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N415XJ
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What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 4:04 pm

While there are exceptions, it seems that most airlines in the US have tail numbers with two final letters, often reflecting their ICAO or IATA codes. For example, Delta is frequently N###DL, American is N###AA or N###AN, jetblue is N###JB, America West used N###AW, Skywest uses N###SW, etc. Even when the letters don't reflect the airline's code, there are still two letters. Allegiant uses N###NV, many Southwest registrations are N###WN or N###SW, Northwest used N###NB (along with US and NW) for many narrowbody airbuses. The only major exception I can think of is Endeavor, which has used N####A for a good portion of its CRJ-200 fleet.

Other than GA planes, the only time I've seen tail numbers that are all numbers has been on former Continental and Continental Express/Connection aircraft. Across the entire CO fleet (with the exception of former Eastern A300s and People Express 747s), it seems like they all have five numbers with no letters going back to at least the 80s.90s. This even extends to many of the regional frames operated by Express contract carriers.

Was there a specific reason for this? It seems strange that while the industry standard seems to be to have registrations that reflect the name of the airline in some way or at least contain two suffix letters, CO would be the only one to not choose something like N###CO N###CA, etc and instead choose N##### for a huge portion of their fleet for decades.
 
SpaceshipDC10
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 4:21 pm

N415XJ wrote:
While there are exceptions, it seems that most airlines in the US have tail numbers with two final letters, often reflecting their ICAO or IATA codes. For example, Delta is frequently N###DL, American is N###AA or N###AN, jetblue is N###JB, America West used N###AW, Skywest uses N###SW, etc. Even when the letters don't reflect the airline's code, there are still two letters. Allegiant uses N###NV, many Southwest registrations are N###WN or N###SW, Northwest used N###NB (along with US and NW) for many narrowbody airbuses. The only major exception I can think of is Endeavor, which has used N####A for a good portion of its CRJ-200 fleet.


In later times it's become more common it seems to have a three numbers followed by two letters, but it's not always been like that. For instance, American has had different vairants of registrations as did many other U.S. airlines. Have a look at the site I link below:

http://www.aeromoe.com/fleets/airlines.html



N415XJ wrote:
Other than GA planes, the only time I've seen tail numbers that are all numbers has been on former Continental and Continental Express/Connection aircraft. Across the entire CO fleet (with the exception of former Eastern A300s and People Express 747s), it seems like they all have five numbers with no letters going back to at least the 80s.90s. This even extends to many of the regional frames operated by Express contract carriers.


You can find that most jetliners ordered and delivered to CO had numbers only registration well before the '80s. The last three digits are both part of the registration and the numbering in the sub-fleet.
 
katwspotter
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 4:48 pm

As to why they did this, I do not know but if they did decide to chose to use letters at the end, the would not be able to use "CO" because per the FAA, no N number can contain the letters "O" or "I" so they are not confused with the numbers 0 and 1.
"You're cleared to land on the green dot"
 
DiamondFlyer
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 4:53 pm

N415XJ wrote:
While there are exceptions, it seems that most airlines in the US have tail numbers with two final letters, often reflecting their ICAO or IATA codes. For example, Delta is frequently N###DL, American is N###AA or N###AN, jetblue is N###JB, America West used N###AW, Skywest uses N###SW, etc. Even when the letters don't reflect the airline's code, there are still two letters. Allegiant uses N###NV, many Southwest registrations are N###WN or N###SW, Northwest used N###NB (along with US and NW) for many narrowbody airbuses. The only major exception I can think of is Endeavor, which has used N####A for a good portion of its CRJ-200 fleet.

Other than GA planes, the only time I've seen tail numbers that are all numbers has been on former Continental and Continental Express/Connection aircraft. Across the entire CO fleet (with the exception of former Eastern A300s and People Express 747s), it seems like they all have five numbers with no letters going back to at least the 80s.90s. This even extends to many of the regional frames operated by Express contract carriers.

Was there a specific reason for this? It seems strange that while the industry standard seems to be to have registrations that reflect the name of the airline in some way or at least contain two suffix letters, CO would be the only one to not choose something like N###CO N###CA, etc and instead choose N##### for a huge portion of their fleet for decades.


The Endeavor 200's (formerly Pinnacle) with the 8xxxA tail number series are actually very simple. They're the serial number of the aircraft + 1000, and the first available letter to be used that wasn't registered at the time of delivery. So S/N 7694 would be registered as N8694A.
From my cold, dead hands
 
Cubsrule
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 4:55 pm

katwspotter wrote:
As to why they did this, I do not know but if they did decide to chose to use letters at the end, the would not be able to use "CO" because per the FAA, no N number can contain the letters "O" or "I" so they are not confused with the numbers 0 and 1.


Good point. It’s also worth remembering that up until somewhere in the 2005-2010 time range, no US carrier other than NW had the IT capability for four digit fin numbers (that’s why AA has/had weird alphanumeric fin numbers). So the three informative digits plus two not-so-informative character system was pretty standard. (NW’s last two digits meant something on the Airbus narrowbodies, which are all N3XXYY, with the 319s having mostly NB suffixes and the 320s more varied but largely US.)

Edit: on further reflection, I think UA also had four digit fin numbers pretty early on.
I can't decide whether I miss the tulip or the bowling shoe more
 
OB1504
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 6:26 pm

United is continuing the former Continental style registrations on their 787s and 777-300ERs.

American employs a similar scheme on some of their A319s and also used to on the A300 fleet, where the last 3 digits of the registration correspond to the ship number, often times followed by a random letter.

The newer 737s use a variation where the first digit and the last two letters correspond to the ship number, and the middle two digits are random.
 
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ikolkyo
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 6:46 pm

OB1504 wrote:
United is continuing the former Continental style registrations on their 787s and 777-300ERs.

American employs a similar scheme on some of their A319s and also used to on the A300 fleet, where the last 3 digits of the registration correspond to the ship number, often times followed by a random letter.

The newer 737s use a variation where the first digit and the last two letters correspond to the ship number, and the middle two digits are random.


Pretty sure on the MAXs the regs go like this, the fleet numbers for the MAX 9 start at 7501, so the first aircraft is registered as N67501. The first digit in the regs seems to be random while the final 4 is the aircrafts specific fleet number. As such, the 2nd MAX 9 is N37502.

Which is inline with CO’s registration strategy on all their other fleet types. The all number regs are essentially their fleet number with some random digits in there as filler. If you look at the 737NGs, 777s and 757s you will notice the pattern there also.
 
Vctony
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 6:52 pm

WN does something similar with their 737-800s/Maxes and used/Airtran 737-700s.

The 737-800s are either N83XXX, N85XXX, or N86XXX. The 737-Maxes are N87XXX. The used/Airtran 737-700s are either N77XXX or N78XXX.
 
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GCT64
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 6:58 pm

ikolkyo wrote:
OB1504 wrote:
United is continuing the former Continental style registrations on their 787s and 777-300ERs.

American employs a similar scheme on some of their A319s and also used to on the A300 fleet, where the last 3 digits of the registration correspond to the ship number, often times followed by a random letter.

The newer 737s use a variation where the first digit and the last two letters correspond to the ship number, and the middle two digits are random.


Pretty sure on the MAXs the regs go like this, the fleet numbers for the MAX 9 start at 7501, so the first aircraft is registered as N67501. The first digit in the regs seems to be random while the final 4 is the aircrafts specific fleet number. As such, the 2nd MAX 9 is N37502.

Which is inline with CO’s registration strategy on all their other fleet types. The all number regs are essentially their fleet number with some random digits in there as filler. If you look at the 737NGs, 777s and 757s you will notice the pattern there also.


The extra digit(s) look random but are required in order not to conflict with other already registered aircraft.
If we take the Nx7501 example mentioned above:
N17501 = WW1 replica
N27501 = (was a PA-31 now vacant)
N37501 = AA-5
N47501 = PA-32R
N57501 = (was a Taylorcraft)
N67501 = UA's MAX9
N77501 = Aeronca
N87501 = (was a Seabee)
N97501 = Stinson
Flown in: A20N,A21N,A30B,A306,A310,A319,A320,A321,A332,A333,A343,A346,A359,A388,BA11,BU31,(..56 more types..),VC10,WESX
 
strfyr51
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 8:03 pm

Here's the deal. the NxxxxU or NxxxUA numbers havevto be reserved well in advance of a fleet purchase. CO's Idea wasn't to use the N-nbr with UA or CO but to use the sequence number like Nxxx01, 02 etc. the Number is really not as important as is the Paint scheme on the airplane to them as many at United are only cognizant of the Nose Number anyway.
 
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ikolkyo
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 8:26 pm

GCT64 wrote:
ikolkyo wrote:
OB1504 wrote:
United is continuing the former Continental style registrations on their 787s and 777-300ERs.

American employs a similar scheme on some of their A319s and also used to on the A300 fleet, where the last 3 digits of the registration correspond to the ship number, often times followed by a random letter.

The newer 737s use a variation where the first digit and the last two letters correspond to the ship number, and the middle two digits are random.


Pretty sure on the MAXs the regs go like this, the fleet numbers for the MAX 9 start at 7501, so the first aircraft is registered as N67501. The first digit in the regs seems to be random while the final 4 is the aircrafts specific fleet number. As such, the 2nd MAX 9 is N37502.

Which is inline with CO’s registration strategy on all their other fleet types. The all number regs are essentially their fleet number with some random digits in there as filler. If you look at the 737NGs, 777s and 757s you will notice the pattern there also.


The extra digit(s) look random but are required in order not to conflict with other already registered aircraft.
If we take the Nx7501 example mentioned above:
N17501 = WW1 replica
N27501 = (was a PA-31 now vacant)
N37501 = AA-5
N47501 = PA-32R
N57501 = (was a Taylorcraft)
N67501 = UA's MAX9
N77501 = Aeronca
N87501 = (was a Seabee)
N97501 = Stinson


Right, I use random in the sense that the most important part of the reg that CO/UA cared was having the full ship number in there no matter what. Probably should went a lil more in depth.
 
MO11
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 9:01 pm

Cubsrule wrote:
katwspotter wrote:
As to why they did this, I do not know but if they did decide to chose to use letters at the end, the would not be able to use "CO" because per the FAA, no N number can contain the letters "O" or "I" so they are not confused with the numbers 0 and 1.


Good point. It’s also worth remembering that up until somewhere in the 2005-2010 time range, no US carrier other than NW had the IT capability for four digit fin numbers (that’s why AA has/had weird alphanumeric fin numbers). So the three informative digits plus two not-so-informative character system was pretty standard. (NW’s last two digits meant something on the Airbus narrowbodies, which are all N3XXYY, with the 319s having mostly NB suffixes and the 320s more varied but largely US.)

Edit: on further reflection, I think UA also had four digit fin numbers pretty early on.


United had 4-digit fleet numbers before there was such a thing as IT. Northwest switched from 3-digit to 4-digit fleet numbers with the Republic merger.
 
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N2111J
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 9:24 pm

Continental's first few A300's were registered N966C-N972C but then were re registered into 5 digit numbers when they took over Eastern's A300's and changed all those to 5 digits as well.
 
UA444
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 9:47 pm

OB1504 wrote:
United is continuing the former Continental style registrations on their 787s and 777-300ERs.

American employs a similar scheme on some of their A319s and also used to on the A300 fleet, where the last 3 digits of the registration correspond to the ship number, often times followed by a random letter.

The newer 737s use a variation where the first digit and the last two letters correspond to the ship number, and the middle two digits are random.

The 787s use the random numbers, but the 777-300 uses the NxxxxU pattern which UA used until the early 1980s.

A lot of the NxxxUA numbers are still in use by UA or still registered to aircraft they used to have or got reserved by someone.
 
wjcandee
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 10:00 pm

It's a cultural choice. Airlines had personalities, and a lot did a lot of little things differently.

Why were the switches on TWA's Boeings the reverse of many other US airlines (i.e. "up for on" rather than "forward for on")? They wanted it that way, that's why.
 
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NWAROOSTER
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 10:23 pm

Under Donald Nyrop's reign at Northwest Airlines Northwest paid the FAA for the exclusive right to use the suffix US (United States) on it's aircraft starting with the DC-8s which were number N801US up to about N805US.They were quickly sold and replaced with the Boeing 720 which were registered N721US through about N737US. The Lockheed Electra L188s used N121US through about N138US. The Boeing 707-351s which also started about the same time were numbered N351US through about N386US. The 727-100s used N460US through through N499US and the 727-251s used N251US through N299US and wound around from N201US through N204US plus four well used Braniff 727-227s were registered as N405US through N2008US. Several Eastern 727s were acquired but used the number that Eastern had used. Northwest also bought 22 DC-10-40s that were registered as N141US through N162US. Northwest also acquired about 14 used DC-10-30s that were registered starting at N211NW skipping there way through N244NW. Northwest acquired the used DC-30s as they were in financial trouble and could not afford new wide body aircraft. The 757s also used the US suffix stating at N501US through N549US except N510US which was already taken and Northwest could not pay the owner to give up the US suffix so that hat number was skipped. I do not understand why Northwest did not use a different suffix such as NW. Starting at N550 the 757s were registered with the NW suffix. The 747-100 and 200 were registered with N601US through N640US. A few used freighters and passenger 747s were registered N641NW through about N646NW. Then the 747-451s came they were registered N661US through N674US. The last two had the NW suffix. Northwest assigned the three numbers as the fleet or ship number. Northwest was the the first North American Airline to acquire the A320 and the first 26 were register N301US through N226US with the remaining A320s having the registration N327NW and up. The A319s acquired were registered N319NB and up as to distinguish them from the A320s. Just as a note after Nyrop left Northwest the US suffix was no longer guaranteed as other operators were using the US suffix, especially US Airways. After the merger with Republic Airline Northwest went to a four number fleet or ship number as as there were over lapping numbers in the two fleets. Also of note N674US was the last passenger 747 by a major airline in the United States. Delta was then the owner. This is a little off the original title but gives some idea of how aircraft were registered. I hope the moderators do not delete it:old:
Procrastination Is The Theft Of Time.......
 
CATIIIevery5yrs
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sat Apr 04, 2020 10:47 pm

NWAROOSTER wrote:
Under Donald Nyrop's reign at Northwest Airlines Northwest paid the FAA for the exclusive right to use the suffix US (United States) on it's aircraft starting with the DC-8s which were number N801US up to about N805US.They were quickly sold and replaced with the Boeing 720 which were registered N721US through about N737US. The Lockheed Electra L188s used N121US through about N138US. The Boeing 707-351s which also started about the same time were numbered N351US through about N386US. The 727-100s used N460US through through N499US and the 727-251s used N251US through N299US and wound around from N201US through N204US plus four well used Braniff 727-227s were registered as N405US through N2008US. Several Eastern 727s were acquired but used the number that Eastern had used. Northwest also bought 22 DC-10-40s that were registered as N141US through N162US. Northwest also acquired about 14 used DC-10-30s that were registered starting at N211NW skipping there way through N244NW. Northwest acquired the used DC-30s as they were in financial trouble and could not afford new wide body aircraft. The 757s also used the US suffix stating at N501US through N549US except N510US which was already taken and Northwest could not pay the owner to give up the US suffix so that hat number was skipped. I do not understand why Northwest did not use a different suffix such as NW. Starting at N550 the 757s were registered with the NW suffix. The 747-100 and 200 were registered with N601US through N640US. A few used freighters and passenger 747s were registered N641NW through about N646NW. Then the 747-451s came they were registered N661US through N674US. The last two had the NW suffix. Northwest assigned the three numbers as the fleet or ship number. Northwest was the the first North American Airline to acquire the A320 and the first 26 were register N301US through N226US with the remaining A320s having the registration N327NW and up. The A319s acquired were registered N319NB and up as to distinguish them from the A320s. Just as a note after Nyrop left Northwest the US suffix was no longer guaranteed as other operators were using the US suffix, especially US Airways. After the merger with Republic Airline Northwest went to a four number fleet or ship number as as there were over lapping numbers in the two fleets. Also of note N674US was the last passenger 747 by a major airline in the United States. Delta was then the owner. This is a little off the original title but gives some idea of how aircraft were registered. I hope the moderators do not delete it:old:


I always assumed the NB on the NWA Airbus stood for ‘Northwest Bus’
 
United1
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Sun Apr 05, 2020 2:39 am

OB1504 wrote:
United is continuing the former Continental style registrations on their 787s and 777-300ERs.

American employs a similar scheme on some of their A319s and also used to on the A300 fleet, where the last 3 digits of the registration correspond to the ship number, often times followed by a random letter.

The newer 737s use a variation where the first digit and the last two letters correspond to the ship number, and the middle two digits are random.


UA continues to use the CO numbers scheme on the 787 N numbers but the 77Ws are different.

The 77Ws are N2XXXU...and sort of follow the pmUA numbering system with a nod to UA in the 70/80's and CO.

For instance...N2331U which is ship number 2131
N - US (duh :) )
2 - All pmUA 777s in UAs fleet four digit ship numbers start with 2 however on pmUA and pmCO registrations the first number is a random number.
3 - The second number is whatever is available to make the next two numbers work however on the ship number the 77Ws are all 21XX.
31 - last two digits of the ship number 31-52 for the 77Ws (both pmUA and pmCO did this)
U - United (UA used NXXXXU numbers back in the stars and bars/friendship livery days before switching to NXXXUA registrations.)
I know the voices in my head aren't real but sometimes their ideas are just awesome!!!
 
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aeromoe
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Tue Apr 07, 2020 10:59 pm

SpaceshipDC10 wrote:

Have a look at the site I link below:

http://www.aeromoe.com/fleets/airlines.html


Kind thanks for the plug. While I haven't updated my fleets in decades ( :o :o ) I am glad there is still some utility in the historical information.

Moe
Since 60s: AA AC AS BA BD BF BN BR(85) BY B6 CO CZ(16) DG DL EA EI EN FI FL FT F9 HA HP ICX JI JQ J7 KE KL KS LH MC NW OC OO OZ(87) OZ(88) PA PI PN(97) PT QF QQ RM RO RV(99) RV(16) RW SK SM SQ S4 TI TS TW UA UK US UZ VS VX WA WN WS W7 XV YV YX(13) ZZ 9K
 
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aeromoe
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Re: What's the reason for N numbers of former CO aircraft being all numbers?

Tue Apr 07, 2020 11:07 pm

GCT64 wrote:
N67501 = UA's MAX9


It's just my OCD but I personally wish UA had gone a different route with the third digit for the MAX9 fleet...it "conflicts" with the 737-800s :(
Since 60s: AA AC AS BA BD BF BN BR(85) BY B6 CO CZ(16) DG DL EA EI EN FI FL FT F9 HA HP ICX JI JQ J7 KE KL KS LH MC NW OC OO OZ(87) OZ(88) PA PI PN(97) PT QF QQ RM RO RV(99) RV(16) RW SK SM SQ S4 TI TS TW UA UK US UZ VS VX WA WN WS W7 XV YV YX(13) ZZ 9K
 
FlyHossD
Posts: 2086
Joined: Mon Nov 02, 2009 3:45 pm

Re: What's the reason for N numbers of former CO aircraft being all numbers?

Mon Apr 13, 2020 12:21 am

United1 wrote:
UA continues to use the CO numbers scheme on the 787 N numbers but the 77Ws are different.

The 77Ws are N2XXXU...and sort of follow the pmUA numbering system with a nod to UA in the 70/80's and CO.

For instance...N2331U which is ship number 2131
N - US (duh :) )
2 - All pmUA 777s in UAs fleet four digit ship numbers start with 2 however on pmUA and pmCO registrations the first number is a random number.
3 - The second number is whatever is available to make the next two numbers work however on the ship number the 77Ws are all 21XX.
31 - last two digits of the ship number 31-52 for the 77Ws (both pmUA and pmCO did this)
U - United (UA used NXXXXU numbers back in the stars and bars/friendship livery days before switching to NXXXUA registrations.)


I like this new use of the old UAL system. I grew up near a UAL hub and remember the the 4-digit followed by a U system well. Yes, I'm old enough that I can get nostalgic about N-numbers.
My statements do not represent my former employer or my current employer and are my opinions only.

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