian judges gave him a 9! Speaking of Russians they once cleared ramps with a jet engine on a truck. The snow then refroze as pure ice. 3 knot taxi speed with fingers on the reversers at all times and they were needed.
Personally I use 5 knots on snow covered taxiways and creep into ramps.

[punkalouver]

I would not agree on taxi speed. Runways are usually predictable in frozen precipitation events. Taxiways and ramps are all over the place and can vary wildly at different points on a airport. I once watched a SWA 737 come into the ramp in Kansas City at a good clip. Taxiways were pretty good. Ramp was horrible. When he realized he had no braking he yanked both engines into reverse. Sadly one did not spool up right away and he did a beautiful almost 360 degree pirouette. Even the Russian judges gave him a 9! Speaking of Russians they once cleared ramps with a jet engine on a truck. The snow then refroze as pure ice. 3 knot taxi speed with fingers on the reversers at all times and they were needed.
Personally I use 5 knots on snow covered taxiways and creep into ramps.

I think you are right. It appears from the video(although not sure if it was speeded up) that the taxi speed was too fast, which is what I was saying in my previous post. Especially with the modern digital groundspeed display, one should not hesitate to use 1 knot taxi speed in certain situations/locations if necessary.

[mustangsally]

I've taxied the 74 in that corner of the airport many times. The plane was obviously moving to fast. The conditions were poor, good time to call for a tug, lot cheaper than buy a replacement cowling etc.... One can see the wing tips from either seat, during initial upgrade training we used to demonstrate where the wing tip was. One crew member would walk out to the wing tip then forward to abeam the cockpit window. Not a perfect method but would give a new Captain an idea of where it was. Also with the wing sweep the wing tip arc grows in tight turns. With enough damage we just may have a three engine ferry flight to the bone yard.

[Chiefttp]

Sailvi767,
I have witnessed these trucks in action in Shermetyevo. The only problem was the Soviets (back then late 88/89) charged my crew to de-ice the jet AFTER we landed and were enroute to the Hotel! The US embassy official said it was the cost of doing business.https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1739x1134/ae5fd53f_1843_4bef_a255_82e101d88e33_542bc80af5f0fe8ad268c1d b43cd86f8f8baed6f.jpeg

[DuncanDoenitz]

British military aviators of a certain age will remember the Machine, Runway De-icing (MRD), which was in RAF service well into the 1980s. A pair of (I think) DH Derwents fitted with fishtail nozzles and mounted on a castoring structure, apparently from Harland and Wolfe. Typically issued at about 3 per airfield, come the winter, these were hitched to the front of a fuel bowser and were to be operated by Propulsion Technician NCOs (having the benefit of 15 minutes of instruction in early autumn), who occupied a plywood and perspex cabin between the 2 compressors intakes. A rudimentary intercom facilitated coordination between the operator and bowser driver.

The salient morsel of knowledge, I recall: "if the bowser starts moving backward, reduce thrust".

[Chiefttp]

The ones I saw operating in Russia had the MiG engines mounted on the back of a tow truck and manipulated via chains.

[B2N2]

That right-left turn from S3 to S2 is challenging in a 74 on a nice clear Sunday afternoon let alone at night with snow and ice.
Its also non-movement area with retarded local procedure of calling on a Unicom frequency and S2 for inbound and S1 for outbound.
Combine that with how well they take care of their ramp :} , think Mogadishu….with snow.

[Sailvi767]

Sailvi767,
I have witnessed these trucks in action in Shermetyevo. The only problem was the Soviets (back then late 88/89) charged my crew to de-ice the jet AFTER we landed and were enroute to the Hotel! The US embassy official said it was the cost of doing business.https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1739x1134/ae5fd53f_1843_4bef_a255_82e101d88e33_542bc80af5f0fe8ad268c1d b43cd86f8f8baed6f.jpeg

That would be the trucks. I once diverted to Domodedovo Airport. They parked us on a taxiway. Once we got fueled which was a long negotiation we tried to startup and depart. The person on the headset would not let us start. We asked why and she said we must have a push. After another 30 minute wait a tug showed up. They pushed us back 3 feet and left. Billed the company 5000.00 for the push! Station manager said they would negotiate it down to a couple of hundred dollars.

[CCA]

There’s another video doing the rounds and it’s from the yellow snow plow directly in front of the aircraft, looks like it possibly got collected down the right hand side of the aircraft towards the end from the first video.

Sadly he or she decides safety is more important than getting likes and the phone is put away hastily prior to being actually run over to take evasive action. (This is a joke obviously).

[atpcliff]

The 747 is one of the few widebodies where you can see your wingtips from the cockpit window. In fact if you plonk your cheek on the glass you can see number one engine too. In a tight spot you can always use that secret look out the window technique. Coupled with slowing down there is no need to vacuum up half the airport.
I know of two pilots taxiing a 747-400, that were stopped short of the mark by the marsheller. They were pissed, because they both looked out the Capt's window and could clearly see there was nothing in their way. They couldn't understand why the marshaller stopped them early. After they got out of the aircraft, they decided to check their obstacle clearance, to show the marshaller he was wrong. When then got to the wingtip area, they could see they would have hit the object. The Capt was very experienced. Both Capt and FO were 100% sure they were safely clear of the object. In the -400, it is VERY difficult to tell how much room you have, and the 747-8 is worse.

[atpcliff]

I taxied into ANC lately. The ramp had so much snow, it was all white. No taxiway markings, no lights, no nothing, just a lot of white. Ahead of us a good ways we could see some markings, which helped us stay on the center of the taxiway. We just had to go straight a ways, and then were turned in with marshaller help. If we had to make any turns, going a longer distance, guess we would have needed a tug. Not sure how bad the ORD ramp was at this time...could have been a factor...

[dixi188]

Back in the day the Lockheed L188 Electra had clearance lights that shone down vertically from the wingtip. It made it easy to see where the wingtip was going. Why don't modern aircraft have this?

[anson harris]

Most US cargo ramp areas are an absolute mess of containers, vehicles, inadequate markings and lighting, often with zero ATC control or co-ordination. I'm not saying any of that was to blame, but I'm surprised there aren't more incidents tbh.

[punkalouver]

I know of two pilots taxiing a 747-400, that were stopped short of the mark by the marsheller. They were pissed, because they both looked out the Capt's window and could clearly see there was nothing in their way. They couldn't understand why the marshaller stopped them early. After they got out of the aircraft, they decided to check their obstacle clearance, to show the marshaller he was wrong. When then got to the wingtip area, they could see they would have hit the object. The Capt was very experienced. Both Capt and FO were 100% sure they were safely clear of the object. In the -400, it is VERY difficult to tell how much room you have, and the 747-8 is worse.

There are ways to ensure you are aware of whether you have sufficient clearance such as for each wingtip and outside edge of main gear that require advance preparation.

While at a gate waiting for your freight delay one day, have a crew member, who has been properly briefed for this procedure, go out and stand at several locations, so that can you to take some pictures of him.

For example, the first location, which was briefed, is to stand in front of the aircraft so you can easily see him out your window but with him ensuring that he is always aligned with the left wingtip. Make sure your seat is adjusted so you are at the designed eye reference point(using the three reference balls).

Signal him to move forward or aft as required(with him always ensuring that he stays aligned with the wingtip).

When he reaches the location where your view of him is such that his image touches the aft edge of the main window, get him to stop and stay in position. He is now the obstacle that you can see would just barely strike the wingtip if he was tall enough.

Note his location for the memory banks(how far up from the base of the window). One can also put a camera where your eyes were located and take a picture.

The same can be done for the other wingtip and for gear or even outboard engines. Note: a gear leg position will be an intersection with the MCP panel.

One might forget these reference points when an obstacle situation arises, so you could print off the pictures you took and have them in your notes(if you carry such stuff) for the rare occasion where you are in a tight situation. Then you could stop, set the park brake, get your pictures out, ensure your seat adjustment places your eyes at the reference point and know if you would clear that object.

It may sound odd to take the time to do this but my company provided these pictures to us during our training, which I carried with me. Otherwise, you are just guessing if you will clear an obstacle. And we have had more than one wing tip strike....which is probably why they started providing pictures to us.

[armchairpilot94116]

One possibly two new engines needed looks like

[RVF750]

I landed into GVA once in a blizzard just as the airfield surface de-icing had given up. managed to pick up the RET edge lights just enough to clear the runway but had to stop and ask for guidance for taxiing to stand as we couldn't make out enough of the markings. Not worth the risk. if it stops all movements then so be it.

[BraceBrace]

Most US cargo ramp areas are an absolute mess of containers, vehicles, inadequate markings and lighting, often with zero ATC control or co-ordination. I'm not saying any of that was to blame, but I'm surprised there aren't more incidents tbh.

Absolutely. Lost count on how many times we stopped taxi entering the cargo apron in JFK and just waiting and waiting. There were always "stranded" containers.

[RedBelt]

All good points that are mentioned here, but all of them are assuming the operating pilots were properly rested and in possession of normal skills. It is known that China Airline's pilots have been submitted to very harsh FTL by the Taiwanese Aviation Authorities in the last 2 years. We all know the meaning of chronic fatigue! While we are all siting in our homes trying to understand what has happened the best is to imagine the last time we had a couple of drinks and we were not in good condition to drive our car, to imagine taxying a 747 in poor visibility with icy taxiways under the influence. I hear some colleagues stating they would slow down....chronic fatigue is a killer.

[no sponsor]

Anyone who has taxied a 744 knows that the nose wheel will skid a lot in corners, even in very light damp conditions. If you’ve ever taxied an airplane, and it starts skidding on ice there isn’t a lot you can do. Selecting reverse, stamping on the breaks, or trying to power out of it isn’t assured to save you.

In these circumstances probably best to just get a follow me van and max speed less than 5kts. I hope the guys/gals keep their jobs.

[Pogie]

If you watch the beginning of the video from the plow, it starts before the video above. The aircraft was barely moving, going at 5 KTS max (appropriate taxi speed), then it abruptly and sharpy turns about 60° to the left and accelerates straight towards the ramp. Not the type of spin and acceleration that I would associate with just losing traction at idle thrust. It looked and sounded like he gave it some thrust, and the thrust reversers aren't deployed. You can see that in the above video. Maybe he hit the TOGA switches by drooping his fingers over the thrust levers and it spun and launched him before he knew what was happening. Maybe he got too far to the right and just panic reacted by cranking the nosewheel to the left and goosing it. I'm sure the two in the cockpit know what happened. Can't wait for the investigation report on that one. BTW, the original video is not sped up. He was moving that fast.

[CCA]

TOGA switches aren’t armed with the flaps up.

Certainly sounds like some differential thrust being used to “help”.

[20driver]

What would be the price per engine for new ones?

[andrasz]

List price is around $10M. However insurance would only pay for repair or replacement with engines having equivalent hours/cycles, whichever lower. These will probably be repaired, I would expect damage to be limited to fan & cowling.

[DaveReidUK]

List price is around $10M. However insurance would only pay for repair or replacement with engines having equivalent hours/cycles, whichever lower. These will probably be repaired, I would expect damage to be limited to fan & cowling.

That's probably true for #2, but unless I'm mistaken it looks at one point in the video like #1 ingested and spat out bits of a container.

[Chiefttp]

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1323x1039/6bc59b0c_60b6_4dec_8e00_c77ee83aacbd_793d93adee7ebb8c9af1d53 33280bbecbca7ccff.jpeg

[andrasz]

... #1 ingested and spat out bits of a container.

Probably both injected bits and pieces, but with a bit of luck these would be shredded and ejected in the bypass duct (per design), should not enter the core. If the core did ingest something, that indeed pushes the repair bill up a few notches.

[Pilot DAR]

Letting alone probable damage to both engines, I cannot imagine their being released to service without at least a full overhaul.

[andrasz]

I cannot imagine their being released to service without at least a full overhaul.

A boroscope inspection will reveal if there is any damage to the engine core. If yes, indeed a full teardown. Regardless of the core, the fan disk will need extensive testing to check for any signs of overstress, if the test is positive it will need to be discarded, such damage is non-repairable. Any visible damage on the fan blades and especially the cowling is the least of the worries here.

[cwatters]

I suspect that the video is showing the event very "speeded up". The time between the two flashes of the top and bottom red flashing beacons is 12.3 seconds in the video, where other videos I find of B747 beacons appear to show the beacon flash period to be just over a second. So the video is maybe ten times actual speed?

If the video was speeded up the interval between flashes would reduce not increase.

[Pilot DAR]

If the video was speeded up the interval between flashes would reduce not increase.

Yup, you're right! I was so surprised by what I saw, I figured there must be another factor, but no, it was just poor airmanship!

[tdracer]

Yup, you're right! I was so surprised by what I saw, I figured there must be another factor, but no, it was just poor airmanship!
Most likely, it's the frame rate of the video - strobe duration is very brief, so if the frame rate is slow it's going to miss many of the strobe flashes.

[Lordflasheart]

Anyone who has taxied a 744 knows ...

Anyone remember this ... ?

https://aviation-safety.net/database/record.php?id=19751216-0


https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1134x647/jal_at_anc_3012ec259e6fe942bf532dd4c97cb7d5113ba541.jpg
Qui a dit - 'Suivez moi' ?

LFH

[megan]

Occurs even when not in a rush, author and Braniff 747 Captain Len Morgan wrote of sliding off a taxi way onto the grass in a 747 at JFK.

[N707ZS]

The report says they repaired that JAL 747.

[prozak]

Lining it up against timecode, the video is indeed at normal speed

[Turbine D]

A boroscope inspection will reveal if there is any damage to the engine core. If yes, indeed a full teardown. Regardless of the core, the fan disk will need extensive testing to check for any signs of overstress, if the test is positive it will need to be discarded, such damage is non-repairable. Any visible damage on the fan blades and especially the cowling is the least of the worries here.
Given the unusual circumstances of this accident, IMO, the two engines will be completely torn down and inspected, replacing any suspected or damaged parts. A simple boroscope inspection isn't good enough. There is much potential liability to be avoided by doing a complete teardown, internal inspection and subsequent engine testing before a return to service...

[fdr]

A few lost baggage claims going on after that shambles.

[fdr]

Given the unusual circumstances of this accident, IMO, the two engines will be completely torn down and inspected, replacing any suspected or damaged parts. A simple boroscope inspection isn't good enough. There is much potential liability to be avoided by doing a complete teardown, internal inspection and subsequent engine testing before a return to service...

And the engine pylons, and the upper attach pinions... That bulldozed a fair bit with a hefty lever arm back to the wing.