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Thread: Was the Albatros DVa poor at climbing?

  1. #101

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    Quote Originally Posted by 'Warspite' View Post
    ...My best guess was, and still is to this day, that either the DIII was tested with the guns not fitted or else the DVa data was sourced from captured machines which were either damaged or not flown correctly...
    The exceptional climb of the DIII could be that the figures quoted are for the Austro-Hungarian version of the plane
    The Osprey’s Duel Series SE.5a vs. Albatros D.V – Western Front 1917-1918 by Jon Guttman page 30 has the following stats quoted for the Albatos DIII
    3,050ft 2mins 30
    6,i00ft 6mins 0
    9,i50ft 11mins 0
    12,200ft 17mins 0
    15,250ft 24mins 30

    Now the AIR VANGUARD 13, ALBATROS D.III Johannisthal, OAW, and Oeffag variants, also by Osprey has widely worse stats for the Albatros DIII on page 43
    1,000m (3,281ft) 4 min = 820ft per minute
    2,000m (6,562ft) 10 min = 656ft
    3,000m (9,843ft) 19 min = 518ft
    4,000m (13,123ft) 30 min 30 min = 437ft
    But the stats for the Austro-Hungarian version (oef) are not that much different from that quoted in Osprey’s Duel Series SE.5a vs. Albatros D.V.

    In addition, the worse stats for the Alb DIII still look good up to 1,000m (820ft per minute) but get much worse very rapidly.

    Based on these widely contradictory reports, I'm happy with the official Climb Rate for Wings of Glory for the Alb DIII is correct.

    On the other hand this may all be a red-herring as I don't know what stats you've got for the Alb DIII.

    PS Added
    In addition, the Rise of Flight figures look possible - worse than the SE.5a vs. Albatros D.V and better than the
    AIR VANGUARD 13, ALBATROS D.III
    http://en.wiki.riseofflight.com/inde...Albatros_D.III

    PPS Added
    In short there is a lot of debate about what the climb rate of a typical DIII should be.
    Last edited by Nicola Zee; 12-24-2014 at 07:37. Reason: PPS Added

  2. #102

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    Quote Originally Posted by flash View Post
    Climb rate is proportional to excess power.
    When the Merc DIIIaü engine was introduced they added a new altitude-compensating carburettor, which improved performance at higher altitudes.
    Power output: 129.75 kW (174 hp) at 1,400 rpm (rated power at sea level), 152.12 kW (204 hp) at 1,600 rpm (maximum power at altitude), it couldn't be used at max revs at sea level.
    That and the various changes to fuselage shape and construction and wing 'gapping' may explain the better ceiling but slower climb rate...?
    Or maybe not !
    I agree with Flash. Of course there are some other factors thrown in. But, the major ability of an aircraft to have a high service ceiling is how well does the engine carburetor function with less oxygen.

  3. #103

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    Quote Originally Posted by Zoe Brain View Post
    Propellor pitch.

    You can either optimise for low climb rate but low drag or high climb rate, but low top speed due to high drag.

    The Luftstreitkrafte was on the defensive for much of the war. They needed a high climb rate to intercept intruders with little warning. This meant accepting a lower top speed.

    http://www.pilotfriend.com/training/...wing/props.htm

    Attachment 153469
    But that doesn't explain why the D.Va had a poor climb rate.
    Karl
    It is impossible for a man to begin to learn what he thinks he knows. -- Epictetus

  4. #104


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    The climb and ceiling is also effected by wing area – I'm presuming the bigger the wing the lighter the wing loading but the DIII and DVa have the same wings and the wing loading of the DVa is higher, if we've got our weight figures right. I did wonder if the DIII wings might work more efficiently since the top one of the DV is closer to the fuselage and I wondered if that disrupts the airflow enough for the wing to loose lift in that area. I'm clutching at straws but I'll be reading some more to see what the pilots say, to me that is what counts.

    A snippet from the Osprey SPADVII v's DIII;

    "Von Richthofen, for one, stated his preference for the DIII over the 'lousy' DV that summer. [1917] Oblt Rudolf Berthold was still flying a DIII when he commanded Jasta 18 as late as October 1917. Idflieg agreed, and in a report on 24 July it stated:

    The Albatros DIII is more robustly constructed than the DV. The DV is merely regarded as a lightened DIII. The performance of both is equal. the DV will not be manufactured further, only the DIII.

    (That didn't quite happen due to the need for aircraft.) The author adds:

    It's engineers' efforts to correct the new fighter' shortcomings led in August to the DVa, whose higher compression Mercedes DIIIa engine compensated for the beefed up fuselage and wing structure. Even then Albatros hedged its bets by having its OAW subsidiary continue building DIIIs.
    Last edited by Timmo UK; 12-24-2014 at 12:49.

  5. #105

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    Quote Originally Posted by Timmo UK View Post
    The climb and ceiling is also effected by wing area – I'm presuming the bigger the wing the lighter the wing loading but the DIII and DVa have the same wings and the wing loading of the DVa is higher, if we've got our weight figures right. I did wonder if the DIII wings might work more efficiently since the top one of the DV is closer to the fuselage and I wondered if that disrupts the airflow enough for the wing to loose lift in that area. I'm clutching at straws but I'll be reading some more to see what the pilots say, to me that is what counts.

    A snippet from the Osprey SPADVII v's DIII;

    "Von Richthofen, for one, stated his preference for the DIII over the 'lousy' DV that summer. [1917] Oblt Rudolf Berthold was still flying a DIII when he commanded Jasta 18 as late as October 1917. Idflieg agreed, and in a report on 24 July it stated:

    The Albatros DIII is more robustly constructed than the DV. The DV is merely regarded as a lightened DIII. The performance of both is equal. the DV will not be manufactured further, only the DIII.

    (That didn't quite happen due to the need for aircraft.) The author adds:

    It's engineers' efforts to correct the new fighter' shortcomings led in August to the DVa, whose higher compression Mercedes DIIIa engine compensated for the beefed up fuselage and wing structure. Even then Albatros hedged its bets by having its OAW subsidiary continue building DIIIs.
    Firstly, a very happy Xmas to everybody. It's nice being able to post that I agree with you. The Alb DV was a bit of a turkey - note Xmas themed and polite substitute word for something ruder. The only clarification I'd raise is the statement 'The performance of both is equal'.
    In a sense this is very true. The planes have different performances but the advantages and disadvantages cancel each other out so much that for practical purposes the Alb DV offers no real advantage.

    Alb DV wings are even weaker than the DIII - based on pilots reports of crashes and near crashes
    Alb DV is faster but not significantly faster to offset the wings falling off
    Alb DV climb is either slightly better, the same or slightly worse - if the change is big, the pilots don't notice it or report it

    PS Added
    I'm starting to come to the conclusion that Andrea Angiolino got the official climb counter numbers (4) for the Albatros DIII and DV right. I'm, also, impressed by the work done by Andrea Angiolino and the stats committee in sorting through the incredibly confusing and contradictory evidence! I believe there is an argument the figure for the DVa with DIIIau high compression engine to be 3 but (as Andrea deliberately and wisely does not distinguish between engines) that's really a moot point.
    Last edited by Nicola Zee; 12-25-2014 at 00:45. Reason: PS Added

  6. #106

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    Quote Originally Posted by Nicola Zee View Post
    ....I believe there is an argument the figure for the DVa with DIIIau high compression engine to be 3 ...
    I still can't see how you can reach this conclusion Nicola.
    The Alb D.III was mounted with the Merc D.IIIa engine from the get go.
    The Alb D.V was mounted with the same engine and couldn't climb as well as the Alb D.III despite being lighter.
    How would an Alb D.Va that is heavier than the D.V mounted with the same Merc D.IIIa engine then climb better or as well than the Alb D.III ?
    That's not logical.
    When the Alb D.Va was then mounted with the improved Merc D.IIIa engine (the au version) it compensated for that extra weight & is said to match the D.V performance but might, at best, have matched that of the Alb D.III in regard of the climb rate; though I'd think that more unlikely now in light of the carburettor fitted & rev restriction.

    Oh, here's the family - have a good Christmas !

    "He is wise who watches"

  7. #107

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    Quote Originally Posted by flash View Post
    I still can't see how you can reach this conclusion Nicola.
    The Alb D.III was mounted with the Merc D.IIIa engine from the get go.
    The Alb D.V was mounted with the same engine and couldn't climb as well as the Alb D.III despite being lighter.
    How would an Alb D.Va that is heavier than the D.V mounted with the same Merc D.IIIa engine then climb better or as well than the Alb D.III ?
    That's not logical.
    When the Alb D.Va was then mounted with the improved Merc D.IIIa engine (the au version) it compensated for that extra weight & is said to match the D.V performance but might, at best, have matched that of the Alb D.III in regard of the climb rate; though I'd think that more unlikely now in light of the carburettor fitted & rev restriction.

    Oh, here's the family - have a good Christmas !
    You're argument seems sound but highlights one of the underlying problems with the performance stats of the Albatros DIII. By the time the DV came along newly made Alb DIII were being produced with the same engine (DIIIa). But the Alb DIII had been around before the existence of the DIIIa engine. I believe a typical Alb DIII (and some of the poor climb rates claimed) reflect this worse engine. Some of the outstanding climb rates may come from later better engines.
    In short a typical Alb DIII did not have the same engine as an Alb DVa but new Alb DIII did. The trouble is trying to make sense of the different figures when often it's not clear which figures go with which engine version.
    In short the statement "The Alb D.III was mounted with the Merc D.IIIa engine from the get go." is I believe misleading

    Have a great Xmas

    PS Added: Even more bad news with trying to untangle the Gordian knot, the Idflieg tests include tests for DV with the obsolete DIII engine and even tests for the DVa with the obsolete DIII engine. With various figures quoted without clear reference to the original engine it's a real mess!
    To be honest I don't know what the answer is going to be. But that (for me) makes it interesting

    PPS Added
    AIR VANGUARD 13, ALBATROS D.III Johannisthal, OAW, and Oeffag variants
    Page 25
    In early 1917 the Mercedes piston heads were redesigned from concave to flat,
    with a resultant increase in cylinder compression that generated 175Ps, but it
    is difficult to establish which particular Albatros airframes were outfitted with
    the stronger engine. Both the 160 and 175Ps engines were identical outwardly;
    new engines could be retrofitted into older machines; and already-purchased
    160Ps engines had to be used prior to production use of 175Ps engines. For
    example, the D.III(OAW) test flown on June 9, 1917 was equipped with a
    160Ps Mercedes.
    Last edited by Nicola Zee; 12-26-2014 at 11:25. Reason: PS Added

  8. #108

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    A lot has been posted. At this point it would be good to see if we can form some kind of consensus on the Alb DIII and the Alb DV - note the DV not the DVa. After gathering and pooling the evidence I have the following:

    AIR VANGUARD 13, ALBATROS D.III Johannisthal, OAW, and Oeffag variants
    Albatros DIII - DIII engine.
    The timings are based on performance tests at factory and the author has studied and evaluated the original Idfleig reports
    1,000m (3,281ft) 4 min = 820ft per minute
    2,000m (6,562ft) 10 min = 656ft
    3,000m (9,843ft) 19 min = 518ft
    4,000m (13,123ft) 30 min 30 min = 437ft per minute
    The rate of climb starts very good but falls off rapidly with altitude.
    Based on this the WGF Climb Rate should be 5.

    On the other hand on Page 21 there is the following quote
    "This solid and reliable engine enabled the D.III to attain a maximum speed of 175km/h (109mph) and climb to 5,000 meters (15,250 feet) in 30 minutes."
    Based on this the WGF Climb Rate could (at a stretch) be 4.

    Then we have the DIII with the DIIIa engine
    http://en.wiki.riseofflight.com/inde...Albatros_D.III
    Albatros DIII - DIIIa engine
    1000 m — 3 min. 57 sec.
    2000 m — 8 min. 14 sec.
    3000 m — 13 min. 37 sec.
    4000 m — 20 min. 52 sec.
    5000 m — 32 min. 13 sec.
    If these figures are right, the WGF Climb Rate should be 3. But they could (at a stretch) fall into the 4 category.
    We, also, don't know what the rise of flight figures are based on. Extra source material would be helpful.


    Captured DV (document dated 14&16 March 1918)
    1000 m — 4 min. 17 sec.
    2000 m — 8 min. 49 sec.
    3000 m — 14 min. 27 sec.
    4000 m — 22 min. 42 sec (Does not match time on axis on graph)
    4500m (14763 ft) — 29 min. 23 sec (N.B. Not to 5000m)

    Dan San Abbot for Alb. D.V which matches performance figures exactly for the captured plane
    http://www.theaerodrome.com/forum/showthread.php?t=2084
    1000 m 4' 20"
    3000 m (9840 ft) 14'30"

    Osprey’s Duel Series SE.5a vs. Albatros D.V – Western Front 1917-1918 by Jon Guttman pag. 31.
    3,050ft 4 20
    6,000ft 8 50
    9,050ft 14 30
    12,200ft (3,718m) 22 40
    15,250ft 30min

    We have multiple sources for the Alb DV all of which match nicely.
    With 3 completely different sources all matching I'm reasonably confident these figures are right.
    With these 3 figures the WGF Climb Rate would fall within the 3 category. But they could, also, fall into the 4 category.

    At altitude, the Alb DV (DIIIa engine) climb is better than the Alb DIII (DIII engine). This might explain MvR's claim that at altitude the Alb DIII could not maintain a turning climb as well as the DV.

    The Alb DV (DIIIa engine) climb is worse than the Alb DIII (DIIIa engine) but only slightly worse.
    Last edited by Nicola Zee; 12-27-2014 at 08:30. Reason: Clarifications

  9. #109

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    Lots to digest... thanks for the efforts!

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    I suspect they are all using the same source figures. They've been through the same debate on Rise of Flight… I haven't read it to a conclusion that is if they ever reached one.

  11. #111

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    Quote Originally Posted by Nicola Zee View Post
    Osprey’s Duel Series SE.5a vs. Albatros D.V – Western Front 1917-1918 by Jon Guttman pag. 31.
    You only quote the D.V figures - why not the D.III direct comparison figures that show much quicker climb rates ?
    That gives its climb data as:
    3,050ft 2:30
    6,000ft 6:00
    9,050ft 11:00
    12,200ft 17:00
    15,250ft 24:30

    These figures are comparable to those I gave you from Fighter Aircraft of the 1914-1918 War by W.M Lamberton.
    If you are going to pool figures given in the thread you have to pool them all.

    Quote Originally Posted by Nicola Zee View Post
    ...The Alb DV (DIIIa engine) climb is worse than the Alb DIII (DIIIa engine) but only slightly worse.
    So it's fair to say that the Alb D.Va, that is considerably heavier than the D.V, with same engine is going to climb 'slightly worse' than that....?!
    Though I think a combat pilot would regard being 20 seconds slower to 1000m (on the figures given) is more than slightly worse !

  12. #112


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    Quote Originally Posted by flash View Post
    You only quote the D.V figures - why not the D.III direct comparison figures that show much quicker climb rates ?

    So it's fair to say that the Alb D.Va, that is considerably heavier than the D.V, with same engine is going to climb 'slightly worse' than that....?!
    Though I think a combat pilot would regard being 20 seconds slower to 1000m (on the figures given) is more than slightly worse !
    Agreed. And since nobody has yet produced any combat pilot evidence to counter the view it follows that the DVa with the au engine, only compensated for the extra weight.

    What might be more interesting to ask is did the DIII ever get retro fitted with high compression pistons and if so what could that do but again a lack of evidence suggests this either didn't happen or the benefit was negligible.

    The reality was that the better pilots were still getting kills against allied scouts using out classed Albatros fighters – it's the guy flying and shooting who counts for as much as the airframe, if not more.

    If you split the Albatros into every last modification for the game purposes then you have to do the same with the Fokker DVII, where the differences between the Merc and BMW engines were noted to have made a significant difference. The same goes for the Clerget and Bentley engined Camels and the Fokker DR1 fitted with captured Oberursel engines over German built copies.

  13. #113

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    Quote Originally Posted by Timmo UK View Post
    If you split the Albatros into every last modification for the game purposes then you have to do the same with the Fokker DVII, where the differences between the Merc and BMW engines were noted to have made a significant difference. The same goes for the Clerget and Bentley engined Camels and the Fokker DR1 fitted with captured Oberursel engines over German built copies.
    And the planes with worn out engines, particularly the German rotaries.
    Karl
    It is impossible for a man to begin to learn what he thinks he knows. -- Epictetus

  14. #114

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    Quote Originally Posted by flash View Post
    You only quote the D.V figures - why not the D.III direct comparison figures that show much quicker climb rates ?
    That gives its climb data as:
    3,050ft 2:30
    6,000ft 6:00
    9,050ft 11:00
    12,200ft 17:00
    15,250ft 24:30

    These figures are comparable to those I gave you from Fighter Aircraft of the 1914-1918 War by W.M Lamberton.
    If you are going to pool figures given in the thread you have to pool them all.



    So it's fair to say that the Alb D.Va, that is considerably heavier than the D.V, with same engine is going to climb 'slightly worse' than that....?!
    Though I think a combat pilot would regard being 20 seconds slower to 1000m (on the figures given) is more than slightly worse !
    On the figures quoted for Osprey’s Duel Series SE.5a vs. Albatros D.V (page 31) there is no indication of which DIII these figures relate to. With the
    AIR VANGUARD 13, ALBATROS D.III there is an attempt (and I think mostly successful) to separate out the various versions and to take into account the varying Idfleig tests. The really exceptional figures quoted for the Osprey’s Duel Series SE.5a vs. Albatros D.V mostly closely match the Austro-Hungarian version of the plane. A DIII(oef) has widely different performance from a DIII with the original DIII engine. In short, the engine is critical and we need to know which engine is involved in which test.

    PS I can't give info on the figures in Fighter Aircraft of the 1914-1918 War by W.M Lamberton because I don't have access to this work. It may refer to a specific DIII but if it does I have to rely on you to provide this information.

    As Dan San Abbot puts it
    "One of the problems that most informants do not relate which engine and the source of their data."
    I'm trying to deal with this as best I can.

    PPS With the DV figures quoted in Osprey’s Duel Series it's reasonable to take these as a DV with DIIIa engine as they closely match 2 separate sources (one from Idflieg tests and the second from a French test of a captured plane).
    Last edited by Nicola Zee; 12-28-2014 at 04:13. Reason: PS Added

  15. #115

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    Quote Originally Posted by Timmo UK View Post
    Agreed. And since nobody has yet produced any combat pilot evidence to counter the view it follows that the DVa with the au engine, only compensated for the extra weight...
    That seems to follow the form Tim - Dan Sams quote from the link above states the performance of the Alb. D.Va with the 170 Ps Mercedes D.IIIa engine is:
    187 Km/hr @ sea level climb:
    188 " @ 1000 meters (3280 ft). 4' 0".
    165 " @ 3000 meters (9840 ft). 17'8".
    maximum altitude is: 6250 meters (20500 ft.).
    I have emphasised the climb times - to 3k it was over two and a half mins slower !

    "He is wise who watches"

  16. #116

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    Quote Originally Posted by flash View Post
    That seems to follow the form Tim - Dan Sams quote from the link above states the performance of the Alb. D.Va with the 170 Ps Mercedes D.IIIa engine is:
    187 Km/hr @ sea level climb:
    188 " @ 1000 meters (3280 ft). 4' 0".
    165 " @ 3000 meters (9840 ft). 17'8".
    maximum altitude is: 6250 meters (20500 ft.).
    I have emphasised the climb times - to 3k it was over two and a half mins slower !
    I, also, emphasised I'm trying to form a consensus on stuff we can agree upon - so (at this stage) I'm focussing on the DIII and DV.
    I may get around to the DVa but my investigations are far from complete.

  17. #117

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    Quote Originally Posted by Nicola Zee View Post
    ... I can't give info on the figures in Fighter Aircraft of the 1914-1918 War by W.M Lamberton because I don't have access to this work. It may refer to a specific DIII but if it does I have to rely on you to provide this information.
    I have been doing my best but you don't seem to want to accept them !
    And that work does quote the Austro version separately which has 'slightly' better than the D.III figures I've already quoted

    Quote Originally Posted by Nicola Zee View Post
    ..On the figures quoted for Osprey’s Duel Series SE.5a vs. Albatros D.V (page 31) there is no indication of which DIII these figures relate to.
    But it does quote the figures as with the same engine as that of the D.V you gave as a direct comparison and they match what I found previously so they cannot just be dismissed.
    As the thread is about the D.Va climb rate I think it's clear from all figures given that it had a climb rate no better than its predecessors

    "He is wise who watches"

  18. #118

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    Quote Originally Posted by flash View Post
    I have been doing my best but you don't seem to want to accept them !
    And that work does quote the Austro version separately which has 'slightly' better than the D.III figures I've already quoted


    But it does quote the figures as with the same engine as that of the D.V you gave as a direct comparison and they match what I found previously so they cannot just be dismissed.
    As the thread is about the D.Va climb rate I think it's clear from all figures given that it had a climb rate no better than its predecessors
    Let us be absolutely clear on this. You honestly and truly believe a German Albatros DIII had only a slightly worse climb rate than an Austro-Hungarian Albatros DIII Is this just a wind-up

  19. #119


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    The problem is Nicola with all these figures is they are only theoretical. What about the weather? In the summer afternoons and evening the climb rates might be higher still, in lighter winds they might be higher and so the un-measurable variables go on.

    What probably has more of a bearing on combat and thus this game, which deals with the nitty gritty bit of air fighting, than out and out climb performance is how well an average pilot was able to maintain altitude in a turn in a given aircraft.

    Really if the DVa had been measurably different I doubt some Jasta, let alone some Aces would have been using DIII's as late as they did. Jasta Leader Paul Strahle was flying a DIII mid 1918!

    If I were you and wanting to try to flesh out this theory to a point where it could have a bearing on what the game tries to represent I'd be reading every book and finding every combat pilot reference I could to see if there is any evidence that your theory was actually a reality on the Western Front 1917/18. I'd also be looking at allied combat reports to see if the pilots felt they were fighting Albatros fighters that seemed to be better than average. That's what counts in the game – the typical day-to-day performance, an average plane flown by an average pilot in typical weather with typical fuel, ammo and later a parachute. I wouldn't spend any more time hunting out test figures – it's pretty clear that real like for like numbers don't exist. You'd have to have an official test from 1918 using same fuel, weather etc for it to be really meaningful. Whatever the numbers the only thing that really matters is what the performance was in combat situations. I think we probably know the answer to that: great pilot will still be able to make a less good airframe count. The reality is the game is probably balanced correctly so that the technology isn't too important in the overall mix of things. As mentioned before once you start tweaking one airframe/engine combination then you have to apply the rule consistently, if you are to maintain the balance of play v's historical reality. If you do that then there are far better candidates for having their stats adjusted than the DVa. Then if you decide engines matter that much I'd present a counter argument that relative performance at altitude mattered even more, oh and being an exceptional shot mattered even more in combat.
    Last edited by Timmo UK; 12-28-2014 at 06:57.

  20. #120

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    Quote Originally Posted by Nicola Zee View Post
    Let us be absolutely clear on this. You honestly and truly believe a German Albatros DIII had only a slightly worse climb rate than an Austro-Hungarian Albatros DIII Is this just a wind-up
    Not what I said but your reaction speaks volumes. I'm out.

    PS. For those interested the figures referred to were for the series 53 Austro-Daimler 185hp powered version not the uber 253 variant
    Last edited by flash; 12-28-2014 at 10:28.

  21. #121

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    Quote Originally Posted by flash View Post
    Not what I said but your reaction speaks volumes. I'm out.

    PS. For those interested the figures referred to were for the series 53 Austro-Daimler 185hp powered version not the uber 253 variant
    I'm sorry for offending you but even though I already stated the type of engine is critical, you still left out the engine version.

    AIR VANGUARD 13, ALBATROS D.III Johannisthal, OAW, and Oeffag variants has timings for this version and the timings for the DIII with the DIII engine are very much worse. The Albatros DIII with DIIIa engine are indeed slightly worse. The timings for the Oeffag with the uber engines are indeed very much better.

    As I've already said when quoting the performance statistics, knowing the type of engine is critical.

  22. #122

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    Quote Originally Posted by flash View Post
    Not what I said but your reaction speaks volumes. I'm out.

    PS. For those interested the figures referred to were for the series 53 Austro-Daimler 185hp powered version not the uber 253 variant
    AIR VANGUARD 13, ALBATROS D.III Johannisthal, OAW, and Oeffag variants quotes the following figures for the Oeffag variants
    Oeffag D.III(Oef), Series 53
    1,000m (3,281ft) 4 min 30 sec
    2,000m (6,562ft) 7 min
    3,000m (9,843ft) 30 sec – 19 min

    D.III(Oef), Series 153
    1,000m (3,281ft) 2 min 35 sec
    2,000m (6,562ft) 6 min 34 sec
    3,000m (9,843ft) 11 min 21 sec
    4,000m (13,123ft) 18 min 16 sec
    5,000m (16,404ft) 31 min 42 sec

    These figures are worse than those you posted for the German Albatros DIII. Not surprisingly it seemed to me you were arguing the German version of the DIII had only slightly worse climb than the Oeffag version

    PS Added
    You're quote "And that work does quote the Austro version separately which has 'slightly' better than the D.III figures I've already quoted"
    Last edited by Nicola Zee; 12-29-2014 at 01:33. Reason: PS Added

  23. #123

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    Quote Originally Posted by Timmo UK View Post
    The problem is Nicola with all these figures is they are only theoretical. What about the weather? In the summer afternoons and evening the climb rates might be higher still, in lighter winds they might be higher and so the un-measurable variables go on.

    What probably has more of a bearing on combat and thus this game, which deals with the nitty gritty bit of air fighting, than out and out climb performance is how well an average pilot was able to maintain altitude in a turn in a given aircraft.

    Really if the DVa had been measurably different I doubt some Jasta, let alone some Aces would have been using DIII's as late as they did. Jasta Leader Paul Strahle was flying a DIII mid 1918!
    ...
    On the subject of the Idflieg tests, I agree. When I started this debate I reasonably thought it could be a simple matter of someone just posting up an original Idflieg test or a test from a captured aircraft. But the figures form only part of the evidence and indeed must be placed into context.
    I would disagree there is no point in finding performance figures - these count as evidence but they are (as you imply) just part of the jig-saw.

    I like Zoe's general rule of thumb that the reports from the enemy pilots on the performance of their opponents plane's is very important. A big problem we have with the German 'V' strutters is that in combat they all look the same - in effect they all look like DIII's. This may explain the different and conflicting reports from British pilots of how the 'V' strutters performed in combat.

    On the subject of the DIII, it was a good basic design and only needed the right modifications to make it a truly worthy match for a Camel and even the SE5a - as proved by the Austro-Hungarians. It's a shame when the DIIIau engine came out that the Albatros factory did not take an original DIII and put the new engine into it. It's a even bigger waste they did not learn from the Austro-Hungarians.

  24. #124

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    Nicola, your dedication to this subject is amazing.
    You may be wrong but your rationale is spotless.
    For such dedication, I must give you REP.

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    If I may throw a few points in at this stage. I spent most of yesterday going through all my books. I have stuff going back to the 1960s including Harleyford books, Profiles, etc. My plan was to post every Albatros figure I could find but I was also struck by the general trend I was seeing in performance data. Having done all this before (research for air wargaming in the 1970s) I suddenly realised something I did not realise way back then. Some aircraft data is unreliable, some is contradictory and some is highly dubious. It looks as if some authors may have copied from each other but it also looks as if facts have been grabbed from various sources by some authors and just thrown together. A service ceiling from one source, a take-off weight from another source and climb rates from a third source.

    While looking at Albatros fighters in the eminent 'Profile' series, I also started comparing data for other types as a matter of curiosity:

    I found the Hanriot HD-1 'Profile' quoted three sets of figures - one French, one German (captured) and one Italian for the same engine type (and presumably same weight) and there was a marked difference in how the type climbed. Roughly a 15% variation across the three columns.
    On the Sopwith Snipe I found a very interesting comparison on a single service Snipe. A set of climb figures based on a freshly delivered machine and another set - on the SAME machine - re-tested after 24-hours of flying time. There was a sharp drop in climbing performance.

    So… are we dealing with figures derived from a 'factory fresh' Albatros D-III and a war service 'tired' Albatros D-V?
    Are we dealing with 'manufacturer' figures for the D-III compared with a captured and possibly badly rigged or badly flown D-V?

    Looking through the Albatros figures quoted by Profile there were test figures for Albatros D-Vs which performed marvellously on trials or with experimental propellors. On paper they could out-climb a BMW DVII or an S-S D-IV.

    My position is this: unless we have a set of figures (engine size and HP, take-off weight, climb rates and ceiling) derived from one machine compared with the same figures taken from a single rival machine, very little can be gleaned from published and generally available performance data. There are too many variables.

    General trends would suggest that if two aircraft of similar design are being compared (the D-III and D-V ARE similar), the type with the larger engine and the higher quoted service ceiling (service ceiling being the point defined as a climb rate decaying to just 50 feet per minute) should probably be able to out climb the type with the smaller engine. However differences in weather, humidity, pilot skill, the rigging of the machine and the all-up weight being carried will all affect these figures.

    Humidity will make a particular machine damp and damp equals weight. Also, damp machines may also experience wing droop if the wooden airframe is slightly swollen - this will affect dihedral on the wings, the angle of attack, and the way the aircraft is 'rigged' by the turnbuckles on the rigging wires. In a recent YouTube film of Kermit Weeks flying a replica Albatros DV from New Zealand, the first thing he complained about, upon landing, was the rigging. He thought it was too slack.

    Remember also that weight is critical, especially in WW1. Some aircraft were so close to the edge of their load-carrying capacity that the addition of a second gun (say on the Nieuport 17) was found to adversely affect climb rate and ceiling.

    I was carrying the reserve fuel can for my car yesterday. Only a few litres but it was HEAVY. So also remember that fuel state will affect performance. Was the Albatros D-III tested with a half-empty fuel tank? Was the D-V tested with a full tank? My source says the D-V carried 17 gallons* in the main tank with another 5 in the reserve. If the reserve was empty on one machine that could also affect the trim of the machine and therefore its performance.

    There are a lot of variables in play and too much information has been lost in time. So let's all be polite with each other and each of us remember that - in WW1 aviation terms - a single set of numbers can be about as useful as my ability to guess the lottery numbers

    *EDIT 17 gallons of petrol = 124 pounds if my calculations are correct. Petrol/gasoline is lighter than water.
    Last edited by 'Warspite'; 12-30-2014 at 04:49.

  26. #126

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    Quote Originally Posted by 'Warspite' View Post
    ...In a recent YouTube film of Kermit Weeks flying a replica Albatros DV from New Zealand, the first thing he complained about, upon landing, was the rigging. He thought it was too slack.

    Remember also that weight is critical, especially in WW1. Some aircraft were so close to the edge of their load-carrying capacity that the addition of a second gun (say on the Nieuport 17) was found to adversely affect climb rate and ceiling.

    I was carrying the reserve fuel can for my car yesterday. Only a few litres but it was HEAVY. So also remember that fuel state will affect performance. Was the Albatros D-III tested with a half-empty fuel tank? Was the D-V tested with a full tank? My source says the D-V carried 17 gallons* in the main tank with another 5 in the reserve. If the reserve was empty on one machine that could also affect the trim of the machine and therefore its performance.

    There are a lot of variables in play and too much information has been lost in time. So let's all be polite with each other and each of us remember that - in WW1 aviation terms - a single set of numbers can be about as useful as my ability to guess the lottery numbers
    ...
    These are all good points. Timings must be treated with caution. We cannot provide absolute timings which are certain to be correct.
    But when dealing with the same aircraft (and as you have pointed out the DIII\DV\DVa are essentially the same) we can try to maintain timings where the relative values make sense.
    If the timings for an Alb DIII with an DIIIa engine matches that of an D.III(Oef), Series 153 it's reasonable to raise concerns.
    So (taking this into account) I think it's possible to a broad conclusion about the climb rate of a DVa with DIIIa engine compared to a Alb DV with the same engine.
    The DVa is slightly heavier so it's to be expected the climb rate will be slightly worse. The DVa is slightly worse than the DV which is slightly worse than the Alb DIII.

    At 3000m (9840 ft) Dan San puts the figure at 17mins 8 secs - a few minutes slower.
    http://www.theaerodrome.com/forum/showthread.php?t=2084

    Rise of flight puts it a few seconds slower.
    http://en.wiki.riseofflight.com/inde...=Albatros_D.Va

    Given the vagaries of testing either figure is possible and anything in between is equally possible.
    Now we know that the forward speed of the DV and DVa was greater than the DIII.
    Based on this it's reasonable to supose the power went in forward speed and any improvement in streamlling and reduction in drag also went in forward speed and not climb.

    And (given the same DIIIa engine) you're right the max altitude of the DVa should be less than the DIII. The plane is geared to forward speed (or to be more exact) the propeller is pitched to this.

    I leave the last word on the Albatros DIII, DV and DVa to Dan San. I'm going to take the liberty of suggesting his timings refer to all versions using the same DIIIa engine - it's a bit naughty he does not make clear which engine his figures refer to

    http://www.theaerodrome.com/forum/sh...light=albatros

    In an effort to improve the perforamce of the d.III series, Albatros Werke attacked the problem through improving the power to weight ratio over the Alb.D.III by a sever weight reduction and improve the design of the D.II by reducing the drag by better streamlining of the fuselage. This resulted in the Alb.D.V. In addition to a more streamlined fuselage the gap between the wings was reduced, thus shortening the strutsand cable lengths which reduded the frontal area and further reduced the drag, thus improving the lift to drag ratio. When they were finished, they had the looks of a good machine.
    The empty weight of the D.III was 661 kg.(1454 lbs.) Its maximum airspeed was 175km/hr @sea level. The weight to power was 661/160=4.13 kg/hp The Alb.D.V empty weight was 680 kg.(1496 lbs.) the maximum airspeed of the D.V was 186km/hr @sea level. the power to weight ratio was:
    1496/175=3.88 kg/hp. Albatros engineer achieved what they were after, however, the Alb.D.V did not have strength of the Alb.D.III. In service use structural problems arose because of the lightened airframe. Albatros engineers went back to the drawing and reassessed the D.V design and restructured the airframe. this recsulted in a new design, the Alb.D.Va. To achieve the strength, the weight increased, the D.Va weighed 717kg (1577 lbs) empty weight. The power to weight ratio became 717/175=4.09 kg/hp.
    It was slightly better than the Alb.D.III, however it was able to be as fast as the Alb.D.V.
    The Idflieg (Inspektion der Fliegertruppe) wanted machine that had a good rate of climb rather than high speed that the Allies preffered. The Alb.D.V rate of climb was not as good as the Alb.D.III. It took the D.III 28min. 48 sec to climb to 5000 meters, the D.V took 32 minutes to reach 5000 meters. The D.Va to 35 minutes to reach 5000 meters. The Ceiling of the D.III was 5800 meters the ceiling for the D.V was 6500 meters and the D.Va declined to
    6250 meters.
    During the this period oif time the Royal Aircraft Factory had improved on the S.E.5 with its 150 hp Hispano-Suiza Model 8Aa @ 1500 rpm, V-8 engine. The S.E.5 with this engine This engine with 5.3 compression ratio produced 180 hp at 1800rpm and @ 2000 rpm produced 230hp. The S.E.5 with this engine had a ceiling of 22000 ft(6700meters), did 132.5 mph (213.7km/hr) at 10000 ft(3048meters) and 123.5mph (199km/hr.) at 15000 ft (4573 meters) altitude
    The improved S.E.5a went to 56 Squadron in June 1917, about the same time as the Alb.D.V. was being delivered to the Jagstaffeln. The S.E.5a had a 200 hp Hisso, Model 8Bb, with 4.7 compression ratio. This engine was rated at 200 hp @ 2000 rpm, at 2200 rpm it produced 218 hp. With the improved Model
    8Bc 220 hp @ 2100 rpm, produced 237 hp @ 2200 rpm. T this is the engine that went to S.E.5a in late1917. With this engine the S.E.5a was more than a match for the Albatros D.V/D.Va, Pfalz D.III/D.IIIa and The Fokker DR.I. The German pilots had their hands full with the S.E.5a. The S.E.5a @ 10000 ft would do 128 mph (206.5 km/hr) and at 15000 ft., 115 mph (185km/hr). The Alb.D.V and D.Va would do 165km/hr (102.3mph.)at 3000 meters (9840 Ft). with this kind of performance the S.E.5/ S.E.5a pilot could pick his fight and had the speed differential to withdraw from the fight. The Sopwith F.1 Camel's performane was in the range of the Albatros D. types, however, the Camel handling characteristics were much better the the Albatros D.V/D.Va and Pfalz D.III/D.IIIa machines. with the Fok.Dr.I I would say they were an even match, pilot for pilot and machine for machine.
    Last edited by Nicola Zee; 12-30-2014 at 08:05. Reason: Added link

  27. #127

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    I am planning a separate thread about the climb rates of the Pfalz D-III and D-IIIa in Wings of War/Glory. However while reading Peter Gray's eminent 1965 'Profile' (No 43, it cost a whole two-shillings back in those days!) I came across a very interesting quote:

    Writing of a Pfalz DIII, someone from Jasta 24 wrote this in a report dated 25th October, 1917:

    "It is slower than the Albatros DIII; it is fast in a dive and is then faster than the Albatros DV. The climbing performance of the Pfalz DIII varies greatly, sometimes almost as good as the average Albatros DV but never better…." The author then recommends that mixed units of Pfalz and Albatros are not recommended.

    Now… in my previous posting I did suggest that supposedly identical machines actually varied in performance due to age and quality of manufacture or servicing, etc. This author implies that there was certainly a variation in Albatros DV's with his words: "almost as good as the average Albatros DV". Clearly there was a wide variation in performance between several machines of the same type and we should be wise to remember that.

    I will post shortly on the Pfalz.

  28. #128

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    Quote Originally Posted by 'Warspite' View Post
    I am planning a separate thread about the climb rates of the Pfalz D-III and D-IIIa in Wings of War/Glory. However while reading Peter Gray's eminent 1965 'Profile' (No 43, it cost a whole two-shillings back in those days!) I came across a very interesting quote:

    Writing of a Pfalz DIII, someone from Jasta 24 wrote this in a report dated 25th October, 1917:

    "It is slower than the Albatros DIII; it is fast in a dive and is then faster than the Albatros DV. The climbing performance of the Pfalz DIII varies greatly, sometimes almost as good as the average Albatros DV but never better…." The author then recommends that mixed units of Pfalz and Albatros are not recommended.

    Now… in my previous posting I did suggest that supposedly identical machines actually varied in performance due to age and quality of manufacture or servicing, etc. This author implies that there was certainly a variation in Albatros DV's with his words: "almost as good as the average Albatros DV". Clearly there was a wide variation in performance between several machines of the same type and we should be wise to remember that.

    I will post shortly on the Pfalz.
    I look forward to your post on the Pflaz - you've clearly spent many years passionately studying WW1 air combat. I'm a bit of a newbie but I'm catching up. I had a period of illness - so I spent a lot of time reading on various subjects.

    For what it's worth, I think the reported worse climb of the Pflaz compared to the Alb DV can be partly explained in terms of different engines.
    If the climb of the Alb DVa (DIIIau) is made better (reduced from 4 to 3) the relative performance differences are not so bad.

    This gives the following climb rates - all official except the last one
    Pfalz DIII (Mercedes DIIIa engine?) 3
    Alb DV (Mercedes DIIIa engine) 4
    Alb DVa (Mercedes DIIIa engine) 4
    Alb DVa (Mercedes DIIIau engine) 3

    Now this, also, fits better with the relative performance of the famously good fighter - the Fokker DVII - one of the ultimate climbers.

    The Fokker DVII started with a DIII engine and its climb was not that great. It became great when fitted with the over-compressed BMW DIIIa engine. But it was also fitted with the DIIIau engine and when fitted its performance was similar to the BMW DIIIa engine. I can, therefore, conclude with confidence the pilot of the replica Alb DVa got it right - the Mercedes DIIIau engine does indeed have tremendous power.
    This leads to the following climb rates for the Fokker DVII taking into account engines
    Fokker DVII (Mercedes DIII) 3 (made worse - definitely worse engine than DIIIau)
    Fokker DVII (Mercedes DIIIau\BMW DIIIa) 2

    I have the reply of the pilot from the company producing the replica. His timings for the Alb DVa with DIIIau engine
    are 900ft per minute and the climb remains good. Of course, I doubt he takes the plane to a very high altitude but the engine is over-compressed for altitude - so should perform well at altitude. Based on this figure, a Camel would still climb better at low altitude but a Alb DVa (DIIIau engine) could outclimb it at high altitude.
    Last edited by Nicola Zee; 01-02-2015 at 01:19. Reason: Lost connection several times

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    Quote Originally Posted by Nicola Zee View Post
    I look forward to your post on the Pflaz - you've clearly spent many years passionately studying WW1 air combat. I'm a bit of a newbie but I'm catching up. I had a period of illness - so I spent a lot of time reading on various subjects.

    For what it's worth, I think the reported worse climb of the Pflaz compared to the Alb DV can be partly explained in terms of different engines.
    If the climb of the Alb DVa (DIIIau) is made better (reduced from 4 to 3) the relative performance differences are not so bad.

    This gives the following climb rates - all official except the last one
    Pfalz DIII (Mercedes DIIIa engine?) 3
    Alb DV (Mercedes DIIIa engine) 4
    Alb DVa (Mercedes DIIIa engine) 4
    Alb DVa (Mercedes DIIIau engine) 3

    Now this, also, fits better with the relative performance of the famously good fighter - the Fokker DVII - one of the ultimate climbers.

    The Fokker DVII started with a DIII engine and its climb was not that great. It became great when fitted with the over-compressed BMW DIIIa engine. But it was also fitted with the DIIIau engine and when fitted its performance was similar to the BMW DIIIa engine. I can, therefore, conclude with confidence the pilot of the replica Alb DVa got it right - the Mercedes DIIIau engine does indeed have tremendous power.
    This leads to the following climb rates for the Fokker DVII taking into account engines
    Fokker DVII (Mercedes DIII) 3 (made worse - definitely worse engine than DIIIau)
    Fokker DVII (Mercedes DIIIau\BMW DIIIa) 2

    I have the reply of the pilot from the company producing the replica. His timings for the Alb DVa with DIIIau engine
    are 900ft per minute and the climb remains good. Of course, I doubt he takes the plane to a very high altitude but the engine is over-compressed for altitude - so should perform well at altitude. Based on this figure, a Camel would still climb better at low altitude but a Alb DVa (DIIIau engine) could outclimb it at high altitude.

    Bless you. Note that the date of the report which I quoted suggests this was for an original Pfalz DIII (not DIIIa) which had not been in service for very long and an Albatros DV not a DVa.

  30. #130

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    Quote Originally Posted by 'Warspite' View Post
    Bless you. Note that the date of the report which I quoted suggests this was for an original Pfalz DIII (not DIIIa) which had not been in service for very long and an Albatros DV not a DVa.
    Hmmm... That's interesting...you've piqued my interest

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    The report I quoted is dated Oct 25, 1917. The Pfalz DIII had only entered service in August 1917 while, the same month, Idflieg had placed its first order for the DVa. The DVa was probably only reaching the best German squadrons in October - hence the author's reference to the DV and not the DVa.

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    I spoke of this debate with an ex Fleet Air Arm aircrew member today. He told me that the weather conditions; both wind speed, wind direction (relative to the aircraft throughout the duration of the climb) and the weather itself will make enough difference in each instance to make comparing the quoted climb figures from a variety of sources a totally pointless and meaningless exercise. He added that the only way for any such test figures to have any relevance in a debate of relative performance would be if all the aircraft were flown together under a range different weather conditions with the same load weight.

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    Quote Originally Posted by Timmo UK View Post
    I spoke of this debate with an ex Fleet Air Arm aircrew member today. He told me that the weather conditions; both wind speed, wind direction (relative to the aircraft throughout the duration of the climb) and the weather itself will make enough difference in each instance to make comparing the quoted climb figures from a variety of sources a totally pointless and meaningless exercise. He added that the only way for any such test figures to have any relevance in a debate of relative performance would be if all the aircraft were flown together under a range different weather conditions with the same load weight.
    I think this may be one reason why the Idflieg held fighter trials in 1918. The machines were flown on the same day, in similar conditions and with the same cadre of pilots at the controls.

  34. #134

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    Quote Originally Posted by 'Warspite' View Post
    I think this may be one reason why the Idflieg held fighter trials in 1918. The machines were flown on the same day, in similar conditions and with the same cadre of pilots at the controls.
    Quote Originally Posted by flash View Post
    ....PS - At the First Fighter Competition at Adlershof they put a 185hp BMW IIIa engine in an Albatros D.Va and it got to 6,000m (19,680') in 24.5min & 25.5min in two different runs and got a max ceiling of 10,500m. Postwar British tests put the rating of the BMW IIIa at 230 hp so it appears it just lacked BMW grunt !

    PPS: That's in the Profile 9 book - and no they didn't give a source for it
    The Fokker DVII started with a Mercedes DIII engine and its climb was not that great. It became great when fitted with the over-compressed BMW DIIIa engine. But it was also fitted with the Mercedes DIIIau engine and when fitted its performance was similar to the BMW DIIIa engine. Worse - but only slightly worse. I can, therefore, conclude with confidence the pilot of the replica Alb DVa got it right - the Mercedes DIIIau engine does indeed have tremendous power. On British tests the BMW DIIIa engine was rated at 230hp but the Mercedes DIIIau engine was rated at 220hp - just slightly worse.

    An Albatros DVa with a DIIIau engine should perform only slightly worse than an Albatros DVa with a BMW DIIIa engine.

    Based on the timings from the First Fighter Competition at Adlershof the Albatros DVa with a DIIIau engine should have a good climb rate.

    QED

    P.S. Just before I get blasted for relying on a single climb result, firstly my argument is based mainly on the engine and not just the timings. Secondly, the exact timing is not important - what is significant is that the plane performed well compared to the other planes in the competition. It was not the turkey people have suggested it was. Mediocre and obsolete but only in comparison to the top British fighters such as the SE5a and Bristol Fighters - and of course the Fokker DVII.
    Last edited by Nicola Zee; 01-08-2015 at 02:40. Reason: PS Added

  35. #135

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    You have more confidence than me ! All British references I have seen rate the Merc D.IIIau engine about 200hp (the D.IIav was about 220hp).
    This is borne out somewhat by the Replica pilot who gave the rate of climb as 900 ft/min. That rate would get him to 3000ft in 3min 20sec, about 1000m (in a few more secs - incidentally the same as figures for Alb D.III with a Merc D.IIIa engine according to some sources...). If the engine were up around the 220hp mark we could expect much quicker timings to that height - maybe similar to the oeffag D.III 253 series with the 225 Austro Daimler engine that could do that in 2min 15sec (according to some sources). This would also go some way to explaining the pilots clamouring for the BMW version of the Fok D.VII rather than the Merc engined variant.

  36. #136

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    Quote Originally Posted by flash View Post
    You have more confidence than me ! All British references I have seen rate the Merc D.IIIau engine about 200hp (the D.IIav was about 220hp).
    This is borne out somewhat by the Replica pilot who gave the rate of climb as 900 ft/min. That rate would get him to 3000ft in 3min 20sec, about 1000m (in a few more secs - incidentally the same as figures for Alb D.III with a Merc D.IIIa engine according to some sources...). If the engine were up around the 220hp mark we could expect much quicker timings to that height - maybe similar to the oeffag D.III 253 series with the 225 Austro Daimler engine that could do that in 2min 15sec (according to some sources). This would also go some way to explaining the pilots clamouring for the BMW version of the Fok D.VII rather than the Merc engined variant.
    Yes - you're right. Good call. In hindsight, I should have double-checked my sources for both the 220hp claim for the British test and the claim the performance of the Fokker DVII was not that much different from the BMW and Mercedes engines. A lesson I should have learnt from this debate is just because a figure is quoted in a book or on the web does not make it true. Double-checking multiple sources is needed.

    PS: And the other things I've learnt from this debate is that all the stats have to be taken as very broad guestimates - I liked your (according to some sources) proviso and the relative comparisons between different planes - and including the engine.
    Last edited by Nicola Zee; 01-09-2015 at 00:39.

  37. #137

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    One thing which has bothered me about comparing the Alb DIII (DIIIa) engine with the Alb DVa (DIIIau) engine is that the unloaded weight of the plane is significantly more for the DVa but the loaded weight is not. It's been suggested this is because they made the petrol tank for the Alb DVa smaller - reducing the number of hours it could fly but making it lighter.

    After getting burnt once by just going by one source, I'm going to ask if anyone can confirm or deny this as I can't find an additional source which confirms this.

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