"Somewhat scary one near Winnipeg" - The AC Master Incidents Thread
Jan 14, 2019, 9:26 pm
#3826
FlyerTalk Evangelist
Join Date: Mar 2005
Location: YYZ
Programs: AC*SE 2MM
Posts: 16,655
Except, a leaky door won't be unsafe at all until the pressure difference becomes significant. Should not be an issue if they immediately turn around and land. BTW nothing is ever 100% safe. And a rejected takeoff for sure entails greater risks than going around and landing with a leaky door.Anyway, my point really is that there must have been more to this story than a leaky door.
Jan 14, 2019, 9:29 pm
#3827
FlyerTalk Evangelist
Original Poster
Join Date: Jun 2003
Location: YYC
Posts: 23,809
Someone with greater knowledge of the limits of a 7M8 would need to do the math, however my suspicion is that a reasonably full aircraft flying from PSP-YYZ would probably take off well above its maximum landing weight, so in this scenario the captain flies the plane with a suspect door while they dump fuel or they land an overweight aircraft - both of those carry risks.
Second indeed would. First not so sure if indeed they can dump fuel. But is the 7M8 set up to dump fuel at all? So yes, you might make a good point. Still does not explain why a door indication would only show up during takeoff roll though.
Jan 14, 2019, 9:38 pm
#3828
Join Date: Nov 2017
Posts: 3,359
-James
Jan 15, 2019, 11:52 am
#3829
Join Date: Nov 2017
Posts: 3,359
Safe Travels,
James
Jan 15, 2019, 12:08 pm
#3830
Join Date: Apr 2011
Location: YXU
Programs: AC SE100K, National E/E, HH Diamond, IHG Diamond, MB, Avis PC
Posts: 971
As per Boeing, the answer is no, the 737 MAX Series does not have the capability to jettison fuel. Looking at the document I linked, it is surprising how many airliners Boeing has that don't have that functionality! Equally so considering the 737 MAX is now doing TATL flights (I just did one from SWF to EDI)!
-James
-James
Jan 15, 2019, 5:01 pm
#3831
Join Date: Dec 2014
Location: YVR
Programs: Bottom feeder Star Gold
Posts: 2,652
Originally Posted by Stranger
And surely a high speed rejected takeoff (even if below V1) is one of the least safe one might encounter.
Originally Posted by The Lev
...so in this scenario the captain flies the plane with a suspect door while they dump fuel or they land an overweight aircraft - both of those carry risks.
Jan 15, 2019, 6:12 pm
#3832
FlyerTalk Evangelist
Original Poster
Join Date: Jun 2003
Location: YYC
Posts: 23,809
"Faulty" is a bit of a strong word. Only one of a number of possibilities, just not the only one.
I'd say with confidence that flying with a suspect door is more risky and contains more of the 'unknown' element. It's important to note that "landing overweight and fuel jettisoning are both considered safe procedures: there are no accidents on record attributed to either cause" as per https://www.boeing.com/commercial/ae...7_article3.pdf
I would disagree with the first part on its own, as long as they don't go high enough for the pressure difference to build up. However, that would entil landing overweight, which safetywise is probably comparable with rejecting takeoff. Both scenarios entail very hard braking. Which may be relatively safe. And repeating myself, nothing is "safe." there are always risks, and the question is always, what entails less risks, and what risk is taken as being acceptable. With the latter depending upon the circumstances, and the alternatives. Hard breaking may result in losing direction control and veering sideway. Or heating up the brakes to the point of starting a fire. There is a reason why they get fire trucks to line up when landing heavy or faster than normal. And surely the only reason they don't get the same when rejecting a takeoff is that there is no time. But they still get the brakes inspectted ASAP, to lower the risk of fire, and reduce the time until a potential fire is dealt with.
Jan 15, 2019, 6:24 pm
#3833
Join Date: Nov 2017
Posts: 3,359
Was there any indication on the Palm Springs incident as to which runway the aircraft was cleared to take off from? Palm Springs has two runways one with 10,000 ft and the other with 4,952 ft. If it happens to be the former, then an argument could be made that they had ample room to brake.
-James
-James
Jan 15, 2019, 6:26 pm
#3834
FlyerTalk Evangelist
Original Poster
Join Date: Jun 2003
Location: YYC
Posts: 23,809
Was there any indication on the Palm Springs incident as to which runway the aircraft was cleared to take off from? Palm Springs has two runways one with 10,000 ft and the other with 4,952 ft. If it happens to be the former, then an argument could be made that they had ample room to brake.
-James
-James
Not so simple. Remember, they minimize fuel consumption based upon conditions (load, temperature etc.) including runway length. On a longer runway, the accelerate less.
Jan 15, 2019, 6:28 pm
#3835
Join Date: Nov 2017
Posts: 3,359
Jan 15, 2019, 6:30 pm
#3836
FlyerTalk Evangelist
Original Poster
Join Date: Jun 2003
Location: YYC
Posts: 23,809
Jan 15, 2019, 7:33 pm
#3837
Join Date: Dec 2011
Location: YYZ
Programs: AC SEMM / HH Diamond
Posts: 3,174
Jan 15, 2019, 7:38 pm
#3838
Join Date: Jan 2017
Location: Halifax
Programs: AC SE100K, Marriott Lifetime Platinum Elite. NEXUS
Posts: 4,571
V1 is V1. If it wasn't safe to abort the take off at that speed then V1 under those conditions would be lower.
Not being in the air is going to be safer than being in the air. For the aircraft, the passengers, and anyone on the ground who could be hit by anything from, I don't know, lose doors falling off, or the entire subject aircraft with possible control problems having to do something more complex than "slowing down".
Not being in the air is going to be safer than being in the air. For the aircraft, the passengers, and anyone on the ground who could be hit by anything from, I don't know, lose doors falling off, or the entire subject aircraft with possible control problems having to do something more complex than "slowing down".
Jan 15, 2019, 7:57 pm
#3839
FlyerTalk Evangelist
Original Poster
Join Date: Jun 2003
Location: YYC
Posts: 23,809
That statement makes little sense. Being a bit above V1 is a little bit less safe than below. V1 is some value more or less arbitrarily selected as being an acceptable limit. In other words, more or less pulled off someone's hat, on the basis of it being reasonable. Keeping odds within a "reasonable" margin.
Not being in the air is going to be safer than being in the air. For the aircraft, the passengers, and anyone on the ground who could be hit by anything from, I don't know, lose doors falling off, or the entire subject aircraft with possible control problems having to do something more complex than "slowing down".
No. First, as long as there is no pressure difference, a door likely won't open on its own. And if it does, it likely won't do much apart from being there open. I cannot imagine that alone being more dangerous than a near V! rejected takeoff.
Jan 15, 2019, 8:22 pm
#3840
Join Date: Jan 2017
Location: Halifax
Programs: AC SE100K, Marriott Lifetime Platinum Elite. NEXUS
Posts: 4,571
That statement makes little sense. Being a bit above V1 is a little bit less safe than below. V1 is some value more or less arbitrarily selected as being an acceptable limit. In other words, more or less pulled off someone's hat, on the basis of it being reasonable. Keeping odds within a "reasonable" margin.
Unless there are two lights: "door not sealed but is ok" and "door broken and likely to fall off" then the first light means the second light.