Polish LOT 767 wheels up landing

[Airbubba]

Not sure about the 767, but on the 727 I can hold a CB closed if I desperately need the associated equipment to operate.

Holding a breaker closed kinda fell out of the vogue with the Air Canada 797 fire in 1983 as I recall. I never knew it was an approved procedure on the '72.:confused: I might try an extra reset or two though.

[aviatorhi]

Obviously it depends on the situation, say you lose your generator fields/generators for whatever reason and desperately need to close a field breaker (IMC with the battery depleted, for instance) you could hold the gen field breaker closed and restore essential power at least and potentially all 3 AC busses (example is 727 specific).

As far as the landing gear is concerned I'm not sure how long the cycle to release uplocks would be on the 767 with the ALT system, and I'm not even sure that a CB was an issue here. Just pointing out an option that is available if the situation calls for it.

Theoretically, let's say the weather was not clear and calm like on the day of this incident (and diverting to another field with good conditions was not an option). Holding the CB would be taboo on a good day to some, but on a bad day one might want to seriously consider holding that CB in long enough to extend the gear. And, again, not sure that a CB was at issue here.

[MrMark757]

I worked on the 1st 38 767 at the Boeing Everett plant (1981-1983). You are correct. The 1st 767 had a 3 a Flt Engr. At that time, there was a floor panel behind the Flt Engr. He could pop open the latches and 3 telescoping levers were there to Alternate Extend. But with the design change to 2 man Flt Deck, they removed the levers and installed a DC motor to drive all 3 cables.
For alternate gear extension, the guarded alternate extension switch on the P3-1 panel energizes the electric actuator to the extend or retract position. In the extend mode, power from the 28 VDC Hot Battery Bus passes to the actuator when the alternate gear extension switch is positioned to extend and when the landing gear lever is not in the UP position. When the actuator has reached the full extend position, the extend limit switch will open breaking power to the actuator.

[Nepotisim]

I hope you all understand that if the CB has tripped it has done so for a reason.:eek:

All this talk of holding it in scares me a bit. I am damn sure it doesn't permit that in the QRH. One go at resetting and then end it.:ugh:

[fireflybob]

I hope you all understand that if the CB has tripped it has done so for a reason.

All this talk of holding it in scares me a bit. I am damn sure it doesn't permit that in the QRH. One go at resetting and then end it.
6th Nov 2011 05:03

Precisely Nepotism! Also I always understood that circuit breakers were there to protect against potential fire - a far bigger hazard on board than not being able to extend the landing gear.

[Capetonian]

Holding a CB in, or replacing a fuse with one of a (significantly) higher value is highly dangerous. The last time I saw it done, it resulted in the total destruction by fire of a Jaguar Mk X on its way to a car concourse when the wiring loom overheated and started a fire behind the dashboard which spread with terrifying speed. I was witness to this.

It is hard to imagine that professional flight crew would have held in a CB for more than a few seconds in a last ditch attempt to solve the problem, but desperation and fear are strange motivators. I hope the crew are exonerated from this.

[Peter1964]

Hi, have been away for a while... Thanks for a very interesting discussion!

Just a quick question to those in the know: we know that Boeing/LOT technicians extended the LG from the cockpit. If they used ALTN LG extension then the landing gear doors (e.g. forward nose gear doors) would have remained in the open position. In this picture it is clearly in the closed position, which perhaps indicates the C HYD system was somehow pressurized and normal extension was used. Am I correct? Could someone correct me if I am not?

[Reinhardt]

Another accident with a Boeing ....

[aviatorhi]

Typical talk by souls who've never learned on "old iron", nor learned the finite properties of the various systems on board their craft.

Bet you don't know you can restore your ESS busses with "brute force" if necessary.

If the situation would have benefited from "overriding" the breakers for 5 seconds I'd take that over a belly landing any day of the week, month or year.

(RE: holding CBs)

[punkalouver]

Precisely Nepotism! Also I always understood that circuit breakers were there to protect against potential fire - a far bigger hazard on board than not being able to extend the landing gear.

Very true Capetonian and FireFlyBob, I was just pointing out what appears to be a Boeing design for holding in a couple of popping CB's that would be used in a desperation scenario. I assume that it is FAA approved and I thought it was interesting when I came across it.

[piotro]

If they used ALTN LG extension then the landing gear doors (e.g. forward nose gear doors) would have remained in the open position. In this picture it is clearly in the closed position, which perhaps indicates the C HYD system was somehow pressurized and normal extension was used. Am I correct? Could someone correct me if I am not?http://www.sfora.pl/Zobacz-jak-przeniesli-Boeinga-Okecie-dziala-g37387-34006http://www.sfora.pl/Zobacz-jak-przeniesli-Boeinga-Okecie-dziala-g37387-34006

Landing gear doors were open when they extended LG after lifting the airplane, this can be seen i.e. on this video:

OxQ_XDDMKzQ

[Airbubba]

Typical talk by souls who've never learned on "old iron", nor learned the finite properties of the various systems on board their craft.

We new lads appreciate your sharing of ancient wisdom. Yep, on the 'old iron' we pulled and held breakers and used them for a switch. We psychoanalyzed our aircraft systems and came up with brilliant CB workarounds to overcome malfunctions and provide undocumented operational modes. We pulled the breaker on the gear horn to avoid nuisance warnings. We pulled those LE CB's so we could cruise at flaps 2 on the 727-100.

But, some of these unauthorized 'techniques' caused mishaps and cost lives.

Who knew the ground air sensing CB out would pop the spoilers when they were armed? Who knew we would forget to set the flaps for takeoff with the horn CB out? Who knew the lav flush motor would catch fire with the CB held in?

Bet you don't know you can restore your ESS busses if with "brute force" if necessary.

As I recall, on the 727 transfer of the essential busses is voice actuated by yelling 'Check Essential!' at the FE. Is 'brute force' hitting him with your Maglite?:)

[Neptunus Rex]

And where are our magnificent Flight Engineers when we need them?

Sorely missed on many a Flight Deck.

[Jet Jockey A4]

I agree with Airbubba here.

Unless it specifically says in the QRH or emergency check list that you can reset a CB more than once then one should adhere to the procedure.

Again, with all the time available to them in the crossing I'm sure they would have gone through all the procedures for the hydraulic failure and its consequences.

I'm sure their maintenance would have been called up to help trouble shoot the problems and go through the systems with the crew. Perhaps even Boeing got involved.

Do we know for a fact at this time if LOT's maintenance and/or Boeing got involved prior to the landing?

[aviatorhi]

FAR 91.3 (b); and I happen to consider Gear Down safer than Up.

As I recall, on the 727 transfer of the essential busses is voice actuated by yelling 'Check Essential!' at the FE. Is 'brute force' hitting him with your Maglite?

No, residual voltage (built up in the voltage regulator) can be used to close a Field Relay if "traditional" methods don't work. As referenced in another thread on this forum, the minimal ground training crews receive every year and lack of experience moving down from (partially due to the advent of the "regional") has caused a lack of total/complete knowledge of the aircraft. As a side effect of this, unfounded and irrational fears are very common in aviation.

[blind pew]

I find it rather incredulous in this day and age and after many deaths due to wiring fires that ANY educated pilot would consider "holding" a circuit breaker in.
Are there still pilots who don't know or understand the risks associated with Kapton and resetting a CB after it has tripped?
The American military either rewired their aircraft or scrapped them nearly two decades ago because of the risks associated with that stuff!

[r75]

Looking at the picture in #222 it looks as if the ground release for the MLG door uplocks have been deployed,you can see the service door for each uplock release lever open.These actually release the door uplock via the ALT release system..When you select MLG door close, on the ground,you in fact use that ALT release lever and do they go up very rapidly.
Regards holding a tripped C.B. in, very poor practice,we in the industry have to abide by SFAR 88,so apart from going against AMM procedures you would also be going against FAA rules.

[Escape Path]

As a side effect of this, unfounded and irrational fears are very common in aviation.

Right, that's why everybody has ever told me not to reset a CB more than once. They have all lived their (long) lives afraid! :oh:

Unless it specifically says in the QRH or emergency check list that you can reset a CB more than once then one should adhere to the procedure.

I'll second that and I'll leave the bloody tripped CB alone.

[repariit]

Are there still pilots who don't know or understand the risks associated with Kapton and resetting a CB after it has tripped?

Forcing a circuit to run higher than rated loads is never a good idea, and is even more risky if Kapton wiring is involved. The LOT 767 was described as being 13 years old in a previous post. Boeing stopped using Kapton wire in 1992 so it would not have been a factor in this particular incident.

[glhcarl]

For the old timers of this forum...

"THIS NEVER WOULD HAVE HAPPENED IN THE L-1011!"

(forwarded from Capt Bob somewhere in the Flight Levels)


Capt. Bob was right!!

For several reasons:

o The L-1011 has two alternate gear extension systems.

1. Manual system which uses cables release the locks. No electronics.

2. Alternate hydraulic system that powers the gear down.

When the manual release is used:

o The L-1011 main gear has no up-lock. The lock is on the door and the gear is resting on the door. Door opens gear falls out.

o When the nose gear is unlocked the gear gaps the forward doors and aerodynamics and gravity take over and the nose gear falls out.

When the alternate hydraulic system is used: system pressure in ported to the extend side of the retract cylinder powering the gear down.

[Antek22QR]

Below is a statement given by "Boeing" in relation to "the use" of circuit breakers by flight crews (during the 2004 Flight Operations Symposium, May 9 – 12, 2004, Bell Harbor Convention Center):

Flight crews are not trained in circuit breaker location or use. In many cases, circuit
breakers are installed in different locations on different airplanes within a model. Circuit
breakers are not designed to be switches; this impacts life expectancy of the circuit
breaker. The flight crew is not always in a position to easily reach circuit breakers. In
addition, the circuit breakers themselves are not necessarily clearly and uniformly
labeled. Boeing is also concerned that if the crew becomes habitualized to using circuit
breakers they will eventually use them in a situation they should not use them.

[silverstrata]

Chyla says he now credits God, as well as Capt. Tadeusz Wrona and his crew, for the safe landing that some in Poland have hailed as miraculous.



This Goddy guy must be a complete wally. If he/she/it was going to spiritually intervene, why did he/she/it not just make the gear come down?? I don't know, as far as omnipotent deities go, this one must have come from the bargain-basement department. Trust us to get the retard of the Universe to oversee us.



BTW - I thought the best comment came from the captain. The aircraft came to a rest on the runway intersection, and completely closed the airport. So the captain mused: "If we had wheels-up landing distance tables, we could have cleared the cross runway.....". Nice thought, Capt Wrona, nice thought.


.

[fireflybob]

Chyla says he now credits God, as well as Capt. Tadeusz Wrona and his crew, for the safe landing that some in Poland have hailed as miraculous.


Somebody needs to relate this story to him!

A farmer is in Iowa during a flood. The river is overflowing, with water surrounding the farmer's home up to his front porch. As he is standing there, a boat comes up, The man in the boat says "Jump in, I'll take you to safety."

The farmer crosses his arms and says stubbornly, "Nope, I put my trust in God."

The boat goes away. The water rises to the second floor. Another boat comes up, the man says to the farmer who is now in the second story window, "Jump in, I'll save you."

The farmer again says, "Nope, I put my trust in God."

The boat goes away. Now the water is up to the roof. As The farmer stands on the roof, a helicopter comes over, and drops a ladder. The pilot yells down to the farmer "I'll save you, climb the ladder."

The farmer says "Nope, I put my trust in God."

The helicopter goes away. The water comtinues to rise and sweeps the farmer off the roof. He drowns.

The farmer goes to heaven. God sees him and says "What are you doing here?"

The farmer says "I put my trust in you and you let me down."

God says, "What do you mean, let you down? I sent you two boats and a helicopter!!!"

[Airbubba]

When the manual release is used:

o The L-1011 main gear has no up-lock. The lock is on the door and the gear is resting on the door. Door opens gear falls out.

o When the nose gear is unlocked the gear gaps the forward doors and aerodynamics and gravity take over and the nose gear falls out.

Isn't 767 alternate operation very similar with mains resting on the doors and nose gear uplock released to push the doors open mechanically? This sort of detail used to be in the pilot manuals but they have been dumbed down in recent years to expedite training and keep us from thinking too much.

There is no alternate hydraulic gear operation on the 767 as far as I know so the TriStar has the customary extra Lockheed redundancy (and complexity, those planes sure have a lot of electrical busses and hydraulic systems).

[Ronald]

I believe that the Alternate switch operates an electric motor beneath the flight deck floor that operates cables connected to the uplocks. On the ground the main door locks can be released individually by using a manual lever accessed via hatches under the aircraft (aft of the undercarriage doors?). These levers when operated manually operate the release cables. Perhaps an engineer can confirm.

[Mac the Mechanic]

Yes can confirm that is the case, the nose gear is unlocked by a cam on the same actuator.
Just a note some 767's (the 400) do have hyd alt system same as the 757

Just like to add great landing lets hope it was'nt due to pilot error in the first place

[Airbubba]

I believe that the Alternate switch operates an electric motor beneath the flight deck floor that operates cables connected to the uplocks.

And for the mains at least, as in the L1011, there are no uplocks on the 767 gear, they rest on the doors. When the door uplocks are released, the main gear falls down and (hopefully) locks.

[cat3autoland]

I am a bit confused by all the posts on "holding" a c/b in. The alt l/g c/b on the 767 is a trip free c/b. If it pops and the condition that caused it to pop still exists, the c/b can not be held in to force power into the circuit. If the fault is still there, the c/b will pop again regardless of the position of the actuating button. The danger in doing a reset is that power will be introduced into a circuit that may have a fault and during the time it takes for the c/b to react, a severe reaction "could" take place.

[Ratso18]

It is possible, but highly unlikely. Center hydraulic systems controls normal gear extention/retraction. Can 'free-fall' gear as long as you retain some main battery power. The fact that the tail-skid was shown extended tells me the handle was in the down position (it goes up and down with the gear handle). It will be interesting to hear what issues this aircraft had. Don't believe that has ever been a 767 gear up landing in its 25+ year history.

[OilCan]

Any tech types,

What holds the tail skid up if there's no pressure?

[763 jock]

If my memory serves me right, we had a 763 that was losing centre fluid on every sector. When it was topped up on the ground and tested, no leak could be found. There was no evidence on the airframe of where the fluid was leaking from and eventually it went into the hangar for further investigation.

It was jacked up and gear swings carried out. In the end, it was found that the tailskid was leaking, but only when "in the air". Apparently, hydraulic pressure is applied in flight to keep it retracted.

This was a few years ago, but I think the details are correct. Certainly foxed everyone for a while at the time.

[Airbubba]

The fact that the tail-skid was shown extended tells me the handle was in the down position (it goes up and down with the gear handle).

Well, actually, with alternate gear extension and no center hydraulics, you normally end up with the gear and gear handle down and the tailskid up at the completion of the checklist.

The handle does nothing for the alternate extension itself without hydraulics but you lower the handle after the gear is down to avoid the Gear Disagree (and GPWS/Config) warning. It is normal to have a Tailskid light and EICAS message with alternate gear extension since the tailskid remains up but the gear handle is down.

That's how it 'should' work. I agree with everyone who is puzzed about the gear up and the tailskid down. Did the tailskid never retract on takeoff? And was the hydraulic leak at the tailskid itself as in the incident that 763 Jock remembers? Maybe the fluid was pumped out after the gear came up through the tailskid retract mechanism, perhaps?

[Sillert,V.I.]

The danger in doing a reset is that power will be introduced into a circuit that may have a fault and during the time it takes for the c/b to react, a severe reaction "could" take place.

Not just could, but did - resulting in the loss of a Vickers Valiant on 11 May 1956.

Read about it here: ASN Aircraft accident 11-MAY-1956 Vickers Valiant WP202 (http://aviation-safety.net/wikibase/wiki.php?id=71801)

[OilCan]

763 jock

Thanks, classic leak in the up lines scenario.....foxed many people on manys an occasion.

By implication therefore, it would appear if there is no pressure the tail skid may droop. (I assume it's a fairly heafty bit of kit)

Airbubba

you normally end up with the gear and gear handle down and the tailskid up at the completion of the checklist.



surely that depends if there's pressure available or not? :confused: (even with pumps off, the pressure may still take some time to dissipate)

The handle does nothing for the alternate extension itself

If you don't open the return lines won't you create the potential for a hydraulic lock? :confused:

It is normal to have a Tailskid light and EICAS message with alternate gear extension since the tailskid remains up but the gear handle is down.



So back to my original question; What holds the tail skid up???

sounds like an oversight in your sim scenario to me.

[r75]

The MLG does not have its own uplock viz 744 but the MLG doors do.However,the gear does not rest on the doors in flight.Now as it looks like the doors were released via the ground ALT release,we may have an issue with the electrical ALT actuator.Perhaps the best option is to wait and see the preliminary report,after all,we can only make educated guess's.I am very sure that this one will not take very long to find the cause.

[Airbubba]

sounds like an oversight in your sim scenario to me.

Well, them's the procedures from Mr. Boeing. With loss of center hydraulics you do alternate gear extension with the gear handle off, then put the handle down when you get (hopefully) three green. And the tailskid does not extend, it is held up by PFM. You also hit the Reserve Brakes and Steering switch in my purely fictional Microsoft flight simulator version of the procedure which I downloaded from BitTorrent.

That's my story and I'm stickin' to it.:E

It may work different on the -400 (or the -200;)).

How could you tell I wasn't really a pilot?:{

However,the gear does not rest on the doors in flight.

It has no uplocks, it is not pressurised in flight, what holds it up?

[OilCan]

How could you tell I wasn't really a pilot?



I couldn't...thats what worries me. :\

I could tell you weren't an Engineer though.

Rem; Simulators and Lawyers understand checklists.....aeroplanes don't. :cool:

[PW2040]

The B767 main gear do rest on the gear doors when gear handle in off and no pressure in the system.

[Roo]

The main landing gear door supports the weight of the retracted main gear when the landing gear system is depressurised.
More precisely, there is a gear support attached to each main gear door. When the door closes the gear support folds under and locks the main gear. The door is held closed by the door uplock hook. When the landing gear system is depressurised the weight of the gear rests upon the gear support.
During alternate extension, the uplock hook is released mechanically and the weight of the gear pushes the door open.
It is a little more sophisticated than the tyres resting on doors :)

WRT to the tailskid and what holds it up. C HYD pressure does.
It has no uplocks, it is not pressurised in flight, what holds it up?

Incorrect, Unlike the gear, it IS pressurised in flight. The retract pressure is maintained by the centre system with the tail skid retracted as the control valve is in the same position with the landing gear lever UP or OFF.

[jamesbond6]

In Polish: Awaria Boeinga mog (http://www.tvn24.pl/12690,1723337,0,1,awaria-boeinga-mogla-nastapic-zaraz-po-starcie-samolotu,wiadomosc.html)

Data in this article seem to be quite precise, so I suppose it's from reliable source (reference to unofficial information from State Commission on Aircraft Accident Investigation) and worth quoting.

According to the DFDR the failure of C HYD occured just after the retraction of landing gear during departure from Newark, or even at the same time. It's impossible to point the exact moment of failure as this data is recorded only once every 64 seconds. The same minute the gear was retracted there was a sudden drop in hydraulic pressure from 3000 to 400 PSI and 90% of the fluid (3 out of 40 gallons remaining) apparently leaked out to some "hatch" in the aircraft.

Indeed, the circuit breaker had been found tripped by LOT engineers, but it was possible to press it into proper position during the first attempt and that is how the landing gear was extended on ground. Finding out the exact moment when the CB tripped might be tricky (no such data on DFDR), but hopefully entirely possible using the memory of certain individual units (any ideas on this one?).

[MurphyWasRight]

Indeed, the circuit breaker had been found tripped by LOT engineers, but it was possible to press it into proper position during the first attempt and that is how the landing gear was retracted on ground.


Before jumping to conclusions about the circuit breaker not being reset in flight rememeber that -something- caused it to trip in the first place and
whatever that something was may well have been jarred loose during the landing.

JB6: BTW, this is meant for general consumption, not at all saying you implied anything - or that the landing was not amazingly smooth given the conditions.

[763 jock]

The CB that controls the ALTN landing gear is located on the sidewall behind the F/O's seat. As such, it is in a vulnerable area with regards to things like passing nav bags, overnight bags and the usual stuff that lives on the floor. I have come across "tripped" breakers in this area during pre-flight on more than one occasion. It is also close to a 115V AC outlet.

It would be very bad luck if it was out due to a bag moving in flight or being snagged by a cable. Unlikely, but not impossible.

[Airbubba]

I could tell you weren't an Engineer though.

Fair enough!;) Anyway, it may defy logic but I think I have correctly described the gear handle operation in the alternate gear extension checklist. Do you have another version of this checklist, perhaps?

Rem; Simulators and Lawyers understand checklists.....aeroplanes don't.

Well, we pretty much have to go by the book and the checklist from the operator side of things. And I agree with you that some of this stuff is fit for an attorney. The FAA and Boeing have been trying to go to 'integrated checklists' for systems malfunctions, e.g. if you lose C HYD, you will have to do alternate gear and flap extension so the procedures are rolled into one big checklist rather than having you hop around the QRH.

Earlier, even though you knew normal operation would not work, you would position the gear or flap controls, get a 'Disagree' light and it would lead you to a separate checklist with double negatives and other challenges for each inoperative item on the lost hydraulic system.

The new integrated checklists have a laundry list of other checklists that you don't do, e.g. the 'Tailskid' checklist with loss of C HYD since it is an expected indication with the gear handle down and no center pressure.

The main landing gear door supports the weight of the retracted main gear when the landing gear system is depressurised.
More precisely, there is a gear support attached to each main gear door. When the door closes the gear support folds under and locks the main gear. The door is held closed by the door uplock hook. When the landing gear system is depressurised the weight of the gear rests upon the gear support.
During alternate extension, the uplock hook is released mechanically and the weight of the gear pushes the door open.
It is a little more sophisticated than the tyres resting on doors

Thanks for this explaination, I appreciate it.:ok:

Incorrect, Unlike the gear, it IS pressurised in flight. The retract pressure is maintained by the centre system with the tail skid retracted as the control valve is in the same position with the landing gear lever UP or OFF.

I was actually referring to the gear being unpressurized during flight but I didn't realize that the tailskid stayed pressurized, it sure increases the possibility that the leak was there it seems.

Years ago I did a crossing with the tailskid MEL'd. Seems like we took a couple of thousand pound performance hit on the runway limit weight and maybe a couple of percent on the fuel burn. The tailskid was locked down, maybe it was pinned somehow, it's been quite a while since we did this.

[VNAV PATH]

Thanks for polish press link above given by jamesbond6


I have a question :


Flaps geometry as shown on the link shows aft flap gapped with the main flap .


As this aft flap is moving as soon main flap moves beyond 20 ° , and as alternate flaq sequence is limited to 20 ° , I see quite an technical contradiction ..

Any comments ?

[763 jock]

The centre hyd system failure QRH calls for ALTN flap and gear. If this runs to plan, flap 20 is used for landing. However, if you look at the "Gear Disagree" QRH, you are advised to land on available gear. In that case, flap 30 is required to reduce the Vref.

[r75]

Perhaps I was a little simplistic in my explanation, Roo is quite correct.In fact there have been cases of the MLG hanging up on the doors during swings testing the Alternate Extension.Fortunately we have never encountered this doing swings.As they say, a picture is worth a thousand words,I wish our MLG bays were that clean too!

Boeing 767 - teste trem de pouso - landing gear test - YouTube

[Chu Chu]

006,

I'm just SLF, but retracting the gear on the ground doesn't seem like a very good idea, somehow. :hmm:

[SadPole]

The hydraulics failure was detected 30 minutes after takeoff and the pilot considered returning to Newark. But, after contacting the HQ the "technical engineers" on the ground made the decision that they cross the ocean.

The decision was probably correct but it brings us back to the usual post-commie block topic of who makes the final decision on issues like this one - the pilot or some ground "specialists" or politicians breathing down your neck.

[r75]

Its standard practice to function check gear operation on the ground after a gear main component change,the aircraft is either on jacks or jacks and wheel pit.As for worrying about retraction whilst standing on main gear,that is why you install "the pins" in the downlock links and sign for it in the Tech Log.Should someone select "gear up",the pins will not allow the downlock links to fold.

[Stuck_in_an_ATR]

@ Sadpole

Consulting one's own airline in such cases has nothing to do with communist mentality, as you suggest. In fact it is standard practice in all airlines I know - the tech staff on the ground have better knowledge of the aircraft's systems than the flight crew, access to documentation etc. and usually are able to provide invaluable advice to the crew. However, the final decision lies with the commander and he may continue, or divert wherever he sees fit. Period.

Besides, all the data presented so far suggests that the decision to continue to the destination had no impact on the (in)ability to extend the gear and in fact, had been the most sensible in the circumstances and in line with the basic concept of triple-redundant systems (such as 767 hydraulics), which allows to continue safe flight in case of single failure...

[radken]

r75

Have seen a/c sitting OG in mx with hydraulics on and w/o "safe'd" gear handles, i.e., "tagged." Have seen other techs working other systems run tests requiring movement of same handles, and w/o checking gears for pins or even asking around. Result? Nose goes to ground with surprising ease, noise, embarrassment, and, why sometimes, even causing a delay. Can't speak for 767 tho. As for the mains? The unlock would actuate, but the over center can't move. Something about 100 plus tons of weight just being a little too much for even 3500 psi to lift up and get those tires sliding.

[r75]

If you were to perform a retraction function on the ground in a 74 without the pins in (heaven forbid),you would be well advised to not only keep away from the NLG but also the BLG.You need to perform this function to bleed various components you have changed in the Landing Gear actuation systems,not to mention leak checking.Apologies to all concerned for thread drifting.

[Christodoulidesd]

LiveLeak.com - Boeing 767 - Warsaw - A few days later.

[Lost in Saigon]

An Air Canada 767 that ran out of fuel, commonly referred to as the Gimli Glider, couldn't get it's nose gear to extend during 'free-fall' extension, due to the strong airflow. It landed on its mains and its nose. As a result the tail stuck way high in the sky when the plane came to rest. The slides were almost vertical, and that's where most injuries were sustained during the evac.

Incorrect. The B767 nose gear extends down and rearward, so extension is AIDED by strong airflow.

Alternate Gear Extension is done with the lever in the OFF position.


http://i2.photobucket.com/albums/y17/msowsun/_1f.jpg

[stepwilk]

It's true that people were injured on the Gimli Glider's slides because the nosegear didn't come down and the tail therefore was elevated, but if the nosegear -had- come down, there would have been far greater carnage because the airplane would have rolled into the autocross crowd on the ostensibly closed runway. With the entire nose on the concrete, the airplane was dragged to a stop far more quickly.

[Jeeper]

The Gimli Glider nose gear did extend as per the alt extension procedure. The first indication of trouble was when the nose was lowered after landing and it lowered beyond what the pilots expected. The contact with the runway was described as akin to a shotgun blast beside your ear. Boeing were, in a perverse way, happy to find out that that the over center lock on the nose gear was not aligned properly. This problem was corrected on the assembly line and the aircraft in line operations and problems solved. BTW the cockpit indication on landing in Gimli was "three greens".

[Lost in Saigon]

The Gimli Glider nose gear did extend as per the alt extension procedure. The first indication of trouble was when the nose was lowered after landing and it lowered beyond what the pilots expected. The contact with the runway was described as akin to a shotgun blast beside your ear. Boeing were, in a perverse way, happy to find out that that the over center lock on the nose gear was not aligned properly. This problem was corrected on the assembly line and the aircraft in line operations and problems solved. BTW the cockpit indication on landing in Gimli was "three greens".

Are you saying that up to that point in time all B767's had a design flaw which would prevent a successful alternate gear extension if it was needed?

This is the first time I have heard this. Also please explain how it is possible to get "Three Green" if the nose gear is not locked down.

EDIT: This link says they did not get "Three Green": Gimli: A Race to the Finish (http://flatrock.org.nz/topics/flying/gliding_into_infamy.htm)
Pearson ordered a "gravity drop" as Pearson thumbed frantically through the Quick Reference Handbook, or QRH. Quintal soon tossed the QRH aside and hit the button to release the gear door pins. They heard the main gear fall and lock in place. But Quintal only got two green lights, not three: the nose gear hadn't gone over centre and locked, despite the "assist" it was given by the wind.

[Mr @ Spotty M]

I thought that the reason the nose gear retracted on the landing run was because the gear lever was left in the off position.
Not sure if the procedure at that time failed to list gear lever in down position after getting the three greens.
You need to remember this happened very soon after the B767 entered service.

[Self Loading Freight]

As SLF with some experience of fault-finding in complex systems, albeit noncritical ones, I think the crew acted very well. Given the fault occurred practically at take-off, was intimately connected with gear movement and didn't seem to be symptomatic of wider problems, the probability is that it wouldn't affect the flight until landing. Thus, taking as much time as possible to fix it is sensible and continuing to the destination while running through diagnostics and taking advice over the blower is eminently sane.

I agree completely with Mr Boeing in that a popped CB should stay that way, through experience of my own in blowing expensive things up. Given that the crew was in contact with tech support, it seems very unlikely that the CB being popped went unchecked or unknown - with all that time in hand, you have the luxury of going into as much detail as you like short of actually disassembling the gear.

Also, it is very hard to imagine that the flight crew lacked the motivation or skills to do a proper investigation of the problem; unless it was a very dysfunctional cockpit indeed with terrible CRM and a nutsoid skipper, I can't see any of the factors present which normally couple bad decisions to bad outcomes.

More information may render any or all of the above moot, of course, and the thoughts of a Sunday afternoon non-pilot are worth the pixels they're written in, but I'd fly across the Atlantic with that crew as happily as I'd down a shot of Żubrówka.

[boskee]

A preliminary report will be released online on Thursday. According to a member of the commission, the incident was caused by a knocked breaker used by several systems and "located at the bottom, near the first officer's seat", but neither the crew nor manufacturer knew that it may affect gear extension system.

Source (http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://www.tvn24.pl/12690,1726036,0,1,wstepny-raport-ws-ladowania-boeinga-piloci-bez-winy,wiadomosc.html&usg=ALkJrhirB6lCJ71G3ziekQIHALTPgPLaLQ)

[stilton]

A 'knocked circuit breaker'


Not sure what is meant by that and I can't pretend to fully understand the translation in the article.


However, if a circuit breaker was found to be out after being unable to extend the gear I fail to understand why they would not reset it.


It does remind me, however that the ancillary / additional functions of circuit breakers on the 75 /67 are not all known to the crew.


For example, did you know, on the 757 if you pull and then reset the 'speed card' circuit breakers for the left and right side simultaneously you will extend the RAT ?



One of our crews did this half way across the Atlantic,after both speed cards (vertical IAS tape on the left side of the PFD ) failed and displayed a flag




In attempting to restore operation of these instruments they reset the speed card cb's after which the RAT immediately dropped, much to their surprise.



Apparently this is how maintenance tests the operation of the RAT but no one thought to tell the Pilots.

[Capn Bloggs]

nor manufacturer knew that it may affect gear extension system
I find that a bit hard to believe.

Apparently this is how maintenance tests the operation of the RAT but no one thought to tell the Pilots.
Did the QRH tell the pilots to cycle the Speed Card CBs?

[JeV]

Preliminary report (Polish)

http://doc.rmf.pl/rmf_fm/store/Boeing_raport.pdf


circ. braker C829 BAT BUS DISTR (pos. A1) was found in OFF position after landing
circ. C4248 LANDING GEAR – ALTN EXT MOTOR was ON


C289 is also breaking alternate systems of alternate gear ext. (pict. from Boeing manual on page 5)

C829 in OFF pos. is not indicated on FRD & EICAS

[NotaLOT]

Some photographs from the preliminary report - showing also a "popped" circuit breaker.

Upubliczniono wst (http://wiadomosci.gazeta.pl/wiadomosci/51,114883,10739317.html?i=0)

[jamesbond6]

The actual report in English:

http://www.transport.gov.pl/files/0/30680/20111400RWenglish.pdf

[aviatorhi]

As an FE I find it amusing (in an anti-comedic way) that they did not think to check ALL CBs (not just directly related CBs) when experiencing a fault.

Though I am willing to bet some will still say that even if it had been found the wheels up landing was the "safer" alternative to resetting/holding the CB. :ugh:

[gopher1]

As an FE I find it amusing (in an anti-comedic way) that they did not think to check ALL CBs (not just directly related CBs) when experiencing a fault.In recent interview Captain claims that all circuit breakers were checked twice, and none was found popped.

[SadPole]

1. No procedure in current-production airplanes calls for the pulling (and resetting) of any CB's

2. Flight Crew reset of tripped fuel pump control circuit breakers in flight is prohibited. Reset of any other tripped circuit breaker is not recommended unless in the judgment of the Captain, the situation resulting from the circuit breaker trip has a significant adverse effect on safety. These other tripped circuit breakers may be reset once, after a short cooling period (approximately 2 minutes).

Source:
http://www.ukfsc.co.uk/files/Safety%20Briefings%20_%20Presentations/Manufacturers%20-%20Boeing%20Circuit%20Breakers.pdf


Very precise and sane. One cannot start a fire on a plane by resetting a tripped circuit breaker once. One can only do it by burning out wiring by resetting repeatedly/holding in a CB that's being tripped by a shorted out component.

Now the amusing part is that the crew already got a medal for bravery, so it will be a political problem if they are found to have overlooked this little thing.

Don't you just love it when the politicians get involved in these things even before the preliminary report is issued.

[aviatorhi]

In recent interview Captain claims that all circuit breakers were checked twice, and none was found popped.

Well... none was found popped, but it doesn't change the fact that it should have been found.

[eprn1n2]

Had the opportunity to look at cockpit indications in a 767-300ER simulator. With c/b C829 BAT BUS DISTR popped, there are no adverse indications in the cockpit (e.g. no EICAS messages present). Essentially you wouldn't know this c/b was popped unless you physically looked at it and saw it out.

I then took the liberty of putting the simulator at cruise, failed the center hydraulic system, and pulled the C829 BAT BUS DISTR c/b. Incidentally, the gear handle was inop (as expected w/ a ctr hyd sys failure). The ALTN EXT function of the landing gear was inop as well. I then pushed the c/b back in, kept the center hyd sys failed, and the gear dropped when I selected ALTN EXT a second time.

In other words, SP-LPC operated as designed.

[aerobat77]

it cannot be excluded that the cb popped during landing, why ever.

the fdr does not report its position, but on the cvr the investigation should hear if discussion and checking of the cb,s was made.

i must say its doubtful that at this overall very good managment of this situation they forgot such a thing like checking the cb. but the devil is sometimes in the little things. it would be insane when the conclusion is that he finally settled the 767 down without gear due to a simple popped cb.

what can be said: after lifting the plane and resetting the cb on ground the alt gear worked and the gear came down :uhoh:

[Self Loading Freight]

Is it possible that the CB popped electrically but didn't show mechanically until jarred during the landing?

It seems most unlikely from the CBs I've disassembled in the past, but I don't know anything at all about the design of the ones used on the 737. If the shaft of the button was sticking in its collar and the mechanical action that broke the contacts wasn't enough to overcome that... all depends on the design.

[Chu Chu]

Maybe there was an overload in another piece of equipment powered by the bus, tripping the breaker and preventing it from being (or staying) reset in flight. That piece of equipment might have been shut down by the time the breaker was reset on the ground. Of course, that doesn't exactly square with the reported interview with the Captain . . .

[aviatorhi]

I've said it before, and I'll say it again, there is a severe lack of basic airmanship at the transport level these days. Regardless of what your procedures guide you to do, you are dealing with matters of life and death, anyone who does not go out of their way to check every single CB (particularly with over an hour of holding involved) with a major malfunction in an electrically powered item, and attempt to troubleshoot a problem this severe with "systems knowledge" after the book ends (I say "ends" because there is no official procedure, which I've seen, for ALTN GEAR EXT FAILED) does not belong on the flight deck. Following the book into the side of a proverbial mountain is not acceptable to me, no matter how anyone would like to justify it.

Even if it was another piece of equipment which was causing the fault in that particular distribution bus, company MX would have had access to the wiring diagram and listing of all associated items with the CB. I'd say pull them all until you can get the gear dropped. They were particularly lucky the winds were calm and the visibility was clear. If it hadn't been so the outcome would probably have been vastly different.

Bottom line, this incident is reminiscent of the Eastern L1011 in the Everglades, though thankfully it did not result in a loss of life. But goes to show how a $10 piece of equipment working incorrectly can contribute to/cause tremendous damage.

[Mac the Mechanic]

Bottom line, this incident is reminiscent of the Eastern L1011 in the Everglades, though thankfully it did not result in a loss of life. But goes to show how a $10 piece of equipment working incorrectly can contribute to/cause tremendous damage.

Having worked the B767 for quite a few years, i have been called to look at system faults by outbound crews that were not reported by inbound crew or the engineers doing the turn. In this situation first thing to do is ask what they touched then check the CB's and on many occasions we've found CB's "popped" on that panel, usually caused by F/O putting his flight bag in to the stowage area (esp if the company has not fitted the metal bars or plastic guards) What we could do with is some sort of monitoring system:rolleyes:

[grebllaw123d]

Chu Chu,

You wrote:

Maybe there was an overload in another piece of equipment powered by the bus, tripping the breaker and preventing it from being (or staying) reset in flight. That piece of equipment might have been shut down by the time the breaker was reset on the ground.

Not very likely, as you by studiing the picture of the CB panel and the system schematics in the preliminary report will see that the CB A1 BAT BUS DISTR is a 25A CB, protecting mainly low power consumers (control systems mostly).
On the picture several CBs associated with these consumers may be identified and their ratings are 1,5 or 2,5A. (Enlarge the pictures).
I find it very remote that consumers of this size would be able to trip a 25A CB - in any case a possible overload in a system should (normaly) trip its own associated CB.

Possible reasons for the trip could be:

- Faulty CB.
- External interference - the CB is situated in a rather exposed position close
to the floor.

I wonder what advice the LOT maintenance gave to the crew.

This accident ought not to be a big puzzle for the investigation board.

[aviatorhi]

on many occasions we've found CB's "popped" on that panel, usually caused by F/O putting his flight bag in to the stowage area

Makes my point quite well, MX should not be being called by the flight crew when they haven't even bothered to check the CBs.

[Capn Bloggs]

Makes my point quite well, MX should not be being called by the flight crew when they haven't even bothered to check the CBs.
What a ridiculous statement. Instead on ranting on about bad airmanship, Perhaps you should ask: Why didn't Mx say "are you absolutely sure that CB is in? That's the only thing stopping the alternate gear extension". Aviatorhi, the ace from aerospace...:cool:

[Roo]

What a ridiculous statement
+1

AviatoRhetoric, lets not pass judgment on the F/C, until someone ascertains when and why the CB was popped/off shall we.

[aviatorhi]

Capn and Roo, maybe you should double check which post I was replying to.

That being said, missing a CB during an emergency situation... no excuse for that.

[Chu Chu]

Grebllaw,

Good point, though I do see several breakers (in the second row up) that look like they say 7-1/2A.

I guess another possibility might be that the 25A breaker wasn't holding its rated current, but would power the alternate gear extension motors once the other loads were disconnected on the ground. Even then, as you point out, the crew could have solved the problem by pulling the other breakers on the bus.

[LeadSled]

Folks,
A caveat on the following comment --- I have not had time to read all the posts, or the preliminary reports or reports of same, maybe the point has already been covered.

It is a long time since I was on the B767, but I clearly remember that there was a particular type of "trip free" Cb used on some systems which could only be reset with power to the circuit removed.

With one of this type of Cb, pushing in a "popped" Cb then looked like a Cb that was set/reset, but wasn't, a potential "gotcha".

Tootle pip!!

[NigelOnDraft]

A CB, particularly a "BUS" one, needs some sort of overload to trip it - and I doubt it could have been tripped long term e.g. from start of sector without being apparent (e.g. Generator controls run off it).

Some sort of coincidence that a rarely required system is used, and it's supply CB "pops". Suspect that is not a coincidence. Whether it popped immediately (in which the crew's account does not tally) or later (with Altn Gear Extension being ON for some time?).

Fine for those flying in the FE days to say "unforgiveable" etc., but the modern aircraft are supposed to be designed around no FE. In practice, training and manuals are now rather "minimal", no doubt judged "cost effective." a few things immediately spring to mind to me:

I'm a little surprised to find that circuit protected by both a Bus CB and it's own CB
Again, surprised that there is no warning, or other indication of that Bus not being powered
If you read the Tech Manual, you see reference to this Busbar. In your troubleshooting you might identify services from the same Busbar that remain powered... so a reasonable conclusion that is not the issue. Shame that in practice the busbar is split in 2, and half the "busbar" (only) protected by this CB. Thus with the CB popped, half the systems work and half don't... sounds to me like it's really 2 busbars
Accidents are rarely simple / one cause. As above, modern training also is to contact company for curious technical issues, and I am told they can get quick access to experts from the manufacturer. Failure for Gear Altn Extend to work, and nobody mentioning this CB, would indicate some sort of failure in that system.

Finally, looking at the items on that Bus, very different set of loads engines off sitting on the ground after the accident to airborne. I would not be too quick to hang the crew ;)

Edit - really => rarely - thanks!

[Roo]

...Some sort of coincidence that a rarely required system is used, and it's supply CB "pops". Suspect that is not a coincidence. Whether it popped immediately (in which the crew's account does not tally) or later (with Altn Gear Extension being ON for some time?).

This is where my suspicions lie. The Alt gear ext DC motor and actuator have a limit of two duty cycles followed by a 10 min cool down. Normally this would be no problem as the actuator takes just over 5 sec to run at which point a limit switch shuts it off. The QRH directs the crew to leave the switch in DN for the remainder of the flight. So if something precluded the actuator from moving, it cannot reach the limit switch and it will attempt to run continuously. Because it has a duty cycle, you would eventually expect a circuit breaker to trip. It could have tripped well after the crew attempted the unsuccessful ALT extension for all we know.

PS You of course meant to say "Accidents are rarely simple / one cause."

[EEngr]

"Trip free" circuit breakers typically refers to a C/B mechanism that will trip and open the circuit even if the operating handle or knob is held in the closed position. That's pretty much standard in aircraft (and many other applications).

Also, in reading through this thread, it appears that the Captain claims to have checked and found no open C/Bs. The open breakers were found some time after the landing. Its possible that with a landing such as this, a fault may have occurred and tripped something. That's not something the crew would be likely to notice at this point (what with landing the plane and kissing the ground, etc.)

[IFixPlanes]

The Alt gear ext DC motor and actuator have a limit of two duty cycles followed by a 10 min cool down. Normally this would be no problem as the actuator takes just over 5 sec to run at which point a limit switch shuts it off. The QRH directs the crew to leave the switch in DN for the remainder of the flight. So if something precluded the actuator from moving, it cannot reach the limit switch and it will attempt to run continuously. Because it has a duty cycle, you would eventually expect a circuit breaker to trip. It could have tripped well after the crew attempted the unsuccessful ALT extension for all we know.

In this case the CB C4248 (LANDING GEAR - ALT EXT MOTOR) should trip and not the CB C829 (BAT BUS DISTR).

[Bearcat]

Is LOT repairing aircraft to fly on the line again?

The cb issue is a big thing, especially with 6 and half hours of codigitating ones navel over the Atlantic before show time.

[poldek77]

Also, in reading through this thread, it appears that the Captain claims to have checked and found no open C/Bs. The open breakers were found some time after the landing. Its possible that with a landing such as this, a fault may have occurred and tripped something. That's not something the crew would be likely to notice at this point (what with landing the plane and kissing the ground, etc.)


But after reading the report - I can't find any other reason that ALTN GEAR EXT didn't work. Or have I missed something?

[fotoguzzi]

[Not a pilot] Should there have been an anticipation that the backup system would fail too?. My understanding from previous posts is that this double-failure is unique to the type and perhaps unique for all aircraft with electrically-operated backup landing gear systems.

Re: circuit breakers. (Sorry for using household terms.) The only way that I can conceive of inadvertently popping a breaker (based on the photograph only) is by hooking the "button" with the strap of a bag. Is there another way?

Also, I recognize that there is a wide variety of breaker types, but would someone please explain how many positions the "button" could be in? The most I can conceive of would be:

- Pushed in and connected
- Pushed in but internally disconnected
- Popped out a bit and disconnected
- Pulled out all the way and disconnected
- Intermediate (say from being bent or sticky) and either connected or disconnected

- [just thought of:] held pushed in by a bag or something and either connected or disconnected

Thank you.

[Roo]

...if something precluded the actuator from moving, it cannot reach the limit switch and it will attempt to run continuously.
IFixPLanes wrote:
In this case the CB C4248 (LANDING GEAR - ALT EXT MOTOR) should trip and not the CB C829 (BAT BUS DISTR).
I agree, C4248 Should have been the CB to trip. But the combined loads further upstream may have caused the BAT BUS DISTR to trip first.

[aerobat77]

@ fotoguzzi : assuming the cb by itself is ok there are only two positions : pushed in and connected or popped out and disconnected. there are no intermediate positions or possibility to disconnect electrically while physically pushed in or vice versa.

my best quess is the cb popped during first try of alt gear extension and they did not checked and tried again or truly it was popped by e.g a pilots case and they overlooked it. i doubt they forgot to look at the cb,s its one of the first things when a system in an aircraft refuses to work.

the interesting question is if they checked the cb after first try of alt gear extension or if they tried alt gear a single time and after alt gear failed just prepared for a gear up landing.

the next question is if in any case the crew can be blamed directly. does the abnormal checklist on a 767 cover the rechecking of the cb,s when alt gear fails?

when not the pilot can say- " procedures were followed, i tried alt gear, it did not work, so a gear up landing was the final result, for anything else ask the manufacturer of this aircraft and not me "

[Chu Chu]

Duty cycle limits are normally designed to prevent a motor from overheating. Not sure why exceeding them would cause a breaker to trip. Unless, of course, the motor overheated to the point where the insulation burned off the coils and caused a short. But then it presumably wouldn't have worked on the ground.

A mechanical jam that stalled the motor might cause an overload and trip the breaker, but that wouldn't be directly related to duty cycle.

[IFixPlanes]

...But the combined loads further upstream may have caused the BAT BUS DISTR to trip first. ...
C829 = 25 A and C4248 = 7,5 A.
I could say it politely: Maybe possible,
but when i must be honest: NO !

[IcePack]

Bet it was left tripped by engineering after their work. Difficult breaker to see especially if bags papers giraffes & whatever other toot gets piled around cockpits these days.
But every breaker should be looked at intently.

[IFixPlanes]

... Bet it was left tripped by engineering after their work. ...
I bet you are a pilot :E

[aviatorhi]

I bet you are a pilot

Adding on to that...

How would the generators have closed onto the busses with that CB tripped? Since the CB in question controls those (and a large portion of the other, if not all, electrical control units) as well.

IMHO everything is pointing to a CB trip of C829, probably at the activation of the ALT GEAR extension sequence.

I suspect the final report will say the crew failed to identify the C829 as tripped and was unable to resolve that resultant issue in flight (including in discussion with MX).

Even if it tripped but not popped and was "jarred" loose during the "grind-out", as some have suggested, I would still be surprised that a basic "cycling" of the breakers was not done when dealing with an issue as severe as this.

To each their own though, I guess my "archaic" techniques learned as an engineer don't have a lot of room in the age of EICAS.

[OilCan]

...I'm reminded of a quote from a grizzled old FE.

One of the less obvious benefits of the old 3 man Flt Deck was the fact that Pilots and Engineers (FEs) were trained differently which could produce a parallel and complementary approach to problem solving and priorities.

Given a telescope, a Pilot would naturally look through it, an FE would look at it.......
.......then make sure the Pilot was looking through the right end. :ouch:

[Iceheart]

Duty cycle limits are normally designed to prevent a motor from overheating. Not sure why exceeding them would cause a breaker to trip.

In fact, this is possible with certain types of DC motors. Overheating may cause permanent magnets to lose some of their strength (way before reaching Curie point when magnets turn into a paperweights), which may cause motor to stall under less than rated load - and then overcurrent protection device will trip, be it a circuit breaker or something else. I've observed this many times while doing servo drive programming. Normally, a thermal protection - if it exists - should kick in earlier, but under certain conditions it is perfectly possible.

[suninmyeyes]

A couple of points interest me.

Will it be worth spending millions on repairing the aircraft which at 14 years of age and with 80,000 flying hours is about 2/3 into its useful life?

I wonder how the flight crew will be handled and if they are back flying yet. LOT may decide the crew have done a great job of the landing and it all depends on whether management regard missing the popped cb as a minor error that any crew might have made or an extremely serious one. There will doubtless be a big debate on whether they did well or not.

It reminds me a litle of the Air Transat glider into the Azores. The crew did a great job of the deadstick landing and saved the plane but might have managed the circumstances that led to it a bit better.

I hope they keep their medals and jobs.

[Serafim Kamoutsis]

Today ( Dec. 07. 2011 ) i was hearing that a c.b. found poped- up on the lower panel behind the pilots !

[FA10]

Wow - really? You are quite up to date... :ouch:

[emmatabby]

"Bet it was left tripped by engineering after their work..."

Pure rubbish. Do a bit of research and find out which systems are powered by the popped c/b. Then, do a bit more research and determine when these different systems are used in the course of operating the aircraft. You will clearly be able to determine that the c/b popped AFTER a certain point in time.....and this point in time was after the flight crew was operating the aircraft.

You wont be able to determine why it popped or exactly when it popped but it should be clear (and easy to determine) that it popped AFTER the aircraft was configured for flight.

[Antek22QR]

According to rumours from "credible" sources in Warsaw,
LOT's B767 SP-LPC won't be repaired.
Although it would have been, apparently, possible to repair the damaged structures relatively cheaply, neither engine can be repaired economically.

[glhcarl]

neither engine can be repaired economically.

They can't be replaced?

[glhcarl]

Bet it was left tripped by engineering after their work.

Standard procedures for maintence is to tag a breaker when it is pulled. The tag should contain who pulled it and why.

[exeng]

Standard procedures for maintence is to tag a breaker when it is pulled.

Might be SOP's for maintenance, but I'm sorry to say as an ex Engineer that SOP's are not always followed.

Not saying this was the case in this incident of course - how would I know - but the possibility is there.

Despite that, the responsibility for checking CB's rest with the Crew before flight and also when a system fails (easy to overlook in the heat of the moment I might add)

[grounded27]

I wonder how the flight crew will be handled and if they are back flying yet. LOT may decide the crew have done a great job of the landing and it all depends on whether management regard missing the popped cb as a minor error that any crew might have made or an extremely serious one. There will doubtless be a big debate on whether they did well or not.

May be a horrible truth what you are saying but why does this crew not deserve the same respect as sully in the Hudson for performing a perfect PERFECT gear up landing resulting in NIL casualties? Sully and crew were (well he did have less time to prepare) subject to a potential disaster as were the LOT crew. Below a news clip in honor of the gentlemen who did their job well!

[quote]
President Bronislaw Komorowski (http://www.seattlepi.com/?controllerName=search&action=search&channel=news&search=1&inlineLink=1&query=%22Bronislaw+Komorowski%22) expressed his heartfelt thanks to the crew and the ground workers "on behalf of all Poland, which held its breath while watching the dramatic developments."
Komorowski said the pilot's skill and expertise saved many lives, but also gave the Poles a powerfully "positive" outcome.
The LOT airlines plane carrying 231 people from Newark, New Jersey made the emergency landing Nov. 1 after its landing gear failed to open.
Komorowski decorated the crew members and representatives of airport ground and rescue services with medals. Among them was pilot Capt. Tadeusz Wrona (http://www.seattlepi.com/?controllerName=search&action=search&channel=news&search=1&inlineLink=1&query=%22Tadeusz+Wrona%22), who became an instant hero in Poland, who was awarded the Officer's Cross of the Order of Poland's Rebirth.
Wrona and co-pilot Jerzy Szwarc (http://www.seattlepi.com/?controllerName=search&action=search&channel=news&search=1&inlineLink=1&query=%22Jerzy+Szwarc%22) landed the plane so carefully that some passengers thought it had landed on wheels until they saw smoke, fire and sparks. Emergency workers immediately doused the plane and nobody was hurt.


Read more: Poland honors crew who made safe emergency landing - seattlepi.com (http://www.seattlepi.com/news/article/Poland-honors-crew-who-made-safe-emergency-landing-2256133.php#ixzz1gvw1HJMD[/quote)]

Seems to me they are to be handled very well!

[punkalouver]

May be a horrible truth what you are saying but why does this crew not deserve the same respect as sully in the Hudson for performing a perfect PERFECT gear up landing resulting in NIL casualties?

Seems to me they are to be handled very well!

Because the USAir crew had no engines over the middle of a huge city all of a sudden at low altitude. An immediate decision was made that led to a successful ditching.

This crew had all kinds of time to deal with their problem. Time will tell if it was handled properly. There appears to be potential for it looking like an aircraft writeoff due to a popped CB, but that is only speculation at this point(with solid reasoning for that speculation).

However it turns out, this thread is a good reminder to never assume that a second failure happened because of an earlier failure.

[Green Guard]

Because the USAir crew had no engines over the middle of a huge city all of a sudden at low altitude. An immediate decision was made that led to a successful ditching.


...or was it "over huge bay or river " rather then above "middle of huge city" ?

[punkalouver]

...or was it "over huge bay or river " rather then above "middle of huge city" ?

Either way, they had no airport options and extremely little time.

[aviatorhi]

I'm no "Sully-a-holic" like some, but guess the difference is (in metaphor format);

The US Airways crew were driving along and suddenly found themselves hurtling at a brick wall with 2 seconds to figure out what to do, yet managed to avoid it.

The LOT crew were driving along, just the same, and received a few text messages and roadside alert that there was a brick wall several hundred miles away and to be ready for it. Yet, somehow, they still managed to :ugh: right into it (as far as the initial report makes it seem at this time)

Just because they were LUCKY enough to not kill or injure anybody does not mean they did an excellent job. If so much as one person ended up in the hospital and/or died due to this landing their heads would be rolling over the CB instead of receiving "medals".

[Green Guard]

suddenly found themselves hurtling at a brick wall with 2 seconds to figure out what to do, yet managed to avoid it.


I am not so sure that "they avoided it", they went right through that "brick of wall"...
now if they were in IMC or if that "brick of wall" consisted of sparrows, okey.
but to hit the whole formation of huge geese ... on initiall climb speed.... in good VMC
I mean helloooo...!

[stepwilk]

but to hit the whole formation of huge geese ... on initiall climb speed.... in good VMC. I mean helloooo...!

I'm guessing you've never even flown a Cessna. Ding ding ding...back you go to the keyboard.

Oh, and by the way, what's a "brick of wall"?

[Bearcat]

Is the aircraft an economic write off or is it being returned to service?

[TURIN]

Standard procedures for maintence is to tag a breaker when it is pulled. The tag should contain who pulled it and why.

Never heard of that one before. It's certainly not standard practice anywhere I've been.

Good idea though.

Normally if a breaker is pulled it is flagged and either a log entry made or job card raised to reset it.

But, as has been said, in the real world SOPs are not always adhered to are they.

[readywhenreaching]

Is the aircraft an economic write off or is it being returned to service?

According to this thread (http://www.forum.spotter.pl/losy-sp-lpc-po-awaryjnym-ladowaniu-t12261/index.html?), there is a strong tendency towards scrapping.
Insurance value and repair cost calculations considerations made it unlikely that the 14year old airframe will return to the skies, if I conclude the polish translations correctly..

[rmiller774]

I'm not sure I understand why some say that this crew had lots of time to fix the problem. As I read this thread the crew didn't know that they were going to experience a problem with lowering the gear at WAW until they tried to do so on final. They then had only 1+ hour to try to solve this "new" unexpected problem because they ran low on fuel and were forced to land with gear up. Puzzled.

[aviatorhi]

If you can't find a popped CB in one hour you must not be able to see anything past the tip of your nose.

[Flightmech]

TURIN,

In our company we have white circuit breaker labels (approx 2" by 1.5") which have cut outs to clip around the c/b when it is temporarily pulled for mx purposes. You can also write a name/reason on them and they can't really be missed.

[Check Airman]

Surprised this hasn't been posted yet. It seems that the alternate extension CB had popped.

http://www.transport.gov.pl/files/0/30680/20111400RWenglish.pdf

[aviatorhi]

Check by post 317.

[RedFoxy_PL]

The Interim Statement (http://www.transport.gov.pl/files/0/30651/20111400InterimStatementAccidentNo14002011B767SPLPC.pdf) was published on SCAAI website.

[Espada III]

So, it was a simply a switch in the off position. Now comes the hard question - Why?

[Clandestino]

Why some around can't tell a difference between a switch and a circuit breaker, was that a question?

Seems that contributing factors were checklist not calling for CB check and popped CB being unmonitored by EICAS. Take note and learn.

[BOAC]

A little slack, eh?

Espada claims zero technical knowledge of a/c systems. This forum is open to all.

Semantically a CB could be defined as as 'switch' ie you can make or break the circuit with it.

Bigger fish to fry than a poster?

[Espada III]

Clandestino -

Most CBs do look like switches - have you looked in your house's (inaccurately named) fusebox recently?

[Clandestino]

Of course it is open to everyone but it is still called Professional Pilots Rumour Network. Those having luck to fly last couple of years have emphatically being told that CB is not designed to operate as switch and must not be used as such - maintenance cutting the supply of the MELed item by collaring the CB notwithstanding. A little that I know about 767 enables me to categorically state that my house is nothing like it. Hopefully the final report will make it clear what was the position of popped CB, why it wasn't not monitored by EICAS, what was the LOT's policy regarding the CBs, how come no one either in the aeroplane or on the ground remembered to suggest checking CBs, why Boeing didn't include "check CBs" in checklist, etc.

Check CBs. It might result in large cost savings.

[ATC Watcher]

Interesting reading . Aside from the recommandations on the Check lists. the one (4) about protecting CBs from shoes , flight bags etc, is an old story . But in the aircrfat I flew at least , CBs were push/pull type .( you pull a CB to cut it off and for those that need to be off , a removable colored plastic ring prevents them to be accidentally pushed .)
Is this not the case in Boeings 767s ? just curious.

[BOAC]

make it clear what was the position of popped CB - I don't think there is much margin for confusion in the interim report on that? On a quick skim, however, I could not see an explanation as to why. I'm not sure we should expect CBs to be 'monitored' by EICAS on a/c of that vintage.

[TURIN]

Most CBs do look like switches - have you looked in your house's (inaccurately named) fusebox recently?

The RCD (CBs) in your house do look like switches but they bear no resemblance to an aircraft CB.

CB Image (http://www.google.co.uk/imgres?imgurl=http://www.pacoplastics.com/images/DSC_0155.JPG&imgrefurl=http://www.pacoplastics.com/products.php?product%3DS4933959-521%26p%3D68%26n%3DCircuit%2BBreaker%2BLockout%2BRings%2Band %2BTags&h=428&w=640&sz=48&tbnid=rXlH5VrY5kZXAM:&tbnh=92&tbnw=138&zoom=1&usg=__zOzgCpbbhSbluzD6zJFNVEsagh4=&docid=Cc_eXSAajIV6DM&sa=X&ei=R9uSUPbAIYuN0wXGyYDAAg&ved=0CC4Q9QEwBA&dur=1094)

Looks like one of Flightmech's CB tags too. :ok:

[splinterniki]

767 can't extend the landing gear by gravity?

[EMIT]

C/B s on B-767 are pull/push type.

C/B s pulled by maintenance prior to flight are collared (for amateurs on the forum, this is not a typo for coloured/colored, it means a plastic, distinctively coloured/colored collar is fitted around the CB to make clear that it is out on purpose).

Yes, during abnormal sytem behaviour, checking CB s should be a natural step after completion of QRH procedures, BUT, the alternate gear extension system is FREE FALL, that doesn't quite ring a bell that something electrically could be in the way of gear extension - Oh yeah, the hooks that hold the gear doors locked are operated by electrical motors, rather than hydraulic actuators, during alternate gear extension.

CB s are not monitored by EICAS in a 767, but the fact that the popped CB did not cause any other (obvious) failure on the flight deck did not help to discover the fault in the electric system. Remember that alternate gear extension is one of the systems that have to work when (almost) all electrics on the machine have died - surprising that part of that last ditch portion of the electric system can die unnoticed.

Lastly, the particular position of that CB is prone to being bumped accidentally by pilot s bag, and sits in a corner of the panel that is awkward to view from pilot s seat.

Seems lot of holes lined up.

[ATC Watcher]

EMIT, thanks for these , now the report makes a lot more sense ( to me at least )
Indeed a lot of holes waiting to be lined up. You would not expect that in an old Boeing design , but it proves Murphy is still alive and going strong.

[BOAC]

Indeed - those of us who have tried to 'check CB's' during an abnormal know how hard that can be - a bewildering array of buttons. Without some direction from the QRH it can be extremely difficult to track down the culprit, if any.

EMIT - are you saying that a 'total electrics' on a 767 would render free-fall inop? There is no mechanical over-ride?

[EMIT]

Hello BOAC,

Well, just a total electrical failure (also battery dead), would of course not inhibit normal gear extension, because the primary system is hydraulic (the opening of the up latch hooks).
The extension itself is free fall already.

If the total electrical failure is accompanied by hydraulic failure, yes, then you are without gear extension, but for that unlikely combination of failure, there is the back up mode of a belly landing.

[charliemouse]

BOAC,

Bewildering array or not - I think if you look at the picture in the report, you might wonder "why is that one with the little white ring on it pulled out", even if you had never seen a 767 flightdeck or Boeing breaker before.

A simple 10 second scan of the bewildering array might have made you think "what happens if I push this back in"? There being no collar with tag from maintainance to tell you not to...

I gather many pilots have used CB's to shut up annoying buzzers (that might for instance tell them CFIT is a bad idea...), or if not seen the memo's telling them NOT to...

So - given that I am sure your rating gives you a passing familiarity with the bewildering array - back to "why didn't the checklist ask the crew to CHECK CB's"? (or did it?).

Over an hour for the peeps on the flightdeck and in the help centre to think to check the ELECTRICALLY powered backup had ELECTRICITY... :hmm:

[BOAC]

Ta - that makes sense of course, I just wasn't clear from your earlier post re the uplocks' activation..

[NigelOnDraft]

Crew checking / resetting CBs can be an option / drill / consideration. However, as BOAC says, given today's poor manuals and low technical training, I would hardly describe it as a "catch all" for situations like this.

I cannot recall the earlier report and/or timings, however, for something like this I would have thought the crew in contact with Engineers on the ground, especially at home base, and they in turn, as required even with Boeing. Certainly half the time I call engineering, I am told to pull / reset CBs X, Y and Z.

AL 1:After completing the QRH procedure and consultation with the operator's operations centre, the flight crew decided to continue the flight to Warsaw.ex-EWR
The crew checked correctness of the procedure and then reported to the air traffic control service (ATC) inability to extend the landing gear and asked operations centre for help.
The airplane was directed to a holding zone. Around 12:25 hrs the flight crew declared EMERGENCY situation. At 12:45, after consultation with the Command Post of Air Operations Centre, it was decided to activate ground alert combat aircraft from an Air Force base to check visually the landing gear.
At 13:06 hrs the pilots of combat aircraft informed the Boeing flight crew that the all landing gear was still in the retracted position. During the flight in the holding zone the flight crew consulted their actions with the operator operations centre.
The crew carried out an attempt to extend the landing gear in the gravitational way, which ended in failure. Due to small fuel quantity and unsuccessful attempts to extend the landing gear, the crew decided to execute an emergency landing with landing gear retracted. The plane landed at Warsaw-Okecie aerodrome (EPWA), on runway 33 at 13:39.So about 90mins from "gear won't lower" to wheels up on runway, and in consulation with their Ops for that ~90mins - having given a heads up ~8hours earlier. Certainly in my outfit, after the 8hours I think I would have had more "help" than I needed on the R/T / ACARS ;)

Looking at the manual extracts, even if they traced the Alt Ext motor in the CB chart, this was not the CB tripped - you had to go back to the power source for that busbar.

[BOAC]

As I said earlier to Clandestino - there are 'bigger fish to fry' here. It is beyond belief that as NoD says, no-one from Company suggested this breaker. Crew-wise, charliemouse, I agree that a 'one isolated photo' presentation shows it to be obvious, but I would prefer to sit in the cockpit before I passed judgement - and the report does say it is 'very difficult' to see this breaker.

[Joker72]

From the B767 FCOM:

The alternate landing gear extension system uses an electric motor to trip the locking mechanism for each gear.

No electrical power, no gear extension, regardless of status of the center hydraulic system. This is the precise result when the CB controlling the motors is popped.

Can't seem to find it, but recall from a previous aircraft's QRH a warning to extend landing gear prior to battery depletion in a "Loss of All Generators" c/l.

[Island-Flyer]

Anyone remember years back when the G-V had a gear wedge against its gear door due to bad sequencing? If I recall that plane circled for hours while every engineer, mechanic, and pilot at Gulfstream ran the array of possible fixes from the mundane to the borderline insane. In the end they got the gear down.

I'm surprised Boeing wasn't brought more into the loop on this during the 9+ hour flight.

[EMIT]

Island-Flyer

The entire flight may have lasted 9 hours, but the tricky problem just came up on final approach to Warsaw. Until then it had just been a case of, lost centre hydraulics, gear will be extended by alternate gear sytem, no need to wake up Boeing for such a straight forward situation.

Joker 72
No electrical power, no gear extension, regardless of status of the center hydraulic system.I hope you do realize that with centre hydraulics available, there is no need for alternate extension, and gear can be extended normally, without any electrics (with normal extension, uplocks are released by hydraulic actuators).

[suninmyeyes]

I'd like to bet the problem would have been successfully solved in the olden days with a 3 man flight crew and a Flight Engineer addressing the problem.

Apologies for slight thread drift but talking about popped cbs ....

In the old 747 the problem was often a popped cb normally spotted by the Fight Engineer. Although one event not spotted resulted in doing 2 goarounds in BOS due inability to keep it on the centreline manually or autocoupled. It turned out the cb responsible for the circuit that locked out the outboard ailerons when flaps were up had popped and both approaches were flown using inboard ailerons only. They managed to get down on the third approach and only after parking did they spot the popped circuit breaker.

I seem to remember on the 747 if the nose gear did not come down using the alternate method the third method was for the flight engineer to go down into the lower equipment bay (lower 41, 707 term that remained) and unscrew screws that held it up, after a number had been unscrewed the weight would strip the remaining screws and the nose gear would fall down. I wonder if it was ever used?

To be fair to the LOT guys in the last 10 years I have not had a single flight deck circuit breaker pop on its own accord and I understand the offending circuit breaker was obscured by the first officer's briefcase. I bet the two pilots must be kicking themselves and thinking "if only".

[aerobat77]

does anybody know for sure if the PIC is still flying for LOT ?

[criss]

He is. . . .

[Island-Flyer]

The entire flight may have lasted 9 hours, but the tricky problem just came up on final approach to Warsaw. Until then it had just been a case of, lost centre hydraulics, gear will be extended by alternate gear sytem, no need to wake up Boeing for such a straight forward situation.

Ah my bad, I had thought I read that they had a hydraulic problem on departure but opted to continue.

[dash6]

Yes. Why not?

[EMIT]

Island Flyer,

To make sure: the CTR HYD problem developed shortly after departure, but that is no reason not to continue the flight. The 767 has 3 HYD systems. Loosing one is not a daily occurrence, but according Boeing procedures, not a reason to terminate the flight immediately.

[Island-Flyer]

Yeah my knowledge of 767 systems are nonexistent. I know in pretty much all the aircraft I fly if the primary hydraulic system that drives gear extension/retraction fails there is going to be some sort of abnormal gear extension procedure (such as gravity drop, pumping the gear down, or running it off of a separate system driven by a DC pump). I should have guessed larger aircraft would have their primary gear extension driven by multiple hydraulic systems.

If I read it right the failure of the electric motors to release the landing gear uplocks was a completely independent failure (caused by popped CBs) from the hydraulic system failure (which was not caused by the popped CBs that caused the uplock failure)?

[NigelOnDraft]

2 comments:
I'd like to bet the problem would have been successfully solved in the olden days with a 3 man flight crew and a Flight Engineer addressing the problem.It was earlier pointed out here the unusual (electrical) Altn Gear Extend on the 767 was because it was designed wth a Flt Engineer, and a "mechanical wind handle" (or similar). When the Flt Engineer got "removed", the motor to drive this system was implemented.

was a completely independent failure (caused by popped CBs)Co-incidences are rare, and need to be checked they truly are. Nobody seems to allow for the fact that this CB might have popped when the Altn Extn button was operated? Who knows the condition of the motor / the system? Was there a temporary seizure (frozen water?) in the system somewhere that caused the CB to trip? By the time the aicraft has sat on the runway for X days, been lifted and dragged off to the hangar, who knows what "issues" disappeared / melted away / resolved themselves?

Something, or somebody tripped that CB. The assumption here is that is was "somebody" and others failed to notice / check. It would be pretty hard to prove it was not tripped as per design at the time?

[ATC Watcher]

NoD :
Something, or somebody tripped that CB. The assumption here is that is was "somebody" and others failed to notice / check. It would be pretty hard to prove it was not tripped as per design at the time?


Excellent remark ( as nearly always from you :E ) . sometimes the obious can be front of our eyes but we keep on looking for the improbable difficult possibilities.

[Golf-Sierra]

Excellent remark ( as nearly always from you ) . sometimes the obvious can be front of our eyes but we keep on looking for the improbable difficult possibilities
The reason why this CB tripped is not relevant. The worrying thing is that no one noticed the CB was tripped during the event prior to the landing. The crew were apparently in contact with engineers on the ground, it is surprising that no one had a look at the wiring diagram and noticed the altn gear ext circuit is protected by two fuses.

[konradeck]

There are several questions, which need to be answered:
- Main one: Was the CB in off position?
- Why didn't they found the tripped (or switched/ripped off) CB, although it is claimed, that the breakers were checked by F/O and the purser (highly experienced one)?
- As they were in contact with Maintenance, were they asked to check the specific ones (both relevant CBs)?
- If not, was Maintenance able to find this CB on the schematics?
- Was the Maintenance in contact with Boeing? Did they receive information to check the tripped CB?

I believe we all are convinced, that CB was tripped off during approach, although I think we'll never find the reason. I believe the crew checked the emergency gear extension fuse to be OK and they gave the "all CBs are OK" information to the maintenance, which mislead them.

A superior pilot uses his superior judgment to avoid having to exercise his superior skill.
Unfortunately here cpt. Wrona had to use his skills...

[criss]

You're jumping too far in your conclusions.

[Joker72]

You are correct, Emit. That's what I get on depending on my tired old memory (and having flown too many different types). I was thinking of the straight 300 I once flew, without an HMG. Mea culpa :ouch:

[Golf-Sierra]

Unfortunately here cpt. Wrona had to use his skills...

Well, at least they showed that it can be done (belly landing a 767).

[IFixPlanes]

I believe we all are convinced, that CB was tripped off during approach...
If you believe this, you are wrong!
I am not convinced about this. :=

[andrasz]

Unfortunately here cpt. Wrona had to use his skills...

While I'm not questioning that the crew did a decent job, IMHO a gears up landing on a hard runway requires no exceptional skills other than being able to land an airplane in the first place. Once touching down, cutting fuel, electric power and slowing to a speed where rudder is no longer effective, the crew become front seat passengers with zero further control over events...

[ATC Watcher]

IMHO a gears up landing on a runway in no way requires any special skill
The 767 . like many othe large twins has the engines hanging well below the main fuselage , a couple of inches asymetrical and you could end up like the Ethiopian 767 who did this on the water some years ago,

Of course, as "Sully" himslef says :an amount of luck was required ... but as a glider pilot himself he knew that wings absolutely level is an absolute prerequisite when attempting such a thing. So superiors skills , yes.. in both cases.

[andrasz]

...a couple of inches asymetrical and you could end up like the Ethiopian 767...

I said runway, not water, that's a different story. On a hard runway it will settle on the two engine pods as it would on wheels, as it was ably demonstrated. Rudder is more than sufficient to counteract any yaw from only one engine dragging momentarily.

The Ethiopian 767 cartwheeled because it was in a steep bank and out of control. There was a scuffle in the cockpit with the highjacker, it was not a controlled ditching.

[ATC Watcher]

Andrasz: Point taken, I never belly- landed a large aircraft on a runway, so I take your word for it.
For the Ethiopian you are right, I should have looked at the report again before posting.( as I just did now !) was just remembering the video .

[Machinbird]

The Ethiopoan 767 cartwheeled because it was in a steep bank and out of control. I think hitting a reef with the low wing also had something to do with it.

[DownIn3Green]

It was out of fuel and optins...THAT Captain is a true HERO...

[andrasz]

I never belly- landed a large aircraft on a runway...

Nor did I, and I assume neither did the vast majority of forum readers, fortunately :)

However if you look at the records, I cannot think of any planned gear-up landing on a hard runway that went wrong in the past couple of decades. The plane might not be useable again, but everyone walks away - that qualifies as a good landing.

As you correctly point out, ditching is a different story.

[Passenger 389]

CHICAGO (AP) — Passengers on a plane that crash-landed in Poland last year when its landing gear failed to deploy have sued Boeing and the firm that inspected the airliner before it departed New Jersey, with one attorney saying his clients suffered severe emotional trauma from thinking they were about to die.

A lawsuit claiming both physical and psychological damage was filed this week in Cook County Circuit Court in Chicago, where Boeing is headquartered, contends design flaws in the 767-300 led to fluid leaking from the hydraulic system. It said workers of New York-based Mach II Maintenance should have detected it.

* * * *

[T]he psychological trauma was intense, as the pilot told passengers over the intercom that the crew had no choice but to land without wheels, the Chicago-area attorney representing the plaintiffs told The Associated Press on Friday.

"You've got the pilot telling them that things aren't looking good, you had people texting their loved ones saying, 'I don't know if I'll ever see you again, goodbye,' " said Floyd Wisner. "There's the terror that you are about to die."

Some of the around 80 passengers listed as plaintiffs still are plagued by nightmares, he said, and some say they can never set foot on a plane again, Wisner said, calling it "classic post-traumatic stress disorder."

People who are skeptical of such claims don't understand what his clients went through, he added.

"This is a near-death experience," he said. "That you didn't die is great. But you suffered damage from thinking you would die."


[ Uh.... I've been in several "near-death" situations. Never sued anyone because of it. And this was a near-death experience in their own minds only. Not a particularly difficult landing for a competent crew, as many on this thread already have pointed out.

Some passengers may have PTSD. But many are greedy, or for various reasons (money being one) have chosen to embrace a victim personna. Our legal system in America encourages that.

Suing the manufacturer and maintenance company may allow the Plaintiffs to circumvent the liability and damage limitations of the Warsaw/Montreal Convention (for an international flight).

There are many good things about America. Jury roulette just isn't one of them. ]

[JammedStab]

I seem to remember on the 747 if the nose gear did not come down using the alternate method the third method was for the flight engineer to go down into the lower equipment bay (lower 41, 707 term that remained) and unscrew screws that held it up, after a number had been unscrewed the weight would strip the remaining screws and the nose gear would fall down.


That access door is frequently blocked by cargo on the freighters.

Any update on the final report or did I just miss its publication?

[RAT 5]

Some passengers may have PTSD. But many are greedy, or for various reasons (money being one) have chosen to embrace a victim personna. Our legal system in America encourages that.

I hope, sincerely, that they get what they truly deserve and what is coming to them: as the Americans will understand.."sweet FA".