DH.4 Eagle VIII vs. DH.4 Liberty 12

[Honza]

Guys, i have found some information on DH.4 powered by 375 HP Eagle VIII.
Empty weight: 1084 kg
Operational weight without bombs: 1433 kg (2 crew and fuel included)
Take off weight: 1575 kg
http://www.aircraftinvestigation.inf...H.4_360hp.html

I can't find anything on Liberty plane apart from something called Gross Weight, which is 1953 kg.
https://www.si.edu/object/de-havilla...m_A19190051000

I need:
Empty weight
Operational weight without bombs
Take off weight

The Liberty 12 engine (383 kg) seemed to be just a bit heavier than Eagle VIII (379). But Liberty plane Gross weight is apparently 400kg more than the type with Eagle VIII. So what made the difference?

[Jager]

Guys, i have found some information on DH.4 powered by 375 HP Eagle VIII.
Empty weight: 1084 kg
Operational weight without bombs: 1433 kg (2 crew and fuel included)
Take off weight: 1575 kg
http://www.aircraftinvestigation.inf...H.4_360hp.html

I can't find anything on Liberty plane apart from something called Gross Weight, which is 1953 kg.
https://www.si.edu/object/de-havilla...m_A19190051000

I need:
Empty weight
Operational weight without bombs
Take off weight

The Liberty 12 engine (383 kg) seemed to be just a bit heavier than Eagle VIII (379). But Liberty plane Gross weight is apparently 400kg more than the type with Eagle VIII. So what made the difference?

Probably stronger fittings for the heavier engine. Or maybe just a different attachment due to shape?
Karl

[Honza]

I need someone who has a printed issue of a magazine on Liberty Plane. "The Internet" has only info on Eagle fitted DH.4s. I want the truth, now when we know it is not the engine itself

[Honza]

Someone at the other aerodrome send me this link
https://www.hq.nasa.gov/pao/History/SP-468/app-a.htm

Not sure whether Gross Weight come with the bomb load or not.

[flash]

I have Profile 97 - American DH.4 - Jan, it gives empty weight as 2732lb; Gross weight as 4297lb, nothing more specific than that at first glance.
Max 12 bombs of any combination, not exceeding 322lbs.

[Honza]

Thanks Dave, is the gross weight with the bombs or not?
What puzzles me is the massive gross weight increase and discrepancies in some stats.

You say the empty weight is 2732lb, which is exactly what i would expect, unlike other sources - even Smithsonian institute state 2391lb - which is what the R-R powered machines weighted empty.

[Honza]

I found this page
http://www.aircraftinvestigation.info/WWI_aircraft.html

The fellow there calculates the weights from various components and then compares it to the published numbers.
I just overlooked the Liberty plane, as he marks it as DH.4, while the other two types are marked as D.H.4

I love it.

[flash]

Thanks Dave, is the gross weight with the bombs or not?..

I think in this case it might, the gross weight will change for and during the mission but in this case it will, for the purposes of stats. I take it that it the max gross weight of an aircraft is equal to its take-off weight with a full load of fuel/oil/weapons/ammo/crew/bombs.
Bear in mind also the Liberty DH.4 carried more guns as standard.

[Honza]

That sounds good. Also, apparently the us crews really liked it as an observer aircraft, it became slow only when it carried bombs.