Deaphen From India, joined Jul 2005, 1418 posts, RR: 1 Posted (4 years 5 months 1 week 5 days 17 hours ago) and read 5341 times:
Ok so a small story, a few weeks ago i was spotting in AMS, like i usually do on the weekends, i limit myself to the plaza because having no transport, its the most easily accesible, i normally eat my saturday lunches there while smelling the nice smell of jet fuel.
So anyways, the other day, this MD11 was pushing back for departure, and i noticed a small door/flap open on the left forward side of the fuselage, not thinking much of it, i carried on looking the the beautiful machine.
They pushed back, started engines, and started taxiing with that door/flap open. It was at that point that i felt that maybe something was wrong, why was that little door open! It really seemed odd!
I watched her taxi by, all along with that flap open, and i seriously contemplated calling someone to check whether that door was supposed to be open or whether someone had forgot it. There was a big conflict in my head, because if you logically think about it, if something like a door or a flap had been left open, it would surely show somewhere in the flight deck!
After alot of pondering, and after dialling (but not pressing call) for the airport authorities number, it left, and i didnt do anything.
For a number of reasons, i dont know jack about the procedure for the MD11, if i had called it would have caused alot of panic and unnecessary cost and delay for the airline, etc, etc.
I am just sharing this because i have never before felt that something was "wrong"! Its hard to explain, but then i came home and checked my earlier photographs of KL MD11's leaving, and infact all of them have this door/flap open! Here are a few pics to enlighten you on what the hell im talking about!
Have you ever experienced anything of the sort? Spotters can help avert a few accidents, but i feel me calling the authorities would have been downright wrong, what do you think?
Regards
Nitin
The Plane:
The Flap:
Oh and can someone tell me what this flap is used for?
I want every single airport and airplane in India to be on A.net!
EMBQA From United States of America, joined Oct 2003, 9286 posts, RR: 13 Reply 1, posted (4 years 5 months 1 week 5 days 17 hours ago) and read 5345 times:
Pressurization door......Normal position for on the ground...and not the first time this question has been asked.
[Edited 2008-12-12 08:22:56]
"It's not the size of the dog in the fight, but the size of the fight in the dog"
EMBQA From United States of America, joined Oct 2003, 9286 posts, RR: 13 Reply 3, posted (4 years 5 months 1 week 5 days 17 hours ago) and read 5257 times:
The DC-10 design is a little different, but in the same location. Aircraft designers put the valve in different locations and I don't know why Douglas choose there. Most I've seen are on the aft pressure bulkhead or in the wheel well.
"It's not the size of the dog in the fight, but the size of the fight in the dog"
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 10 Reply 5, posted (4 years 5 months 1 week 5 days 15 hours ago) and read 4993 times:
Quoting Deaphen (Reply 4): I know this question belongs to tech ops, but can this valve be opened inflight?
Its called an outflow valve, it is open on the ground because the pressure inside and outside the fuselage are the same. After takeoff it will be closed to allow the pressure in the fuselage to build up as the outside pressure drops during cruise it will open and close to maintain the correct pressure in the fuselage.
EMBQA From United States of America, joined Oct 2003, 9286 posts, RR: 13 Reply 6, posted (4 years 5 months 1 week 5 days 15 hours ago) and read 4912 times:
Quoting Deaphen (Reply 4): but can this valve be opened inflight?
It regulates in flight (cracks open) to maintain proper cabin pressure. What is fun to do... if your sinuses can take it... is to pressurize on the ground, then hit the dump switch.
"It's not the size of the dog in the fight, but the size of the fight in the dog"
WILCO737 From Greenland, joined Jun 2004, 8473 posts, RR: 78 Reply 7, posted (4 years 5 months 1 week 5 days 15 hours ago) and read 4847 times:
AIRLINERS.NET CREW HEAD MODERATOR
Quoting EMBQA (Reply 6): It regulates in flight (cracks open) to maintain proper cabin pressure. What is fun to do... if your sinuses can take it... is to pressurize on the ground, then hit the dump switch.
It is more fun doing this during flight
BTW, you are not the only one gotten paranoid of this door. I heard of a story about an MD11F where the tower informed the crew that there is still a cargo door open... it took a couple of minutes until they figured out that he meant the outflow valve
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 10 Reply 8, posted (4 years 5 months 1 week 5 days 15 hours ago) and read 4832 times:
Quoting EMBQA (Reply 3): The DC-10 design is a little different, but in the same location. Aircraft designers put the valve in different locations and I don't know why Douglas choose there. Most I've seen are on the aft pressure bulkhead or in the wheel well.
Could you tell me what aircraft have the outflow valve in the aft pressure bulkhead and wheel well?
Deaphen From India, joined Jul 2005, 1418 posts, RR: 1 Reply 9, posted (4 years 5 months 1 week 5 days 14 hours ago) and read 4818 times:
Quoting WILCO737 (Reply 7): BTW, you are not the only one gotten paranoid of this door. I heard of a story about an MD11F where the tower informed the crew that there is still a cargo door open... it took a couple of minutes until they figured out that he meant the outflow valve
Yes, it really does look rather large when u see it infront of you, i had dialed the Schiphol emergency number and was going to press "dial". Glad i didnt!
I want every single airport and airplane in India to be on A.net!
WILCO737 From Greenland, joined Jun 2004, 8473 posts, RR: 78 Reply 10, posted (4 years 5 months 1 week 5 days 14 hours ago) and read 4814 times:
AIRLINERS.NET CREW HEAD MODERATOR
Quoting Deaphen (Reply 9): Yes, it really does look rather large when u see it infront of you, i had dialed the Schiphol emergency number and was going to press "dial". Glad i didnt!
Yeah indeed glad you didn't. The one of the MD11 is apparently pretty big and you are not the only and first one who was wondering what this actually is.
If you stand right in front of that valve you can look inside the airplane a bit. I should take a picture of it one day
HAWK21M From India, joined Jan 2001, 31201 posts, RR: 58 Reply 11, posted (4 years 5 months 1 week 5 days 2 hours ago) and read 4443 times:
The Outflow valve....modulates to control pressurization.This is a single gate type,similiar to the B732.The B757 & B737NGs have Dual gates travelling opposite directions.
Its mainly aft on the B757/737/A320s.
regds
MEL
Pilotpip From United States of America, joined Sep 2003, 3082 posts, RR: 12 Reply 12, posted (4 years 5 months 1 week 4 days 23 hours ago) and read 4399 times:
Quoting 474218 (Reply 8): Could you tell me what aircraft have the outflow valve in the aft pressure bulkhead and wheel well?
The Embraer 145 has them in the aft bulkhead and the 170 has them in the wheel well.
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 10 Reply 13, posted (4 years 5 months 1 week 4 days 16 hours ago) and read 4269 times:
Quoting Pilotpip (Reply 12): The Embraer 145 has them in the aft bulkhead and the 170 has them in the wheel well.
Thanks, never been around either of those. A couple more questions:
1. Does the Embraer have a flat aft bulkhead?
2. How does the 170 keep the wheel well door from opening when the valve is open in flight?
3. Since the areas around outflow valves are corrosion prone how does Embraer repair these areas?
Typhaerion From United States of America, joined Jun 2005, 619 posts, RR: 4 Reply 15, posted (4 years 5 months 1 week 4 days 12 hours ago) and read 4159 times:
Quoting 474218 (Reply 13): 2. How does the 170 keep the wheel well door from opening when the valve is open in flight?
Since the wheel well is not sealed, as shown in the below pictures (737 style), it is essentially outside the aircraft pressure-wise. There would not be an issue with it pressure differential opening the gear door in flight.
Pilotpip From United States of America, joined Sep 2003, 3082 posts, RR: 12 Reply 16, posted (4 years 5 months 1 week 4 days 5 hours ago) and read 4048 times:
The 145 does not have a flat bulkhead. It's concave.
Stratosphere From United States of America, joined Sep 2007, 1614 posts, RR: 4 Reply 17, posted (4 years 5 months 1 week 3 days 5 hours ago) and read 3785 times:
Don't feel bad even pilots have moments of ignorance. I remember one pilot who called in who was following a DC-9 who was having an issue with the horizontal stabilizer with the left side up and the right side down. Guess he didn't know the 9 too well.
Pilotpip From United States of America, joined Sep 2003, 3082 posts, RR: 12 Reply 18, posted (4 years 5 months 1 week 3 days 4 hours ago) and read 3768 times:
Quoting Stratosphere (Reply 17): Don't feel bad even pilots have moments of ignorance. I remember one pilot who called in who was following a DC-9 who was having an issue with the horizontal stabilizer with the left side up and the right side down. Guess he didn't know the 9 too well.
HA.
Yeah I can fully understand. The outflow valves were part of the "this is where they are, this is what they do. You can't really do much about them so don't worry about it" portions of training. I really don't even know if you can see them from the wheel well while preflighting. I've never looked. I gotta say I do like the old school approach of working through the "how's" along with the "why's" rather than just "don't worry about it". My understanding is that some airlines aren't even learning operatinging limitations like oil pressure. It's just "green is good, yellow is something to worry about, red is bad".
Soon7x7 From United States of America, joined May 2006, 2799 posts, RR: 14 Reply 19, posted (4 years 5 months 1 week 2 days 19 hours ago) and read 3665 times:
Don't feel bad...sometimes rampers miss things...I was at JFK, Delta terminal, watching an L-1011 during pushback, I noticed the underwing refueling door was still hanging open...(it's pretty large,bout 3.5 feet wide by 18 inches deep)...Wing walkers were not evident. After the plane pushed back and I noticed this...I looked around the gate area I was in and realized no one else was around...I did notice a gentleman outside on the ramp ,down on the ground walking towards me as I was inside up on a higher level. I tried to get his attention by jumping up and down like a monkey in heat!...but to no avail...I looked at the windows to determine how thick they were, if this guy would hear me pounding on the glass to attract his attention...Glass looked like it was inch thick or so...so I pounded and pounded...he noticed me pointing to the plane...He immedietely turned, looked and noticed the opened door...on his hand held radio, he stopped the pushback before they diconnected the towbar and they sent out a baggage conveyor and ran a MX up the conveyor to close the hatch. Don't know if it would have affected anything had it not been caught however if you do see something and it can be corrected...WHY NOT?
I recently had a shot of a MD/80 blasting out of LGA, upon inspection of the photo, I noticed the rampers headset service door was unlatched...guess it happens more than we think.
EMBQA From United States of America, joined Oct 2003, 9286 posts, RR: 13 Reply 20, posted (4 years 5 months 1 week 2 days 7 hours ago) and read 3454 times:
Quoting Pilotpip (Reply 12): The Embraer 145 has them in the aft bulkhead and the 170 has them in the wheel well.
They have the +/- pressure relief valves on the aft pressure bulkhead as well....
Quoting 474218 (Reply 13): 1. Does the Embraer have a flat aft bulkhead?
2. How does the 170 keep the wheel well door from opening when the valve is open in flight?
3. Since the areas around outflow valves are corrosion prone how does Embraer repair these areas?
1).. No.. it's dome shaped like most all are
2).. The door is attached to the main gear. The gear is locked up, the door is closed
3).. Areas around the outflow valves are NOT corrosion prone.
[Edited 2008-12-15 18:45:19]
"It's not the size of the dog in the fight, but the size of the fight in the dog"
The designers take into account that hatches are periodically not entirelly secured so their installation takes into consideration slipstream direction. Their do exists events where larger more permanent type access covers were left opened for some reason and are not part of the normal turnaround chain of events like, intercom and GPU door covers, and remained unsecured...only to find the thing missing upon landing. It's scary to see what airport workers come back with sometimes after performing runway sweeps...
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