Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
Trimeresurus
Topic Author
Posts: 118
Joined: Fri Jun 02, 2017 6:06 pm

Are cargo doors of passenger aircraft operated from the outside?

Wed Oct 28, 2020 10:29 pm

Do they have a switch that the ground crew use to open them? Can it be overridden from the cockpit? What are the conditions necessary for the cargo doors to be available to open?
 
User avatar
Horstroad
Posts: 580
Joined: Thu Apr 08, 2010 8:19 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Wed Oct 28, 2020 11:36 pm

No doors (except for the APU inlet and exhaust doors, if installed) are controlled (or overridden) from the flight deck. Cargo doors are always operated by the ground crew from the outside. An exception would be main deck cargo doors on freighter aircraft, which have the controls usually in the main entry door area and/or next to the main deck cargo door. Cargo doors usually use ground handling or ground service power. The cabin needs to be unpressurized, otherwise it is impossible to open the vent door which is usually connected to the door locks, which would prevent the door from being opened.
Cargo doors usually have a vent door that has to be opened mechanically with a lever directly on the door. This also unlocks the door. Then there is a small access panel next to the door with an open/close switch and the interior and exterior light switches. Cargo doors are driven electrically or with hydraulic power.
 
User avatar
Starlionblue
Posts: 20698
Joined: Fri Feb 27, 2004 9:54 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Thu Oct 29, 2020 2:01 am

Horstroad wrote:
No doors (except for the APU inlet and exhaust doors, if installed) are controlled (or overridden) from the flight deck. Cargo doors are always operated by the ground crew from the outside. An exception would be main deck cargo doors on freighter aircraft, which have the controls usually in the main entry door area and/or next to the main deck cargo door. Cargo doors usually use ground handling or ground service power. The cabin needs to be unpressurized, otherwise it is impossible to open the vent door which is usually connected to the door locks, which would prevent the door from being opened.
Cargo doors usually have a vent door that has to be opened mechanically with a lever directly on the door. This also unlocks the door. Then there is a small access panel next to the door with an open/close switch and the interior and exterior light switches. Cargo doors are driven electrically or with hydraulic power.


Adding to this. Some cargo doors can also be hand-cranked in a pinch if you don't have hydraulic power. For example on the A330, the yellow hydraulic system powers the forward and aft cargo doors. If the yellow system electric pump is inop, there is a hand pump to generate the necessary pressure.

Some smaller cargo doors are operated with muscle power. E.g. bulk cargo doors.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
User avatar
fr8mech
Posts: 8215
Joined: Mon Sep 26, 2005 9:00 am

Re: Are cargo doors of passenger aircraft operated from the outside?

Thu Oct 29, 2020 1:30 pm

As in just about everything in aviation, it depends. On the B747, you can open both the forward and aft doors from the inside. There is a master latch lock release inside and outside. There is an open/close switch both inside and outside. You can close the doors from the inside, but you can’t lock the latches.

The B757 lower doors can also be unlocked and opened from the inside and outside.

But, no, there is no cockpit override. The closest thing I can think of would be on the B747 freighters. If you put both APU generators, or both external plugs on the bus at the same time, the ground service (or is it the ground handling) bus is disabled. The doors will not work, nor will the cargo handling system.
When seconds count, the police are minutes away, or may not come at all.
It’s hard to win an argument with a smart person, but it’s damn near impossible to win an argument with a stupid person. ~B. Murray
Ego Bibere Capulus, Ut Aliis Sit Vivere
 
unimproved
Posts: 260
Joined: Sun Jun 22, 2014 7:14 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Thu Oct 29, 2020 1:39 pm

Starlionblue wrote:
Horstroad wrote:
No doors (except for the APU inlet and exhaust doors, if installed) are controlled (or overridden) from the flight deck. Cargo doors are always operated by the ground crew from the outside. An exception would be main deck cargo doors on freighter aircraft, which have the controls usually in the main entry door area and/or next to the main deck cargo door. Cargo doors usually use ground handling or ground service power. The cabin needs to be unpressurized, otherwise it is impossible to open the vent door which is usually connected to the door locks, which would prevent the door from being opened.
Cargo doors usually have a vent door that has to be opened mechanically with a lever directly on the door. This also unlocks the door. Then there is a small access panel next to the door with an open/close switch and the interior and exterior light switches. Cargo doors are driven electrically or with hydraulic power.


Adding to this. Some cargo doors can also be hand-cranked in a pinch if you don't have hydraulic power. For example on the A330, the yellow hydraulic system powers the forward and aft cargo doors. If the yellow system electric pump is inop, there is a hand pump to generate the necessary pressure.

Some smaller cargo doors are operated with muscle power. E.g. bulk cargo doors.

And on Boeing it's a mechanical receptacle. Takes about 10 minutes to open with a power drill but if you follow the sticker it's only by hand.
 
User avatar
fr8mech
Posts: 8215
Joined: Mon Sep 26, 2005 9:00 am

Re: Are cargo doors of passenger aircraft operated from the outside?

Thu Oct 29, 2020 2:42 pm

unimproved wrote:
And on Boeing it's a mechanical receptacle. Takes about 10 minutes to open with a power drill but if you follow the sticker it's only by hand.


Again, that’ll be aircraft specific. The B757 limits you to 500 rpm and 225 inch-pounds if a power tool is used.
When seconds count, the police are minutes away, or may not come at all.
It’s hard to win an argument with a smart person, but it’s damn near impossible to win an argument with a stupid person. ~B. Murray
Ego Bibere Capulus, Ut Aliis Sit Vivere
 
Max Q
Posts: 8983
Joined: Wed May 09, 2001 12:40 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Thu Oct 29, 2020 9:49 pm

IIRC the 747F nose door can be opened manually with much cranking ?
The best contribution to safety is a competent Pilot.


GGg
 
User avatar
zeke
Posts: 16105
Joined: Thu Dec 14, 2006 1:42 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Thu Oct 29, 2020 11:06 pm

Trimeresurus wrote:
Do they have a switch that the ground crew use to open them?


Generally speaking hydraulically operated cargo doors on passenger aircraft do have controls near the door on the outside under an access panel that enables the operator to ensure the area around the door is clear when operating the door.

Normal operation of the A320 cargo door

https://youtu.be/xCleoApdA7A

Manual operation of an A320 cargo door

https://youtu.be/luqz412AZDo

Trimeresurus wrote:
Can it be overridden from the cockpit?


On all Airbus aircraft the opening and closing of cargo doors using the control panel can be overridden by turning the associated electric hydraulic pump off. By default these pumps are in auto mode, when exercising the switch from the outside it will energize the electric hydraulic pump to enable the door to open and close. When this automatic mode is activated an memo appears for flight crew awareness.

Flight crew cannot override the backup manual controls.

Trimeresurus wrote:
What are the conditions necessary for the cargo doors to be available to open?


On Airbus aircraft the aircraft would ideally need to be electrically powered by the APU or ground power so the electric hydraulic pumps can operate, the area around the door is clear, aircraft depressurized, and wind within the environmental limits specific for the operation of the door and also having the door open.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
Tristarsteve
Posts: 3694
Joined: Tue Nov 22, 2005 11:04 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Fri Oct 30, 2020 4:34 pm

Zeke
On all Airbus aircraft the opening and closing of cargo doors using the control panel can be overridden by turning the associated electric hydraulic pump off. By default these pumps are in auto mode, when exercising the switch from the outside it will energize the electric hydraulic pump to enable the door to open and close.


I don't think that is true. I don't have access to the manuals any more but, the yellow hyd pump on the A320 series can be supplied from the ground service bus on the ground to operate the cargo doors. This will work with the cockpit unpowered. Turning on ground service from the L1 door panel will allow the loaders to operate the cargo doors using the yellow pump. The flight deck switch has no effect in this operation.
I have never tried this (turning off the pump in the flight deck) but the electrical supply route is different.
 
User avatar
zeke
Posts: 16105
Joined: Thu Dec 14, 2006 1:42 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Sat Oct 31, 2020 2:22 am

Tristarsteve wrote:
Zeke
On all Airbus aircraft the opening and closing of cargo doors using the control panel can be overridden by turning the associated electric hydraulic pump off. By default these pumps are in auto mode, when exercising the switch from the outside it will energize the electric hydraulic pump to enable the door to open and close.


I don't think that is true. I don't have access to the manuals any more but, the yellow hyd pump on the A320 series can be supplied from the ground service bus on the ground to operate the cargo doors. This will work with the cockpit unpowered. Turning on ground service from the L1 door panel will allow the loaders to operate the cargo doors using the yellow pump. The flight deck switch has no effect in this operation.
I have never tried this (turning off the pump in the flight deck) but the electrical supply route is different.


They way I understand it the maintenance switch powers the bus, however I think the off switch removes the pump from the bus.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
milhaus
Posts: 89
Joined: Fri Dec 10, 2010 4:19 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Tue Nov 03, 2020 6:29 am

On A320, yellow electric hyd pump is usually off, so when someone downstairs starts to operate door, it starts even when PB is off. Only way to switch it off is to pull C/B. Also note when its activated, by cargo door switches just door is powered, nothing else.
 
User avatar
HAWK21M
Posts: 30130
Joined: Fri Jan 05, 2001 10:05 pm

Re: Are cargo doors of passenger aircraft operated from the outside?

Fri Nov 06, 2020 4:45 pm

As far as concerned MOST Cargo Doors of Passenger Aircraft are ALWAYS Unlocked from the Outside & can be Open/Closed from Outside & can be opened from Inside.
On the Freighters the MDCD [Main deck cargo door] is having the Normal Operating controls from the Inside, the panel is so located that a visual view of the MDCD is available.
I may not win often, but I damn well never lose!!! ;)

Who is online

Users browsing this forum: No registered users and 13 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos