SPAD S.XI

Biplane Fighter Aircraft

France | 1917

"The two-seat SPAD S.XI was dogged by issues which led to limited production during World War 1."

Authored By: Staff Writer | Last Edited: 06/04/2018 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site; No A.I. was used in the generation of this content.

Image copyright www.MilitaryFactory.com; No Reproduction Permitted.

The storied engineering career of Frenchman Louis Bechereau spanned decades and several popular designs during World War 1 (1914-1918). Hired by Armand Deperdussin to head design at Societe de Production des Aeroplanes Deperdussin ("S.P.A.D."), Bechereau delivered the early SPAD S.VII and later SPAS S.XIII. In between these two notable designs fell the oft-forgotten SPAD S.XI, a two-seat reconnaissance-minded biplane fighter attempting to fulfill Specification C2 for the French Air Service. The SPAD S.XI did not prove itself an outright success as other SPAD designs did and witnessed only a short shelf-life during the war, dogged by issues throughout its career. This led to a rather limited production reach of about 1,000 aircraft in the series.

To fulfill the French air Service (Aeronautique Militaire) requirements, Bechereau attempted to continue using the proven qualities of his previous single-seat biplane fighter offerings. A longer fuselage was necessary when incorporating a second observer's/gunner's cockpit aft of the pilot. Sections of the wings were cut out for improved viewing while many other qualities of the design remained consistent with the period - the front-mounted engine driving a two-bladed wooden propeller, parallel struts and cabling to stiffen and control the "over-under" wing structure and conventional single-finned tail unit. The undercarriage was wheeled though fixed through reinforced struts and the tail supported by a simple skid. The pilot was given a single fixed, forward-firing 7.7mm Vickers series machine gun and the observer could manage an optional 7.7mm Lewis machine gun on a trainable mounting. The aircraft emerged under the company model number of "SPAD 11", also written as SPAD S.XI.

Power to the S.XI was served through 1 x Hispano-Suiza 8Bc series V-8 water-cooled engine of 200 horsepower and this allowed a maximum speed was 112 miles per hour with an mission endurance time of approximately 2.25 hours. The aircraft's service ceiling was listed at 23,000 feet with a rate-of-climb of 9,850 feet reached in roughly 12.5 minutes. Some airframes were also fitted with a Renault 12-cylinder engine instead of the aforementioned Hispano-Suiza installation, though this powerplant actually reduced performance figures and was not popular.

The SPAD S.XI joined the war during 1917 and eventually proved itself not a success. The modified single-seat fighter approach for a larger two-seat design made the airframe tricky in its handling while performance from the engine of choice proved underwhelming. The type did hold characteristics that superseded some existing types then in service with French forces so the aircraft still managed to serve in notable numbers. It managed a frontline status until the fall of 1918 before being replaced by the SPAD S.XVI - itself a direct offshoot of the S.XI though outfitted with a Lorraine-Dietrich engine of 250 horsepower. These proved no better than the originals but were kept in action nonetheless.

Operators beyond the French Air Service became Belgium, Italy, Japan, Russia (into the Soviet Union years), Uruguay and the United States (American Expeditionary Force - "AEF").

Content ©MilitaryFactory.com; No Reproduction Permitted.

Power & Performance
Those special qualities that separate one aircraft design from another. Performance specifications presented assume optimal operating conditions for the SPAD S.XI A2 Biplane Fighter Aircraft.

1 x Hispano-Suiza 8Bc V-8 water-cooled engine developing 220 horsepower.
Propulsion

112 mph
180 kph | 97 kts
Max Speed

22,966 ft
7,000 m | 4 miles
Service Ceiling

249 miles
400 km | 216 nm
Operational Range

788 ft/min
240 m/min
Rate-of-Climb

City-to-City Ranges
Operational range when compared to distances between major cities (in KM).

NYC

LON

PAR

BER

MOS

TOK

SYD

LAX

NYC

Structure
The nose-to-tail, wingtip-to-wingtip physical qualities of the SPAD S.XI A2 Biplane Fighter Aircraft.

2
(MANNED)
Crew

25.7 ft
7.84 m
O/A Length

36.8 ft
(11.21 m)
O/A Width

9.2 ft
(2.80 m)
O/A Height

1,499 lb
(680 kg)
Empty Weight

2,293 lb
(1,040 kg)
MTOW

Design Balance
The three qualities reflected below are altitude, speed, and range. The more full the box, the more balanced the design.

RANGE

ALT

SPEED

Armament
Available supported armament and special-mission equipment featured in the design of the SPAD S.XI Biplane Fighter Aircraft .

1 x 7.7mm Vickers fixed, forward-firing machine gun
1 OR 2 x 7.7mm Lewis machine gun on trainable mount in rear cockpit.

Variants
Notable series variants as part of the SPAD S.XI family line.

S.XI - Base Series Designation

S.XI A2 - Formal production model designation

Operators
Global customers who have evaluated and/or operated the SPAD S.XI. Nations are displayed by flag, each linked to their respective national aircraft listing.

Total Production: 1,000 Units
Contractor(s): Societe Pour l'Avions et ses Derives (SPAD) - France

[ Belgium; France; Kingdom of Italy; Imperial Japan; Imperial Russia; Soviet Union; United States; Uruguay ]

Relative Max Speed

Hi: 120mph

Lo: 60mph

Aircraft Max Listed Speed (112mph).

Graph Average of 90 MPH.

Era Crossover

Showcasing Aircraft Era Crossover (if any)

Max Alt Visualization

Production Comparison

1000

36183

44000

Entry compared against Ilyushin IL-2 (military) and Cessna 172 (civilian) total production.

MACH Regime (Sonic)

Sub

Trans

Super

Hyper

HiHyper

ReEntry

♦

Aviation Timeline

EarlyYrs

WWI

Interwar

WWII

ColdWar

Postwar

Modern

Future

♦

1 / 10