Bristol Blenheim

[Hanski]

No it does not make then useless or antique. But it was known before the WW that Fokker D XXI was a second rate fighter (it had been such all the way from the design board). And the need to get more modern fighters was growing - but ignored by Air Force Command.

I am not at all convinced that you are pointing your finger at the right culprit.

About the Fokker acquisition, I just checked the chapter on “The Air Force in the 1930’s – growth to a Branch of Defence makes progress”, p. 59-61, in The History of the Karelian Air Command by Veli Pernaa, Col (ret), 1997.

Without going to a full-length translation of the text (which I highly recommend to all Finnish readers), I will point out some issues in it:

- the new Council of Defence (Puolustusneuvosto) was established in 1931, with expert representation covering also politics and economy
- the apparent lagging behind of the Air Force during the 1920’s had already been investigated by the Hohenthal Committee in 1928. Its proposals had not improved the funding of the Air Force. The Cabinet finally ended up with an “Emergency Program” in 1930, to cover the most crying needs.
- Cavalry General Mannerheim had got thoroughly acquainted with the state of our Defence Forces after his nomination as the Chairman of the Council of Defence. He paid special attention to the performance of the Air Force.
- In 1931 the Council of Defence proposed setting up a committee for investigating the Air Force. The task was given to a committee chaired by Major General Oesch, with its report being presented in 1932.
- The Committee on State Finances established in 1935 ended up proposing remarkable additional acquisitions to especially the Air Force.
- A later Committee on Basic Procurements prepared its report in 1938, when the Act on Basic Procurements was given. It gave a great weight to developing the Air Force, too.
- procurements of aircraft required contacts abroad, as the development of combat aircraft accelerated significantly in the 1930’s. The types with the best performance were generally held secret, which is why Finns had difficulty in getting information on the latest constructs. However, experts of our Air Force did get opportunities to familiarize themselves with the production of the leading European aviation states.
- Mannerheim, promoted to Field Marshal in 1933, showed interest in the Air Force and visited aircraft industry in Britain, Germany, and France. In Germany, he heard Hermann Göring’s lecture on the significance of the air force, which he considered “enlightening”. Mannerheim would have preferred highest quality, which in his view was to be found in Germany.
- despite of the Emergency Program and Mannerheim’s support, politicians axed the budget proposals of the Air Force. The State Finance Committee of 1935 reduced five of the proposed 17 squadrons of the development program. A revised basic procurement program was prepared for the Air Force in 1935, including 12 squadrons as follows:

land army support squadrons (maayhteistoimintalaivueet) 10, 12, 14, and 16 (34% of the aircraft)
fighter squadrons 24, 26, and 28 (34% of the aircraft)
long range squadrons (kaukotoimintalaivueet) 42, 44, 46, and 48 (24% of the aircraft)
maritime support squadron (meriyhteystoimintalaivue) 36 (8% of the aircraft)

- reinforcing the fighter force did not proceed as planned: one squadron (28) was scrapped in 1938
- as the State Aircraft Factory moved from Suomenlinna to Tampere in 1936, its production potential grew remarkably. Both the then Command of the Air Force and the Council of Defence had positive attitude towards domestic aircraft production, as no funding was available for purchasing more expensive aircraft from abroad. Also the State Finance Committee favoured domestic production.
- the Council of Defence decided on the acquisition of the first Fokker D.XXI squadron in October 1936.
- the Council of Defence discussed fighter procurement again in the spring of 1937. The Commander of the Air Force proposed more Fokkers with unlimited license and domestic production. The outcome was a decision on purchase of the license rights and an order on 21 aircraft from the Aircraft Factory. The license production of Blenheim bombers commenced respectively in 1938 and went on till the war years.
- the Council of Defence decided on changing one of the long range squadrons to a fighter squadron on 6 June 1939. The decision was a right one, but it came far too late.
- in the spring of 1939 the Air Force Command made a new operational plan, emphasizing the role of fighters., which led to hurrying up the fighter procurement in the Council of Defence. The Council worked on the fighter question during the summer and autumn of 1939. Fokker was not regarded as fulfilling the requirements for a fighter, and Marshal Mannerheim was doubtful on the selection of Fokker.
- as the international situation grew tense and the possibilities of purchasing aircraft narrowed, the Commander of the Air Force, Major General Lundqvist, proposed in early September 1939 establishing a new aircraft factory in Pori, with raw material to be acquired for one year’s production. The factory was to produce license aircraft at first, to be followed by a new type of fighter of domestic construct later on. The initiative included other plans, like the acquisition of the American Seversky fighter, which however had numerous problems. The plane was expensive, and there were problems in getting the raw materials.
- although the Council of Defence decided on 10 September 1939 to both purchase Seversky fighters and begin their production under license, the political lead refused to grant funding for foreing purchases on a quick schedule. Remarkable procrastination on the aircraft acquisition of the Air Force took place right on the threshold to war.
- on 10 September 1939 an additional batch of Fokkers was ordered from the State Aircraft Factory, and the domestic Myrsky fighter on 20 December 1939.
- in the autumn of 1939, the Commander of the Air Force also made a decision to purchase 25 Fiat G.50 fighters from Italy instead of the long range aircraft. The contract was signed on 23 October 1939.
- G. E. Magnusson later criticized the decisions made in 1939. He felt the acquisition was started far too late, as Finns should have realized by the spring of 1939 the future outcome of the division of spheres of interests between Germany and the Soviet Union. The thought of producing domestic fighters in wartime was in his opinion unrealistic.


As you can see from the above, there were more players involved than the Military Command, and the chronic negligence was mostly due to opposition by frugal civilian politicians, who thought wishfully about international political developments and lacked insight into the long time span required for building up defence.

And finally, I will illustrate this post with my photo of the Fokker D.XXI at the Central Finland Museum of Aviation.

[Vaeltaja]

Could be... Well.. the lack of military spending certainly was the problem.

I had the impression from the books and elsewhere that both Lorenz and Magnusson blamed Lundqvist for the bomber preferring decisions and neglecting the fighters until it was too late.

Which seem to be this one...

- in the spring of 1939 the Air Force Command made a new operational plan, emphasizing the role of fighters., which led to hurrying up the fighter procurement in the Council of Defence. The Council worked on the fighter question during the summer and autumn of 1939. Fokker was not regarded as fulfilling the requirements for a fighter, and Marshal Mannerheim was doubtful on the selection of Fokker.

[Hanski]

Could be... Well.. the lack of military spending certainly was the problem.

I had the impression from the books and elsewhere that both Lorenz and Magnusson blamed Lundqvist for the bomber preferring decisions and neglecting the fighters until it was too late.

It is quite true that there were differences in opinion regarding the doctrine of the Air Force.

A remarkable theoretician in military science was the Italian General of Artillery, Giulio Douhet, who published his main work Il dominio dell'aria (Air Supremacy) in 1921, with the emphasis on strategic bombers to destroy the enemy's air arm in order to gain air supremacy. His thinking favouring the offensive impressed many in the Finnish military as well, and a debate on doctrine ensued (well described in Veli Pernaa's book) long into the 1930's, despite that Finland could never dream of possessing the resources of a great power.

[Juha Tompuri]

Couple of notes and corrections:

Blenheim was the fastest aeroplane in Finnish Air Force arsenal until Brewster came in 1940.

Weren't the Fiat G.50's, when they came to Finnish AF inventory, faster than Blenheims?

It (Blenheim, JT) was more agile than Fokker

Maybe at stories, but how about official tests?

Any fighter bought in 1936 would have been too slow for front line use in 1940.

Fokker D.XXI, which wasn't the fastest of the fighters evaluated, was bought in 1936.

Heinkel with a Jumo in 1938 would have been a poor choice for Finnish field conditions.

Radial engine planes were generally more reliable than the V-engine ones so it does not matter if you've 50 Heinkels and most of them are grounded.

Bristol Mercury wasn't actually a mechanics dream compared to some German engine ideas.
I'm not sure at all about the general mechanical reliability of the radial engines (Mercury) compared to the liquid cooled ones. For instance starting a liquid cooled engine compared to an air cooled (radial) is much more easier at low temperature conditions.

Also the question of spare parts for them would have risen during the War.

The War?
Winter War?
How about the next one when not only "would" but question of spare parts (and engines) of the chosen one did rise up?

I believe Fokker was the only fighter to operate from all major and minor fields during the Continuation War compared to few well mainteined fields on which the Messerschmitt operated.

Where there fields that were fightersuitable just for Fokker D.XXI's ?

At the end bombers were more useful to the war effort than most fighters.

Quite a statement.
For the Finnish war effort the fighters were more important than the bombers.
We could have fought the wars without bombers but not without fighters.

Blenheims mapped the terrain for attacks...

Yes, photorecon planes were very useful.

...and striked hard to enemy pinpoints.

With average Bleheim very modest bombload the strikes were quite far from hard and as earlier mentioned, not pinpointed too.

On the other hand fighters were useless against Soviet night attacks and fast recon/bomber planes attacking Helsinki.

Finnish night fighter arm was quite modest, but IIRC we did acchieve some nocturnial succeses and were able to shoot down some Soviet fast recon/bomber planes over Gulf of Finland.

Much of the captured goods would have been "lost" in 1941 if the Blenheims would not have bombed the stations and tracks at the Karelian Isthmus.

Eight Blenheims from Le.Lv.42 hit Suojärvi railway station on July 14th 1941. According to the aerial photos taken the reports made by the pilots were quite accurate on the damage caused by the bombs. Probably due of this and other Blenheim bombings Finns were able to capture two armored trains, eight locomobiles, a hundred or so railway cars etc.

Any railway equipment caught east of Jänisjärvi could be only evacuated through Suojärvi station. I do not have Finnish railway officer's report (on the status of the station upon captured) in my hands right now, but it's quite possible the captured trains were trapped somewhere in Loimola area for a month

As you might know from for instance Finnish experiences from Winter War, bombed tracks were often repaired in couple of hours.


Regards, Juha

[Mangrove]

First of all I would like to say that I do not have the official test flight reports for all types right now, so I'm partially using Raunio's summaries.

It (Blenheim, JT) was more agile than Fokker

Maybe at stories, but how about official tests?

According to Raunio at 5400 kg Blenheim Mk.I could do a full 360 degrees in 40 seconds. However no diameter for the circle is given. In unknown test Fokker did the same in 25-28 seconds.

Blenheim was the fastest aeroplane in Finnish Air Force arsenal until Brewster came in 1940.

Weren't the Fiat G.50's, when they came to Finnish AF inventory, faster than Blenheims?

FA-31 was test flown in May 1942. At the surface it archived 380 km/h at 890 mmHg pressure. FA-15 archived maximum speed of 430 km/h at unknown altitude (5 km?). Circa 445 km/h could be archived momenteraly. BL-121 did 435 km/h at 4000 meters and 377 km/h at 0 m, both with 5460 kg. Planes equipted with Mercury XV could archive c. 450 km/h.

Any fighter bought in 1936 would have been too slow for front line use in 1940.

Fokker D.XXI, which wasn't the fastest of the fighters evaluated, was bought in 1936.

What I meant was that all types other than maybe Bf 109 and Spitfire would have been more or less obsolete in 1940. Bristol Mercury and Pegasus had been selected as the official engine types for planes other than fighters in 1934. Fokker was natural choice logistically along with Blenheim as Tampella could manufacture spare parts and new engines for them.

Where there fields that were fightersuitable just for Fokker D.XXI's ?

Not exactly, but a simple construction it was easier to operate and repari in remote aerofields. Messerschmitts for example had major problems in 1943 as they were designed to operate from paved airfields.

Quite a statement. For the Finnish war effort the fighters were more important than the bombers. We could have fought the wars without bombers but not without fighters.

Not true. What would have happened at Viipurinlahti in March 1940, Suomussalmi 1939 or at the attack phase in 1941 without support from the bombers? I think we can all say bombers were more cost effective than fighters. Anyway most of the country were shielded only by the AA-units which brought down more aeroplanes than fighters.

As you might know from for instance Finnish experiences from Winter War, bombed tracks were often repaired in couple of hours.

Tracks yes, but if you have a hundred broken railway cars blocking the railyard, then no. Murmansk railway was probably the only case after 1941 where Finnish bombers targeted tracks and trains.

Had Finns been able - and willing as it seems -to buy for example modern (German) AC engines just before or during the war it might have been different thing. But that did not materialize.. all that did were second hand war booty engines of pretty much the same low quality scale as Finns previously had access to.

General Lundqvist wanted to buy a license for DB-605 in June 1942 but the Germans did not grant it or Bf 109s for that matter. Messerschmitts were bought next year along with some war trophy engines.

[Juha Tompuri]

First of all I would like to say that I do not have the official test flight reports for all types right now, so I'm partially using Raunio's summaries.

It (Blenheim, JT) was more agile than Fokker

Maybe at stories, but how about official tests?

According to Raunio at 5400 kg Blenheim Mk.I could do a full 360 degrees in 40 seconds. However no diameter for the circle is given. In unknown test Fokker did the same in 25-28 seconds.

So - which one was more agile?

Blenheim was the fastest aeroplane in Finnish Air Force arsenal until Brewster came in 1940.

Weren't the Fiat G.50's, when they came to Finnish AF inventory, faster than Blenheims?

FA-31 was test flown in May 1942. At the surface it archived 380 km/h at 890 mmHg pressure. FA-15 archived maximum speed of 430 km/h at unknown altitude (5 km?). Circa 445 km/h could be archived momenteraly. BL-121 did 435 km/h at 4000 meters and 377 km/h at 0 m, both with 5460 kg.

So - which one was faster?

Planes equipted with Mercury XV could archive c. 450 km/h.

could be archived momenteraly

Any fighter bought in 1936 would have been too slow for front line use in 1940.

Fokker D.XXI, which wasn't the fastest of the fighters evaluated, was bought in 1936.

What I meant was that all types other than maybe Bf 109 and Spitfire would have been more or less obsolete in 1940.

Against the fighter types Finns faced, Fokkers or some better types that could have been bought instead of them in reality, were not (that) obsolete.

Bristol Mercury and Pegasus had been selected as the official engine types for planes other than fighters in 1934. Fokker was natural choice logistically along with Blenheim as Tampella could manufacture spare parts and new engines for them.

Fokker D.XXI still wasn't the only option.
And Tampella couldn't manufacture enough Mercuries nor spares.

Where there fields that were fightersuitable just for Fokker D.XXI's ?

Not exactly, but a simple construction it was easier to operate and repari in remote aerofields.

So there weren't fighter airfields where only Fokkers could operate:

I believe Fokker was the only fighter to operate from all major and minor fields during the Continuation War compared to few well mainteined fields on which the Messerschmitt operated.

Quite a statement. For the Finnish war effort the fighters were more important than the bombers. We could have fought the wars without bombers but not without fighters.

Not true.

I think we can all say bombers were more cost effective than fighters.

Well, I think that here again you fail to understand the basic technology and history.
Finnish bombers did quite little harm to the Soviet forces specially in the Winter War, but the total lack of fighters and so reducing severly Finnish aerial defence, would most probably been very harmly, if not decisive to the Finnish war effort.

What would have happened at Viipurinlahti in March 1940, Suomussalmi 1939 or at the attack phase in 1941 without support from the bombers?

About the same that happened with their support.
Also with the money for every Blenheim bought, ca three fighters could have been bought.

Anyway most of the country were shielded only by the AA-units which brought down more aeroplanes than fighters.

Yes, Finnish modest AA-units performed very well, but surely you don't mean that they alone could have protected the vital areas?

As you might know from for instance Finnish experiences from Winter War, bombed tracks were often repaired in couple of hours.

Tracks yes, but if you have a hundred broken railway cars blocking the railyard, then no.

A hundred broken railwaycars blocking the whole railyard at Suojärvi station for over a month?


Regards, Juha

[Scharf]

Hi,
Actually I do not have right to get involved because I do not have any new "facts". Just wan't to say one thing: I have read almost every finnish aviation book and I can't recall any of them saying Blenheims were effective. Of course bombs do make harm when hitting, but there were not enought those planes and their capacity was too low.
When finns got Junkers situation and plane was whole different.

And one thing: I am not trying to say our bombers were useless in winter war or in continuation war, but fighters were more usefull.

Best Wishes,

Scharf

[Steady]

Blenheims flew almost solely reconnaissance-bombing missions during the Winter War. That is, recon first, bombing second. They were the eyes of the Finnish general command.

[Mangrove]

And Tampella couldn't manufacture enough Mercuries nor spares.

We're talking pre-war situation when the time of the war was unknown. At the time Tampela could manufacture engines for Finnish series of Blenheim and during the war they bought enough from Germany.

Finnish bombers did quite little harm to the Soviet forces specially in the Winter War, but the total lack of fighters and so reducing severly Finnish aerial defence, would most probably been very harmly, if not decisive to the Finnish war effort.

How do you know that? Have you read such reports saying that? As I tried to explain earlier bombers were able to perform such missions due of their range and load fighters could not have done. Soviet 44th Division was first sighted by Blenheims at Suomussalmi etc.

A hundred broken railwaycars blocking the whole railyard at Suojärvi station for over a month?

The whole west end of the station was still burning in the next day from first bombing. I'm not saying this single bombing blocked the whole traffic at this section, but a series of bombing performed by the Blenheims in following weeks. For example BL-104 claimed a hit on a 100 car train east of Suvilahti/Suojärvi station on the 16th.
http://digi.narc.fi/digi/fullpic.ka?kuid=2916506 (Aerial photograph of the bombing of Suojärvi on July 14th)

[Vaeltaja]

Reading from attached reports the bomber's own view of their bombings was not quite so high. At best one set of bombs is mentioned that it may have hit near the target but that is all they claimed. And from the attached reports it is apparent that most of the smoke is not from the station but instead forest fires (probably) - 'kulot' - possibly intentionally lit by Soviets.

Until the Pe-2s and Pe-3 were acquired the Blenheim was quite good recon platform. And relatively good one at that against early war Soviets with their not so speedy I-16s and I-15 series aircrafts though it seems Blenheim would not have been able to outfly those - I-16 is ~ 100 km/h faster than Blenheim.

As said i doubt no one disagrees with the contribution - especially as recon plane - the Blenheims did but instead the thing is that fighter acquisitions were neglected - or second rate designs were acquired - as FAF concentrated on trying to build a bomber fleet.

[Juha Tompuri]

At the end bombers were more useful to the war effort than most fighters.

Quite a statement. For the Finnish war effort the fighters were more important than the bombers. We could have fought the wars without bombers but not without fighters.

Not true. What would have happened at Viipurinlahti in March 1940, Suomussalmi 1939 or at the attack phase in 1941 without support from the bombers? I think we can all say bombers were more cost effective than fighters.

Finnish bombers did quite little harm to the Soviet forces specially in the Winter War, but the total lack of fighters and so reducing severly Finnish aerial defence, would most probably been very harmly, if not decisive to the Finnish war effort.

How do you know that? Have you read such reports saying that?

I base my knowledge on what for instance Col Risto Pajari (during the wars served at Finnish AF HQ ending to AF cheif of staff) has written based on the reports he had read.
Which I think are quite numerous.

My translation of the relevant parts:

...After the wars (Winter and Continuation, JT) it has been presented that the purchase of Blenheim "long distace operation planes" to Finnish AF would have been a mistake, and fighters should have been bought instead of them...

...Blenheim was a good long distance operation plane at those conditions, a fast and good rate of climb with good crew "operational placing". The plane was reliable and at recon missions much was acchieved at both Winter and Continuation Wars.
Blenheim was built as a bomber. However it suited poorly to the "Finnish AF tasks". The bombing accuracy and the bomb load were modest. Because of them it would better have suited to area bombing than to smaller, close to the front line target bombing. We needed help to the front, we couldn't afford bombing area targets. With the price of a Blenheim it would have been possible to get over a double amount of fighters, with which more could have been acchieved during the war.
Even Blenheims were good and useful at the war, surely it would have been better if fighters would have been bought with the same amount of money instead of them.But there is no "monopoly" for this kind of "blindness". The development was the same at all of the countries. This being noted as after the event wisdom based on the experiences from the wars.
The issue would have been different, if these lines would have been written in 1936, at the time the purchase of Blenheims was decided

Regards, Juha

[Slon-76]

Jarl Lundqvist (Air Force Commander), and his beloved Blenheims instead of modern fighters

Greetings!

Would like to bring to your interesting dialogue in the «5 cents».

I think, that Finns not so understand a real role of the Blenheims in « winter war ». For a long time, when I only started to be engaged in a history of " winter war ", I too thought, that Lundqvist - the fool or had a «personal interest» in a question with Blenheims. But now my opinion has strongly changed.

Let's present, that would change, if Finland would buy instead of Blenheims, for example, 50-60 P-35. Essentially anything. Soviet Union all the same would possess domination in air as on each Finnish fighter would have 10-15. Attempt of the Finnish Air Forces to enter an open antagonism above Karelian isthmus in February 1940 anything good for them was not terminated. And neither Fiats, nor MS406s a situation essentially have not changed.

Yes, most likely losses of the Soviet bombers, flying to bomb rear objects in Finland would be much more. But as though it was reflected in a situation at the front? In any way. Probably, the Soviet command in general would refuse such bombardments. Then these bombs would start to fall on Mannerheim's Line. And Finnish fighters it should to return on a front line where them those would expect 10-15 Soviet fighters on everyone…

And now about role Blenheims.
The Soviet command knew, that Finns have modern high-speed bombers. And it forced to reckon with them. For air defence huge forces of the Soviet aircraft which otherwise would appear at the front have been involved.
For example, 54 aviation brigade - these are 8797 starts on air defence of Leningrad and staff 7 army (i.e. it is more, than all Finnish Air Forces in general) and only 1419 on front.
About two squadrons I-153 have been involved in 9-th army on air defence of objects in rear. Strikes single Blenheims on air station Reboly 3, 4 and 12 on February are interesting. The material damage from strikes was minimal. But! The airgroup supporting 54 division has been compelled up to third of air mission to involve for patrolling above air station! For example, on February, 5 from 82 starts 80 SAP - 19 on patrolling, 10.02 – 32/8, 17.02. – 98/32. Thus, only three starts Blenheims "have cleaned" from the sky above divisions of 9-th infantry division up to 30 Soviet fighters daily. And what such 30 starts? For example on March, 8 I-16 80 SAP in 30 starts only the 20-mm of shells have spent 1375 pieces! What Finnish fighters could brag of such productivity?
No, Lundqvist was very clever and far-sighted person! Simply results of activity of bombers not so are obvious, as results of actions of fighters. I think, that Lundqvist as the former commander of artillery, estimated the Air Forces from the point of view of utility for army instead of as "field" for cultivation of experts.

[*]Wallenius, the hero Lapland and the drunken fool of the Vyborg Bay.

Hmm... It is curious. Whether it is impossible a few details. Anything about it did not hear.

[Vaeltaja]

As said before.. Blenheims were good recon and harassment planes. For which the initial batch of planes would have been more than enough. FAF command however insisted on getting more of Blenheims at the cost of ignoring fighters. Problem was not that FAF bought Blenheims. Problem was that they didn't buy much else.

And Soviet air dominance over the front lines was so total that some 50 or 60 odd fighters wouldn't have done a thing on it. However having 50 or 60 faster real fighters - instead of CAS planes designed for attacking restless natives in Indonesia - would have allowed Finns to make life rather miserable for the arty observation planes as well as for the bombers penetrating deeper into Finland.

As bombers the only redeeming quality Blenheims had was speed. And even that was lost by the time Winter War begun. At that time it was a light level bomber with severely limited bombload (dive bombing capable Fokker C X could carry about the same load).




http://en.wikipedia.org/wiki/Kurt_Martti_Wallenius
And Wallenius.. Commanded in Winter War the Lapland Group which fought at Salla and Petsamo regions. And did so successfully. He and the troops under his command were transfered south to Vyborg Bay when the Swedish volunteers took over in the north. Situation was totally different that we had used to or what he had expected to see. For the following three days Wallenius took to the bottle and stayed drunk until Oesch replaced him. Hero of Salla (etc) ended up being dishonourably discharged from the military, expunged from the officers lists and as an added insult when the continuation war began and he tried to enlist/draft into military as private (former Major General) he was flunked.

And that is even discounting the escapades he had during Lapua/Mäntsälä events - though by most accounts he was stone drunk back then as well...

[Mangrove]

However having 50 or 60 faster real fighters - instead of CAS planes designed for attacking restless natives in Indonesia - would have allowed Finns to make life rather miserable for the arty observation planes as well as for the bombers penetrating deeper into Finland.

Much of the Soviet artillery observing was done by balloons, not aeroplanes. Finnish Air Force was afraid to attack these well protected and difficult targets, so it would not made a difference if we have had more fighters.

As bombers the only redeeming quality Blenheims had was speed. And even that was lost by the time Winter War begun. At that time it was a light level bomber with severely limited bombload (dive bombing capable Fokker C X could carry about the same load).

The maximum combat load for Blenheim Mk. I was about 725 kg while Fokker C.X could carry mere 300 kg of bombs. Junkers Ju 86K was praised for its high load capasity, but was not chosen over Blenheim for its small maximum speed.

[Vaeltaja]

Much of the Soviet artillery observing was done by balloons, not aeroplanes. Finnish Air Force was afraid to attack these well protected and difficult targets, so it would not made a difference if we have had more fighters.

Perhaps... I seem to have read of Fokker attack against Soviet observation aircraft which was considered to be very daring operation in some of Karhunen books (ritarilentue ?)

Hmm.. Not sure which are real data...

From en-wiki.. Blenheim 540 kg, Fokker C X 400 kg.
From fi-wiki.. Blenheim 526-972 kg, Fokker C X 400 - 600 kg.

Regardless... Values are still roughly in the same ballpark. Difference was that Fokker could deliver the amount with enough accuracy to hit individual fireplaces in the woods as was done in 1942 and that for Blenheim required target size of a city block.