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B-737 Cargo Plane down in Hawaii

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B-737 Cargo Plane down in Hawaii

Old 31st Jul 2021, 16:49
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"So if they had as few as 27 quarts and were regularly burning/leaking down to 19 or 18 - wow."

This is totally a non issue. The are typically serviced once a day.
If it is below dispatch minimum it would be serviced then too.

​​​​​​​The leakage limit on these old engines is" It can leak as much as it wants as long as it can complete the intended flight without running out "
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Old 2nd Aug 2021, 17:56
  #242 (permalink)  
 
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I agree with deltahotel (Post #231). (I found freight to be better than pax in several aspects.)

But that doesn't mean that there are not some cowboys out there pushing beyond limits. But they do stand out (in the wrong way). It would be good if they were swiftly dealt with by the regulators.
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Old 6th Aug 2021, 10:02
  #243 (permalink)  
 
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Have the FDR and CVR not been located yet?
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Old 23rd Aug 2021, 07:57
  #244 (permalink)  
 
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I would still like to know what if anything this crew did to prepare for ditching. Did they even slow down? Has anyone seen a wing to see if the flaps are extended?

The aircraft has broken up unto the usual three part 737 fuselage kit, if that is the result of a competent ditching the passenger survival rate would have been very low. If it was the result of ploughing in at 250 knots or even min clean it’s amazing they got out.
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Old 23rd Aug 2021, 19:14
  #245 (permalink)  
 
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Does the forward section of the aircraft look to you like it hit the water at 250kts? FFS. The -200 engine installation is not conducive to a completely intact end result. When the industry switched to the current kind of engine location and mounting one of the stated advantages at the time was a better ditching outcome.
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Old 25th Aug 2021, 13:13
  #246 (permalink)  
 
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IF they had 250 knots to play with, they would have used that energy to their advantage and maybe have made it to Barbers Point, and as Austral points out, no way would that be ditching speed. Low and slow limits your options.
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Old 25th Aug 2021, 15:57
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Where does this "250 kt at impact" scenario come from ?
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Old 29th Aug 2021, 16:30
  #248 (permalink)  
 
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It's not a scenario, it's just that a forum member was wondering whether this was a controlled ditching or whether they bounced in at a hypothetical 250 kts, as the fuselage was pretty broken up. While the speed might be off, I agree that they probably either came in fast or got slow and developed a high rate of descent. Not easy to see the ocean at night.

I'd like it however if the legend about the engines digging in to the water and the aircraft cartwheeling and/or breaking up was laid to rest once and for all. This is not what happens. Otherwise, they would behave the same when landing in a field. And they don't.

When there's casualties in a ditching, it's because the aircraft did not touch down at the correct speed and attitude. And you would have very similar damage on dry land in those circumstances.

Unless you are landing in 10 foot swells, a ditching is just a normal forced landing with the additional risk of drowning.
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Old 29th Aug 2021, 22:21
  #249 (permalink)  
 
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Stuka Child

Speed over the water at impact was roughly half the hypothetical 250 kts. RoD approximately 150 fpm.

Still evidently more than enough energy to split the fuselage into three parts.
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Old 30th Aug 2021, 00:45
  #250 (permalink)  
 
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Where might one find this data? Also wondering what the attitude of the aircraft was at touchdown.

In the rescue video, the sea looks unquiet but not rough.
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Old 30th Aug 2021, 05:50
  #251 (permalink)  
 
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This was similar to Hudson river. Hudson case it was in day time but due to time pressure they were not able to maintain the correct approach speed and resultantly the recommended ROD of 3.5ft/sec. at touchdown. They touched down at 12.5ft/sec. Aircraft was written off due that but remained in one piece. This crew had to do it in the night so may be they just found themselves ploughing into water or stalled into water. Besides this aircraft was much older. More details are required.

Last edited by vilas; 30th Aug 2021 at 08:14.
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Old 30th Aug 2021, 08:35
  #252 (permalink)  
 
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Stuka Child

"Where might one find this data?"

FR24 has excellent detailed coverage of the flight, particularly of the last few minutes.

"Also wondering what the attitude of the aircraft was at touchdown."

Given the low horizontal speed and relatively shallow FPA, I would imagine that it hit the water in a tail-down attitude (more so than US1549), hence the fuselage breach.
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Old 30th Aug 2021, 09:36
  #253 (permalink)  
 
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Cactus 1549 was a premeditated ditching, albeit with only 90 seconds notice. The aircraft was ditched on a flat-calm, inland waterway in good visibility. The modern construction of the airframe no doubt contributed in some degree to the hull remaining intact. Those factors gave the crew the best chance of executing a successful water landing. Had the crew been presented with the same scenario in open coastal waters, even with a slight swell running, the outcome would have been very different.

I am struggling to recall an accident involving a jet aircraft ditching in the open sea that had a good outcome..... regardless of it's attitude at impact.
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Old 30th Aug 2021, 20:28
  #254 (permalink)  
 
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DaveReidUK:

I went on FR24 like you said, and the last data point seems to show 114 KTS and 1088 FPM for the rate of descent - not sure where you saw the 150 FPM. Rescuers say that winds at the time of rescue were at 17MPH, so roughly 15 KTS. Even in the scenario where it was all headwind, 129 KTS is pretty slow if they were heavily loaded - hence the high rate of descent at touchdown. If you listen to the audio, at some point you will hear the crew mention they are worried about their airspeed. We will have more information when the report comes out, but I believe they attempted to slow down their descent and stretch the sort-of-powered glide and in the process ended up on the wrong side of the drag curve and plopped her in like vilas said.

As for the sea, rescuers said they were working in 5 foot swells. There is zero way you will break an aircraft in 5 foot swells in a normal ditching.

You can see in the pictures that the nose was shorn off, indicating the aircraft touched down tail-first and then the front section slammed in in a hard secondary impact, similar to Turkish 1951. Even the way the aircraft broke apart is similar. The forces, however, were of a lesser magnitude, and this crew survived the secondary impact.

Magplug:

That is incorrect. Ditchings usually have a good outcome in the sense that the aircraft remains intact, but unfortunately there is often the risk of drowning.

Air Niugini 73 (B737-800) - aircraft intact but eventually sank to the sea bed 100 ft below - one person drowned
ALM 989 (DC-9) - although landed on significant swells, aircraft intact but eventually sank in 5000 feet of water - 24 drowned or were thrown about at impact due to not wearing seatbelts, as the ditching wasn't properly announced
Japan Airlines 2 (DC-8) - aircraft intact, came to rest on the sea bed in the shallows - 0 fatalities
Lion Air 904 - aircraft only suffered damage upon hitting rocks in the shallows - 0 fatalities

So no, the norm isn't aircraft breaking in pieces when touching the water, regardless of water depth or the presence of waves. People think that because the most famous ditching in history before Sully was the hijacked 767 from Ethiopian, which went down off the Comoros Islands. It broke apart due to impacting the water at high speed with a left bank, which caused the left engine to dig in, while also hitting a reef. Of the fatalities, many drowned as they became trapped in the half-submerged pieces of wreckage. More CFIT into water than ditching.

Last edited by Stuka Child; 30th Aug 2021 at 20:33. Reason: digging through final report, found out the pieces of wreckage were only half-submerged in the shallows
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Old 30th Aug 2021, 23:15
  #255 (permalink)  
 
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Stuka Child

"I went on FR24 like you said, and the last data point seems to show 114 KTS and 1088 FPM for the rate of descent - not sure where you saw the 150 FPM."

Impact occurred at 11:44:54Z. Sixty seconds before that, altitude was 150 ft. While RoD increased during the last few seconds, there's no way it reached over 1000 fpm.

Mode S vertical rates are notoriously inconsistent.
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Old 7th Sep 2021, 17:50
  #256 (permalink)  
 
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Stuka Child

3 of those 4 examples would not really be considered "ditchings" ie purposeful/unavoidable water landings as we are discussing here, Air Niugini, JAL 2 and Lion Air 904 all landed short/contacted the water short of the runway, some more than others.
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Old 11th Sep 2021, 08:25
  #257 (permalink)  
 
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If they ditched at 115 knots why has the fuselage broken up into three pieces?

Imagine if the Hudson aircraft had done that. Seems to me that the 737 has significant weak spots in the design, the fuselage always seems to break into three with anything other than the mildest of impacts.

I realise this isn’t scientific research, however I know where I don’t want to be sitting. Check out the photos below.

https://www.google.com/amp/s/www.ind...137.html%3famp

https://www.flightglobal.com/safety/...136258.article

https://www.baaa-acro.com/crash/cras...8bk-georgetown

https://www.airlive.net/breaking-a-p...okcen-airport/

https://en.m.wikipedia.org/wiki/Cont...es_Flight_1404

Last edited by Locked door; 11th Sep 2021 at 08:39.
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Old 11th Sep 2021, 08:57
  #258 (permalink)  
 
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If the Hudson aircraft had gone down in the open sea, it might well have done.
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Old 11th Sep 2021, 10:07
  #259 (permalink)  

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Locked door

The aircraft is built and designed fine. The relevant crash-worthiness requirements are complied with.

Yes, if you slam the airframe too hard it will break at some specific point first. If you crash-open the same type multiple times, it will disintegrate at the same locations across the hull. Really, there is no magic.

It's the most beaten and hardworking type of all aviation history, and there's absolutely no need to be paranoid.

The general consensus is, not surprisingly, that any impact energy consumed during the destructive deformation of materials is on the good side of survival effects as it is not transferred to occupants. As much as this does not prevent the ceiling panel from slicing one's head off.

It seems to be true, I agree, there are specific seat sections where the chances of walking out from a crash are higher than elsewhere. Well, for the Sukhoi at UUEE it worked exactly the other way, and not everyone has the chance to pick 0A/B.

No need to worry about the 737, really no. It would be a pity if, after 30 years of debunking the Toulouse grass-cutter myths and reaching a bit of a plateau there, we succumb to yet another name shaming contest.
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Old 11th Sep 2021, 12:40
  #260 (permalink)  
 
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FlightDetent

Except, that there was a documentary on Al Jazeera about 737 NG in that Boeing workers had expressed dissatisfaction about fuselage joining process etc. and many NG excursions led to break up of fuselage.
If you compare Hudson river touchdown at 12.4ft/sec as against recommended 2.5ft/sec although damaged still the fuselage didn't breek up.
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