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Dolphin Speed and Specification


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#121 Sensenmann

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Posted 10 June 2011 - 08:23

From the horses mouth:

Attached File  Dolphin Prop.jpg   89.75KB   1084 downloads

And it seems the Datafile has a bit more info in the charts, so…

Attached File  Weights and Performance.jpg   143.78KB   1084 downloads

Attached File  Weights and Performance II.jpg   103.79KB   1084 downloads
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#122 MiG-77

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Posted 10 June 2011 - 10:02

Compared to windsock C3778 perfomance, in game Dolphin perfomance is very close.
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#123 Moot

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Posted 12 June 2011 - 12:35

Acceleration due to gravity in a vacuum would appear to be constant and effectively not dependent on the mass of the object. Gravitational attraction is actually dependent on the mass of both objects and the distance between them - obviously the Sun has a stronger gravitational pull than the moon does but the moon is closer so it has more effect on, say, our tides than the Sun does.

When the discrepancy between the two masses (that of the Dolphin and that of the Earth) is so massive we can disregard the mass of the Dolphin when looking at its fall rate in a vacuum - it effectively falls (accelerates due to gravity) at the same rate as a feather.

When you indroduce a resisting force, in this case the drag of the atmosphere, you then need to consider the falling force of the object. This is the object's weight which is a product of its mass and the acceleration due to gravity. F=ma.

The reason a foam ball falls slower in air than a steel one of the same size is kind of because it has a lower density. It's actually because it has a lower mass and thus lower weight and thus lower falling force and thus is more resisted by the same amount of drag force (if the balls are the same size) and thus has a lower terminal velocity.

It is the weight, a product of the mass and acceleration, that determines an objects ability to push its way through the atmosphere in a fall and thus the speed at which it does so.

That's how I see it but it's a long time since I was at school so all of the above might just be nonsense :D
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#124 MiG-77

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Posted 12 June 2011 - 14:45

It is the weight, a product of the mass and acceleration, that determines an objects ability to push its way through the atmosphere in a fall and thus the speed at which it does so.

Actually it is weight and area = density. Heavier object with less density will fall slower, than lighter more dense object.

But as I said, this topic is about Dolphin, so lets drop this discussion in this topic.
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#125 NickM

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Posted 12 June 2011 - 16:58

Not sure if this has already been posted, but it's an interesting read about the US replica Dolphin built in the 1970s.

http://www.colepalen...g-_Nov_1980.pdf" onclick="window.open(this.href);return false;">http://www.colepalen.../files/Air_Enth … v_1980.pdf
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#126 Flying_Dutchman

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Posted 14 June 2011 - 11:32

have never been able to recover from that spin.

It is possible, entered one yesterday at about 1500 meters and got out of the spin with (verrry) little to spare.
Throttle to idle and switching counter and into the spindirection, hairy business though.
Sweaty palms all the way down! :mrgreen:

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.

According to the windsock data file on the Dolphin (iirc), the decicion was made (in the higher echelons) to equip them with only one mounting for the Lewis gun (right hand only), some pilots switched it to the left hand position, maybe to keep their right hand on the stick.
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#127 =IRFC=AirBiscuit

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Posted 11 October 2011 - 05:21

The Dolphin's wings still pop off too easily. I've never read that this plane had major structural deficiencies, but the plane we have in game will shed its wings about as easily as the N.17 (which is also incorrect or at least inconsistent against its contemporaries).

The Dolphin's wings were comically weak when the plane was released, and Neoqb "fixed" them about 18 months ago. But the fix didn't go far enough. What's the threshold for pilot blackout effect in ROF? 4g? You can't even induce pilot blackout in the Dolphin – you'll lose your wings first.

It's frailty is just insult to injury on top of being about 10mph too slow at sea level and dangerously slow to accelerate on the ground :(
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#128 HotTom

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Posted 11 October 2011 - 05:42

The Dolphin's wings still pop off too easily. I've never read that this plane had major structural deficiencies, but the plane we have in game will shed its wings about as easily as the N.17 (which is also incorrect or at least inconsistent against its contemporaries).

The Dolphin's wings were comically weak when the plane was released, and Neoqb "fixed" them about 18 months ago. But the fix didn't go far enough. What's the threshold for pilot blackout effect in ROF? 4g? You can't even induce pilot blackout in the Dolphin – you'll lose your wings first.

It's frailty is just insult to injury on top of being about 10mph too slow at sea level and dangerously slow to accelerate on the ground :(

+1

The Dolphin model is too slow and too fragile. It doesn't accelerate fast enough to extend if you use it for BnZ and if you try to turnfight in it, you risk a death spin.

Yet Billy Bishop wrote he was very disappointed when he was given command of 85 Squadron, which was supposed to be equipped with Dolphins but received SE5as instead. He said the Dolphin was a better fighter.

Cecil Lewis said the same. He had a mock dogfight with Lewis flying an SE and a friend of his from another squadron flying a Dolphin and Lewis said he couldn't best the Dolphin.

The first Dolphins did have weak wings, actually the connections between the spars and the wing, which broke easily. But they were strengthened early in its service life. I guess 777 didn't get The Memo :mrgreen:

The only reason there weren't more Dolphins was that they were powered by the same geared Hispano (HS 8Ba and HS 8Bb) as the SPAD 13 and it was notoriously unreliable. At the end of the war there was a huge number of Dolphins that never received engines.

Trenchard picked the SE5a over the Dolphin because the SE had the direct drive Viper variant of the Hispano, which was a variant of the HS 8A and much more reliable. But, in RoF, engine reliablity isn't modeled.

The second highest ranking American ace (behind Captain Eddie) was Francis Gilett with 20 kills, all flying Dolphins for RAF 20 Squadron. The real Dolphin wasn't entirely hopeless as the model is.

Yes, the Dolphin model should be both more formidable and more durable. And I've never read anything about the real Dolphin having an unrecoverable spin.

Along with the Noop 17 and Noop 28, the Dolphin is one of several Hangar Queens I bought but won't fly. :roll:
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#129 =Fifi=

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Posted 11 October 2011 - 06:43

Yes, the Dolphin model should be both more formidable and more durable. And I've never read anything about the real Dolphin having an unrecoverable spin.

Along with the Noop 17 and Noop 28, the Dolphin is one of several Hangar Queens I bought but won't fly.

Agreed :(
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#130 piecost

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Posted 11 October 2011 - 08:10

From testing (version 1.014) I have found that the Dolpin wings are a similar to its contemporaries (about 8g) while others are typically 9g to 10g. It may also be that the elevators are more sensitive than most and therefore it is easier to exert the breaking force.

I wonder if the damage model is overcooked for the Dolpin relative to other planes. I also think that generally wooden wing spars were much more durable than modeled.

"THE AERONAUTICAL JOURNAL February, 1921
PROCEEDINGS, FIFTH MEETING, 57th SESSION, Major F. M. Green delivered the following lecture

DEVELOPMENT OF THE FIGHTING AEROPLANE.

Ability to Withstand Damage.

The structure of the aeroplane itself is a large target in comparison with the pilot and the vital parts of the engine. It will be a big advantage if the aeroplane is so designed that it is likely to lose little of its structural strength when hit by the bullets of the enemy. Wooden spars are generally of such a section that many bullet holes are unlikely to cause sufficient damage to make failure in the air likely. There is always the possibility that a wire or the attachment of a wire will be shot away, and it certainly seems a requirement of the modern aeroplane that the structure of the aeroplane should not depend upon any single wire or attachment. Duplicating a wire by means of another wire alongside is apt to be dangerous as one bullet is likely to destroy both wires. The lecturer knows of one case in which an aeroplane partly collapsed when a bullet hit the point of attachment of two wires which left the plane at different angles. The ideal arrangement, therefore, is to make a structure which is braced by two or more independent systems."

I posted some propeller data for the Dolpin

Current ROF Airplanes Flight Model Data Topic..+572&start=50
post#60

so maybe a FM revision may be possible (but not to the same level of detail as for the SE5a)
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#131 MattM

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Posted 11 October 2011 - 08:40

The Dolphin is actually one of the sturdiest planes in a dive in ROF. It will fall apart at 200+ mph, most other planes won't even come close to this speed.

It's true that you lose the wings easily when you give full elevator, but i think that's more because of the effectiveness of the elevator itself and the speed at which you can pull the stick back. As long as you're below ~135 mph, you can give full back elevator without risk of damaging anything.

However, if the wings get damaged, it does become extremely fragile. I think this is a bit overmodelled ingame. Even a very short burst (say 5-10 rounds) can cause the wings to snap-off (not just on the Dolphin, but most other planes aswell).

Since the recent SE5a flightmodel change, the Dolphin has become quite useful, because the Dolphin can climb about as fast as the SE5a now, is only a bit slower (difference becomes less noticable at high altitude) and can turn way tighter and turn with Central planes. I highly suggest flying both the SE5a and Dolphin at ~4000 meters, then it should become quite obvious why the Dolphin isn't as bad as it seems.

Now compared to some other planes, the Dolphin might still be subpar and no real alternative (D.VIIF, Bristol, Camel etc.), but i don't think it's really that much worse than it should be and in case of most better planes in ROF, those better need more attention regardign FM fixes imho.
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#132 =IRFC=AirBiscuit

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Posted 11 October 2011 - 15:00

MattM, I should have qualified my statement. It's not that the Dolphin can't dive; it's that it can't exit a dive once it starts one. And I don't pull out of dives with full elevator.. give me some credit, please. In fact, I never apply full elevator in the Dolphin at all because that instantly results in a spin at < 100mph, and wing failure at > 100mph.

Like I said, I have yet to induce pilot blackout effect in the Dolphin. I lose my wings long before it gets that far. Btw, I'm only re-discovering this frustration with the Dolphin because, now that we have an Aldis sight above the bar, it's *almost* a viable aircraft.
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#133 HotTom

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Posted 11 October 2011 - 15:38

I've flown the Dolphin above 4,000 meters against not very competent AI late war Hun fighters and it is hopeless.

It wasn't in real life. If the Hispano gear reduction box didn't blow up, it gave a good account of itself, especially at higher altitude.

Started a PWCG Dolphin Campaign (not DID). Scrapped it after a half dozen missions. Complete waste of time.

It's the only British plane for which I do not have an ongoing PWCG DID campaign.

The Dolphin simply cannot compete.

It really needs an FM and DM fix.
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#134 =IRFC=AirBiscuit

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Posted 11 October 2011 - 15:51

I think that overall it's pretty close to what it should be. I wouldn't think that it could take a D.VIIF in a 1-on-1 fight at any altitude, or a Dr.I down low. My major gripe with it is just how easily it loses its wings. It happens to me almost every time I fly the damn thing. The Spad 7 is much more durable. The Albatros D.III is much more durable. Yet the Dolphin is a later design. Huh?

It'd be great if it were made a bit faster to better match historical data, or if a spin didn't cost you 1000m or your life (whichever comes first) – but it's much more pressing that its DM is adjusted so that the stupid thing is capable of a respectable bounce.
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#135 HotTom

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Posted 11 October 2011 - 16:07

Well, Jay, nothing can take a D.VIIF at altitude or a Dr.I down low unless you get above them and can BnZ them and extend away.

The point is the Dolphin hasn't the acceleration (nor the speed but that's another thing) to properly extend in BnZ.

As to the wings, I find they are fragile only after they have taken hits (which is what you get when you can't extend).

Perhaps you dive it more aggressively than I do.
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#136 gavagai

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Posted 11 October 2011 - 16:25

You can also stress your wings with exceptionally hard turns. They won't show any damage, but later they will come off like toothpicks from normal maneuvers.
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#137 =IRFC=AirBiscuit

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Posted 11 October 2011 - 17:17

From testing (version 1.014) I have found that the Dolpin wings are a similar to its contemporaries (about 8g) while others are typically 9g to 10g. It may also be that the elevators are more sensitive than most and therefore it is easier to exert the breaking force.

Just curious, piecost, how did you test this?
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#138 piecost

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Posted 11 October 2011 - 18:03

Jay,

I first found the stall speed:

RoF test flight data
post#16

Then, the lowest speed to pull the wings off (i.e. Corner Speed or Maneouvre Speed):

RoF test flight data
post#59

The ultimate load factor “n” = ( Corner speed / Stall Speed )^2

There is a fair amount of experimental error in the data, for instance - it is quite difficult to define a precise stall speed (certain aircraft I could not stall so estimated the speed and hence the load factor for the Fokker DVII/DVIIf/Dr1 are not reliable).

I have not specifically tested for weakening caused by maneouvring, I don't think it is modeled, but I am willing to be proved wrong. gavagai, any ideas on how to demonstrate it?
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#139 piecost

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Posted 12 October 2011 - 17:21

All the Information I have on the Dolphin:

Reports & Memoranda No. 572, Mutual Interferences of 2 Model Airscrews and Sopwith Dolphin
Current ROF Airplanes Flight Model Data Topic.
post#60

R&M 643, Experiments on the Rotation in the Slipstream of a Tractor Aeroplane
Current ROF Airplanes Flight Model Data Topic.
post#38

R&M 676 Component weights
posting.php?mode=reply&f=49&t=11037
post#55, 56

R&M 721 ASI static position (ASI correction)
SE5a FM - review & fixes!
post#78

Reports on Spinning of Negative Stagger Biplanes - not specific to Dolphin

R&M 733 Effect of Stagger on Auto-Rotation of Biplanes
Data Topic for Airplanes Performance.
post#106

Data Topic for Airplanes Performance.
post#24
post#26
post#27


R&M 678 THE INFLUENCE OF MILITARY AND CIVIL REQUIREMENTS ON THE FLYING QUALITIES OF AEROPLANES

"The Sopwith Dolphin and the Sopwith Dragon normally trimmed, seem to have an unstable trimming speed with full engine at about 90 m.p.h."

Martlesham Heath, by Gordon Kinsey (see attached)

Attached Files


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#140 gavagai

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Posted 12 October 2011 - 20:24

I have not specifically tested for weakening caused by maneouvring, I don't think it is modeled, but I am willing to be proved wrong. gavagai, any ideas on how to demonstrate it?

Yes, I'm pretty sure I could come up with a repeatable procedure. Stand by for that.
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#141 piecost

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Posted 12 October 2011 - 20:45

thanks
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#142 gavagai

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Posted 12 October 2011 - 20:59

I gave it my best shot and couldn't reproduce it.

What I observed in the past was that after making a turn that would cause blackout (or close to it), the wings would later collapse in a much less severe turn (If you're seen my post about FFB2 issues, the events I'm describing here happened long before when I was using a CH stick). In each case I knew I had not been shot at, and could not observe any visible damage on my wings.

Maybe I was confused by using the blackout as a cue to magnitude of the radial acceleration? In RoF it seems possible to generate a lot of momentary radial acceleration without the virtual pilot showing any effects.
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#143 piecost

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Posted 12 October 2011 - 23:23

Thanks gavagai. The blackout does seem to be more complex than being simply tied to the g level - it must be related to time as well. I too have found it possible to reach a high enough g to rip the wings off before the onset of blackout.

On a related note; I tried to find out at what g load the F2B observer stops manning the gun and sits down - I failed since, again, it was not simply tied to g levels.

I like the modeling of over-stressing in the latest patch of IL2-46 - with a cumulatively weakened airframe (and performance loss) when exceeding "limit load" and catastrophic failure at "ultimate load".
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#144 stug41

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Posted 20 October 2011 - 15:02

I do not see why a slight delay in the blackout would be unrealistic. Blackout is caused by a starvation of oxygen to the brain, and the blood that is present in it for the moment when enough G's are performed to inhibit flow the blood should have enough oxygen in it to last a second or so under those conditions.
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#145 Wykletypl

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Posted 19 January 2013 - 19:12

I have a question concerning Sopwith Dolphin.
I am playing 'Quick Mission' mode on Fokker Dr. 1 (up till now, the only one I can actually
shoot down a scout with) and everytime I fight with Dolphin, it looks like F6F Hellcat vs A6M Zero.
Which means after just a two second burst, Dolphin falls apart.

Were Dolphins really THAT vulnerable to attack?
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#146 hq_Jorri

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Posted 19 January 2013 - 19:45

In RoF they have always been very vulnerable, especially the wings. I can't believe that would have been true for the real Dolphin, though. But yeah, others have shared your observation.
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#147 gavagai

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Posted 20 January 2013 - 12:47

There is a bug with wing damage in 1.029. The Dolphin has never been known for tough wings, but it is much worse now.
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#148 Spoon

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Posted 18 July 2013 - 00:23

You have to laugh… I have multiple beta campaigns going, including one in the Dr.I and another in the Dolphin. My Dr.I is almost indestructable and has taken massive punishment and brought me home. It's even survived a wingmate diving straight into its side (snapped of the top left wing but was still pefectly flyable afterwards!). The Dolphin on the other hand can be brought down by a single firing pass from any angle by the AI. Three or four bullets into the wings and its all over.

IMHO, all the wings in ROF need to be strengthened except prehaps the Dr.I.
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#149 LEON_CZ

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Posted 06 August 2016 - 15:40

I kindly request the addition of this modification to the next patch.

Thank you for the fulfillment of my request :-D

 

An external shot of the protecting structure on the top of the Dolphin - "Crash pylon"

 

sw-d-c3778_01.jpg?w=1024&h=496

sw-d-c3778_02.jpg?w=1024

https://warbirdtails...-7-the-dolphin/


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