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Dolphin Speed and Specification


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#41 Vati

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Posted 18 June 2010 - 10:57

Unfortunately I have only info on 3500 (prototype Dolphin series).
Maybe this will help: http://www.aeroclocks.com/PrintedBook_pages/WW1_Prop_Design.htm You could send email to the author.
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#42 Tom-Cundall

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Posted 11 July 2010 - 21:49

All of these conversations about "realism" in the plane models are just academic. I've been flying Tiger Moths since I was 15 and no two fly the same (different roll rates, top speeds, stall speeds etc). I found this article which illustrates it:


The State of Testing and Quality Control


The testing figures for all the World War I aircraft can be doubted as to their accuracy, they were at best an honest attempt to obtain quantitative data from an industry that, while high tech for its era, was still a craftsman's industry that produced one off products. Quality Control was by visual inspection with jigs and templates which, while rigorous, still allowed lemons out of the factories and gave high variance to the machines which reached operations.


As an example one squadron received an aircraft whose wings flexed. Naturally none of the pilots liked flying it. They stripped the aircraft down to discover that the aircraft's wing timbers were oil soaked. The squadron struck the aircraft off strength.


As the machines were simple construction of timber, wire and dope painted linen, it allowed for pilots to hot rod their aircraft as well. One naval pilot borrowed the aircraft of Robert Little and was shocked to see his landing speed to be 10 mph higher than normal, it turned out Little had lowered his seat to lower the center of gravity so that he could go into a dive faster. An aircraft that is 1000 lb, moving a 200 lb pilots location in the aircraft can change its flight characteristics significantly.


Of all the World War I qualitative tests it is my opinion that the speed figures for both the Sopwith Camel and Fokker Triplane are the most at odds with observations and writings of both pilots from World War I and modern replica pilots. The Sopwith Camel in particular was known for it's lack of speed. Comparing the Sopwith Snipe and Sopwith Camel purely on the basis of climb and speed data from the period paints an incomplete picture as the test data is in contradiction to the observations of the pilots who flew those aircraft in World War I.


There is one area of performance figure where the Sopwith Snipe did show its 1919 performance and that is in the area of Weight to Power ratio's. This is a figure which shows an aircraft's ability to accelerate which can be especially useful at the end of an energy draining maneuver as acceleration is what gets the aircraft it's speed back. The Sopwith Snipe had a weight to power ratio of 8.98 from 2020 lbs over 230 hp. In other words every horsepower was pulling 8.98 pounds of weight through the air. The Sopwith Camel had ratio of 10.77 for the 140 hp Clerget. Some other comparisons, the Spad had a ratio of 9.44,the SE5a had a ratio of 9.7, the Bristol Fighter a ratio of 10.18, the Fokker DVII a ratio of 10.48 and the Albatros D.Va a ratio of 11.47.

Taken from: http://www.southsear...n_flying_corps/" onclick="window.open(this.href);return false;">http://www.southsear...lic.org/article … ing_corps/

I agree completely with this from my experiences.
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#43 Gimpy117

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Posted 13 July 2010 - 16:45

There is one area of performance figure where the Sopwith Snipe did show its 1919 performance and that is in the area of Weight to Power ratio's. This is a figure which shows an aircraft's ability to accelerate which can be especially useful at the end of an energy draining maneuver as acceleration is what gets the aircraft it's speed back. The Sopwith Snipe had a weight to power ratio of 8.98 from 2020 lbs over 230 hp. In other words every horsepower was pulling 8.98 pounds of weight through the air. The Sopwith Camel had ratio of 10.77 for the 140 hp Clerget. Some other comparisons, the Spad had a ratio of 9.44,the SE5a had a ratio of 9.7, the Bristol Fighter a ratio of 10.18, the Fokker DVII a ratio of 10.48 and the Albatros D.Va a ratio of 11.47.

Taken from: http://www.southsear...n_flying_corps/" onclick="window.open(this.href);return false;">http://www.southsear...lic.org/article … ing_corps/

I agree completely with this from my experiences.

But if im not mistaken…acceleration can also be due to the pitch of the propeller. right? more coarse…better climb and acceleration, but less speed. A finer propeller will do the opposite. and since these were fixed wooden props the propeller could really define the aircraft's flight dynamics.
Also, aerodynamics matters too…if i take 400 lbs block and give it 230 Hp. and but it against a 400lbs bullet with 230 Hp whats going to accelerate faster? at first it will neck and neck, but then drag will take hold…eventually reaching velocity cubed (and as my aerodynamics instructor said "theres not a lot of math in the physics of daily life that has a cubed synbol in it."). So there are more factors to take into account than just that. While I am thinking about it as well…Weight will matter in a Speed burning maneuver. A Heavier D.VIIF will have much more momentum than the lighter Camel, Giving it more energy as it travels through the air. I also have no doubt it my mind the D.VII is more aerodynamic than the camel…so why is it the camel can do loops all day but the D.VII struggles after a few?
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#44 ImPeRaToR

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Posted 13 July 2010 - 17:13

Well it's one of the heaviest planes when empty (only the D.XII and D.IIIa are heavier iirc), that might play a role. The D.VIIF is slightly lighter (BMW is lighter afaik) and with slightly more power down low it is more agile, but down low it is still very impressive if you face the camel.

Which is pretty weird actually, if the D.IIIa is heavier than the D.VII, why is it better? ;) Could be the propeller, but they both seem to have the same.
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#45 Gimpy117

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Posted 13 July 2010 - 18:15

Which is pretty weird actually, if the D.IIIa is heavier than the D.VII, why is it better? ;) Could be the propeller, but they both seem to have the same.

because flight models are a bit off… ;)
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#46 Tom-Cundall

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Posted 14 July 2010 - 14:59

Maybe the pilot of the DVII is fatter than the camel or the DIII or he's had a big lunch- probably explain a lot :)
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#47 NickM

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Posted 14 July 2010 - 15:30

All of these conversations about "realism" in the plane models are just academic.

I disagree. There will be differences between individual actual examples of any one aircraft design. However, in RoF we are attempting to simulate the performance of a typical factory-fresh aircraft. Further, aircraft performance differed more between designs than between examples of designs. I doubt that any Dolphin used in the field was ever outclimbed by any DH-2 used in the field.

Cheers,

Nick
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#48 WW1EAF_Ming

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Posted 14 July 2010 - 17:21

he's had a big lunch

Maybe he is Goering :)

Ming
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#49 Gimpy117

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Posted 15 July 2010 - 01:49

he's had a big lunch

Maybe he is Goering :)

Ming

depends on the skin were flying
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#50 WW1EAF_Ming

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Posted 15 July 2010 - 09:51

I demand a Fat Boy pilot skin :)

He was a hero of WW1 after all…

Ming
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#51 MiG-77

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Posted 15 July 2010 - 10:30

I demand a Fat Boy pilot skin :)

He was a hero of WW1 after all…

Ming

But he was not fat yet during WWI ;)
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#52 WW1EAF_Ming

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Posted 15 July 2010 - 15:22

He cancelled the building of heavy bombers in case people thought it was a personal statement :)

Ming
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#53 Tom-Cundall

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Posted 15 July 2010 - 22:52

All of these conversations about "realism" in the plane models are just academic.

I disagree. There will be differences between individual actual examples of any one aircraft design. However, in RoF we are attempting to simulate the performance of a typical factory-fresh aircraft. Further, aircraft performance differed more between designs than between examples of designs. I doubt that any Dolphin used in the field was ever outclimbed by any DH-2 used in the field.

Cheers,

Nick

Nick - that's my point all of them were built within tolerances but were completely individual - depending on the skill of the carpenter, rigger, mechanic and pilot (they told the riggers how they wanted the planes configured) we've all just got to accept that each ROF plane is just one example from thousands and any perceived "errors" could be that plane's quirks or eccentricities - it was an art not a science. So there is no such thing as a "factory-Fresh" aircraft in the modern sense.
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#54 NickM

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Posted 16 July 2010 - 18:57

You ae so wrong I don't even know where to begin ;)

Cheers,

Nick
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#55 Tom-Cundall

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Posted 16 July 2010 - 20:06

Ok.
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#56 Mogster

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Posted 01 September 2010 - 11:08

There's a Dolphin thread over at SIMHQ, Hot Tom posted about the ROF Dolphin gunsight being in the wrong place. By this cockpit pic the ROF Dolphin gunsight and windscreen should be above the bar… This does make sense if you use the raised view, if it was like this then the default view could be raised up to the correct position.

http://en.wikipedia....hinInterior.jpg" onclick="window.open(this.href);return false;">http://en.wikipedia....hinInterior.jpg
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#57 Gimpy117

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Posted 02 September 2010 - 15:24

There's a Dolphin thread over at SIMHQ, Hot Tom posted about the ROF Dolphin gunsight being in the wrong place. By this cockpit pic the ROF Dolphin gunsight and windscreen should be above the bar… This does make sense if you use the raised view, if it was like this then the default view could be raised up to the correct position.

http://en.wikipedia....hinInterior.jpg" onclick="window.open(this.href);return false;">http://en.wikipedia....hinInterior.jpg

+1
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#58 hq_Jorri

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Posted 02 September 2010 - 17:13

That looks like a Dolphin smoking a cigar and wearing a pair of speccies :lol:.

But it's pretty conclusive evidence.
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#59 arjisme

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Posted 02 September 2010 - 18:44

There's a Dolphin thread over at SIMHQ, Hot Tom posted about the ROF Dolphin gunsight being in the wrong place. By this cockpit pic the ROF Dolphin gunsight and windscreen should be above the bar… This does make sense if you use the raised view, if it was like this then the default view could be raised up to the correct position.

http://en.wikipedia....hinInterior.jpg" onclick="window.open(this.href);return false;">http://en.wikipedia....hinInterior.jpg
I just posted in that thread to point out that the position of the gunsight seems to vary, based on an image search I did via Google. Here are two examples that show the sight below the bar (or, at least, not above the bar). I agree, however, that it makes sense to have the things mounted above the bar since the pilot's view was actually above the bar.
Image
Image
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#60 von_Semmel

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Posted 07 October 2010 - 14:59

Dolphin is a gerat plane … But a huge aim…:•\
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#61 BOLT

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Posted 17 April 2011 - 11:33

Many reports about the Dolphin make note of the fact, that after being introduced to the dolphin, a number of pilots were unnerved at having their heads exposed above the upper wing. So much so, that some pilots had ground crews work up makeshift cages to protect the pilot's head in the event of a crash, or bad landing, as it was prone to nose over, if landing too hard.

Also getting close to the example at Cosford it was easily apparent that taller pilots would in all likelihood sit with the top of their shoulders in line with the upper wing. It is also worth mentioning that the twin Vickers shown in one photo here, were typically removed by ground crews as they would whip about in flight hitting the pilot in the face.

If you manually alter your pov to match something closer to what would seem to be historically correct, it completely changes the perspective from the aircraft and matches more closely the description from pilots at the time. That being, that the aircraft afforded an excellent all round view with the exception of looking down where they could not see through the wings, which is even mentioned in the shop description on this site.

I also have some personal doubts about its propensity to stall in the sim, as I can find nothing to support the idea it was more prone to stalling unlike the camel. There is mention that when it did stall it would be quite vicious, but this is not the same thing at all, and have to wonder if translation errors led to its current characteristics as they don’t really tally with pilot reports at all. However, it is one of those things that are unlikely to change anytime soon, without some stiff evidence to the contrary.
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#62 Tom-Cundall

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Posted 17 April 2011 - 21:21

It is also worth mentioning that the twin Vickers shown in one photo here, were typically removed by ground crews as they would whip about in flight hitting the pilot in the face.

Bolt you mean Lewis guns - some squadrons moved them to the wings:

Image

No 87 Squadron experimented with two Lewis guns, one on each lower wing as in this photograph. With all six guns in place it would have been heavy but formidable.

Sometimes they just fixed the mount to limit movement and had a single gun as well.

It also had oxygen and I'd take a guess that it didn't spin quite as readily as the ROF one does - the worries I've read about it are as you say to do with having an exposed head in the event of nosing over (on takeoff or landing) unlike the Camel I haven't read complaints about it being hard to fly or control.
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#63 WWBrian

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Posted 18 April 2011 - 06:20

Hey Tom - Nevermind my squadron name, I'm assigning you the job of reloading those lewis' m'k?

:lol:

:S!:
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#64 Tom-Cundall

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Posted 18 April 2011 - 09:01

No worries Brian I'll do it after you land I think!
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#65 Mogster

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Posted 22 May 2011 - 14:46

At least with field mods it looks like we'll finally get a gunsight above the cockpit bar :)

I wonder if with flight model review we'll get a bit more top speed.
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#66 arjisme

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Posted 22 May 2011 - 18:42

Really? Where did you see news of that?
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#67 arjisme

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Posted 22 May 2011 - 18:59

Nevermind. I saw in another thread one of the beta testers say it will be above the bar. Good news!
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#68 Chill31

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Posted 22 May 2011 - 19:35

Gents, lets leave the dolphin alone for now.

I have a testing sequence I use for ROF planes.

I have a data collecting sequence for the ROF planes.

It is in the que, and we'll get to it eventually. I have 12 planes already tested that need more work than the dolphin. So lets let this sit for a while instead of doing poor job on it now.
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#69 WWBrian

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Posted 22 May 2011 - 19:52

not to throw a wrench in the works but I found this interesting….

Squadron/Signal Publication - Sopwith Fighters in Action:

…suggests the twin lewis guns were standard
…and our current ROF Dolphin is actually the "field mod"

:lol:

Attached Files


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#70 Gimpy117

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Posted 22 May 2011 - 22:22

lets hope we get more speed, yes. I couldn't out run a D.VIIF in it :?
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#71 HotTom

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Posted 22 May 2011 - 22:39

It really only excelled at high altitudes. It was designed to go up and get the German recon planes that often were above 20,000 feet.

Both Billy Bishop and Cecil Lewis wrote it was better than the SE5a in mock fights. Bishop, who was scheduled to command a Dolphin squadron, was disappointed when it was changed to an SE5a squadron.

The death spin is the deal breaker for me, though. I rarely fly it because I have never been able to recover from that spin.
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#72 Gimpy117

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Posted 22 May 2011 - 23:54

well that and it's weak wings. It just scare me when it stalls easy and isn't fast enough to get away
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#73 HotTom

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Posted 23 May 2011 - 02:34

well that and it's weak wings. It just scare me when it stalls easy and isn't fast enough to get away


It had weak wings when it was introduced. Strut connections broke easily. But they fixed that. 777 didn't get the memo :?
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#74 hq_Reflected

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Posted 23 May 2011 - 06:47

Yes, as Tom said one has to keep in mind that the Dolphin was a VERY high altitude fighter. In 1918, while Camels were doing low jobs (spare me your dirty jokes ) the SEs and Biffs were providing top cover at around 15-17,000 feet, and Dolphins were patrolling even higher!
It would be interesting to try it in a human vs human dogfight up there.
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#75 WWBrian

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Posted 23 May 2011 - 18:36

I'm just starting to dive deeper into the Dolphin.

…I'm finding some very interesting stuff!

I'm really curious why most squadrons/pilots regarding the twin lewis mountings as useless and removed them upon recieving them, yet more often then not, they kept one…if one, why not two? Strange.
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#76 WW1EAF_Paf

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Posted 23 May 2011 - 18:44

I don't know, never flew a plane so maybe its BS. But I can imagine it maybe would be hard for me to reload the Lewis gun on the left and keeping the plane controlled. (as a right hander)
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#77 HotTom

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Posted 23 May 2011 - 18:54

I know. I know. It's Wikipedia…


The Dolphin was armed with two fixed, synchronized Vickers machine guns and one or two unsynchronized Lewis guns flexibly mounted to the forward cabane crossbar. The mounting provided three positions in elevation and limited sideways movement.[11][25] The Lewis guns proved unpopular in service, however, as they were difficult to aim and tended to swing into the pilot's face.[1] Pilots also feared that the gun butts would inflict serious head injuries in the event of a crash. Most pilots therefore discarded the Lewis guns,[1] though a minority retained one or both guns specifically for use against reconnaissance aircraft.

It sounds as though they were a real bother (if not downright hazardous).

Keeping just one still would allow belly shots at recon aircraft with only half the bother (and weight) of two guns.

Just my guess.
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#78 Tom-Cundall

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Posted 23 May 2011 - 21:11

Image

No 87 Squadron experimented with two Lewis guns, one on each lower wing as in this photograph. With all six guns in place it would have been heavy but formidable.

Sometimes they just fixed the mount to limit movement and had a single gun as well.

It also had oxygen and I'd take a guess that it didn't spin quite as readily as the ROF one does - the worries I've read about it are as you say to do with having an exposed head in the event of nosing over (on takeoff or landing) unlike the Camel I haven't read complaints about it being hard to fly or control.

Solution to getting hit in the face!

:S!:
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#79 WWBrian

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Posted 23 May 2011 - 21:36

Yeah, I didn't interpret their consideration as "useless" due to fear of being smacking in the face either…as they had fixed 'em in place to remidy that. Hazardous ok, but "useless"? Am I just taking that word to literally?

…I also didn't think fear of a gun-butt injury in case of a crash would would condiser them useless…they were also worried about a crash in general with the cockpit layout, doesnt mean the whole plane is useless…

…nor is it likely the Lewis guns were useless due to perfomance loss, as they tried them in other places.

…just pondering out loud here is all….

I think I was born some 70 years too late. :geek:
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#80 arjisme

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Posted 23 May 2011 - 22:34

I'd have to dig back through my copy of Gunning for the Red Baron, but I recall reading that a twin-gun configuration on a swivel mount was very hard to handle and aim with. And that was for a rear gunner who could devote his full attention and strength to manning the guns. If true, it would make sense that a pilot would have even greater difficulty with it. With the value being so dubious and the negatives of interfering with the pilot, possibly injuring him, additional workload to reload them, additional weight hampering performance and so on, I can see them concluding they were mostly useless.
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