Serial numbers vs N number.

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Richgj3
Posts: 189
Joined: Wed May 27, 2020 3:13 pm

Serial numbers vs N number.

Post by Richgj3 »

Should these track, at least in blocks?

My 52 is N2444D s/n is 20596.

N2455D which is 11 N numbers later has s/n 20599 which is only three numbers later.

FAA data base shows N2455D originally s/n 20697 which is 11 numbers later. Exported to Canada in 1964.

So, I guess the current 2455D was an available number which the rebuilder assigned to s/n 20599 since the “original” number was not available.

Just curious. 55D is currently for sale on TAP and looks like a very nice 170B. Which is why this caught my eye.
Rich Giannotti CFI-A. CFI-I SE.
1952 C170B
N2444D s/n 20596
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GAHorn
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Re: Serial numbers vs N number.

Post by GAHorn »

Richgj3 wrote:Should these track, at least in blocks?

My 52 is N2444D s/n is 20596.

N2455D which is 11 N numbers later has s/n 20599 which is only three numbers later.

FAA data base shows N2455D originally s/n 20697 which is 11 numbers later. Exported to Canada in 1964.

So, I guess the current 2455D was an available number which the rebuilder assigned to s/n 20599 since the “original” number was not available.

Just curious. 55D is currently for sale on TAP and looks like a very nice 170B. Which is why this caught my eye.
Registration numbers are like automobile License Plates…. they cannot be relied upon to relate to serial numbers. Registration numbers can change anytime for several reasons: 1-The Owner requests a special number to be assigned, 2- the aircraft drops off the registry (for many different reasons such as A-it left the country and was re-registered when it returned to the U.S. registry, B-It was listed as “written off” (destroyed)..and the previously assigned N-number is RE-assigned to a different aircraft,.,…. and other reasons.

Cessna (and most other mfr’s) when deciding to produce a particular line of the same model aircraft (such as the 170s) will often request a contiguous GROUP of Numbers to be reserved with the mfr’r then assigns as the aircraft are produced. Cessna is not required and may NOT assign contiguous numbers to subsequent serial numbers…i.e., they may be assigned OUT of “ordinary order” for various reasons. Example: the 170-A series production was interrupted so that ONE or TW0 of them could be modified as experimental B-models. Then when the B-models receive production approval…those serial numbers which were taken from the A-model assembly-line will then have received registration numbers that are in the middle of the A-model production series.

My 1953 model-year 170B (serial 25713) left the assembly-line in November of 1952…and went directly to El Salvador to receive its first registration number YS-146. In the early 1970s it was imported back to the U.S. and FAA assigned it the registration N4299….and they registered it on its Airworthiness Certificate as a 1972 Cessna 170-B. :lol:
When it was restored it was RE-registered …and the owner requested the N-number it WOULD have left the factor with…but that number is on a Piper.
So the obverse of it’s El Salvador registration was requested…and assigned by FAA….N146YS. (They finally agreed it was NOT a 1972 170-B… but they STILL INSISTED it is a 1952 model despite the fact it’s in the LATTER-END of the ‘53 model production…. (it had the late “lady legs” landing gear. Moral of the story: FAA does not know or understand Serial Number/Production changes…. if it left the assy-line in ‘52…they insist it’s a ‘52 model.). :roll:

I once had a Beech Baron I offered for sale and a potential buyer accused me of hiding it’s history of wreckage! He had relied upon the N-Number to research the aircraft… which indeed, that registration number had certainly been involved in a serious WRECK…. the only problem is the buyer failed to notice the registration number was on a TWIN-CESSNA when it was wrecked….NOT on my Beech Baron…which had never been in any accident.

BEWARE of relying too much on registration numbers. (And this is also why it’s IMPORTANT to use the SERIAL NUMBER when ordering parts or researching for repairs….NOT the N-number and NOT the Year-model.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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Bruce Fenstermacher
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Re: Serial numbers vs N number.

Post by Bruce Fenstermacher »

There was a time when we published a list of members 170s in serial number order in our directory. In recent years we have dropped the list.

But if you saw it, the blocks of N numbers Cessna had where pretty clear. And for the most part sequential with Registration numbers. Enough so, that if you had a custom N number and was curious what your original was, you could figure it out and be reasonably correct.
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Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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Richgj3
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Re: Serial numbers vs N number.

Post by Richgj3 »

Thanks George and Bruce.

I was pretty sure they tracked within blocks which is why I was curious about the one I saw for sale. As I was typing the question I think I answered it myself, coming to the same explanation George gave.

I used to own a 62 Comanche 250 and noticed the same thing with respect to the registration number relationship to serial number although I did see the occasional PA18 sneak into the sequence.

Rich
Rich Giannotti CFI-A. CFI-I SE.
1952 C170B
N2444D s/n 20596
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