How interchangeable were aircraft spares and consumables?

[Admiral Beez]

Was there universality in spark plug threads, Schrader valves, tires, etc. across different nations in WW2? How about propeller blades, machine gun or cannon parts?

 

[FLYBOYJ]

Was there universality in spark plug threads, Schrader valves, tires, etc. across different nations in WW2? How about propeller blades, machine gun or cannon parts?

I know Japanese aircraft had terrible interchangeability issues across the board, don't know how their consumables were.

US, GB and Germany I believe were pretty good, don't know about Soviet equipment.

Propellers were normally made by a major subcontractor (Dowty Rotol/ Ham. Std.) Blades were interchangeable but I don't think it was common to break down a propeller in the field.

 

[Admiral Beez]

I know Japanese aircraft had terrible interchangeability issues across the board, don't know how their consumables were.

US, GB and Germany I believe were pretty good, don't know about Soviet equipment.

Propellers were normally made by a major subcontractor (Dowty Rotol/ Ham. Std.) Blades were interchangeable but I don't think it was common to break down a propeller in the field.

Sorry, I meant between countries. Would a Japanese engine use the same spark plug thread pitch as a French one?

 

[FLYBOYJ]

Sorry, I meant between countries. Would a Japanese engine use the same spark plug thread pitch as a French one?

I would say it would depend on the engine/ manufacturer, but if I had to bet on a specific situation, I would say no

 

[Tkdog]

Packard had to make their own fasteners for the Merlin because their were no suppliers for the British spec fasteners. They would have also needed different wrenches. I don't know if that meant that two sets of wrenches were/are needed to work on a Mustang. I suspect it does.

 

[GrauGeist]

By the 1930's, spark plugs would have had a standardized thread, typically 14mm.
So chances are, a spark plug for a BMW801 would have been able to screw into an R-2800.

However, there was a wide range of temperature ratings for spark plugs to meet an engine's requirements, so just because it would fit, doesn't mean it would work.

 

[msxyz]

There wasn't much standardization on tools, measures, working techniques and technology across different countries, back then. 'Licensed' engines were not 1:1 copies but usually adaptations to the local toolsets, materials and technologies available. If you copy an engine designed with imperial units and all your spark plugs have metric step and diameter, it's easier to redesign the spark plug hole than a whole new spark plug. It's also easier for your logistics.

 

[GrauGeist]

The French set the international standard for spark plugs at the turn of the century with 18mm and 14mm plugs, virtually every engine manufacturer adopted that standard from the 1900's onward.

 

[Admiral Beez]

Packard had to make their own fasteners for the Merlin because their were no suppliers for the British spec fasteners. They would have also needed different wrenches. I don't know if that meant that two sets of wrenches were/are needed to work on a Mustang. I suspect it does.

In 2014 a Canadian-produced, Packard-powered Avro Lancaster flew to Britain. During the UK tour the aircraft suffered, IIRC a catastrophic engine failure. The RAF Historical Flight loaned the Canadians a RR Merlin while they all set to work fixing the Packard engine. I remember wondering at the time if there were many interchangeable parts. I belong to the Canadian Vintage Motorcycle Group (CVMG) - Home and used to ride a 1960s Triumph and that thing had a mix of Whitworth, Standard and other fasteners.

Two Lancasters, One Unforgettable Summer | Classic Warbirds

Summer 2014 saw the Canadian Warplane Heritage Museum's Avro Lancaster link up with the RAF BBMF's Lancaster. This is the story of that unforgettable summer.

www.classicwarbirds.co.uk

 

[pbehn]

In 2014 a Canadian-produced, Packard-powered Avro Lancaster flew to Britain. During the UK tour the aircraft suffered, IIRC a catastrophic engine failure. The RAF Historical Flight loaned the Canadians a RR Merlin while they all set to work fixing the Packard engine. I remember wondering at the time if there were many interchangeable parts. I belong to the Canadian Vintage Motorcycle Group (CVMG) - Home and used to ride a 1960s Triumph and that thing had a mix of Whitworth, Standard and other fasteners.

Two Lancasters, One Unforgettable Summer | Classic Warbirds

Summer 2014 saw the Canadian Warplane Heritage Museum's Avro Lancaster link up with the RAF BBMF's Lancaster. This is the story of that unforgettable summer.

www.classicwarbirds.co.uk

That was at my local airport, it flew over my mothers house coming into land as we set off for the funeral of her ex Bomber Command brother. I presume the RAF memorial flight have the tools to work on any RR or Packard Merlin.

 

[Admiral Beez]

That was at my local airport, it flew over my mothers house coming into land as we set off for the funeral of her ex Bomber Command brother. I presume the RAF memorial flight have the tools to work on any RR or Packard Merlin.

Nice! It's too bad Lancaster NX611 (Just Jane) wasn't ready yet, shown below.



Perhaps the Canadian Lancaster will return and then we'll have three Lancs flying, representing three of the major Lancaster plants, Vickers-Armstrong, Austin Motors and Victory Aircraft.

Lancaster NX611 ‘Just Jane’ – Restoration Update 156

warbirdsnews.com

 

[pbehn]

Nice! It's too bad Lancaster NX611 (Just Jane) wasn't ready yet, shown below.



Perhaps the Canadian Lancaster will return and then we'll have three Lancs flying.

Lancaster NX611 ‘Just Jane’ – Restoration Update 156

warbirdsnews.com

It was on its own on a shake down flight. My ,mothers house isnt in line with the runway, passenger planes passa few hundred yards to the left, but it was labouring into a strong headwind, so I presume he was flying to do a cross wind landing, a special and luck treat.

 

[SaparotRob]

I remember pben's prior post on that flight. Got goosebumps reading about going to the cemetery for a Lancaster vet as a Lancaster flew overhead.

 

[pbehn]

I remember pben's prior post on that flight. Got goosebumps reading about going to the cemetery for a Lancaster vet as a Lancaster flew overhead.

He wasnt a Lancaster veteran, he was invalided off operations with chronic lung problems in the days before heated suits, long before the Lanc. saw service, he ended up in the ROC seconded to the US Navy on D-Day calling friend or foe to the gunners on a Liberty flak ship. My mother wasnt famed for her aircraft recognition but even she recognised it as a WW2 era plane more by sound than sight. Of course when she was a child the sky was full of them, the engine of a crashed Wellington hit her school building, and she didnt even get the day off.

 

[Admiral Beez]

'Licensed' engines were not 1:1 copies but usually adaptations to the local toolsets, materials and technologies available.

I wonder if this was the case for Oerlikon's 20 mm cannon and Bofor's 40 mm cannon that seemed to be used by many nations.

 

[msxyz]

I wonder if this was the case for Oerlikon's 20 mm cannon and Bofor's 40 mm cannon that seemed to be used by many nations.

Germans used a 20x80RB cartridge with a 116g bullet for their Mg FF (the later, high explosive shell weighted only 96g); the Japanese Type 99-I cannon used a 20x72RB cartridge with a heavier bullet of around 130g. Therefore, despite being essentially the same design (Oerlikon FF 20mm), the two weapons used different cartridges and had different performance (muzzle speed, cyclic rate). The Japanese version was also lighter.

When the Germans introduced the lighter 96g HE Minengeschosspatrone, they had to change the recoil spring since the Oerlikon 20mm was an open bolt machine gun that relied entirely on recoil to operate. The lighter shell had lower momentum, so the spring needed to be weaker, otherwise the bolt wouldn't open completely. Therefore, even inside the Luftwaffe, the ammunitions were not interchangeable between the standard Mg FF and the new Mg FF/m that could fire the new high explosive round, despite sharing the same cartridge dimensions and despite being the same weapon in all aspects but the force of the bolt spring!

 

[gumbyk]

Packard had to make their own fasteners for the Merlin because their were no suppliers for the British spec fasteners. They would have also needed different wrenches. I don't know if that meant that two sets of wrenches were/are needed to work on a Mustang. I suspect it does.

Yes, its still the case now. The Kawasaki BK-117 helicopter uses imperial on the engines, which are American, but metric across the airframe/gearboxes which are Japanese and European.

By the 1930's, spark plugs would have had a standardized thread, typically 14mm.
So chances are, a spark plug for a BMW801 would have been able to screw into an R-2800.

However, there was a wide range of temperature ratings for spark plugs to meet an engine's requirements, so just because it would fit, doesn't mean it would work.

One place I worked for many years ago reconditioned an engine for an Oscar. I can't remember exactly what spark plugs we used, but they were modern ones. Likewise, the Ash-82 we've got here (although it's modern) runs with standard plugs.
the Gipsy Major on our tiger Moth, and the Housai-6 on the CJ-6 both use automotive plugs. Given that, I'd be surprised if anyone used a different thread during WW2. it would likely have required changing the manufacturing processes, and for no gain, other than being different from the enemy.

 

[GrauGeist]

Yes, its still the case now. The Kawasaki BK-117 helicopter uses imperial on the engines, which are American, but metric across the airframe/gearboxes which are Japanese and European.

One place I worked for many years ago reconditioned an engine for an Oscar. I can't remember exactly what spark plugs we used, but they were modern ones. Likewise, the Ash-82 we've got here (although it's modern) runs with standard plugs.
the Gipsy Major on our tiger Moth, and the Housai-6 on the CJ-6 both use automotive plugs. Given that, I'd be surprised if anyone used a different thread during WW2. it would likely have required changing the manufacturing processes, and for no gain, other than being different from the enemy.

I wouldn't be surprised if the Ash-82 used a carburetor similar to the Stromberg, which was used on the R-1820, since the Soviets developed a series of engines based on the licensed Wright.

 

[FLYBOYJ]

A post war comparison. 9 years ago I did some work on a MiG-15 UTI located at Wendover Utah. The hangar I was in had a RR Nene, J33 and a VK-1. Looking at them side-by-side they were identical except for some fittings and electrical connectors. I wanted to take a photo of the three but got wrapped up with work and then forgot about the picture.

 

[Admiral Beez]

It must have been a challenge for the FAA's shipboard mechanics to have tools and spares available and organized. One ship could have a combo of RR Merlins and radials from Bristol and P&W (and maybe Curtiss). I expect there was many a rounded bolt or stripped screw head.

Here's the CAG of HMS Furious in July 1944:

880 Sqn - Seafire III
840 Sqn - Hellcat
842 Sqn - Swordfish