FedEx 757

[212man]

Originally Posted by EXDAC

"Landing Gear Alternate Extension

The alternate landing gear extension system uses a dedicated DC powered electric hydraulic pump. Fluid within the supply line to the pump is sufficient for alternate gear extension operation. This fluid is isolated from the left hydraulic system. Selecting the ALTN GEAR EXTEND switch releases all door and gear uplocks. The landing gear free–fall to the down and locked position."

ref - http://navfly.ru/wp-content/uploads/...ons_manual.pdf

I have not found any reference to an associated circuit breaker.

Hard to imagine how it wouldn’t have one!

[Chiefttp]

I fly both aircraft regularly,
It has always been explained to us that the 757 uses isolated left system hydraulic pressure and a dedicated DC powered Hydraulic pump to release the uplocks, allowing the gear to free fall.

The 767 uses an electric motor to trip the locking mechanism (uplocks)

As EXDAC has stated above, there is no mention of an associated CB for the 757 Dedicated DC powered Hyd pump.

[megan]

Summation of the audio courtesy of Avweb..

According to audiotapes of the radio traffic with Chattanooga Approach Control (available here from LiveATC), the crew of Flight 1376 reported shortly after takeoff that it was returning to the airport due to a “flight control issue” and advised they were not declaring an emergency at that time and did not anticipate the need for assistance.But as the flight maneuvered for an ILS approach to Runway 20, they said they needed to break off the approach due to an unsafe gear indication. Later, the crew advised ATC they would not be able to taxi clear of the runway after landing due to “no steering available,” suggesting they would need a tug to retrieve the aircraft. They then declared an emergency, reporting there were three souls on board and “about an hour and a half” of fuel

When the controller asked if the emergency was due to an unsafe gear indication, the crew advised they were activating an “alternate gear extension,” which in the 757 involves a separate battery-operated hydraulic power pack (suggesting that the overriding issue was with the main hydraulic system)

The FedEx crew asked for a low pass over the runway and for ground observers to advise if the gear was extended. Observers in the tower and on the ground said they could not see the gear extended, and the crew said they were going to perform a no-gear landing. ATC told them they would have emergency vehicles standing by

[GAZIN]

There certainly is a circuit breaker for the alternate gear extension, behind the FO's position.

[212man]

Originally Posted by megan

Summation of the audio courtesy of Avweb..

How did they only have one hour of fuel?

[EXDAC]

Originally Posted by GAZIN

There certainly is a circuit breaker for the alternate gear extension, behind the FO's position.

Thanks. I didn't doubt that there was one. I just couldn't find any on-line reference to the location.

So we have at least one 757 pilot here who didn't know where it was. Did this FedEx crew know where it was and confirm it was in?

[Chiefttp]

Found it,


interesting there is no note of this in our emergency checklists, nor in the 767 Emergency checklist either. You would think after the LOT incident there would be a note about checking these CB’s. I did have a note in my personal study guides about the CB in the 767, but nothing was ever mentioned in the *757 checklists. You never stop learning in this profession.

[megan]

How did they only have one hour of fuel?

The quote says

reporting there were three souls on board and “about an hour and a half” of fuel

[VHOED191006]

Originally Posted by Chiefttp

Found it,


interesting there is no note of this in our emergency checklists, nor in the 767 Emergency checklist either. You would think after the LOT incident there would be a note about checking these CB’s. I did have a note in my personal study guides about the CB in the 767, but nothing was ever mentioned in the *757 checklists. You never stop learning in this profession.

Probably a good point to make to all 757/767 crew now: always check those CBs during the preflight, and whilst running the non-normal checklists!

[MarkerInbound]

“How did they only have one hour of fuel?”

The were going to Memphis, 230 miles away. Max TO weight would be landing weight limited.

[fdr]

As the alternate system uses hydraulics, a leak in the wrong place may be nasty, but, there is odds on that a CB will be found in the "lets protect the $500 pump" position.

[EXDAC]

Originally Posted by fdr

but, there is odds on that a CB will be found in the "lets protect the $500 pump" position.

Aircraft circuit breakers are usually rated to protect the wiring that feeds a device not to protect the device itself. However, it will be interesting to see if the NTSB report mentions this circuit breaker.

[stilton]

Originally Posted by BFSGrad

While I wouldn’t expect Fedex (or other operators) to have gear-up landing performance data in-house, it seems likely that Boeing would. Does Boeing provide 24/7 engineering support for emergency situations?

Based on a few photos, appears that N977FD stopped just short of the localizer antenna, so perhaps about 800 ft of overrun? Must have chewed up a portion of the runway 2 MALSR.

Never heard of gear up landing performance data, you’d have to deliberately land gear up during flight test to provide that which would be expensive

[212man]

Originally Posted by megan

The quote says

my comment was based on the RT recording where the crew report an hour of fuel.

[212man]

Originally Posted by MarkerInbound

“How did they only have one hour of fuel?”

The were going to Memphis, 230 miles away. Max TO weight would be landing weight limited.

For an IFR flight they’d need an alternate and 45 min on top of that

[ncthomas]

An Interesting Experience with Nose Landing Gear on 757-200

I wish to start by stating, that I write this only to share an interesting experience and is not an opinion on the Fedex 757 incident.
In Nov 2013, while doing a low drag ILS app into MUMBAI, I got the "Gear Unsafe" warning. The nose gear had no lights, red or green. Initiated a Go Around and by habit retracted the gear.
ATC vectored me to a safe space to the North to do the Checklist. At the end of Check List actions, we had the same situation, main gears down and nose remained up. Gear Unsafe was illuminated.Hydraulics were normal. So we appraised ATC of the impending nose wheel up landing and decided to orbit to burn some fuel. It also helped lots of incoming flights from the Gulf to land.
Now I must say something about my background. Ex Indian Air Force, lots of flying on the MIG 21s and later a Test Pilot. On the Migs, we had a compressed air system, which forced the gear down in case of an Hydraulic Failure. One day, we got a caution from the manufacturer, cautioning us not to use the emergency pneumatic system, if the hydraulics were normal. The explanation given was that, during retraction, may be due poor rigging, the gear may not get locked in the up lock, and when the "up "system gets de-energised, the gear tends to sag and rest on the gear doors. This messes up the sequence between the doors and the gear and gear may not come down.
The solution suggested, was to move the Gear Selector from Neutral to Up position rapidly and select Down without pausing in the Neutral. Kind of pulsing the gear up, before the down sequence is initiated.I wondered if the same solution would work on the 757! My hydraulics were normal and main gears were responding normally. I really couldn't see any problems, if my analysis was wrong. So reached across the FO, whom I was training and hit the selector on the Up Stop and without pausing at the Neutral, to the Down position. Remember telling him that I will explain my actions later. Reassuring "thud" and we had all greens!!!
Of course the management thought poorly of my unauthorised actions, till the man who converted us all, Capt Bellamy (ex BA and DHL) thought I should be rewarded.
Happy Landings.

[Sailvi767]

Originally Posted by stilton

Never heard of gear up landing performance data, you’d have to deliberately land gear up during flight test to provide that which would be expensive

I was once given a rule of thumb to plan twice the normal landing distance.

[BFSGrad]

Originally Posted by stilton

Never heard of gear up landing performance data, you’d have to deliberately land gear up during flight test to provide that which would be expensive

Point of my query was not for Boeing to go out and scuff up some airframes to collect empirical data so pilots can have gear-up landing performance data in their EFBs. Just seems to me that some basic modeling could come up with some ballpark slide distances given a few parameters such as airframe type, runway condition (dry/wet), landing weight, and landing ground speed. Entirely possible Fedex ops could call up Boeing and say, “we’ve got a 757 landing gear up in 30 minutes, what can you tell us?” and Boeing’s answer would be, “I just want to tell you both, good luck, we’re all counting on you.”

Some ADS-B data: runway 20 threshold ground speed 146 kts, touchdown speed 145 kts, touchdown point about 2,000 ft past threshold (just past intersecting runways), speed exiting runway 101 kts (that last data point seems suspect). Aircraft had about another 500 feet of margin before it exited the airport property and crossed a public road.

[hunbet]

The P6-1 panel where the alt gear extension CB is located is to the right of the F/O. It's usually hidden by what we used to call a brain bag. It's almost impossible to see and reset when you are in the seat.

[ncthomas]

Looking for CBs.

Referring to the discussion on CBs.
There's a "STATUS " message that indicates that the emergency pump had come ON. Don't remember the exact words.
So if one doesn't have a STATUS message after,say, a minute, maybe one could go hunting for CBs.
regards,