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View Full Version : The Split Pea Rivet test


Bob Axsom
12-03-2009, 02:17 AM
I am currently reading "Spitfire: A Test Pilot's Story" by Jeffrey Quill. I am used to reading "There I was ..." accounts of pilots but this one is not like that at all - very open and honest personal account of test flying the Spitfire. On page 108 I found the most fascinating test description I can ever remember reading. Flush riveting was used on the prototype Spitfire K5054 for the smoothest possible surfaces but at that time it was considered difficult, expensive and time consuming in production. So they went to a local grocery and bought several bags of dried split peas and glued them on every flush rivet head for an objective test of the benefit over round head rivets. The speed was reduced around 22 mph. That would have been a satisfactory conclusion of the testing in most organizations but not this one. They progressively scraped off the split peas to determine which flush rivets were beneficial and which ones were not and the results were applied to production airplanes.

Bob Axsom

pierre smith
12-03-2009, 06:42 AM
.....meaning that our RV's only gain 4 1/2 MPH with flush rivets because the Spit ran near 400 and we run 200.:)??

Best,

flybye
12-03-2009, 07:48 AM
I've been using Lentils.:D

mark schoening
12-03-2009, 08:13 AM
Ah--if you fly on a hot day in the rain, down south, would you make pea soup ?:confused:

Ironflight
12-03-2009, 10:16 AM
Dang Bob - every time you find and post about a new good book, it costs me money at Amazon....I'll have to add this one to my wish list for Christmas - sound interesting!

Paul

az_gila
12-03-2009, 11:42 AM
Dang Bob - every time you find and post about a new good book, it costs me money at Amazon....I'll have to add this one to my wish list for Christmas - sound interesting!

Paul

...of IFR flying during the test flights is also interesting...

Navigating by reading the "bumps" in the solid stratus below based on what was causing the "bumps" - such an electric generating plant....:eek:

Rick S.
12-04-2009, 09:20 AM
Love that kinda of history...it's the main reason I never considered extended range tanks for my RV-10...Can't hold pea that long:D

Brooklands
12-04-2009, 04:03 PM
Dang Bob - every time you find and post about a new good book, it costs me money at Amazon....I'll have to add this one to my wish list for Christmas - sound interesting!

Paul, while you're at it add "Sign for A Merlin" by Alex Henshaw. Henshaw was the production test pilot at the main factory, and used the 'bumps' from the cooling towers of the nearby power station at Hamms Hall as a guide for letting down through a solid overcast. Alex was also the holder of what must have been the longest standing record in aviation history: London - Cape Town - London, set before WW II and only broken this year.

I bought Jeffrey Quill's book when it first came out in the 1980's, and its an excellent read, in fact I think its time I read it again.

Brooklands

frankh
12-04-2009, 05:40 PM
Read any more books about Spitfires or I'll start thinking of ways i can own one!

Speaking of which, shouldn't all you American guys be drooling over P51's?..:)

Frank

Bob Axsom
12-05-2009, 07:05 AM
It is the content of the book that matters. "Flight of the Mew Gull". "Sigh for a Merlin" and "Spitfire: A Test Pilot's Story" are very enjoyable to read because of the author's personal first hand perspective in the the content and their writing style. I'm sure their are excellent stories about the P-51, F4U, F6F, P-38, P-39, P-40, F-82, P-63 but everything I have read is by a historical writer which amounts to an expanded research paper or a pilot that has nothing to do with the development of an airplane.

At one time in my work life I was one of a group of engineers that took all of the scrap tags and Material Review Records (major discrepancies) at the McDonnell Aircraft Co. on the F-4 and F-15, researching the cause, determining if a trend was indicated and initiating corrective action. This kind of inside information that shows initiative and desire to to get to the hard facts interests me.

Anyway, this thread is about a real world test method and it's implementation that relates to the riveting in our RV's. It is interesting to read an actual test of the benefits in non-text book terms.

Bob Axsom

jsharkey
12-05-2009, 07:58 AM
Read any more books about Spitfires or I'll start thinking of ways i can own one!

Speaking of which, shouldn't all you American guys be drooling over P51's?..:)

Frank

www.supermarineaircraft.com/

www.spitfireaircraftco.com/

There was also an outfit in the UK that replaced the few remaining RAF Gate Guardian real Spitfires with fiberglass copies and then rebuilt the originals to flying standard for a few million. Can't find a link though - fun but not the greatest business model in a recession so they may be bust.

Jim Sharkey
RV6 - Phase 1 - slowed by NE weather and work - darn it!

jsharkey
12-05-2009, 06:16 PM
www.supermarineaircraft.com/

www.spitfireaircraftco.com/

There was also an outfit in the UK that replaced the few remaining RAF Gate Guardian real Spitfires with fiberglass copies and then rebuilt the originals to flying standard for a few million. Can't find a link though - fun but not the greatest business model in a recession so they may be bust.

Jim Sharkey
RV6 - Phase 1 - slowed by NE weather and work - darn it!

Here is the link for real Spitfires

www.historicflying.com.webhosting.interconnect.nl/content.htm

az_gila
12-05-2009, 07:03 PM
www.supermarineaircraft.com/

www.spitfireaircraftco.com/

There was also an outfit in the UK that replaced the few remaining RAF Gate Guardian real Spitfires with fiberglass copies and then rebuilt the originals to flying standard for a few million. Can't find a link though - fun but not the greatest business model in a recession so they may be bust.

Jim Sharkey
RV6 - Phase 1 - slowed by NE weather and work - darn it!

...much earlier than the present business climate....:)

They happened in the early 90's - and when I visited the Duxford branch of the Imperial War Museum around that time they had assemblies from about a dozen Spitfire in jigs in various states of rebuild.

They were all previous gate guards as you mention.

This one, DW-A, is the one I remember from my childhood and was on display outside RAF Sealand (near Chester) in the 60's.

http://forum.keypublishing.co.uk/attachment.php?attachmentid=172935&d=1242243215

It is now in flying state with different markings....

http://www.warbirdregistry.org/spitregistry/spitfire-td248.html

Whoever came up with the idea of replacing historic planes sitting on poles with fiberglass replicas and restoring the originals deserves a medal.

Andy_RR
12-05-2009, 07:34 PM
I recently found my copy of JKQ's autobiography and am in the middle of re-reading it. Like Bob, I highly recommend the read.

My next read will be Neville Shute's autobiography Slide Rule, when I can find a copy of it. Neville was the co-founder of Airspeed, but also worked under Barnes Wallis and as Chief Calculator on the R100 airship program, as well as being a prolific fiction author.

Regarding the gate guard Spitfires, James May (Top Gear presenter) recently presented a series of programs on the Beeb called Toy Stories, one of which was on Airfix plastic model kits. The Cornwall-based company who makes the GRP gate-guard replicas made him a 1:1 scale "Airfix" plastic kit Spitfire for the program.

http://newsimg.bbc.co.uk/media/images/46617000/jpg/_46617234_-1.jpg

http://img98.imageshack.us/img98/1657/imgp1183psweb.jpg

jhausch
12-05-2009, 11:26 PM
Isn't there a similar story about flush vs round head rivets relating to those below the waterline of an Albatross? IIRC, the round head rivets made for shorter TO runs. . .

I am currently reading "Spitfire: A Test Pilot's Story" by Jeffrey Quill. I am used to reading "There I was ..." accounts of pilots but this one is not like that at all - very open and honest personal account of test flying the Spitfire. On page 108 I found the most fascinating test description I can ever remember reading. Flush riveting was used on the prototype Spitfire K5054 for the smoothest possible surfaces but at that time it was considered difficult, expensive and time consuming in production. So they went to a local grocery and bought several bags of dried split peas and glued them on every flush rivet head for an objective test of the benefit over round head rivets. The speed was reduced around 22 mph. That would have been a satisfactory conclusion of the testing in most organizations but not this one. They progressively scraped off the split peas to determine which flush rivets were beneficial and which ones were not and the results were applied to production airplanes.

Bob Axsom

az_gila
12-05-2009, 11:42 PM
.....
Regarding the gate guard Spitfires, James May (Top Gear presenter) recently presented a series of programs on the Beeb called Toy Stories, one of which was on Airfix plastic model kits. The Cornwall-based company who makes the GRP gate-guard replicas made him a 1:1 scale "Airfix" plastic kit Spitfire for the program.
....

...and I hope they show it in the US. I forgot that they used the same company (and moulds) for their 1:1 plastic model as the gate guards.

I thought the theme of kids not knowing what an Airfix kit was, and their dads jumping in remembering their childhood was interesting...:)

gil A - with many Airfix - and Keil-Kraft - models done in the 60's...:)