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aviationfan12
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Delta 737 Winglet Retrofit

Mon Oct 22, 2018 4:36 pm

All of Delta's current B737-900ER's are all being delivered with Split Scimitar winglets, do we know when the -700's and -800's will be retrofitted with then or are they going to be retrofitted at all?
 
Deltabravo1123
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Re: Delta 737 Winglet Retrofit

Mon Oct 22, 2018 5:06 pm

viewtopic.php?t=1388321

Looks like it was discussed a little while back, although the thread appears to have been turned into a 757 thread instead of the 737 that it was originally about. Unfortunately I haven't heard any updates since then.

It doesn't seem as though they'll be installed on the -700 or -800s. It's just the basic ROI calculation - if DL believes it's worth the investment then they'll get installed. The cost of these were somewhere around $600,000 per plane when I last read about the installation. I'm sure the costs have gone up even more by now.
 
ilovelamp
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Re: Delta 737 Winglet Retrofit

Mon Oct 22, 2018 5:15 pm

No plans to install them on anything other than the -900ERs. The modification of remaining fleet of that model won’t be completed until 2020 at the earliest.
 
PotatoPappas
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Re: Delta 737 Winglet Retrofit

Sun Oct 28, 2018 7:18 pm

ilovelamp wrote:
No plans to install them on anything other than the -900ERs. The modification of remaining fleet of that model won’t be completed until 2020 at the earliest.


So the rest of the 900ers are getting them? When are they starting that?
 
burnsie28
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Re: Delta 737 Winglet Retrofit

Sun Oct 28, 2018 9:51 pm

aviationfan12 wrote:
All of Delta's current B737-900ER's are all being delivered with Split Scimitar winglets, do we know when the -700's and -800's will be retrofitted with then or are they going to be retrofitted at all?


They are not being delivered with the split scimitar. The split scimitar is an aftermarket product, Boeing only delivers with standard winglets. Only the -900's will get them.
 
ilovelamp
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Re: Delta 737 Winglet Retrofit

Sun Oct 28, 2018 10:39 pm

PotatoPappas wrote:
ilovelamp wrote:
No plans to install them on anything other than the -900ERs. The modification of remaining fleet of that model won’t be completed until 2020 at the earliest.


So the rest of the 900ers are getting them? When are they starting that?


TechOps has only purchased a limited number to retro fit the older 900ERs. So as it stands now they don’t have enough kits to retrofit all the remaining fleet.
 
Beatyair
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Re: Delta 737 Winglet Retrofit

Sun Oct 28, 2018 10:59 pm

Typically airlines have not gone back to retrofit the scimitar. New plane have the latest and the older model have the older version.
 
United1
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Re: Delta 737 Winglet Retrofit

Mon Oct 29, 2018 12:50 am

Beatyair wrote:
Typically airlines have not gone back to retrofit the scimitar. New plane have the latest and the older model have the older version.


UA retrofitted their entire fleet, WN retrofitted all of their 800s and a number of 700s, AS retrofitted most of their fleet.

Every airline makes a different choice when it comes to figuring out if the ROI is worth it or not. It would be interesting to see why DL and AA decided not retrofit vs their US peers.
I know the voices in my head aren't real but sometimes their ideas are just awesome!!!
 
B757Forever
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Re: Delta 737 Winglet Retrofit

Mon Oct 29, 2018 1:48 am

United1 wrote:
Beatyair wrote:
Typically airlines have not gone back to retrofit the scimitar. New plane have the latest and the older model have the older version.


UA retrofitted their entire fleet, WN retrofitted all of their 800s and a number of 700s, AS retrofitted most of their fleet.

Every airline makes a different choice when it comes to figuring out if the ROI is worth it or not. It would be interesting to see why DL and AA decided not retrofit vs their US peers.


Delta's first 737-800, ship 3701 was delivered in October 1998. The last of the original group, ship 3771 was delivered April of 2002. At this age, a $600K airframe upgrade most likely doesn't make good sense.
The Rolls Royce Dart. Noise = Shaft Horsepower.
 
United1
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Re: Delta 737 Winglet Retrofit

Mon Oct 29, 2018 2:26 am

B757Forever wrote:
United1 wrote:
Beatyair wrote:
Typically airlines have not gone back to retrofit the scimitar. New plane have the latest and the older model have the older version.


UA retrofitted their entire fleet, WN retrofitted all of their 800s and a number of 700s, AS retrofitted most of their fleet.

Every airline makes a different choice when it comes to figuring out if the ROI is worth it or not. It would be interesting to see why DL and AA decided not retrofit vs their US peers.


Delta's first 737-800, ship 3701 was delivered in October 1998. The last of the original group, ship 3771 was delivered April of 2002. At this age, a $600K airframe upgrade most likely doesn't make good sense.


Possibly....those are about the same as UAs 737/739 and half of the 738 fleet is. Perhaps DL doesn't plan on keeping them as long as UA does?
I know the voices in my head aren't real but sometimes their ideas are just awesome!!!
 
justplanesmart
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Re: Delta 737 Winglet Retrofit

Wed Oct 31, 2018 4:00 am

"UA retrofitted their entire fleet, WN retrofitted all of their 800s and a number of 700s, AS retrofitted most of their fleet"

Southwest has not yet retrofitted all of their 737-800 fleet with split-scimitars, but is in the process of doing so. All of the 737-800 and 737-900 aircraft in Alaska's fleet that carry blended winglets now have split-scimitars.
"So many planes; so little time..."
 
deltal1011man
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Re: Delta 737 Winglet Retrofit

Wed Oct 31, 2018 5:04 am

United1 wrote:
B757Forever wrote:
United1 wrote:

UA retrofitted their entire fleet, WN retrofitted all of their 800s and a number of 700s, AS retrofitted most of their fleet.

Every airline makes a different choice when it comes to figuring out if the ROI is worth it or not. It would be interesting to see why DL and AA decided not retrofit vs their US peers.


Delta's first 737-800, ship 3701 was delivered in October 1998. The last of the original group, ship 3771 was delivered April of 2002. At this age, a $600K airframe upgrade most likely doesn't make good sense.


Possibly....those are about the same as UAs 737/739 and half of the 738 fleet is. Perhaps DL doesn't plan on keeping them as long as UA does?

25-30 years old is generally the Delta goal with any aircraft.

but right now the fuel outlook isn't bad enough to justify them. If fuel shoots up into the 100+ (it wont) then you might see Delta push the mods.

edit to add, I'd be willing to bet the current management team at United wouldn't have done a complete re-fit either.
 
716131
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Re: Delta 737 Winglet Retrofit

Wed Oct 31, 2018 5:30 am

aviationfan12 wrote:
All of Delta's current B737-900ER's are all being delivered with Split Scimitar winglets, do we know when the -700's and -800's will be retrofitted with then or are they going to be retrofitted at all?

Not all -900ER I found, actually 70% -900ER already retrofitted.
If it's not Boeing, I'm not going!
 
ilovelamp
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Re: Delta 737 Winglet Retrofit

Fri Nov 23, 2018 1:04 am

SQ789 wrote:
aviationfan12 wrote:
All of Delta's current B737-900ER's are all being delivered with Split Scimitar winglets, do we know when the -700's and -800's will be retrofitted with then or are they going to be retrofitted at all?

Not all -900ER I found, actually 70% -900ER already retrofitted.


And technically, they don’t come from the factory with the scimitar winglets. Delta buys the kits separately and TechOps installs them shortly after delivery.
 
77H
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Re: Delta 737 Winglet Retrofit

Fri Nov 23, 2018 11:21 am

I don’t know how to quantify this but perhaps it has something to do with the roles the 73G and 738 play with AA and DL vs AS and UA or even WN.

My understanding is that the split scimitars’ effectiveness (fuel savings) increase as stage length (time at cruise) increases.

Perhaps AS and UA operate both models on longer trips than AA and DL on average? DL tends to operate quite a few transcons with the 739 where the fuel savings can be better realized?

77H
 
Okcflyer
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Re: Delta 737 Winglet Retrofit

Fri Nov 23, 2018 11:31 am

77H wrote:
I don’t know how to quantify this but perhaps it has something to do with the roles the 73G and 738 play with AA and DL vs AS and UA or even WN.

My understanding is that the split scimitars’ effectiveness (fuel savings) increase as stage length (time at cruise) increases.

Perhaps AS and UA operate both models on longer trips than AA and DL on average? DL tends to operate quite a few transcons with the 739 where the fuel savings can be better realized?

77H


That’s precisely it. UA’s average 737 and 738 stage length is nearly 500mi longer than DL and still considerably more than AA’s. Aircraft utilization rate is also important (usually related to stage length depending on route network)

They do add some additional weight that has to be lifted which hurts on very short routes and airframe maintenance costs are a bit higher. The payback is from drag reduction in cruise and high altitude climb. In fact, airlines like Copa whom stretch the range of the 737 platform are usually careful to match aircraft to the route, and in extreme cases, become the difference between payload restrictions or not.

IIRC, split scimitar 739 aircraft are eligible for updated/revised/optimized single engine performance procedures which call for a lower flap setting which reduces restrictions significantly for 2nd-stage climbout from high altitude airports (Denver for UA). I speculate but never concerned this is due to better lift/drag ratio even at low speeds.
 
audidudi
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Re: Delta 737 Winglet Retrofit

Fri Nov 23, 2018 4:53 pm

The seven latest B739ERs delivered, N901DN-N907DN, have also not had them installed.
 
PotatoPappas
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Re: Delta 737 Winglet Retrofit

Fri Nov 23, 2018 10:05 pm

audidudi wrote:
The seven latest B739ERs delivered, N901DN-N907DN, have also not had them installed.



They also are not ETOPs
 
audidudi
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Re: Delta 737 Winglet Retrofit

Fri Nov 23, 2018 10:22 pm

PotatoPappas wrote:
audidudi wrote:
The seven latest B739ERs delivered, N901DN-N907DN, have also not had them installed.



They also are not ETOPs

None of the following are ETOPS equipped:
N801DZ-N852DN
N875DN -ETOPS decommissioned
N896DN-N907DN
N908DN-and later deliveries.

Only N876DN-N895DN will remain ETOPS equipped.
 
maps4ltd
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 1:04 am

audidudi wrote:
The seven latest B739ERs delivered, N901DN-N907DN, have also not had them installed.


I can't say I'm surprised. Of all the carriers, Delta seems to be the least eager to do winglet mods on 737 series aircraft. I'd say United has been the most willing, followed by Alaska, Southwest, and American. Of course, Alaska does have some 739's without winglets at all, so maybe AS and WN should be switched.
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Runway28L
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 1:25 am

Okcflyer wrote:
77H wrote:
I don’t know how to quantify this but perhaps it has something to do with the roles the 73G and 738 play with AA and DL vs AS and UA or even WN.

My understanding is that the split scimitars’ effectiveness (fuel savings) increase as stage length (time at cruise) increases.

Perhaps AS and UA operate both models on longer trips than AA and DL on average? DL tends to operate quite a few transcons with the 739 where the fuel savings can be better realized?

77H


That’s precisely it. UA’s average 737 and 738 stage length is nearly 500mi longer than DL and still considerably more than AA’s. Aircraft utilization rate is also important (usually related to stage length depending on route network)

They do add some additional weight that has to be lifted which hurts on very short routes and airframe maintenance costs are a bit higher. The payback is from drag reduction in cruise and high altitude climb. In fact, airlines like Copa whom stretch the range of the 737 platform are usually careful to match aircraft to the route, and in extreme cases, become the difference between payload restrictions or not.

IIRC, split scimitar 739 aircraft are eligible for updated/revised/optimized single engine performance procedures which call for a lower flap setting which reduces restrictions significantly for 2nd-stage climbout from high altitude airports (Denver for UA). I speculate but never concerned this is due to better lift/drag ratio even at low speeds.

DL definitely operates their B737s on shorter routes from what I've seen lately. The B739s especially. Looks like they've been making their way onto really short routes over the past few months such as ATL-CMH/RDU/ECP/MEM/JAX and DTW-MSN/PIT/ATL/LGA/BWI. Likely hurts the case of modification costs being worth it for the fuel savings.
 
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CrimsonNL
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 8:30 am

Does anyone know the approximate downtime for an aircraft to get these splits slapped on?

Martijn
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MSPNWA
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 9:12 am

77H wrote:
I don’t know how to quantify this but perhaps it has something to do with the roles the 73G and 738 play with AA and DL vs AS and UA or even WN.

My understanding is that the split scimitars’ effectiveness (fuel savings) increase as stage length (time at cruise) increases.

Perhaps AS and UA operate both models on longer trips than AA and DL on average? DL tends to operate quite a few transcons with the 739 where the fuel savings can be better realized?

77H

It does increase with stage length, but even short stage lengths of ~500 miles see a significant improvement. No matter how you calculate it, the Scimitar upgrade pays for itself eventually and then becomes value-added. It's really inexcusable that AA and DL are not installing them on at least their new/newer 737s. Roles only affect how much they save over time, not whether they will pay for itself. Artificial CapEx budgets are my guess to why they haven't been installed at AA and been limited at DL.

https://leehamnews.com/2013/10/28/how-t ... -winglets/
 
strfyr51
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 9:32 am

deltal1011man wrote:
United1 wrote:
B757Forever wrote:

Delta's first 737-800, ship 3701 was delivered in October 1998. The last of the original group, ship 3771 was delivered April of 2002. At this age, a $600K airframe upgrade most likely doesn't make good sense.


Possibly....those are about the same as UAs 737/739 and half of the 738 fleet is. Perhaps DL doesn't plan on keeping them as long as UA does?

s-30 years old is generally the Delta goal with any aircraft.

but right now the fuel outlook isn't bad enough to justify them. If fuel shoots up into the 100+ (it wont) then you might see Delta push the mods.

edit to add, I'd be willing to bet the current management team at United wouldn't have done a complete re-fit either.

the current UA management team just kept on with the plan the S-CO management team had in place. So far? It's worked out.
 
jagraham
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 4:23 pm

Okcflyer wrote:
77H wrote:
I don’t know how to quantify this but perhaps it has something to do with the roles the 73G and 738 play with AA and DL vs AS and UA or even WN.

My understanding is that the split scimitars’ effectiveness (fuel savings) increase as stage length (time at cruise) increases.

Perhaps AS and UA operate both models on longer trips than AA and DL on average? DL tends to operate quite a few transcons with the 739 where the fuel savings can be better realized?

77H


That’s precisely it. UA’s average 737 and 738 stage length is nearly 500mi longer than DL and still considerably more than AA’s. Aircraft utilization rate is also important (usually related to stage length depending on route network)

They do add some additional weight that has to be lifted which hurts on very short routes and airframe maintenance costs are a bit higher. The payback is from drag reduction in cruise and high altitude climb. In fact, airlines like Copa whom stretch the range of the 737 platform are usually careful to match aircraft to the route, and in extreme cases, become the difference between payload restrictions or not.

IIRC, split scimitar 739 aircraft are eligible for updated/revised/optimized single engine performance procedures which call for a lower flap setting which reduces restrictions significantly for 2nd-stage climbout from high altitude airports (Denver for UA). I speculate but never concerned this is due to better lift/drag ratio even at low speeds.


An additional factor with DL is their capex discipline. Even if they decided to retrofit all their 900s and some 800s, they spread it out so the total capex doesn’t exceed certain internal limits. The rest is pushed out to future years. Just like the interior mods on the widebodies.
 
jetmatt777
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Re: Delta 737 Winglet Retrofit

Sat Nov 24, 2018 7:57 pm

CrimsonNL wrote:
Does anyone know the approximate downtime for an aircraft to get these splits slapped on?

Martijn


If my memory serves me correct, I believe about 5 days to a week, at least at United.
 
Dalmd88
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Re: Delta 737 Winglet Retrofit

Sun Nov 25, 2018 2:20 am

jetmatt777 wrote:
CrimsonNL wrote:
Does anyone know the approximate downtime for an aircraft to get these splits slapped on?

Martijn


If my memory serves me correct, I believe about 5 days to a week, at least at United.

I can't see it taking that long. If there is no changes to the aircraft structure it is a simple bolt off/on affair. It only took a shift to remove the regular winglet and another to install it. From what I've heard the structure in the wing is already prepped for the simitar winglet.
 
jetmatt777
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Re: Delta 737 Winglet Retrofit

Sun Nov 25, 2018 3:02 am

Dalmd88 wrote:
jetmatt777 wrote:
CrimsonNL wrote:
Does anyone know the approximate downtime for an aircraft to get these splits slapped on?

Martijn


If my memory serves me correct, I believe about 5 days to a week, at least at United.

I can't see it taking that long. If there is no changes to the aircraft structure it is a simple bolt off/on affair. It only took a shift to remove the regular winglet and another to install it. From what I've heard the structure in the wing is already prepped for the simitar winglet.


I think for the ones rolling out of the factory today that is the case, but the earlier NG’s needed some additional modification?

I could be wrong.
 
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DL_Mech
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Re: Delta 737 Winglet Retrofit

Sun Nov 25, 2018 11:39 am

There are structural mods when installing the split scimitar winglets. The trailing edge wedge was installed on our -900ERs when the scimitars were added.

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