Mosquito dataplate & constructor numbers

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11 years 8 months

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Does anybody know :
a) whether there was a DH constructor number dataplate for Mosquitos and where it would be located.

b) The logic behind the constructor number system.
I understand that the constructor number was an alpha-numeric, eg RR299, painted on the fuselage immediately for'd the tailplane.
If 7,781 were built then a purely sequential alpha numeric system starting at AA-000 would arrive at AH-781 to account for all production.
If the 7781 were supplied in 43 marks or types, eg recon, fighter bomber, bomber, night fighter etc then perhaps each alpha code denoted a type and the numeric the sequential manufacture of the type?

This system would allow for 23 repeats of DK-XXX then 211 of DZ-XXX as a logical interpretation of the constructor number system. A sequence of actual constructor numbers and approximate chronology is listed below, from 'DH Mosquito Crash Log' by David J Smith.

c) Can anybody connect the constructor codes below to actual types ?

d) Did this system extend to Canadian and Australian Mosquito production ? Do any of the alpha characters relate to factory location ?

Thank you

DD601 (1942)
DK301
DZ369
W4099
HJ713
HK172 (1943)
HP848
HX915
LR477 (late 1943)
KA970
KB161
ML917
MM578 (1944)
MV565
MT456
NS900
NT186 (mid 1944)
PF391
PZ196 (late 1944)
SM700
RF858
RS571 (1945)
RR287
RV357
PF517 (mid 1945)
PZ280
TA502 (1946)
TE593
TW102
VL731 (1948)
VT625 (1953)

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Member for

11 years 11 months

Posts: 549

Those things painted just forward of the tailplane (and in your list above) aren't constructors numbers, they're the RAF serials. When the RAF serial allocations reached the end of DG, they deliberately skipped to DJ to avoid confusion with De Havilland.

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24 years 2 months

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The serials can be related to constructor and mark though. For example KAxxx marked Mosquitos were Canadian built FB's and KBxxx marked aircraft were Canadian bombers. The others are trickier as they have to be related back to production records. Generally it's possible to see that a certain serial block (say, ED500-EE250) would be for a certain production contract with a certain factory.

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Electrical fitter notes

Those things painted just forward of the tailplane (and in your list above) aren't constructors numbers, they're the RAF serials. When the RAF serial allocations reached the end of DG, they deliberately skipped to DJ to avoid confusion with De Havilland.

I have hand written electrical fitter/inspector notes which seem to deal with the construction of MX XXX series aircraft, the notes making megger testing comments on a sequential number of aircraft. If the numbers are RAF serials, then perhaps it is logical that an Air Ministry allocation of serials became the default 'constructor number'. I wonder if this is true for Australian built Mosquitos, or Canadian built Mosquitos in US service, let alone Chinese Nationalist service.

I have asked my father who flew Mosquitos where the 'dataplate' was and he can't recall, probably as most people don't know where the dataplate on the car they drive is located, let alone the manufacturers actual serial number. B for Baker is what you got shot down in.

I have seen on the oil tank of the NZ Avspecs Yagen Mosquito a painted decal which has come as close to a manufacturers ID as anything I have seen to date.

Perhaps there is no ID dataplate on a Mosquito.

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11 years 8 months

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Mosquito dataplates

Perhaps there is no ID dataplate on a Mosquito.

After much sleuthing I believe that it is correct that there never was any ID dataplate on a Mosquito that detailed its Air Force identifier or the ‘public personality’ detailed on its paintwork. What does exist are numerous, small dataplates for various sub assemblies incorporated within the one airframe. This conclusion arises from matching these sub assembly numbers to original airframe logbooks preserved by the Australian National Aviation Museum in Moorabbin, Victoria.

I would welcome any constructive criticism or further supporting evidence for the description of the system adopted by DEHAVILLAND Australia below, which I posit was a direct mimic of DH UK and DH Canadian practice. Reproduced below are photos of Australian Mosquito wing and tailplane assemblies in the process of scrapping in 1958 and an undercarriage door assembly dataplate excavated from a scrapping site in later years. These are matched with photos from an original airframe logbook from the era to build the following theory.

The Air Force issued a contract to DEHAVILLANDS to supply a number of aircraft to specification.

DH established a sequential file for aircraft, in the case of the Chronological Log reproduced the aircraft ultimately known as RAAF A52-302 was Aircraft DH 3219 to DEHAVILLANDS. I theorize that this file was retained by DH for warranty and future factory maintenance records, and ultimately disposed off by the factory once a reasonable warranty or service period expired. I have seen photos of part assembled, unpainted Mosquitos in Downsview Canada with a paper fixed to the nose cone, which I theorize was the Canadian factory file identifier. This system would allow for the removal of an airframe from the assembly line for quality or design issues, before it acquired an Air Force identity.

DH utilized an alpha numeric system to mange recording of sub assemblies and components within the airframe, largely supplied by third parties. In practice a Mosquito was a “kit plane”. Sub assemblies included fuselage, mainplane, ailerons, flaps, tailplane, rudder, elevators, radiators, fuel tanks, undercarriage, undercarriage doors etc. Typical codes, as reproduced in the “Particulars of Components” photo below, were Fuselage MN 293, Mainplane MM322, Starboard Aileron MAS 145, Rudder MER 114, Control Column MCU 307, Compression Leg Inner Starboard MUA 1272. In the photos below are close ups of Australian Mosquitos being scrapped in 1958 that substantiate this practice : painted on the Tailplane is the ID MEF 103, Rudder MER 13x and Mainplane MM 327. The photo of the dataplate for undercarriage door shows the code MCA 1025.
As the airframe progressed through assembly it acquired its Air Force identifier, in this case A52-302, which ultimately became its public persona. I understand that in the UK the fuselage identifier became shorthand for the entire assembly, eg MN 293, or RR 299. This was painted on the fuselage, but no identifying plate was fitted in the cockpit with this information. There would seem to be no practical purpose to fit such a plate : the external painted code would serve for all purposes.

Sub assemblies are extensively fitted with dataplates or manufacturer ID codes. A theoretical dug up wreck could be indisputably confirmed in its Air Force identity by cross referencing sub assembly dataplates with the original airframe logbook which recorded this, beyond other contextual evidence. Contextual matching of sub assembly IDs for theoretical remnants in a place like Turkey, Israel or China could assist in matching with fuselage IDs and service records to build a more accurate historical record.

I would welcome any information on sub assembly IDs or manufacturer codes that anybody may have to further build this understanding of Mosquito identification.

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DHP & DHA

Does anybody know if any of the alpha characters relate to factory location ?

Australian Mosquito and Vampire parts have many DHP inspection stamps on them : I have always understood this to signify DEHAVILLAND Preston as the origin of the parts. I interpret this in the context of the rapid adoption of Mosquito manufacture in Australia, when there would not have been the time or contractor base in Australia to meet needs and many assemblies and parts were imported. This is also consistent with the initial supply of UK manufactured Vampire trainers to Australia, before Australian Vampire production ramped up.

Later Swedish Mosquitos, in the Illustrated Parts manual, have many DHA part numbers in them : I have always understood this to signify parts sourced from DEHAVILLAND Australia. If this is correct, as Australian Mosquito production found its legs postwar, many sub assemblies for Swedish Mosquito production in the UK may have been sourced from Australia, as the UK tooled up for the jet age.

Can anyone confirm this and the basics on DHP = DH Preston, DHA = DH Australia, DHC = DH Canada.
What other codes are there, eg for Hatfield production ?

DHP Vampire parts seem to come in a drab green and I have seen the same colour on DHC Caribou parts. Does anybody know what this colour is?

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11 years 8 months

Posts: 1,354


Can anyone confirm this and the basics on DHP = DH Preston, DHA = DH Australia, DHC = DH Canada.
What other codes are there, eg for Hatfield production ?

DHP Vampire parts seem to come in a drab green and I have seen the same colour on DHC Caribou parts. Does anybody know what this colour is?

Bump. Or because it's Mosquito : .....rrrrrrrrrRRRRRRRRRRROOOOOAAAARRRRRRRRRRRRRRRrrrrrrrrrr......:love-struck:

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For what its worth, here's what I know on the subject:

What is commonly referred to as an aircraft data plate would contain the fuselage assembly construction number, and the RAF identifying serial if built for them, and other info. I will update this posting with a photo of one or two examples, including one from my Hornet DH103.

I have seen examples of DH data plates and mod plates from Vampires DH100, Venoms DH112, Doves DH104, Sea Vixens DH110, etc. and they all show the same information in the same format. I haven't seen one for a pre-DH100 type aircraft though, so I don't know if they used them or indeed used the same format.

Wooden fuselages of Hornets, Mosquitos and Vampires were frequently (but not always) painted with the construction number of the airframe on the side of the cockpit exterior, prior to being finally painted. I have also seen the actual serials being chalked onto the fuselage sides prior to being painted in the factory too.

Member for

11 years 8 months

Posts: 1,354

Thank you

For what its worth, here's what I know on the subject:

What is commonly referred to as an aircraft data plate would contain the fuselage assembly construction number, and the RAF identifying serial if built for them, and other info. I will update this posting with a photo of one or two examples, including one from my Hornet DH103.

I have seen examples of DH data plates and mod plates from Vampires DH100, Venoms DH112, Doves DH104, Sea Vixens DH110, etc. and they all show the same information in the same format. I haven't seen one for a pre-DH100 type aircraft though, so I don't know if they used them or indeed used the same format.

Wooden fuselages of Hornets, Mosquitos and Vampires were frequently (but not always) painted with the construction number of the airframe on the side of the cockpit exterior, prior to being finally painted. I have also seen the actual serials being chalked onto the fuselage sides prior to being painted in the factory too.

Thank you David, I would love to see the later dataplates.

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Thank you David, I would love to see the later dataplates.

As a starter, here is the one for the Hornet. All the post DH.100 data plates I have seen have the same format.

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dH didn't have a factory in Preston - that was English Electric. DHP is de Havilland Portsmouth - or Airspeed division.

You might also see DHB which is the factory at Broughton, Chester.

With regard to Mosquito serials, the airframes were serialled 98xxxx on the production line, though I cant see it in my references at present. The RAF serial was applied some way down the line.

Bruce

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20 years 3 months

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dH didn't have a factory in Preston - that was English Electric. DHP is de Havilland Portsmouth - or Airspeed division.

You might also see DHB which is the factory at Broughton, Chester.

With regard to Mosquito serials, the airframes were serialled 98xxxx on the production line, though I cant see it in my references at present. The RAF serial was applied some way down the line.

Bruce

Yes, and English Electric parts were marked with "EEP" letters: English Electric Preston too.

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Thank you

As a starter, here is the one for the Hornet. All the post DH.100 data plates I have seen have the same format.

Thank you, good to see the Hornet sample. I have not seen anything like it (yet) for Mosquito.
Where are these plates located on Hornet and Vampire?

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dH didn't have a factory in Preston - that was English Electric. DHP is de Havilland Portsmouth - or Airspeed division.

You might also see DHB which is the factory at Broughton, Chester.

With regard to Mosquito serials, the airframes were serialled 98xxxx on the production line, though I cant see it in my references at present. The RAF serial was applied some way down the line.

Bruce

Thank you for putting the P in DHP, so now we have :

DHS - deHavilland Standard
DHA - deHavilland Australia
DHB - deHavilland Broughton
DHC - deHavilland Canada
DHP- deHavilland Portsmouth (Airspeed)

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Thank you, good to see the Hornet sample. I have not seen anything like it (yet) for Mosquito.
Where are these plates located on Hornet and Vampire?

Hi,

The Hornet data plates are located on the right hand inner wall of the cockpit.

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11 years 8 months

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Great picture

Hi,

The Hornet data plates are located on the right hand inner wall of the cockpit.

Thank you.

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20 years 3 months

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Thank you.

And in the FB.5 Vampire too. RH side of cockpit just below window.

Image from the net, taken by D.Coombe

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Wooden fuselages of Hornets, Mosquitos and Vampires were frequently (but not always) painted with the construction number of the airframe on the side of the cockpit exterior, prior to being finally painted. I have also seen the actual serials being chalked onto the fuselage sides prior to being painted in the factory too.

With that in mind, any idea what this number might be? It was found under the fabric on the fuselage of NZ2328/TE758, immediately aft of the trailing edge on the port side, and appears to have been stenciled on.

[ATTACH=CONFIG]231634[/ATTACH]

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With that in mind, any idea what this number might be? It was found under the fabric on the fuselage of NZ2328/TE758, immediately aft of the trailing edge on the port side, and appears to have been stenciled on.

[ATTACH=CONFIG]231634[/ATTACH]

TE758 was originally made in the UK - Standard Motors at Coventry.

Any numbers sprayed onto the wooden airframe under the doped fabric, are likely to be the construction number of the airframe on the line, before it is allocated a service serial.

Using Vampires an example (from the www.airhistory.org.uk website):

Vampire F3, VT833 was manufactured at English Electric Preston, with a construction number of - EP42408.
Vampire FB5, VV217 was manufactured at English Electric Preston, with a construction number of - EP42461.
Vampire FB5, VZ252 was manufactured at ???, with a construction number of - PS870.
Vampire FB5/J28B, FV28114 was manufactured at Chester, with a construction number of - V0053.
Vampire F30, A79-153 was manufactured in Australia, with a construction number of - 4019.

As you can see, the airframe construction number does not have any numerical tie-in to the serial number. Also, the airframe construction number follows a different format depending on which factory it was made in. Maybe the "36" visible under the fabric is part of the construction number?

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dataplate

[QUOTE=HR339;2167165]With that in mind, any idea what this number might be? It was found under the fabric on the fuselage of NZ2328/TE758, immediately aft of the trailing edge on the port side, and appears to have been stenciled on.QUOTE]

HR399, are there any dataplates on your aircraft that correspond to Hornet/Vampire onwards ?

On the Mosquito the entry door and electrical/fuel gauge box on the starboard side occupy the zone where Hornet/Vampire dataplates are.
On DHA PR41 there is refererence in cockpit diagrams and corresponding logbooks to an engine dataplate on the port side, above the usual plate above the throttle controls instructing on RPM,pitch settings.

Given that the corresponding logbooks show that a number of engine changes occurred over the life of the airframe I cannot imagine that this dataplate was an etched or stamped metal plate. From the cockpit diagram it looks like the frame of an old compass corrector card, which would allow a paper card slip with engine details to be fitted in.

I understand that in RAAF and RAF service the Aeroplane Maintenance Form (RAAF E/E 77 Travel Copy) was carried on board the aircraft (in map case?) and had to be updated by the pilot after each flight. In this respect, via the Maintenance Form which had the Air Force serial clearly marked on the cover, the aircraft serial was clearly obvious to pilot and fitters inside the cockpit. For most of these folk, a squadron code such as 'B' for Baker would have been a more obvious means of communicating identity.

I wonder if the move to designs with overhead canopies for entry and egress shifted deHavillands to change their practice in respect of airframe dataplates.

I wonder if Hornet (?) and early Vampire assembly in DHP-Portsmouth introduced a practice of dataplate use at that facility that was later adopted throughout the DH empire. What component dataplates I have seen on Mosquitos to date are Brass with stamped numbers, rather than etched aluminium.

I wonder if a growing appreciation within DH for the potential of stress cracking to develop from stamped identification codes on parts, or the riveting on of separate plates, shifted the emphasis to acid etching of part numbers postwar. Certainly DHP Vampire parts seem to be acid etched rather than stamped in my experience, while Mosquito parts are stamped. Mosquito fuel and oil tanks, however, have always seemed to have painted dataplates, which shows some wartime appreciation of the potential for stress cracking. I have seen these painted decals on period photos of RAAF PR41 tanks and the oil tanks on the originally Canadian KA 114 restored in NZ.

I have before me a 1955 DEHAVILLAND AIRCRAFT Inspection Handbook (LJ Woodward Chief Inspector :"You will ensure that all inspectors under your control are familiar with the procedures laid down..") which describes the blue part etching fluid, using rubber stamp pads and a fluid based on copper sulphate and hydrochloric acid.

So I wonder if postwar, with a lot more time on their hands, the inspectors of DH convened and discussed improvements to manufacturing practice that resulted in the adoption of better methods of identification that incorporated a move away from part stamping, the use of stamped brass or irregular and ad hoc component ID plates, future acid etching of part numbers and a consistent method using fuselage dataplates.

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[QUOTE=powerandpassion;
I have before me a 1955 DEHAVILLAND AIRCRAFT Inspection Handbook (LJ Woodward Chief Inspector :"You will ensure that all inspectors under your control are familiar with the procedures laid down..") which describes the blue part etching fluid, using rubber stamp pads and a fluid based on copper sulphate and hydrochloric acid. [/QUOTE]

Chemical Etching of Parts (1955 DH Inspection Handbook)

Acid Composition :
Hydrochloric acid 150mL
Copper Sulphate crystals 25 grams
Nickel Nitrate crystals 25 grams
Selenium Dioxide 20 grams
Water 200mL

Marking Methods :

Castings : casting number raised on platform during casting, separate platform for DH marking of assembly number, batch number and inspection mark.
Forgings : similar to castings
Large Components : when a series of operations is carried out on a large component, additional markings will not be made on the component, but its progress will be recorded on the Inspection History Card which will accompany the component through the shops.
Large Component Assemblies : Large component assemblies such as fuselage bulkheads will be marked with a suitable ink on a white painted patch (I have seen this on the front fuselage of Canadian Mosquitos in photographs) protected by a temporary adhesive cover during detail assembly and varnished over on final clearance.
Major Components : Wings, Ailerons, Elevators etc will bear a label securely attached by rivets etc to the component. The label, made of black anodised aluminium alloy is 3"X 1 1/2" in size, the markings being in white letters 1/8" high, with 1/16" spacing between rows.