Poor performance

[greybeard_52]

I bought FC1 yesterday and started a campaign with PWCG (thanks Pat!).
I was immediately surprised by the mediocre performance of the Albatros D.V. I did some tests with it and, for comparison, with the Sopwith Camel, and here are the results in terms of maximum speed at ground level:

 

Albatros D.V: 168 km / h (should be 196 km / h; -14%)
Sopwith Camel: 184 km / h (should be 202 km / h; -9%)

 

I enclose a table in two parts, developed at the time for Red Baron 3D, the result of twelve years of research. It shows the historical values of the various characteristics, where I have highlighted the maximum speed at sea level and cruising (expressed in MPH) and climbing (in FPM). I hope it is put to good use.

[jollyjack]

Interesting ... now if you buy FC2 pre-release you might get this free add-on for all the old planes:

 

Edited May 31, 2022 by jollyjack

[Cynic_Al]

2 hours ago, greybeard_52 said:

I enclose a table in two parts, developed at the time for Red Baron 3D, the result of twelve years of research.

 

There is only one way to research the performance of WW1 aircraft; it starts with procuring both original plans of said aircraft, and suitable premises in which to build their replicas.  I doubt those tables are the result of so doing.

[Zooropa_Fly]

I would also note, that no two aircraft were the same back in the day.

Performance varied from Alb to Alb, Camel to Camel.

 

I believe these things are modelled as per an average of data, thus at some point someone has to 'pick a number'.

 

S!

[ST_Catchov]

38 minutes ago, Zooropa_Fly said:

I would also note, that no two aircraft were the same back in the day.

Performance varied from Alb to Alb, Camel to Camel.

 

Yeah don't I know it! I always get the dud Camel while you're doing vertical barrel rolls and hammerheads swanning about easy as you please in that damn Alb like you're Tom Cruise or something.

[greybeard_52]

Pay close attention, because I will explain it to you only once, and only about the Albatros D.Va.

 

ALL the sources (which for the most part refer to the trials conducted at Adlershof during the period of 21 January to 12 February 1918, report a maximum speed between 186 and 188 km / h. All but one omit to specify that these speeds of peak were obtained at an altitude of 1000 meters (ALL the speed tests of the Germans were conducted at 1000 m, as well as all those of the French were conducted at 2000 m, while the English adopted an unspecified "low-down" altitude, intended as "minimum possible" during the test).

 

Now, referring to the only source that specifies this height of 1000 m, this TAS of 188 km / h must be increased by reporting the increase in power that the engine undergoes with the increase in pressure from 1000 to 0 meters (yes, of PRESSURE, not density, because the power of such an engine with the density of the air not only for the consequent charge density but also for what concerns important secondary effects, such as the aerodynamic drag of the moving parts inside the crankcase - pistons, crankshaft, connecting rods - which varies as well with air density and on the whole give a resulting power proportional to the MAP - also applies to supercharged).

Since the pressure at zero altitude is equal to 1013.25 hPa, and that at 1000 m equal to 898.76, their ratio results in greater engine power at zero altitude equal to 1.1273866215. The corresponding speed increase is equal to its cube root, that is: 1.0407352583. The latter gives as a final result a maximum speed reported to zero of: 195.658 - which can easily be rounded up to 196 km / h.

[Todt_Von_Oben]

On 6/1/2022 at 7:45 AM, greybeard_52 said:

 

 

ALL the sources (which for the most part refer to the trials conducted at Adlershof during the period of 21 January to 12 February 1918, report a maximum speed between 186 and 188 km / h. All but one omit to specify that these speeds of peak were obtained at an altitude of 1000 meters (ALL the speed tests of the Germans were conducted at 1000 m, as well as all those of the French were conducted at 2000 m, while the English adopted an unspecified "low-down" altitude, intended as "minimum possible" during the test).

 

 

 

Greybeard, during those flight tests back in the day, what device was used to determine the aircraft's speed?  An anemodynamic airspeed indicator, or...?

 

In the old-timer's testing records, were the variables in weather (air pressure and humidity) on testing days documented as part of the data ? 

 

Assuming your point about different testing altitudes is correct, were there any other variables in how the Entente and Central planes were tested that you've heard of?

 

 

Edited June 5, 2022 by Todt_Von_Oben
spelling

[greybeard_52]

Von Oben! But are you the von Oben I know? You have chosen a rather macabre avatar!

 

4 hours ago, Todt_Von_Oben said:

Greybeard, during those flight tests back in the day, what device was used to determine the aircraft's speed?  An anemodynamic airspeed indicator, or...?

Speed was measured from the ground with a theodolite.

 

4 hours ago, Todt_Von_Oben said:

In the old-timer's testing records, were the variables in weather (air pressure and humidity) on testing days documented as part of the data ?

Yes, and performance was reported to standard atmosphere conditions.

 

4 hours ago, Todt_Von_Oben said:

Assuming your point about different testing altitudes is correct, were there any other variables in how the Entente and Central planes were tested that you've heard of?

No.

[Todt_Von_Oben]

Thank you.  I've often wondered about that.