Part numbers

[Robert M]

Hi gang!

I understand the part numbering system that Vans' uses to identify parts, (i.e F-9XX). The "9" designates the particular flavor of aircraft, (i.e. the RV-9/A)

So, if the RV-9/A was designed and built and flown before the Rv-7/A, why are there parts in the RV-9 kit label F-7XX?

The only reasoning I can come up with is that the part was made better for the -7/A and then got incorporated into the -9.

Anyone know fur sure?

 

[N916K]

RV9's are the special children of Van's

Now Robert, do you really have to ask that? The RV9A is the red headed step child and the RV9 is the ******* child of the red headed step child at Vans. Do you really think if the 7 and 9 are to share a part that it will be called a 9 part?

 

[mannanj]

Part #'s

It's my belief that if a part designed for the RV-6 and was labeled F-6XXX, then was used on the 7, 8, or 9, then it retains the original part number even though it's used on subsequent models.

There were numerous F-6, W-6 etc. in my RV-8 kit.

 

[N916K]

It's my belief that if a part designed for the RV-6 and was labeled F-6XXX, then was used on the 7, 8, or 9, then it retains the original part number even though it's used on subsequent models.

There were numerous F-6, W-6 etc. in my RV-8 kit.

Yes, but Robert was asking why does an RV9 that came out before an RV7 have 7 part numbers.

I believe I read in the RVator or somewhere that the 7 was designed well before it went into production. Probably a marketing thing or just getting rid of 6 parts. Also why would you put "trainer" parts on your number one selling kit?

 

[Robert M]

It's my belief that if a part designed for the RV-6 and was labeled F-6XXX, then was used on the 7, 8, or 9, then it retains the original part number even though it's used on subsequent models.

There were numerous F-6, W-6 etc. in my RV-8 kit.

Oh yeah, I understand that - what I don't understand is how the -7 was designed and built after the -9 and yet there are parts in the -9 marked as, for example, F-704.

Red headed what????? The RV-9 is the flagship of the Vans line. Even as the RV-12 was under design, comments were made like "We would like the performance to be similar to the RV-9." and "the handling with be close to the RV-9."

Oh yeah, I'm building the best of the best...... I'm convinced!

 

[noelf]

Pure speculation on my part, but as Van started his Design for Manufacturing process with CNC match-punched-parts, it was far easier to implement the design of a new aircraft when the use of the CNC punched parts was a given.

The RV-7 series was a follow on to the RV-6 series. The 6's were not pre-punched, and to retro-fit / design this into CNC'd parts was not possible. It is sometimes impossible to go back and CNC parts that were never intended to be CNC'd in the first place. The "look" of the 6's and 7's are quite similar, but underneath the design, I am sure there is a lot of tooling and software that allows the CNC'd parts to align together on the 7 and 9.

In the interest of keeping the total number of different parts in the different models of aircraft to a minimum, and the requirement to stock all of the different parts (and pay state and federal tax on year-end inventory), it is desirable to reuse as many items as possible in the new design. No new parts means no new stocking locations and no additional inventory to track.

Now, back to my speculation...I think it took quite a bit of time for the engineers to comb through all of the RV-6 parts and determine what could be CNC'd for the RV-7 aircraft. It was quicker to do a clean-sheet design with the RV-9. The 6 series was selling well, and the 7 was a new-and-improved replacement. It was ok to have the 7 arrive after the 9. Therefore, the part number(s) used in any model of aircraft could have a mix of prefix numbers from any of the other aircraft models.

 

[N941WR]

With all that was said above, I'm still trying to figure out why Van's used RV-4 bell cranks for the ailerons. Go figure.

 

[Robert M]

Pure speculation on my part, but as Van started his Design for Manufacturing process with CNC match-punched-parts, it was far easier to implement the design of a new aircraft when the use of the CNC punched parts was a given.

The RV-7 series was a follow on to the RV-6 series. The 6's were not pre-punched, and to retro-fit / design this into CNC'd parts was not possible. It is sometimes impossible to go back and CNC parts that were never intended to be CNC'd in the first place. The "look" of the 6's and 7's are quite similar, but underneath the design, I am sure there is a lot of tooling and software that allows the CNC'd parts to align together on the 7 and 9.

In the interest of keeping the total number of different parts in the different models of aircraft to a minimum, and the requirement to stock all of the different parts (and pay state and federal tax on year-end inventory), it is desirable to reuse as many items as possible in the new design. No new parts means no new stocking locations and no additional inventory to track.

Now, back to my speculation...I think it took quite a bit of time for the engineers to comb through all of the RV-6 parts and determine what could be CNC'd for the RV-7 aircraft. It was quicker to do a clean-sheet design with the RV-9. The 6 series was selling well, and the 7 was a new-and-improved replacement. It was ok to have the 7 arrive after the 9. Therefore, the part number(s) used in any model of aircraft could have a mix of prefix numbers from any of the other aircraft models.

That would explain it. I was under the impression that the -9 was "designed" AND manufactured before the -7 but if I understand what you wrote, the -9 was really designed after the -7 but was put into manufacturing before. Is that right?

 

[noelf]

Only Van's Engineering folks can provide the definitive answer of when (date) specific parts were designed and committed to drawings (paper or CAD). They can also provide the same info on when those parts get incorporated into assemblies of larger parts and structures. New parts will get new part numbers. If the engineers know of an existing part, one that is designed, manufactured, in stock...then great. No new design work needs to be performed.

That same part "could" reside only in a data base and its true physical fabrication never initiated due to a number of reasons (work priorities, market pressures, the part just did not work for the envisioned application). But it is still a real part in the minds of the engineers, and probably has an assigned part number for easy identification and retrieval of information. This "part" could be used anywhere in the design and construction of a new aircraft.

So, here we have parts that carry a RV 6/7/9 designation. Van, for economic reasons, will attempt to use existing parts where ever possible, and create new parts when needed. The new parts "could" have been designed previous to the introduction of any aircraft (well, that make sense), but the date at which any "common" part appears on the engineer's drawings for any aircraft type has no bearing on the actual date the part was created and assigned a given part number.

Now, get the marketing folks involved, and the actual date that any new airframe gets announced could completely re prioritize the engineering effort and direction that involves existing and new parts design. It really is no surprise that later prefixed p/n's show up on "earlier" announced aircraft.

Bottom line...only the folks at Van's can provide the definitive answer of which came first. And maybe they could also provide insight to the chicken vs egg debate.