Takeoff alternate and 121.197

ak_mavic

Well-Known Member
Boeing absolutely provides the data to calculate stopping distance above Max Structural LDW. Your performance handbooks should have that data if your electronic tools do not.



100% this.
I don’t Dispatch Boeings or airbus or anything fancy for that matter
 

jynxyjoe

The Kickin' Chicken!
The problem with all this, is the manufacturer of the airframe doesn’t give performance data for landing above max structural, only up to its MLW. Therefore I can’t prove it can land above it’s structrual. I completely agree in knowing realistically that it can, I just don’t have proof. I also don’t have access to fancy computer programs that will calculate above what the manufacturer lists. All what I’m asking is for proof saying that I can deviate from 121.197, not logic because I agree that The plane would be able to land above max structural
I get the feeling this isn't a company restriction, this is a you restriction. You don't need to find something saying you can do something that is industry standard and FAA approved/assumed. You need to find something that says you can't. Welcome to airplanes.

I'm being serious when i say get off the web boards and talk to your supervisors and FSDO. This is basic material you missed somehow, which is fine, but your looking at this backwards and asking us to do it too.
 

dispatchguy

Well-Known Member
When I was at an Aerodata airline, I declared a TOA coming off of JAC one day on a D328 Prop and my MTOW went from 29K down to 22K. WTF? Our trainer called Scottsdale and the answer was that Aerodata was calculating a Method I Terrain Clearance MTOW from JAC to my TOA with an engine out and anti-ice on, and to clear the terrain west of JAC single engine, we had to reduce MTOW to 22K. To be honest I'm not worried about landing weight at any of my C070 airports, but I am worried about terrain in the rockies... it sounded good to me.
 

Altimeter

Well-Known Member
That’s kinda what I’m confused about. I’ll use an example with generic numbers:

Let’s say you’re leaving KJFK on a 757 at max structural take off at 250,000lbs, you need to add a take off alternate of KBDL. Now, I have a max structural landing weight of say 210,000lbs according to Boeing. But I have runway perf data that says I can land at 250,000lbs and stop the airplane in 60% of the length KBDL’s runway. It’s about a 4,000lb burn from KJFK to KBDL. The 757 cannot dump fuel.

Soooo are we trying to say the airplane is this example needs to have the Take Off weight reduced to the 214,000lbs or that it’s good to go as is with a Take off weight of 250,000lbs? Just trying to have a clear understanding of the original question.

My opinion, in this situation you’re good to go at 250,000lbs because you can stop the plane in under 60% off the runway at the take off alternate (KBDL in this example) and meet the 121.197.
For this scenario for us the Runway Limitied Landing weight is the same as MTOW. So it would be a legal T/O Alt, as long as everything else is legal of course.
 
F

Flying Saluki

Guest
The problem with all this, is the manufacturer of the airframe doesn’t give performance data for landing above max structural, only up to its MLW. Therefore I can’t prove it can land above it’s structrual. I completely agree in knowing realistically that it can, I just don’t have proof. I also don’t have access to fancy computer programs that will calculate above what the manufacturer lists. All what I’m asking is for proof saying that I can deviate from 121.197, not logic because I agree that The plane would be able to land above max structural
You cannot deviate from 121.197. 121.533 obligates you to flight plan in compliance with all regs. and Ops Specs. You must be able to show that your airplane can land and stop in the required 60/70%. If the aircraft manufacturer does not provide any data above MSLW, then that is your limit. You can interpolate from available data. You can't extrapolate.
 

DispatcherSam

Well-Known Member
Why is this thread still happening? If there’s an emergency, emergency authority covers all bases. If it’s not an emergency, just stay up and burn fuel for a bit or dump until you can land safely
 

ak_mavic

Well-Known Member
You cannot deviate from 121.197. 121.533 obligates you to flight plan in compliance with all regs. and Ops Specs. You must be able to show that your airplane can land and stop in the required 60/70%. If the aircraft manufacturer does not provide any data above MSLW, then that is your limit. You can interpolate from available data. You can't extrapolate.
I agree with what’s being said here. My aircraft manufacturer does not provide any data above MSLW, therefore when a T/O Alt is required, I’m not sure I can actually prove that the aircraft can safely land within 60/70% if I don’t have actual data for it. So therefore wouldn’t I have to restrict my takeoff weight?

Here ya go.
What’s this from?
 

Altimeter

Well-Known Member
I agree with what’s being said here. My aircraft manufacturer does not provide any data above MSLW, therefore when a T/O Alt is required, I’m not sure I can actually prove that the aircraft can safely land within 60/70% if I don’t have actual data for it. So therefore wouldn’t I have to restrict my takeoff weight?


What’s this from?
I agree with what’s being said here. My aircraft manufacturer does not provide any data above MSLW, therefore when a T/O Alt is required, I’m not sure I can actually prove that the aircraft can safely land within 60/70% if I don’t have actual data for it. So therefore wouldn’t I have to restrict my takeoff weight?


What’s this from?
Our FM1. So yes you’re right in some situations, it MLW is a combination of things. Climb Limted Landing Weight, Runway Linited Landing Weight, and Structural. If you say don’t have the information to be able to accurately calculate Landing distance, what happens when you have an emergency if flight? How do you determine runway length required for the Weight you’re at? I think you do have the information you need you just don’t know where it’s at, which is a problem.
 

DispatchDan

Well-Known Member
I agree with what’s being said here. My aircraft manufacturer does not provide any data above MSLW, therefore when a T/O Alt is required, I’m not sure I can actually prove that the aircraft can safely land within 60/70% if I don’t have actual data for it. So therefore wouldn’t I have to restrict my takeoff weight?


So when you don't list T/O altn, Which means if needed to you are going back and landing at your departure airport, does that mean you have to ristrict your takeoff weight so you can turn around and land right back???
You only list T/O altn if WX at departure prevents you from landing so if you are restricting yourself for T/O altn than, when T/O altn not listed, you need to wight ristrict your flight so that you can turn around and land at departure airport?
Like someone said before, this is basic stuff you should have been tought in ground school, or during on the job training (surprised this didn't come up then since this will happen most of the time when you have T/O altn)...
Also check you company FOM or CFM there should be overweight landing procedure for pilots and ask MX controllers about overweight landing inspections... happens pretty often
 

belgiumania

Well-Known Member
My aircraft manufacturer does not provide any data above MSLW
So what happens if one of your company flights has to land overweight for an emergency? The crew just WAGs it? There is no way that is the case.

I guarantee there is data somewhere with stopping distances for weights over MLDW, typically it is published up to MTOW, you just need to find it. Check the landing tables in your performance manual.
 
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ak_mavic

Well-Known Member
So what happens if one of your company flights has to land overweight for an emergency? The crew just WAGs it? There is no way that is the case.

I guarantee there is data somewhere with stopping distances for weights over MLDW, typically it is published up to MTOW, you just need to find it. Check the landing tables in your performance manual.
I’ve looked through the manuals and it just isn’t there. CFM, AOM, AFM, DPM, performance charts. None of them have landing performance that go over the MSLW. If they did, I wouldn’t be asking this question to begin with.

This all came about because I asked the question at work and no one could actually point their finger to where we can do what we’ve been doing. I was purely just looking for what proof other people have so that I can take it to my company and say “Hey we’re still good.”
 

Karee

Goldmember
I’ve looked through the manuals and it just isn’t there. CFM, AOM, AFM, DPM, performance charts. None of them have landing performance that go over the MSLW. If they did, I wouldn’t be asking this question to begin with.

This all came about because I asked the question at work and no one could actually point their finger to where we can do what we’ve been doing. I was purely just looking for what proof other people have so that I can take it to my company and say “Hey we’re still good.”
While the release requires listing a t/o alternate, you aren’t actually planning to use it so your weight restriction needs to align with your plan, not your plan B.
 

womanpilot73

Well-Known Member
So what happens if one of your company flights has to land overweight for an emergency? The crew just WAGs it? There is no way that is the case. I guarantee there is data somewhere with stopping distances for weights over MLDW, typically it is published up to MTOW, you just need to find it. Check the landing tables in your performance manual.
I’ve looked through the manuals and it just isn’t there. CFM, AOM, AFM, DPM, performance charts. None of them have landing performance that go over the MSLW. If they did, I wouldn’t be asking this question to begin with. This all came about because I asked the question at work and no one could actually point their finger to where we can do what we’ve been doing. I was purely just looking for what proof other people have so that I can take it to my company and say “Hey we’re still good.”
So, you have people here across the industry from just about every major airline explaining to you why you shouldn’t be limiting payload for a takeoff alternate, but you are still looking for “proof”? I guarantee the entire airline industry isn’t doing it wrong. I would go back to my earlier suggestion for you and reach out to your dispatch fed for further clarification on this matter. Also, you can check with the manufacturer for further performance data. Have you sat down with MX and asked them where their data is for overweight landing inspections and what the aircraft are certified to for landing? (MTOW).

Can you imagine my airline actually pulling off 75-100,000 pounds of payload out of Asia so they aren’t over landing weight at the takeoff alternate? I don’t think I’d have a job lol

I understand wanting to be legal and not breaking regs. This is a great place to come for help. But you don’t seem to want to accept the multiple and repetitive answers given?

Sent from my iPhone using Tapatalk
 
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BayouMLU

Well-Known Member
We plan to land overweight at the takeoff alternate all the time. Makes sense to me that it's legal to do that since you really are looking at it as an emergency airport. Obviously it still needs to meet alt mins.
Can you back it up? I’m just asking what reg says I can ignore 121.197 when I’m listing a T/O alternate. Believe I get the whole, it’s an emergency thing so who cares if we’re over weight. I can only deviate from regulations when an emergency has been declared, not before hand.
Something to consider is that lots of factors come into play with real, live landing weights, including altitude, pressure, the runway, rate of descent, etc that is probably just being taken for granted in this conversation. Now, it can potentially land overweight if the actual correct descent rate isn't observed or if the longer runway becomes unusable because of a broken down aircraft on the ground or the visibility drops below mins, etc. but it wasn't an issue when planned and at departure. The short answer here being that you're probably NOT planning it overweight at all just like the many aircraft I have had return to field not land overweight despite being tankered for 2+ hour long flights.
 

ak_mavic

Well-Known Member
So, you have people here across the industry from just about every major airline explaining to you why you shouldn’t be limiting payload for a takeoff alternate, but you are still looking for “proof”?

I understand wanting to be legal and not breaking regs. This is a great place to come for help. But you don’t seem to want to accept the multiple and repetitive answers given?

Sent from my iPhone using Tapatalk
I have no problem accepting this, and believe me I want to. Is it really that wrong of me to ask for proof? I get it’s the industry standard and everyone does it. Believe it or not, I even do it. I was asking where it says we can do this, and everyone here just responded it’s common practice and common sense. I’ll agree with all of that too. If I ask where the proof is though, for just about any other question people could point me to the reg or guidance. That’s all I’m asking for here.

I was told to look into this by my supervisor, figured I could come here and someone would point to me telling me where we can do this legally instead of just accepting that it is industry practice. I think I’d look kind of ridiculous coming back to my boss telling him, “Hey womanpilot73 and tons of other people agree with us and say we’re good but I couldn’t find regs or guidance for it.” None of our manuals prove that we can safely use a weight greater than the MSLW, and I don’t think I could say “There are MX procedures for when we land overweight so that means I can plan on it.”

But I’ll withdraw my question from here. Thank you everyone for your help in this matter.
 

BayouMLU

Well-Known Member
So, you have people here across the industry from just about every major airline explaining to you why you shouldn’t be limiting payload for a takeoff alternate, but you are still looking for “proof”? I understand wanting to be legal and not breaking regs. This is a great place to come for help. But you don’t seem to want to accept the multiple and repetitive answers given? Sent from my iPhone using Tapatalk
I have no problem accepting this, and believe me I want to. Is it really that wrong of me to ask for proof? I get it’s the industry standard and everyone does it. Believe it or not, I even do it. I was asking where it says we can do this, and everyone here just responded it’s common practice and common sense. I’ll agree with all of that too. If I ask where the proof is though, for just about any other question people could point me to the reg or guidance. That’s all I’m asking for here. I was told to look into this by my supervisor, figured I could come here and someone would point to me telling me where we can do this legally instead of just accepting that it is industry practice. I think I’d look kind of ridiculous coming back to my boss telling him, “Hey womanpilot73 and tons of other people agree with us and say we’re good but I couldn’t find regs or guidance for it.” None of our manuals prove that we can safely use a weight greater than the MSLW, and I don’t think I could say “There are MX procedures for when we land overweight so that means I can plan on it.” But I’ll withdraw my question from here. Thank you everyone for your help in this matter.
Agreed. If you're ever asked by someone with authority, "polled a message board and this is the answer they came up with"won't cut it. Nothing wrong with understanding the "why". Just be careful not to get lost in your search through FAA regs. Lol
 

who'swho

Don't hesitate. Penetrate!
So, you have people here across the industry from just about every major airline explaining to you why you shouldn’t be limiting payload for a takeoff alternate, but you are still looking for “proof”? I guarantee the entire airline industry isn’t doing it wrong. I would go back to my earlier suggestion for you and reach out to your dispatch fed for further clarification on this matter. Also, you can check with the manufacturer for further performance data. Have you sat down with MX and asked them where their data is for overweight landing inspections and what the aircraft are certified to for landing? (MTOW).

Can you imagine my airline actually pulling off 75-100,000 pounds of payload out of Asia so they aren’t over landing weight at the takeoff alternate? I don’t think I’d have a job lol

I understand wanting to be legal and not breaking regs. This is a great place to come for help. But you don’t seem to want to accept the multiple and repetitive answers given?

Sent from my iPhone using Tapatalk
Capture.png

Would've bumped almost 65,000 kgs today of my 113,000 payload going to ANC out of Asia.
 

jynxyjoe

The Kickin' Chicken!
I have no problem accepting this, and believe me I want to. Is it really that wrong of me to ask for proof? I get it’s the industry standard and everyone does it. Believe it or not, I even do it. I was asking where it says we can do this, and everyone here just responded it’s common practice and common sense. I’ll agree with all of that too. If I ask where the proof is though, for just about any other question people could point me to the reg or guidance. That’s all I’m asking for here.

I was told to look into this by my supervisor, figured I could come here and someone would point to me telling me where we can do this legally instead of just accepting that it is industry practice. I think I’d look kind of ridiculous coming back to my boss telling him, “Hey womanpilot73 and tons of other people agree with us and say we’re good but I couldn’t find regs or guidance for it.” None of our manuals prove that we can safely use a weight greater than the MSLW, and I don’t think I could say “There are MX procedures for when we land overweight so that means I can plan on it.”

But I’ll withdraw my question from here. Thank you everyone for your help in this matter.
if you were planning to go to the alternate we wouldn't send/plan you to the destination.

Getting off a web board for answers is a good start. Someone on here said that in an earlier post.
 
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