Best twin engine dogfighter

[jim]

They built 380 Hornets. 11 were rebuilt from F3 to FR4. A small but credible force.

They only built 37 Do 335's. Deliveries to combat units commenced in January 1945. When the United States Army overran the Oberpfaffenhofen factory in late April 1945, only 11 Do 335 A-1 single-seat fighter-bombers and two Do 335 A-12 trainers had been completed. These were production units that maybe got delivered and maybe not all. The rest were prototypes and test birds. There is a picture in Wiki showing the ramp at the Oberpfaffenhofen factory when it was taken with 9 Do 335's, only one of which looks like maybe it could be made to fly, though some pieces are missing. The rest are minus engines and major pieces of airframe, so at least these nine were never delivered, and the picture caption does not say if the nine were test birds or production units. That leaves 28 possible birds, with 11 production fighters built and 2 trainers. That's less even than the Ta 152's, of which never more than 25 of the 43 delivered were in service at any one time.

Performance-wise, the Do 335's speed was almost identical with the Hornet at 474 mph to the Hornet's 472 mph. But the speed of 474 mph was only with emergency boost for a few minutes and was 413 mph on what we would call military power. It supposedly had a 721 mile combat radius at half load. The Hornet had a 3,000 mile range which equates to a 1,500 mile radius with probably a 1,100 – 1,200 mile combat radius. Interestingly, the Hornets with 1,770 HP per side were the fastest variants at 472 mph. The NF21 with 2,030 HP per side was the slowest at 430 mph and the PR22 with 2,070 HP per side went 467 mph. Naturally, these Hornet speeds are at max boost, as with the Do 335, but it was faster at military power than the Do 335 by a margin.

If you dig around, you can find an initial climb rate for the Do 335 of 4,600 feet per minute, but they don't tell you at what weight that was recorded. The Hornet can be found to have a climb rate of 4,650 feet per minute with the same caveat. The people reporting these data obviously aren't thinking about analysis by someone at a later date.

Wing loading for the Do 335 at 25,800 pounds is 43.6 pound per square foot. At the empty weight of 16,975 pounds it was 28.7 pounds per square foot. Combat wing loading was in between the two. I'd estimate it was probably in the 38 – 40 pounds per square foot range typically.

Wing loading for the Hornet at 19,500 pounds was 54.1 pounds per square foot (NF). At the F1's normal weight of 16,100 pounds it was 44.6 pounds per square foot. At the empty weight of 12,502 pounds (F1) it was 34.6 pounds per square foot. The heavy Hornets were the night fighters with radar and antennas. I'd estimate the fighter variants at 38 – 40 pounds per square foot typically, without drop tanks (or after dropping them).

On paper they have close to the same speed, climb about the same and the Do 335 has a possibly lower wing loading, but maybe not by as much as it might seem at first. The Do 335 SHOULD be able to roll better, but I can't find any data to support the contention. I also cannot find any CL data at all for either aircraft.

The Hornet had four 20 mm cannons and the Do 335 had two 20's and one 30. Call the armament a wash.

But with something like 28 Do 335's perhaps flyable and something like 11 or less production units completed and maybe delivered, the Do 335 must be considered against 380 Hornets delivered. If the types had met, the Hornets would have overwhelmed the Do 335 if only by virtue of there being 10 times more available, all of which had longer range. Even if the Hornets couldn't catch the Do 335's, and it is probable they could after emergency boost was used up, they could certainly follow them (or it, if only one) until the Do 335 had to land or become a glider. I'd say advantage Hornet in the real world with the comparsion being essentially unkown in a one-on-one mixup.

Sorry, that was not a best twin dogifghter response, it was copmaring the Hornet with the Do 335 ... I didn't mean to wander, but noticed it after I posted and figured I'd just leave it in for postetrity.

Mr GreqP
As far as range is concerned , i would like to notice that the Do 335 had the option to use its bomb bay for additional fuel tank if nessecary
Also Mw 50 could be used up to 10 min continiously. Do you believe that merlin s could be used at max boost for longer periods?
Also Do 335 made 474 mph on DB603A.Single stage engines while Hornet on two stage engines . I believe that this means that above 5000m the Hornet had plenty more power yet had near identical top speed By the time Hornet entered service much more powerful engines would be available for the 335 and two stages as well
On the other hand Hornet could NOT recieve any other engine than the Merlin 130
I believe Do 335 had greater potentional ,but was very complicate, and required a lot of maintance
Hornet is extremely beautiful as well as its cousin the Argentinian Namcu. A comparison between them would be very interesting . I think Namcu was somewhat lighter

 

[DonL]

They built 380 Hornets. 11 were rebuilt from F3 to FR4. A small but credible force.

They only built 37 Do 335's. Deliveries to combat units commenced in January 1945. When the United States Army overran the Oberpfaffenhofen factory in late April 1945, only 11 Do 335 A-1 single-seat fighter-bombers and two Do 335 A-12 trainers had been completed. These were production units that maybe got delivered and maybe not all. The rest were prototypes and test birds. There is a picture in Wiki showing the ramp at the Oberpfaffenhofen factory when it was taken with 9 Do 335's, only one of which looks like maybe it could be made to fly, though some pieces are missing. The rest are minus engines and major pieces of airframe, so at least these nine were never delivered, and the picture caption does not say if the nine were test birds or production units. That leaves 28 possible birds, with 11 production fighters built and 2 trainers. That's less even than the Ta 152's, of which never more than 25 of the 43 delivered were in service at any one time.

Mr. GregP,

your are always repeating your same useless opinion about german a/c's. It's boring, because at 90% of your posts about german a/c's you have not much knowledge about what you talk, nor you have any knowledge about primary sources of various german a/c's.
The numbers that were built of an a/c says nothing about it's performance or it's potential to perform with further development.

Every german a/c from FW 187, Ta 152H, FW 190D-9, He 177 or Do 335 is simply **** to your opinion, because not much were built, and as I have seen at the FW 187, you have not a single clue about, what you are talking (The FW 187 had no single drop clue, because it was a full metal a/c).
If you want to talk about german a/c's and their performance you should read some well researched sources or better primary sources, inclusive performance datas from E-Stelle Rechlin. The numbers built at such a discusion are totaly irrelevant.

 

[GregP]

Hi Jim,

I really like the Namcu, but have only seen 1 or 2 pics of it and only have the performance data numbers from the web, no test data. The Do 335 was a pretty interesting bird and, potential-wise it of course had room for development as it was so early in its development cycle when the cycle was terminated. Later Do 335 variants might have been quite a package. But all we have to compare with is what was actually built, flew, and for which we have data. So I use that data, not paper "what if" data.

Thank you for your opinion DonL. Actually I like most German birds. No plane, Allied or Axis, was best at everything. Each has strengths and weaknesses. If an Allied late-war type got a ltittle slow, a well-flown Bf 109 would hand him his walking papers pretty quick. Seems like the Fw 190 and Spitfire traded the top pure fighter spot back and forth for a few years.

I get a little tired of hearing about the Ta 152 wonder plane not because it didn't have potential (it DID), but because so few made the war and they did so little. The performance numbers look sparkling and it is likely that if it had been built in numbers and deployed in numbers, it would have been formidable indeed. In real life, it only did what it did and that wasn't much. Great potential just too late to do any real good for the war effort from the German side. Sorry if you don't like it.

None of the late-war German prototypes were crappy at all. They showed great engineering and promise, all unfulfuilled due to the war ending before they could get built and deployed. Unlike what you state above of me, I like most of the German equipment as far as design, quality, and potenial goes ... maybe except for the Bachem Natter. That one you'd never get me to believe was ever going to be practical in any way.

However, they were beaten in real life by large numbers of mid-war designs through no fault of the aircraft designers or the average German pilot.

We all have our own opinions and if mine is absolutely useless to you as you say, you can imagine how valuable your opinion is to me. As for not knowing what I am saying, let's jusy say, with over 50 years as an avid reader of WWII aviation (from all sides, I might add), over 30 years as a pilot and over 8 years restoring WWII fighters (including our Hispano Ha.1112 Buchon), I have a slightly different take on it that you seem to. However, you certainly don't have to agree with me and you rather obviously don't.

By the way, just foir the record, in my post about the Hornet vs. the Do 355, I believe I did state that one-on-one, the outcome would be uncertain. That doesn't favor the Hornet or the Do 355. It would probably favor the better pilot.

Have a nice day in Germany, wherever you are. Cheers.

 

[DerAdlerIstGelandet]

DonL if you find someones opinion boring, then ignore it. If you wan't to discuss their opinion, do it respectfully and in an adult like manner.

You know that childish ignorant comments are not tolerated here.

 

[GregP]

Hi Jim, I didn't address one of your points but, no I don't think the emergency power was of any longer duration for the Merlin than it was for the German engines. The Hornet was faster at max continuous power than the Do 335 was, barely, and just barely slower at WER (or the British term) boost. All in all, pretty even. The differences were easily covered by the differences in individual aircraft trim and fit. Of course, the max numbers are at critical altitude. I don't have sea level numbers for either type.

I did not know the bomb bay could be used for extra fuel but, with a 700+ mile radius, I doubt it needed to abandon armament for extra fuel very often. Late in the war they were pretty desperate to stop bomber streams, not so much to attack the UK. If the Do 335 had reached anything like service with a regular group, I think it would have been employed against bombers, probably at lighter weights than 25,500 pounds. But I don't know for sure and there weren't enough that we could establish what their deployment strategy might have been.

Perhaps some German members might know.

If not, we have a good airplane with a lot of potential that was flown just before the war ended. The only combat I have read about was in April 1945. A lone Do 335 was seen at low altitude (treetop height) by Tempests lead by Closterman who were not able to catch it and engage, despite diving on it from height. I have no knowledge of any Do 335 victories, but am interested enough now to at least look around to see if any were claimed by the type, but haven't done so yet.

 

[bobbysocks]

i would pull for the Do335. they had a captured one at neubiberg whle the 357th was there. they flew it several times and had a dogfight with it in one of their 51s. they said its extremely fast but not as agile as the mustang. its a bigger plane and heavier....how it stacked up against other twins is a guess. i would think its slimline and counter rotating props/engines would have made it a pretty good contender.

 

[vikingBerserker]

I have to admit, the Fokker G-1 was a beautiful aircraft.

 

[altsym]

I have no knowledge of any Do 335 victories, but am interested enough now to at least look around to see if any were claimed by the type, but haven't done so yet.

There are no known air to air victories for the DO 335.

 

[vikingBerserker]

Luftwaffe's Classics Dornier Do 335 Pfeil only has a short blurb about the dog fighting ability of it on page 48.

Dipl. -Ing Beauvais (a highly experienced test pilot) fly in mock combat against a Fw 190 which he quickly left in the dust. He found that the aircraft:

"possessed excellent handling characteristics, and was extremely manoeuvrable for its size."

 

[GregP]

"Extremely manueveragle for its size" doesn't tell us much about maneuverability versus the Fw 190, but it's all we're likely to get. They aren't flying any these days.

 

[Marcel]

"Extremely manueveragle for its size" doesn't tell us much about maneuverability versus the Fw 190, but it's all we're likely to get. They aren't flying any these days.

the G-1 was even bigger and could turn with the nimble D.XXI.

 

[parsifal]

It certainly did well by the accounts ive read, in a hopeless fight.

 

[OldSkeptic]

Wing loading can't be compared to a normal wing mounted twin.
That is because, with a wing mounted twin, you have accelerated air coming off the prop's flowing over the wing. This produces additional lift.
The 335 had to have a big wing, otherwise it would never have taken off. let alone climb.

You have to compare it to single engined aircraft in term of the wing loading affecting performance.

Now it wasn't bad (using the A0's numbers), at max wight it's loading was 33 lbs/sq ft. Compare that to a FW-190 A8 which was 49.3lbs/sq ft.
If fact about equal to a Spit XIV.

Then look at the thrust loading (at max weight and power). About 5.6 lbs/bhp. An 190A8 was actually poorer at 6.4lbs/bhp.
But now compare that to a Spit XIV at 4.1lbs/bhp.

So you can say straight off, that it should outclimb a 190A8 (all other things like drag being equal, but that is less of an issue in the climb) , but nowhere near a Spit XIV, and the Hornet was much better than the Spit.
Now obviously climb rates will drop the higher you go and how they drop off will be a function of the high altitude performance of the engine.
Given that its max altitude was only about 35,000ft you'd expect it climb rate would drop off rapidly.

Finding figures for this is not easy. Janes has no climb ones and Wikipedia is wrong (wrong for the Hornet too)
The ones I have are from Eric Browns book "Wings of the Luftwaffe", have it taking 1.3 mins to 1000m, which is about 2,500ft/min, not that great, especially when the Hornet was 5,000ft per minute at that altitude.

Now more power helps of course, but even with a later model DB 603 (the A- used the A1), and MW-50 I think you'd struggle to get to 3,500ft/min (plus who'd want to waste MW-50 for take off, you need it for combat).

Anyway, where could you fit MW-50 (let alone GM-1) without having to remove a fuel tank, thus cutting range.
Looking at the cut away for the 335B-2 there is no MW-50 tank and precious little room for it. There is so little room in the fuselage that the oxygen tanks are in the wings!!!!
So you'd have to cut out one of the fuel tanks in the rear.

The more and more I look at this plane the more absurd it seems. Do you know the bale out procedure was:
(1) press button to blow off the rear propeller.
(2) press button to blow of upper tail piece.
(3) press button to arm ejection seat.
(4) Pull handle to remove canopy.
(5) Press ejection button....


And those long oxygen runs, you'd be petrified of freezing in the lines.
Not to mention that if your rear engine went on fire (a common occurence, killed a RAF test pilot that one) you can't see it...
And rear visibility was non existent (which for a late model plane like that was criminal).

Then you think of how much more work was needed to make it reliable (if it could be done) .. and how difficult it would be to manufacture and that maintenance would be a nightmare.
And resistance to battle damage, hit on the rear and your prop and/or top tail piece blows off if the explosive charges are hit??? Hit on the wing that hits the oxygen tanks and your wing blows off.
And the rear engine (and its radiator) and so on and so on...

Absurd as I said, I suppose it could have, in the end been, been turned into a fair day/night bomber destroyer ... but why bother.

 

[GregP]

Some pretty good points in the OldSkeptic. I've been accused of disliking German equipment and didn't want to bring up some of them myself since thye Do 335 turned into a dead end anyway with the end of the war.

The Hornet served well and reliably though it didn't really have to fight much maybe except for the Mayalan Emergance. It operated against guerilla insurgency there instead of aircraft.

With different circumstances after WWII, who knows the Do 335 might have found a niche ... maybe not. It was a very interesting project nonetheless.

 

[OldSkeptic]

Some pretty good points in the OldSkeptic. I've been accused of disliking German equipment and didn't want to bring up some of them myself since thye Do 335 turned into a dead end anyway with the end of the war.

The Hornet served well and reliably though it didn't really have to fight much maybe except for the Mayalan Emergance. It operated against guerilla insurgency there instead of aircraft.

With different circumstances after WWII, who knows the Do 335 might have found a niche ... maybe not. It was a very interesting project nonetheless.

Oh they had much better designs available for development. The TA-154 for example would have been superb and uprated engines and the like later on could have put it into the 450+ class easily.
Typical Kurt Tank design ... it worked and very well too (did that man and his team ever make a bad aeroplane?).
The RLM were against it though, preferring (or at least some did) the vastly overweight 219 (33,000lb fully loaded, no wonder it was a dog) and the glue factory being hit by a bomb was more a political rational for dropping it than anything else.

Unfortunately for them, fortunately for us.

And you see the same old pattern over and over.. Excepting Tank and his team, designs ranging from bad to terrible (Me 210 and 410 anyone?), or even if they were good, vastly too complex.
Far too many prototypes, far too little development of successful ones.

In the end the Luftwaffe basically ended up (with a few exceptions, nearly all by Tank) with a lot of very obsolete equipment making up the bulk of what it had, with small numbers of high performance types that were competitive (or in the case of the 262 superior), hence it got swept from the sky.

Still building and using the Me-110 in 45 for example.
And take the 109 as another example, it could have been fixed up and developed further, but good old Willy had lost any interest in it.
The fact that even the K still had the same miserable aileron and elevator performance the E had was a damning indictment of Messerschmitt (and the RLM), let alone the terrible visibility.
What was needed was a thing like a Typhoon to Tempest design upgrade (or the 190A to D). Something that fixed the major issues and could be put into production quickly and actually contribute to winning their side of the war.

And don't even get me started about the engine manufacturers, if anything they were worse (excepting BMW, after the usual teething issues were sorted out, the 801 was probably one of the best of its type around).

So I'm not anti-German in that sense, just anti stupidity and incompetence.

As the old saying goes, wars are usually won by the side that makes the least mistakes. And in the air war, despite the massive number the Allies made, the Germans made even more.

 

[delcyros]

I too, would prefer the Hornet over the Do-335. However, that beeing said, I remain not convinced that either of those two is superior to late war single engine A/C types.

 

[OldSkeptic]

I too, would prefer the Hornet over the Do-335. However, that beeing said, I remain not convinced that either of those two is superior to late war single engine A/C types.

Depends what you mean as superior. The key is too identify a need and then come up with a design that will meet that, plus be easy to manufacture, maintain, fly, et al.

The Hornet design came from early studies on the Mosquito being looked at as a long range escort fighter.
The results were that it couldn't, but they did some trials with a (very) lightened Mosquito and the performance was remarkably better, but not operationally practical.

Hence the Hornet. Smaller, lightened, huge range, incredible climb and speed, agile, capable of hanging lots of kit off of it (though not a true bomber). And of course easily converted to carrier operations (one of the very few that could do both). It was the British answer to the need for a long range fighter.
Basically the Hornet was to the Mosquito what the prototype super lightweight Mustangs* were to the P-51D (with their also remarkably better performance).

Now DH was pushed to the limit producing Mosquitos and developing new models (eg NF 30 series, etc). If the need for the Hornet had become really necessary (eg the TA-154 had gone into mass production) then resources would have been shifted and it would have gone into production earlier.
How well would it have done? Well it had the capability of 'booming and zooming' just about anything else (except a jet) to death. Very probably ... quite well.

*Note the P-51H was not one of those, it was only slightly lighter and the real rational for it was the ever decreasing G limits of the P-51 A, B D (each model going down) especially with high fuel loads.
The H restored those even with high fuel loads and its higher performance really came from using a 100 series Merlin.

 

[Sid327]

The Whirlwond was a hot aircraft - both in specs and looks! Given the high wingloading, I do not think it was a particularly good turner, and there was its relatively short range.
It would have been a stellar bomber destroyer during BoB.

Westland Whirlwind gets my vote. I love the Mossie, but dont think she was a genuine dogfighter?

Agree,

pity it wasn't ever developed to show it's potential.

 

[jim]

Wing loading can't be compared to a normal wing mounted twin.
That is because, with a wing mounted twin, you have accelerated air coming off the prop's flowing over the wing. This produces additional lift.
The 335 had to have a big wing, otherwise it would never have taken off. let alone climb.

You have to compare it to single engined aircraft in term of the wing loading affecting performance.

Now it wasn't bad (using the A0's numbers), at max wight it's loading was 33 lbs/sq ft. Compare that to a FW-190 A8 which was 49.3lbs/sq ft.
If fact about equal to a Spit XIV.

Then look at the thrust loading (at max weight and power). About 5.6 lbs/bhp. An 190A8 was actually poorer at 6.4lbs/bhp.
But now compare that to a Spit XIV at 4.1lbs/bhp.

So you can say straight off, that it should outclimb a 190A8 (all other things like drag being equal, but that is less of an issue in the climb) , but nowhere near a Spit XIV, and the Hornet was much better than the Spit.
Now obviously climb rates will drop the higher you go and how they drop off will be a function of the high altitude performance of the engine.
Given that its max altitude was only about 35,000ft you'd expect it climb rate would drop off rapidly.

Finding figures for this is not easy. Janes has no climb ones and Wikipedia is wrong (wrong for the Hornet too)
The ones I have are from Eric Browns book "Wings of the Luftwaffe", have it taking 1.3 mins to 1000m, which is about 2,500ft/min, not that great, especially when the Hornet was 5,000ft per minute at that altitude.

Now more power helps of course, but even with a later model DB 603 (the A- used the A1), and MW-50 I think you'd struggle to get to 3,500ft/min (plus who'd want to waste MW-50 for take off, you need it for combat).

Anyway, where could you fit MW-50 (let alone GM-1) without having to remove a fuel tank, thus cutting range.
Looking at the cut away for the 335B-2 there is no MW-50 tank and precious little room for it. There is so little room in the fuselage that the oxygen tanks are in the wings!!!!
So you'd have to cut out one of the fuel tanks in the rear.

The more and more I look at this plane the more absurd it seems. Do you know the bale out procedure was:
(1) press button to blow off the rear propeller.
(2) press button to blow of upper tail piece.
(3) press button to arm ejection seat.
(4) Pull handle to remove canopy.
(5) Press ejection button....


And those long oxygen runs, you'd be petrified of freezing in the lines.
Not to mention that if your rear engine went on fire (a common occurence, killed a RAF test pilot that one) you can't see it...
And rear visibility was non existent (which for a late model plane like that was criminal).

Then you think of how much more work was needed to make it reliable (if it could be done) .. and how difficult it would be to manufacture and that maintenance would be a nightmare.
And resistance to battle damage, hit on the rear and your prop and/or top tail piece blows off if the explosive charges are hit??? Hit on the wing that hits the oxygen tanks and your wing blows off.
And the rear engine (and its radiator) and so on and so on...

Absurd as I said, I suppose it could have, in the end been, been turned into a fair day/night bomber destroyer ... but why bother.

Mr OldSceptic
I would like to obsrve that the climb performance at Erich Browns book is at 9500kgr . That means it includes a 500kgr bomb. Also is WITHOUT MW50
The non spectacular ceiling of 35000 is not the airframes fault. It s the result of use of single stage engines. Availability of Jumo 213E &EB or DB 603 L would have added several thousands meters of ceiling
Some of the reliability issues of Do 335 was not airframes faults , but the lack of raw materials. Weak breakes, weak batteries,weak landing gears were results of lack of proper alloys and materials
Also notice that the Do335A1 with MW50 and the basic sinle stage DB603As with 87 octane fuel , achieved similar performance with the Hornet using two stage engines and 130 octane fuel
The real engine overheating was a problem but could be fixed given reasonable development conditions . The same is true for the high speed shaking
Also the batlle damage issues . Do 335 was extremely fast on one engine ,at 560 km/h.Thats good for escaping Also hits on the wings of any aircraft can be disastrous .In alleid fighters could explode the ammo
Do 335 appears to have been an excellent idea from aerodynamical point of view . In my opinion , the real problem with the aircraft, was that TA152 ,Fw157C and an all metal Ta 154 could offer similar (even if not fully equal) performance as fighters at much lower cost and sooner and with less fuel consuption

 

[wuzak]

Also Do 335 made 474 mph on DB603A.

Smith and Creek have the Do 335 as making 455mph with DB 603A/QA.

I think the 474mph was with the L.

Single stage engines while Hornet on two stage engines.

Hornet's engines did not use, or need, ADI (MW50) to get the boost.

Hornet's total engine capacity was 54l. Do 335's total engine capacity was 89l.

As with the DB 601 DB 605, the DB 603 used higher compression ratios which enabled the compressor to run at lower pressure ratios at lower altitudes, which negated, somewhat, the need for 2 stage superchargers.

That said, the Do 335's service ceiling was 35,000ft at 18,300lbs, but only 31,200ft at 20,944lbs - equipped weight plus 4000lb fuel, ammo for the three guns, oil, etc.

The Hornet's service ceiling at normal loaded weight would be, I suspect, approaching 40,000ft. Certainly for teh Spitfire XIV it was over 40,000ft.

I believe that this means that above 5000m the Hornet had plenty more power yet had near identical top speed

I would like to see the FTH for the DB 603A and Db603L.

The maximum power for the Merlin 130/131 was 1625hp @ 11,000ft, +20psi FS gear, and 1850hp @ 6,250ft, +20psi boost. It could also use +25psi boost, which would allow 2090hp, but at only 2,000ft.

By the time Hornet entered service much more powerful engines would be available for the 335 and two stages as well

There were more powerful versions of the Merlin potentially too. The Merlin 130/131 were to the RM.14SM rating. There was also the RM.16SM, which was the rating for the V-1650-9 - 1920hp @ 9,500ft, +20psi boost MS gear and 1620hp @ 21,750ft FS gear. Sure, it has less hp in FS gear than the 130/131, but it makes that power more than 10,000ft higher.

Then there is the RM.17SM - flight cleared for +30psi boost. It was rated at 2200hp @ 2,000ft and 2100hp @ 15,000ft, and flight cleared for 2380hp! The end of the war meant that no Merlins were built to that rating.

On the other hand Hornet could NOT recieve any other engine than the Merlin 130

Not true. Later Hornets got different versions, but still to the same basic rating, RM.17SM. The Merlin mark numbers changed with differences in gearing for the supercharger or reduction gearing, or any number of other variations.

There is no reason a RM.16SM or RM.17SM version of the Merlin could have been made for the Hronet. The only major change was the downdraft carburettor. The 130 series Merlins had all the strengthening of the 100 series Merlins required for the higher ratings. So, to get the higher ratings would basically have meant changing the supercharger gearing in a 130/131 Merlin.

Also, the Griffon could, I am sure have been made to fit. The Griffon was no much larger than the Merlin, though 300lbs heavier.

By the end of the war the Griffon was becoming available in the 100 series. This meant 2 stage, 3 speed superchargers, contra props as an option, and 2400-2500hp in LS gear (3 speeds - Low, Medium, Full).