Form 765c / AIR81 files related to Hawker Hurricanes

**Jagan** · 5th June 2022, 04:44

Requesting help from members who may be holding on to AIR81 files related to Hawker Hurricane related incidents/ losses.

I have noted that many of the AIR81 files actually have a Form 765c that lists out the Merlin engine number.

Listing out a few here that I found thanks to theh Form 765cs

Z2519 RR Merlin XX 25393/A188325
Z3150 RR Merlin XX 25989/A188623
BN563 RR Merlin XX 86467/A336695
KZ486 RR Merlin XX 96971/A350233
KZ861 RR Merlin XX 57063/A276444
LB606 RR Merlin XX 103419/A351457
LB720 RR Merlin XX 351468/A103444
LB800 RR Merlin XX 29993/A189625
LB935 RR Merlin XX 351760/A104025
LD723 RR Merlin XX 137065/A415871
LE346 RR Merlin XX 13821/A416749
LE807 RR Merlin XX 140531/A417604
LE950 RR Merlin XX A417917
PJ672 Packard Merlin 29 100552/A393071

If anyone is holding these AIR81 files related to Hurricanes, can you look to see if the 765c form exists and extract the engine number? would appreciate all the instances.

-Jagan

**Ross_McNeill** · 5th June 2022, 07:22

Going down a rabbit hole there Jagan.

The engine numbers from 765c usually have the full data plate reference which has both the manufacturer number and the A prefixed Air Ministry contract number.

Usually, but not always, Form AM78 records the manufacturer engine number rather than the A prefix.

Form 1180 lists only the A prefix but drops the A eg F1180 for Z3150 records engine as Merlin XX 188623

Rolls Royce Heritage records are indexed on manufacturer engine number and as far as I'm aware they do not have a corresponding database indexed on A prefix number.

Ross

**Ross_McNeill** · 5th June 2022, 09:34

A few years ago I did a scoping exercise on the F1180s to see if useful correlation could be done on the engine serials recorded.

Threw up a few results
1 the less flying hours the airframe had between delivery and F1180 the more likely it was to still have the same engine.
2 Looked like the 100*hr service was where an engine change would typically take place but seemed to be more common change on uk airframes rather than overseas

So other than a batch of Am engine serials and grouping to engine types a data extraction did not give much useful info that could be extrapolated to engine fit to airframes not recorded on F1180.

3 Looking specifically at RR Merlin types I reasoned that engine serial and Air ministry number were fixed correlation at time of manufacture and so could I dump RR A numbers and use spot checked 765c/AM 78 to link RR number and extrapolate to any engine between. As per your spot groups above - there seemed to be no linear correlation between RR and A - possibly intelligence driven manufacturing blackout areas to prevent enemy doing same action as I proposed.

Put the task on the "could do but cannot see accurate result" spike.

Ross

**Jagan** · 5th June 2022, 16:30

Agree with you that its never going to be an accurate indicator.. but it is worthwhile information to crowdsource and capture - just like the POW sheet .

Originally Posted by Ross_McNeill

1 the less flying hours the airframe had between delivery and F1180 the more likely it was to still have the same engine.
2 Looked like the 100*hr service was where an engine change would typically take place but seemed to be more common change on uk airframes rather than overseas

The correlation to airframe hours is a good point.. yet another data point to record against a Hurricane Database if it is available on any of the documents
------------------------------------------------------------------

Additionally I was trying to understand if I can use the datapoints to accurately pindown the id of the Moradabad Hurricane whose engine number is 42639/A219867

Its a MkIIB Hurricane and if it was an original install, it might like between the two blocks..

Z3150 RR Merlin XX 25989/A188623
BN563 RR Merlin XX 86467/A336695

Assuming that the Moradabad Hurricane had its original engine when it crashed.

Elsewhere Jon Leake had suggested:

We might therefore be looking for a Hawker-built Hurricane produced at the end of 1941 or during early 1942, if the aircraft still had the original Merlin when it made its presumed forced landing, and if the Merlin was a new engine when installed rather than a recently overhauled engine. The similarity between the numbers on the booms of the front and rear centre-sections of the Moradabad Hurricane and the ex-Soviet Hurricane thought to be Z2330 suggests that the Moradabad aircraft may have been built somewhat later than the Russian aircraft but not too much further along in the production sequence. If these assumptions are correct, then the most likely production batch ought to be BM898-BP772, delivered during Dec 1941-May 1942 by Hawker, a total of 1250 aircraft. This might be the best place to start to look for identification of the aircraft.

Darren Pitcher shared this bit

apparently Merlin XX 42639 was manufactured at Glasgow 10/11/1941 it was despatched to an unknown destination on the 17/11/1941 and later recorded as written off. And that’s all the information he has.
----------------------------------------------------------------------------

**Ross_McNeill** · 5th June 2022, 18:31

3 days after the bird strike in the F1180 I sent you the squadron ORB says the unit was allocated another IIB which coupled with the soon after station move may have accounted why the Cat.B was not returned to service and possibly the vulture damage to prop and canopy/doghouse not repaired on site.

Ross

**Jagan** · 5th June 2022, 20:07

Thanks Ross,

For the benefit of others - Ross has traced down a Form 1180 relating to Hurricane IIB BN225 operated by 17 Sqn at Jessore. The Form 1180 confirms the engine number to the airframe.

The aircraft suffered a bird hit on 19.6.42 and landed safely. Pilot was Sgt F McClure 402555 RNZAF - https://www.aucklandmuseum.com/war-m...024?lang=en-nz

it is likely that the aircraft was alloted to some other unit for repair and then was lost on another flight 1400km away at Moradabad in a belly landing, which may have caused extensive damage to the propeller , including the blades breaking away.

17 Sqn ORB is sparse but it does record receiving IIBs during the month.

Air Britain BA-BZ Serials book lists BN225 as serving with 607 Sqn, and SOC on 1st July 1942, not many days after the above incident and that it was "DBR during operations - no further details"

However 607 Sqn only operated IICs - its ORB making it clear that it received the first Aircraft in June 42 and they were all IICs.. They were however located at Alipore, in close environs of 17 Sqn. so that may be one source of confusion.

Considering the RAF records the aircraft as SOC on 1 July 42, and the engine was last seen on BN225, it is safe to assume the survivor in Moradabad is BN225.

But the explanation on how it made the journey from Jessore to Moradabad is still a mystery at this point .

There is a chance that the engine was pulled off BN225 and reused on another aircraft.. but then a good start would be to see if there are other F1180s out there for the same serial or engine number.. Also trying to understand the RSU work out of Jessore may be a good lead as well. I will try and check if the Bamboo Workshop mentions anything more..

**Ross_McNeill** · 5th June 2022, 20:57

Ok checked to end of 1942 BN225 does not appear again as a serial on the cards indexed under Hurricane.

Neither does engine 219867 appear as specifically listed associated with another airframe (not conclusive as there are a number of Hurricane for India with no engine numbers recorded)

two bracket numbers do appear
6/10/42 BN174 219864 Cat B
27/10/42 BG994 219871 Cat B

Ross

**Jagan** · 5th June 2022, 22:36

Thanks Ross,

Just to consolidate - I have added the numbers you have given me till now. All the 2198* seems to fall in the BG-BN block

Z2519 RR Merlin XX 25393/A188325
Z3150 RR Merlin XX 25989/A188623
BG994 RR Merlin XX _____/A219871
BM926 RR Merlin XX _____/A219553
BM990 RR Merlin XX _____/A219889
BN167 RR Merlin XX _____/A219748
BN174 RR Merlin XX _____/A219864
BN187 RR Merlin XX _____/A219834
BN225 RR Merlin XX 42639/A219867
BN332 RR Merlin XX _____/A219557
BN563 RR Merlin XX 86467/A336695
KZ486 RR Merlin XX 96971/A350233
KZ861 RR Merlin XX 57063/A276444
LB606 RR Merlin XX 103419/A351457
LB720 RR Merlin XX 103444/A351468
LB800 RR Merlin XX 29993/A189625
LB935 RR Merlin XX 104025/A351760
LD723 RR Merlin XX 137065/A415871
LE346 RR Merlin XX 13821?/A416749
LE807 RR Merlin XX 140531/A417604
LE950 RR Merlin XX _____/A417917
PJ672 PkrdMerlin 29 100552/A393071
DR394 RR Merlin XX _____/A220418

**Ross_McNeill** · 6th June 2022, 06:48

Was going through early part of 1943 to see when it looked like engine changes happened

16/1/43 BM929 219799 Cat A
6/2/43 BN379 219991 Cat A
15/2/43 BN274 219756 Cat B
2/3/43 BN209 219811 Cat B
2/3/43 BN225 21987 Cat B

Now flying with No.6 RIAF (15 take off for transit flight - B flight gets lost and all 6 force land) - Cat B at Biaora wheels up forced landing. Same engine (missing digit on F1180)

Ross

**Ross_McNeill** · 6th June 2022, 08:08

Now swept up to end of 1943 - no further listing of BN225 or engine 219867 (again many India Hurricane F1180 into late 1943 with no engine serial recorded)

Very few BN airframe F1180 in the later part of 1943 - impression is that most India spread over 681/6/17 and 151 OTU retained original issue engine. Middle east - more records in the later part of 1943 and occasional engine change noted from Aug but not wholesale so just occasional replacement rather than 100*hrs.

Ross