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Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 1:40 pm
by jrenwick
Just a curiosity question: most of the world besides the US has adopted the metric standard. Are there any aircraft manufactured in foreign countries that use metric sized (ISO) nuts, bolts, etc.? I know Rotax engines have metric fasteners, but what about airframes?
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 3:55 pm
by Metal Master
Yes, My German made gliders one type certificated the other experimental used exclusively metric hardware. the Socata Tobago I used to maintain used a combination of AN & Metric hardware in the airframe and AN hardware around the engine
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 6:05 pm
by wingnut
The Shorts Bros, and Fokker aircraft use some British Standard (BS). That's a whole other toolbox. Probably some others over there that use BS, or metric, just never worked on any others.
I do recall an aircraft I worked on a couple years ago, I think was Cirrus SR22, that had some metric hardware on the alternator and some other odds and ends
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 6:20 pm
by GAHorn
The English-Electric Canberra used Whitworth standard hardware...yet another British deviation of tooling. The Martin B-57 was a U.S.-license-built copy using standard US/AN hardware. They were used by SAC for high altitude recon until the development of U-2's and SR-71's.
B57's initiated the famous "Rolling Thunder" bombing of North Viet-nam during that war.
Pakistan used them against India during both of their wars.
NASA has the last two still flying, converted to Fan-engines I believe.

Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 8:09 pm
by blueldr
When I was stationed on Guam, one of my shops was the engine shop which had both recip and jet engines, one model being the engines for the WB-57 airplanes used by the weather outfit. They were, if I memory serves, license built British Saphire engines which caused us problems with tools since we had only american fraftional sized hand tools at that time. The engine rotation was also opposite from the american standard. This gave us a particular problem when required to use a torque wrench on rotational components since our torque wrenches were not usable on left hand threads. The answer turned out to be a locally fabricated "U" shaped socket wrench adapter to reverse rotation for the torque wrenches.
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 8:43 pm
by Metal Master
The Canadian built Lockheed T-33's (CT-133's) I work on now have Rolls Royce Nene 10 engines in them They use British standard and Wentworth fasteners as well as AN and MS hardware. We have three tool boxes with different tools in them.
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 9:37 pm
by jrenwick
Thanks for all the answers. Does anybody know what hardware Airbus uses? Metric, AN, or something else?
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 10:13 pm
by mbram
Airbus 320 series and 330 are for most part SAE with some exceptions.
Nord 262 used metric hardware and plumbing.
Last aircraft I worked on with Wentworth fasteners was a Super DC 3 with dart engines. (engines only)
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 10:52 pm
by GAHorn
jrenwick wrote:Thanks for all the answers. Does anybody know what hardware Airbus uses? Metric, AN, or something else?
Papier-Mache' !
Re: Do any aircraft use metric parts?
Posted: Thu Feb 03, 2011 11:07 pm
by GAHorn
blueldr wrote:.... They were, if I memory serves, license built British Saphire engines which caused us problems with tools since we had only american fraftional sized hand tools at that time. The engine rotation was also opposite from the american standard. ....
The original engines were RR Avons, but the Martin was built with Armstrong-Siddeley Sapphires that were license-built by Wright as the J65. Wright contracted with Buick for them but those were really troublesome so Armstong-Siddeley sent over technical advisors and Wright made them in-house.
After bluEldr twisted them the wrong way the WB57 was converted to fans and the designation changed to WB57F using an entirely different American-built engine (GD-TF33) . Pima Air Museum is still trying to un-twist and restore that one and hopes to have it on display later this year.
Re: Do any aircraft use metric parts?
Posted: Fri Feb 04, 2011 3:46 am
by mekstrand
I owned a Sukhoi for a few years before I had kids. It used all metric hardware, hoses, tires, and instruments (airspeed KPH, Altimerter read in meters, MP was displayed in mm of mercury, and the compass had a crazy looking H for south and a C for north). Replacment parts are available, just not where I usually needed them. I modified the aircraft fluid and pneumatic systems to utilize standad AN fittings, western hoses, Cleveland wheels and brakes, and completely rewired the electrical system. As far as the airframe was concerned, it was very durable and required little maintenance.
Re: Do any aircraft use metric parts?
Posted: Fri Feb 04, 2011 6:35 am
by marathonrunner
I use metric measurements often. They are so much easier than the English system and make much more sense. I guess that is why the rest of the world uses them. Example...what is half of 304 centimeters? Ok what is half of 19 and 13 64ths inches?
Re: Do any aircraft use metric parts?
Posted: Fri Feb 04, 2011 1:32 pm
by Bruce Fenstermacher
9+77/128 inches. Easy.
I usually mark those kind of measurements with a grease pencil to be more accurate.

Re: Do any aircraft use metric parts?
Posted: Fri Feb 04, 2011 3:42 pm
by cessna170bdriver
I do admit that saying your airplane goes 193.12128 kilometers per hour sounds much cooler than saying it goes 120 miles per hour. Even better would be to say it goes 322,560 furlongs per fortnight.

Re: Do any aircraft use metric parts?
Posted: Fri Feb 04, 2011 4:41 pm
by mekstrand
Miles,
Very true. I remember VNE was 450 KPH! That still sounds cool.