Over-Compressed Engines

[+VonS 1,424]

Hello fellow FE/FE2 flyers,

As a continuation of my experiment to include over-compression tendencies in the 200hp Daimler engine for Geezer's Junkers J.1 model, I did some (successful) tweaking of the previously tweaked data inis for the the BMW-powered Fokk. D.7 and late, 200hp Alb. D.5a.

Tinkering with the following values in the data inis is required to get things working well, under the Engine section:

AltitudeTableNumData

AltitudeTableDeltaX

AltitudeTableData

The NumData should reflect how many values are present under the AltitudeTableData section. The DeltaX number is finicky, the general rule being that a higher number gives more powerful engine results across wider alt. bands but is perhaps less historically realistic, while in some cases a lower number is required, for example to "unglue" the AI from the ground in case the AI has trouble handling a particular plane, and also to create more subtle and gradual performance drops across smaller/thinner alt. bands. [Edited this section to include more accurate info.]

TheAltitudeTableData entry begins with a value of 1.000 - ground level number, and then gradually falls off to 0.000. Correct over-compression of an engine requires that a number higher than 1.0, usually a few entries that are higher than 1.0, are included at the start of the AltitudeTableData entry - to generate the correct effect if an over-compressed engine is at full throttle near sea level. Values under the FlightControl section, particularly top speed values, then become a reflection of top speed at altitudes between about 1000 and 1500m - typical heights at which Idflieg would have over-compressed engines tested. (This also depends on the DeltaX number and where the AltitudeTableData value of 1.000 begins: for example, values of 1.200, 1.050, 1.000, etc., with a DeltaX no. of 500, would mean that 100% performance is at 1000 m alt.) It's no wonder that there is some confusion therefore regarding top speeds of the BMW-powered Fokk. D.7, and if its numbers are reflections of what happens near sea level or at 1 km alt. approximately. [Added important info. here too.]

Here is a snippet from TheAerodrome.com for the 180hp Mercedes (au) installed in many Fokk. D.7s:

"Climb rate is 5 m/s at sea level, falling linearly to 0 m/s at 6 km, marked as the "theoretical ceiling". Climb rpm begins at 1400 rpm at sea level, falling to 1310 rpm at 5600m."

"Level speed:

0 km: 190 km/h @ 1570 rpm
1 km: 188 km/h @ 1580 rpm
2 km: 182 km/h @ 1530 rpm
3 km: 177 km/h @ 1490 rpm
4 km: 167 km/h @ 1430 rpm
5 km: 152 km/h @ 1360 rpm
6 km: 124 km/h @ 1280 rpm"

Here are the results for the newly tweaked BMW-powered Fokk. D.7:

near sea level: 210-211 kph @ 100% throttle

near sea level: 176-177 kph @ 70% throttle (cruise, not using high alt. throttle)

1000 m: 201 kph @ 100% throttle (this is the top speed usually cited for the BMW-powered D.7, but probably refers to at alt., not at sea level)

1500 m: 198 kph @ 100% throttle

3000 m: 187 kph @ 100% throttle

4000 m: 176 kph @ 100% throttle

climb rate to about 1000 m, at 70% throttle, is around 3.5 m/s; climb rate remains fairly consistent beyond 1000 m, at 100% throttle, if speeds in 120s and 130s kph are maintained

Results are a noticeable improvement over the Mercedes-powered D.7 (no wonder pilots wanted this type).

Here are results for the newly tweaked 200hp Mercedes-powered Alb. D.5a:

near sea level: 206 kph @ 100% throttle

near sea level: 183 kph @ 70% throttle (cruise, not using high alt. throttle)

1000 m: 202-203 kph @ 100% throttle (Goering supposedly reported maintaining over 200 kph in level flight in an Alb. D.5a...perhaps the 200hp variant?)

1500 m: 198-199 kph @ 100% throttle (this is the top speed sometimes cited for the late variant Alb. D.5a, again perhaps referring to at alt. and not sea level)

3000 m: 187-188 kph @ 100% throttle

4000 m: 177 kph @ 100% throttle

5000 m: 165 kph @ 100% throttle

6000 m: 110-112 kph @ 100% throttle (noticeable drop, since exceeding its ceiling here of about 5900 meters)

6025 m: 90-95 kph @ 100% throttle (begins to shudder and stall)

climb rate to about 1000 m, at 70% throttle, is around 4 m/s; climb rate is around 3 m/s at 100% throttle beyond 1000 m, in 120s and 130s kph (slamming the throttle to 100% below 1000 m would not have been recommended historically, but gives a climb rate of about 5-6 m/s, similar for the Fokk. D.7...probably used in emergency scenarios)

Results for the late Alby. are a noticeable improvement over the 180 hp Mercedes (au) Albies, and similar to results for the Fokk. D.7 - watch the wings though in dives on the Alb., especially with the now excess power.

Also interesting is the historical realism of how the speed advantage at alt. for the high-compression engines remains fairly consistent across the altitudes (dropping off in small steps of about 5-10 kph per 1000 m), and then severely drops off close to the ceiling for the type. A gradual, more "curved" drop of speed for high-alt. engines should be seen for WW2 types - but is usually, mistakenly assumed of WW1, over-compressed types too, which would remain fairly consistent in power until close to their ceiling (see relevant discussions on TheAerodrome.com for more info.).

Attached are the two tweaked data inis (will roll this eventually into a ver. 9.0 of the FM update pack). I'm still debating if I will tinker with the 180hp (au) Mercedes-powered types...the benefit of over-compression on those types would be small, probably too small to make any noticeable difference in FE/FE2.

Happy flying,

Von S

 

[Files included in ver. 9.0 and later of my FM updates pack.]

Edited September 28, 2018 by VonS
Removed obsolete link.

[+Stephen1918 1,474]

Thanks for posting this. Parts of the data.ini have always been something of a mystery to me. This helps.

[gambit168 27]

nice to see the d7 hanging on the prop 

[+VonS 1,424]

That was actually the top of an engine-off loop on the D.7 but they sure do hang on the prop nicely (the BMW-powered ones). Also good at prop-hanging is the late Alb. D.5a with the 200hp auv Mercedes.

Happy flying,

Von S

[Heck 496]

One odd observation. I remember reading a long time ago of American pilots flying these over compressed engines just after the Armistice, and discovering that they had to be throttled back at low altitudes, or they would overheat. I apologize for not being able to remember the source I found it in, but it might have been a Frank Tallman book, like "Flying the Old Planes." I know I was reading that book while I came across this tidbit in research. I'll look through my old paper notes and see if I can find the source.

[+VonS 1,424]

38 minutes ago, Heck said:

One odd observation. I remember reading a long time ago of American pilots flying these over compressed engines just after the Armistice, and discovering that they had to be throttled back at low altitudes, or they would overheat. I apologize for not being able to remember the source I found it in, but it might have been a Frank Tallman book, like "Flying the Old Planes." I know I was reading that book while I came across this tidbit in research. I'll look through my old paper notes and see if I can find the source.

Hi Heck, yes I remember reading that too - that over-compressed engines would overheat and cause cylinder damage, also damage of other components, if run at full throttle below about 1000m alt. It also depends on the fuel type used (as extensively debated over on TheAerodrome...I printed out that whole debate...makes for a nice, small book ). Fuel was low octane in WWI (octane ratings weren't even applied until after the mid-1920s I think)...ranging anywhere from about 50 octane to 70-72 octane for the "cleaner" stuff that was hard to come by, particularly for the Germans after supplies began to run short in 1918.

Such fuel burns differently than high-octane stuff and would increase the temp. dangerously on over-compressed engines, at full throttle, below recommended alt. This is likely what the Entente found when testing such engines - since the Entente was using fairly low-compression, low-octane fuel. The Germans added benzole (synthetic additive, not benzine although they sound similar) to their fuels from about late 1917/ early '18, improving hp output of over-compression engines, and possibly not overheating as much if max. throttle had to be used below recommended alt. in emergency settings - although sources vary on this.

Using high-octane, modern airplane fuel in such an engine might give different results, or the engine would just cut out if recommended throttle settings at low alt. were bypassed.

Can't remember reading when 100-150 octane fuel became available, probably during WWII, although aero-engine technology by then was different and would utilize high-octane stuff efficiently. I'm theorizing here but it's possible that the best fuel for over-compressed WWI engines is what the Germans were using, fairly low-octane ("low burning") stuff with a synthetic additive thrown in to improve hp output, probably better than clean fuel with no additives for that kind of engine. The low-compression engines worked perfectly fine on the low-octane fuel, on the other hand. The Germans also had summer and winter mixtures of benzole/fuel, with more benzole thrown in for winter use, something like 60/40 for winter, and 30/70 or 40/60 for summer (less benzole in the summer I think).

Von S

[Heck 496]

Interesting, VonS. That's why I love talking to the modders here. The members here are well springs of very little known information. I was unable to find my notes on my source, they were on paper from 20+ years ago, so I'm glad someone else can confirm it. I'm slowly rebuilding my FE2 install, so I'll be adding your flight models in as soon as I recover some other stuff from my recovery flash drives. Thanks for all the work you've put into them, it's much appreciated.

[+VonS 1,424]

Note the info. in bold in the old ad below: easy starting, smooth running, also more miles per gallon. This is with reference to the coal-tar derived product consisting of benzene and toluene, similar in chemical structure to German benzole (benzene)...apparently it "spikes" the octane rating since benzole/benzene is of high-octane content, also helps with anti-knock tendencies in an engine. Also note the spelling "benzene," not to be confused with "benzine" (light petroluem and the word for gasoline in several languages).

Von S

Edited October 2, 2017 by VonS
Added some comments.

[Heck 496]

I love old magazine ads like that. Between classes at Siena college in upstate New York, too many years ago, I used to sit in the upper stacks at the college library and read bound copies of old Scientific American magazines from the World War One time period. They had an amazing collection at Siena in those days.

[+VonS 1,424]

Hello FE/FE2 flyers,

Inspired by Stephen1918's fine-looking cabin for the AEG G.IV, I've now tweaked its FM to include proper, subtle over-compression of the Mercedes IVa engine that would have been installed on it. Historical stats. for the IVa engine are as follows:

- typical output of about 252-260 hp at 1400 rpm

- if full-throttle with over-compression, about 268 hp, to be used above an alt of about 1200 m

Stats. for the tweaked data ini are now as follows:

- 168 kph near sea-level at full-throttle with over-compression

- 146-7 kph cruise speed near sea-level at about 80% throttle

- 80% throttle gives a steady climb rate of about 2 m/s in the 120s kph, and can be held that way to about 1000 meters

- open throttle to full beyond about 1000 m alt., to give:

          1000 m: 162 kph @ 100% throttle (close to historical top speed for the type)

          3000 m: 146 kph @ 100% throttle

          4000 m: 140 kph @ 100% throttle

          4500 m: 128 kph @ 100% throttle (noticeable drop off in top speed since this is its historical ceiling)

          4580 m: 103 kph @ 100% throttle (anything higher in alt and it begins to drop into the 90s kph, stalling and shuddering)

          (a stable climb rate of about 2 m/s @ 100% throttle can be maintained in the 120s kph above 1000 m alt and to about 3000 m)

- type holds its power well to about 4000 m alt. as indicated above; rudder and elevator are adequate; ailerons are numb, as typical of this big crate

- also tweaked some of its inertia settings and stall/climb numbers for the airfoils (for more realistic stall speeds...performs best above 100 kph; also can attain dive speeds of close to 400 kph in the type but I wouldn't recommend it...see pics. below...had an engine fire and broke up when trying to exit a fast dive with engines full on)

Happy flying,

Von S

 

[Files included in ver. 9.0 and later of my FM updates pack.]

Edited September 28, 2018 by VonS
Removed obsolete link.

[Silberpfeil 363]

Be interested to try your revised flight model out, Von S - thank you!  Note that using the G4 as a dive bomber is about the only way I can put ordnance anywhere close to on target unless I'm mostly lucky with my release point.  I pull the power way back and use the props as speed brakes to better manage the aircraft's diving velocity...at least that's the way it generally works...  

[+VonS 1,424]

Hello again flyers,

Well the A-Team Gotha has finally had its FM retweaked - did a major overhaul and further subdivided the types into the G.II, G.III, G.IV, and G.V. The III, IV, and V have the same over-compressed Mercedes IVa that the AEG does (posted above). The G.II gets the inline 8 Merc. IV with about 280 hp and the long crankshaft susceptible to breakage (a new sound for the inline 8 is included).

Stats. are as follows:

G.II

top speed 148 kph near sea level (as historical)

climb rate about 1.5 m/s @ 100% throttle at about 120 kph

G.III

142 kph @ 100% throttle // 137 kph @ 90% throttle, near sea-level

climb rate to 1000 m at 90% throttle is 2 m/s in 100s kph

1000 m alt: 136 kph @ 100% throttle (its historical top speed)

G.IV

140-141 kph @ 100% throttle // 137 kph @ 90% throttle, near sea-level

climb rate to 1000 m at 90% throttle is 2 m/s in 100s kph

1000 m alt: 137 kph @ 100% throttle (very close to historical top speed)

G.V

142-143 kph @ 100% throttle // 138 kph @ 90% throttle, near sea-level

climb rate to 1000 m at 90% throttle is 2 m/s at about 110-115 kph

1000 m alt: 140 kph @ 100% throttle (its historical top speed)

- the G.II/III are easier to break than the IV/V

- the G.IV is the best handling of them all

- the big ailerons tend to give side-slipping more than turning ability (use rudder and slight opposite aileron in turns); sometimes you might need correct aileron to enter a turn but then have to go opposite aileron, otherwise you will slip into a descending stall; also you'll notice how the types tend to swing (with the long wingspan) after a turn is completed, for a while; this can be countered with opposite rudder but eventually disappears on its own; the G.IV is the most tamed of the types; open throttle to 100% beyond 1000 m alt. to take advantage of the over-compression on the III, IV, and V; 90% throttle is fine for climbs to 1000 m on these types; the G.II with its inline-8 climbs best at full throttle

- the Ottomans may have had a G.III or IV in their collection; the Eastern and Balkan fronts had the G.II and III types; the Western front had the G.IV and V (bombing of London and other cities); a few G.III types were also on the Western front; the G.IV served until the Armistice; the G.V was taken out of service by the summer of '18 (Va and Vb variants followed); the Italian front saw a few of the G.IV types (I will update these little things for a formal roll-out of the ver. 9.0 FM and Realism Pack)

- the types stall below the low 90s kph and fall into a spin; stalls occur already at about 100-105 kph in tight maneuvers

- take offs are best when you pass about 120 kph

- avoid rough maneuvers if flying with AI Gothas since some of the earlier types (the II and III) might fall into stalls/sideslips while trying to imitate you (flying these is risky business, as historical)

- have included subtle vapor trails from the two engines, to make side-slipping/swinging more noticeable and easier to correct

Happy flying,

Von S

 

[Files included in ver. 9.0 and later of my FM updates pack.]

Edited September 28, 2018 by VonS
Removed obsolete link.

[+VonS 1,424]

Hello fellow flyers,

If you've downloaded the Gotha FM tweaks, here's some info. to get the gunners a little more aggressive, and also so that their feet don't stick out of the fuselage.

Under the AIData section, comment out the following three lines:

GunnerFireChance=80
GunnerFireTime=2.5
GunnerAimOffset=0.0050

Add the following for the front gunner entry, under Crew (paste over old entries and add the new ones):

GunRange=600
PitchAngleRate=35
MaxPitch=15
MinPitch=-15
DefaultPitchAngle=5
YawLimited=TRUE
YawAngleRate=40
MaxYaw=100
MinYaw=-100
DefaultYawAngle=0
GunnerFireChance=70
GunnerFireTime=0.5
GunnerAimOffset=0.07
GunnerAimAccuracy=60

For the back gunner, use (again paste over old entries and add the new ones):

GunRange=800
PitchAngleRate=35
MaxPitch=15
MinPitch=-15
DefaultPitchAngle=10
YawLimited=TRUE
YawAngleRate=50
MaxYaw=225
MinYaw=-225
DefaultYawAngle=180
GunnerFireChance=80
GunnerFireTime=0.7
GunnerAimOffset=0.080
GunnerAimAccuracy=70

They are fairly accurate with those entries and the Gothas put up a nice challenge... (will roll these little tweaks into a ver. 9.0 of the FM update pack...in the meantime there it is).

Happy flying,

Von S

Edited October 11, 2017 by VonS

[+Geezer 3,569]

On 10/2/2017 at 11:28 AM, VonS said:

Can't remember reading when 100-150 octane fuel became available, probably during WWII, although aero-engine technology by then was different and would utilize high-octane stuff efficiently.

I read somewhere that the first experiments with 100+ octane fuel were done by the Brits in the 1920s.  Their specific focus was wringing the most performance they could from experimental engines for the Schneider Cup competitions, not everyday use by commercial or military customers.  Mass produced 100+ octane fuel for everyday use was not developed until the 1930s, and required concurrent improvements in engine technology.

[+VonS 1,424]

Hello FE/FE2 flyers,

Here's one more over-compressed engine that I've overhauled, for one of my favorite planes - the Pfalz Dr.1. This one is now powered by the over-compressed variant of the Siemens-Halske engine (the III.a variant).

Historical stats. for the over-compressed engine:

6.0:1 compression ratio (high for the WWI period)

160hp @ 900 engine rpm

200hp @ 950 engine rpm

240hp @ 1000 engine rpm (over-compressed; for short periods, below about 1500-2000 m alt.)

(could output 160hp @ full throttle as high as 3700 m alt.)

Other interesting details about the engine:

Propeller and 11 cylinders spin in one direction, the crankcase in the other (see TheAerodrome.com for more info.)

Historical stats. for the uncompressed III (not III.a) variant:

160hp @ 900 engine rpm

200-210hp @ 950-970 engine rpm

Stats. for the Sh.IIIa-powered Pfalz Dr.1 in FE2 after the FM overhaul are:

- very short run-up for takeoff @ full throttle (less than 30-40 meters)

- take offs are fine @ about 100 kph

- powerful engine allows level flight, even gentle/longer-run take offs, @ about 50% throttle

- stalls below low 70s/high 60s kph in a climb, similar stall in straight line (mid-60s kph)

- tends to slip out of very tight turns and very tight loops on occasion, at speeds as high as 130s/140s kph (in gentler turns slips happen below about 100-110 kph); symptoms not as noticeable as on Pfalz. D.III/IIIa, and easier to correct

- top speed at full-throttle (over-compression near sea level): 202 kph

- cruise speed @ 80% throttle (near sea level): 174-5 kph

- climb @ 80% throttle in 120s kph to about 1000 m alt.: 7-8 m/s (amazing climb rate even with non-overcompressed throttle, better than the Fokk. Dr.1 and D.VII/VIIf, thanks to its three wings, powerful engine, and better aerodynamic qualities/slipperiness than on the Fokk. Dr.1; also has thinner airfoils than the Fokk. Dr.1 but not as thin as on allied types such as the SPADs, Se5a, etc.)

1000 m alt: 196-7 kph @ 100% throttle

1500 m alt: 190-1 kph @ 100% throttle (this is the sometimes-cited top speed for the Pfalz Dr.1)

3000 m alt: 178-9 kph @ 100% throttle

4000 m alt: 170 kph @ 100% throttle

5000 m alt: 160-1 kph @ 100% throttle

6000 m alt: 153 kph @ 100 % throttle

(theoretical ceiling for Sh.IIIa variant is about 6300 m)

6500 m alt: 81-2 kph @ 100% throttle (easily falls into 70s kph and stalls/spins here; notice also the drop off in top speed since the theoretical ceiling has been passed by about a couple of hundred meters)

- climb rate @ 100% throttle from about 1500 m alt. to 5000 m alt. is fairly consistent @ about 120 kph, averaging 8-9 m/s (very impressive for a WWI type); drops to about 5-6 m/s @ 120 kph and full throttle beyond about 5000 m alt; going into the 130s kph to climb beyond 5000 m alt improves the rate slightly to about 7-8 m/s (again @ full, over-compressed throttle)

- the Pfalz Dr.1 is on average about 10 kph slower at the higher altitudes than the 200 hp Alb. D.Va and the Fokk. D.VIIf, but the climb rate is better by about 3-4 m/s (a noticeable difference)

- approximate engine rpm equivalents and throttle settings seem to be as follows:

 100% (over-compressed) throttle: about 240 hp (this gives you as much power as the later SPAD 13, the Ansaldo, also the high-compression Fokkers and Albatroses; and don't forget the improved climbing power you have)

80% (normal) throttle: about 200-210 hp

50% (half) throttle: about 150-160 hp

25% (quarter) throttle: about 80-100 hp

- to land, cut the throttle to idle since otherwise you already have ample power; or switch off the engine

- avoid rough exits from dives exceeding about 250 kph; type dives easily to nearly 400 kph on full power; model now has MaxG limits implemented and is more realistic; also with improved damage ratings included, and a new sound for the Siemens-Halske engine

- if you want a Pfalz Dr.1 with the uncompressed variant of the engine, Sh.III (160 hp, max 210 hp), include the following changes in your data ini:

under MissionData:

change service dates to April-July 1918 (educated guess for the end date)

also change the ceiling to between 5800-6000 meters

under the Engine section, paste over the following entries, for the relevant sections (which will give a top speed of about 200 kph near sea level, another often cited number for its top speed):

AltitudeTableNumData=23
AltitudeTableDeltaX=504.8
AltitudeTableStartX=0.0
AltitudeTableData=1.000,0.996,0.988,0.982,0.964,0.945,0.927,0.909,0.891,0.873,0.855,0.836,0.818,0.800,0.782,0.764,0.745,0.727,0.709,0.691,0.673,0.655,0.000

Happy flying,

Von S

 

[Files included in ver. 9.0 and later of my FM updates pack.]

Edited September 28, 2018 by VonS
Removed obsolete link.

[+Geezer 3,569]

I can see why VonS likes the triplane - there is something really appealing to the classic point defense fighter.  No range or load carrying capability to speak of, but it climbs and dives like a bat outta hell.  I can adapt a D.VIII to make a DR.I, but the middle wing root will be a fair amount of work.  I like to "grow" my wing roots out of the fuselage to simulate the compound curves of a wing fillet.  Also shots of a master craftsman making a wood fuselage shell for a D.VIII, and a factory shot of the two shells being mated together.

Edited October 17, 2017 by Geezer

[+VonS 1,424]

A new Pfalz Dr.1 model sure would be a great addition to FE2, but take your time on the model if you decide on it Geezer. I'm sure the final product will be amazing.

My modified FM for the Pfalz Dr.1 is a major overhaul -  it incorporates the modifications to the airfoils for the D.III/IIIa, among other changes, that file itself being an overhaul of the Alb. D.V FM. I'm sure the data ini can be used with a new Pfalz Dr.1 - might only require a change to the rolling radius for the wheels and coordinates to the tailskid, so it sits on the ground properly, and maybe adjustments to the center of gravity, for a proper view from the cockpit.

Happy flying,

Von S

P.S. Speaking of FMs, it shouldn't be too much trouble to re-work my Pfalz Triplane FM into one for the Pfalz D.VIII (removal of the middle wing, changes to weight, also power output, etc., the D.VIII being powered by the uncompressed version of the Siemens-Halske 11-cyl. rotary). Will get to that once I finish with the Caudron R.11 FM.

Edited October 18, 2017 by VonS
Added more comments.

[+VonS 1,424]

Successful over-compression of the late Spad 13 (235hp variant), Se5a (Viper), and Ansaldo SVA.5 now completed. Detailed stats follow below, and a ver. 9.0 update pack is soon to follow. Also I'm happy to see that the altitude tests are not far off from some of the numbers, for example, that the venerable Dan-San Abbott had posted on TheAerodrome.com:

http://www.theaerodrome.com/forum/showpost.php?p=492512&postcount=3

Stats. in FE2 for the Viper-powered Se5a, with a slightly high compression ratio of 5.6:1

100% throttle @ near sea-level: 228kph

85% throttle @ near sea-level: 222-3kph

100% @ 1500m alt: 223-4kph (often-cited top speed)

climb @ 85% throttle in 120s kph to about 1100m: 4-5 m/s

climb @ 100% throttle in 120s kph from about 1500 to 4000m alt: 5-6 m/s

100% @ 3000m alt: 212kph

100% @ 4000m alt: 200kph

100% @ 5000m alt: 187kph

100% @ 6000m alt: 134kph (noticeable drop off since exceeding ceiling here)

100% @ 6050m alt: 70s kph (drops quickly to 60s kph and into a spin)

can attain about 440kph in a dive with engine full on (good stats., comparable to the nearly "300mph" in a dive as reported figure; 440kph is about 275mph)

 

Stats. for the Spad 13 (235hp), with a slightly high compression ratio of 5.6:1

100% throttle @ near sea-level: 222kph (close to sometimes-cited top speed)

85% throttle @ near sea-level: 213kph

100 % @ 1500m alt: 215 kph (close to sometimes-cited top speed)

climb @ 85% throttle in 130s kph to about 1100m: 4 m/s

climb @ 100% throttle in 140s kph from about 1500 to 5000 m alt: 4-5 m/s

(starts to stall if climbed below about 120kph)

100% @ 3000m alt: 207kph

100% @ 4000m alt: 196kph

100% @ 5000m alt: 184kph

100% @ 6000m alt: 173kph

100% @ 6930m alt: 142kph (noticeable drop off since exceeding ceiling here)

100% @ 6960m alt: 117kph (on verge of stall/spin here)

can attain about 445kph in a dive with engine full on (good stats. again, comparable to historical notes on the type; this one doesn't break when pulled out of a dive that fast, although there is creaking of the frame; the Se5a does lose some of its wings if pulled out roughly at these speeds...see notes on how to "really dive" in the Se5a, available on the internet; watch for one buckle in the wings said the flight commander, two buckles getting close to 250mph, etc., three buckles and away the wings go)

 

Stats. for the Ansaldo SVA.5, with high compression at a ratio of 6.0:1

100% throttle @ near sea-level: 232kph (close to sometimes-cited top speed)

85% throttle @ near sea-level: 226kph

100% @ 1500m alt: 229kph (close to often-cited top speed)

climb @ 85% in 120s kph to about 1500m alt: 4 m/s

climb @ 100% in 130s kph from about 1500 to 4000 m alt: 5 m/s

100% @ 3000m alt: 217kph

100% @ 4000m alt: 203kph

100% @ 5000m alt: 190kph

100% @ 6000m alt: 179kph

100% @ 6340m alt: 111kph (noticeable drop since exceeding its ceiling here, stalls/spins easily at this height)

can attain about 430kph in a dive with engine full one (doesn't lose wings when pulling out roughly, but frame does creak)

 

Happy flying,

Von S