FedEx 757
 

Just in, a FedEx 757 landed gear up at Chattanooga Tennessee Airport KCHA . . Early reports say It was intentional as there was a hydraulic problem and they couldn’t use the alternate gear extension system. Again, these are early reports. No injuries reported.

https://cimg8.ibsrv.net/gimg/pprune....0a5826317.jpeg

Video
 

Close up video of touchdown gear up

https://reddit.com/r/aviation/s/KqKfHwYPbG

Excellent job from the guys at the pointy end 👏

The aircraft involved was N977FD, line number 163, built in 1988 and originally G-BNSD with Air Europe. https://www.planespotters.net/airfra...express/r644l3

Having had to use Alternate Gear Extension on a 757, lets hope the reason it did not work here is an actual issue, not just a CB as LOT on a 767. Good work getting it on the ground in one peace, without significant injuries. Probably end of the line for this airframe.

Normally doesn't take much to write-off a 35 year old airframe...
While narrow body FedEx and UPS aircraft tend to be relatively low hour/cycle for their age, this was originally a passenger 757 and probably racked up a fair number of hours/cycles before FedEx converted it roughly ten years ago.
In the old days I could check the Boeing data base and get the latest hour/cycle numbers, but lost that ability when I retired.

The video of the landing looks just like the end sequence of the film 'Airplane'.

I suspect no calculations exist for no gear landing. However some data from accidents may exist.

What is the runway required? Seems like 7,000 may not be enough. This was a short flight and may not have been fully loaded. What if it was at MTOW?

How would one know runway requirements?

Surely you can't be serious?

Back in about 1972 when Don Smith, who was the FE on the SAA B707A that performed the wheels up landing at Niarobi following ground contact someway short of the airport, was giving us a course, he mentioned that after touchdown they had a issue slowing down as the aircraft slid along on the keel beam and they even deployed speed brakes to assist.

Hadn't heard of that incident, Embakasi seems to gave been popular for landing short - or nearly so!
https://aviation-safety.net/database...?id=19601029-2

I flew the 757/67 for eleven years, other than the LOT 767 gear up I don’t remember another case where the gear could not be extended by any means on either aircraft ?

I am, and don't call me Shirley!

Since it looks like most of the braking force came from the nacelles, which will (with the bypass ducts) have deformed quite a lot on touchdown, it’s possible the primary airframe damage will only be the tail drag.

That said, the LOT 767 that landed in similar fashion at Warsaw Chopin some years ago was a hull loss.

The 757 alternate gear extension utilizes hydraulic power to release the uplocks which allows the gear to free fall. The 767 utilizes a small electric motor to release the uplocks. The LOT 767 gear up landing was due to a popped circuit breaker which also powered the small electric motor that released the uplocks which then allowed the alternate gear extension to work. 2 different systems, so an electrical issue shouldn’t affect the 757 alternate gear extension system. This will be an interesting investigation.
We had a similar scenario in the C-141, where a crew due to limited fuel, rushed the alternate gear extension checklist and failed to secure the nose gear. It collapsed upon landing.

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.

"The alt gear ext on the B757 uses a small hyd power pack with its own electric motor. This runs for about 10 secs to unlock the gear and doors."
ref - https://www.pprune.org/archive/index.php/t-382117.html

If that's true then wouldn't this electric motor have a circuit breaker?

"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!

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.

Summation of the audio courtesy of Avweb..

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

How did they only have one hour of fuel?

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?

Found it,

https://cimg9.ibsrv.net/gimg/pprune....f7ca9a776.jpeg
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.

The quote says

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!

“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.

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.

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.

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

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

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

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.

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

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.

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.

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,