Why have American DH.4s such a bad climb? I thought they were equipped with 400hp Liberty engines.
Why have American DH.4s such a bad climb? I thought they were equipped with 400hp Liberty engines.
There's not a lot of difference between the 400hp Liberty and the 375 Eagle engine that most of the UK DH-4s were powered with.
Karl
It is impossible for a man to begin to learn what he thinks he knows. -- Epictetus
I have these data for the D.H.4.
Engine time to altitude (minutes.seconds/meters) Ceiling (meters) 230hp B.H.P 3.18/608, 11.48/1520, 24.36/3040. 4114 200hp R.A.F. 3a 1.25/304, 8/1981, 25.15/4267, 41.3/5181. 5334 230hp Puma 7.3/1981, 14/3040, 28.3/4560. 5303 375hp R.R. Eagle VIII 4.5/1828, 9/3040, 14.45/4267, 23.3/5486. 6705 400hp Liberty 12 8.3/1981, 14.48/3040, 33.42/4560. 5334
Last edited by Angiolillo; 04-17-2022 at 11:57.
IIRC, weight. The Liberty was a powerful engine, but its power to weight ratio was hot steaming garbage. Might as well pack the nose full of boat anchors...
The DH.4 started with 250 hp (190 kW) Eagle III engines and subsequently built with improved versions of that engine until the 375hp R.R. Eagle VIII was developed. It was the shortage of supply of that later engine that led to it being fitted with the Liberty L12 and other engines listed by Andrea. I wonder what the stats of those earlier RR types would look like ?
Currently the model uses the fast deck H - fitted with the Eagle VIII the (wiki) stats suggest it could be used with the very fast A* deck - 143mph (230kph) at sea level so, potentially, maybe this model could be used at different times with different deck speeds ? (*sans Immelmann)
I've used it in the past with the average speed K deck as a loaded weight, switching to the H deck once it dropped it's eggs for a fast getaway. It worked well and allowed the intercepting Fokker D.VII's a chance to catch their targets on the way in.
Sapiens qui vigilat... "He is wise who watches"
Thank you guys!
Last edited by Honza; 04-18-2022 at 05:19.
The Liberty might have been rated at 400 HP, but in practice it delivered considerably less.
Its power-to-weight ratio was very poor.
I laugh in the face of danger - then I hide until it goes away!
Not that I know of, but I've often downgraded a bomb-carrying 2 seater to the next slower deck.
What Dave mentions above with the K deck for a loaded DH-4 is exactly what I do.
I find this works much better than a required stall move in each turn; that's very jarring.
Karl
It is impossible for a man to begin to learn what he thinks he knows. -- Epictetus
Do you guys play steep maneuvers while loaded?
Of course!
Climb, Dive and Stalls are all "steep", and can all be played while "loaded".
I laugh in the face of danger - then I hide until it goes away!
Steep 90 turns and wide side slips may be too much.
Last edited by Honza; 04-21-2022 at 00:33.
I've only used it with tandems, more as a mechanic to allow the interceptors to intercept and as Sam says it makes thing a bit smoother than using a stall every turn. The only tandem with a steep 90 turn is the Hannover & I'd allow it as its few bombs are carried internally. None have a wide sideslip, steep or otherwise. It's not steep but I wouldn't allow the Immelmann card for the few that have it.
Sapiens qui vigilat... "He is wise who watches"
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