The Westland Lysander is a British army co-operation and liaison aircraft that was utilized immediately before and during the Second World War.
In 1934, the Air Ministry issued Specification A.39/34 for an army co-operation aircraft to replace the Hawker Hector.
Hawker Aircraft, Avro, and Bristol were initially invited to submit designs, but after some debate within the Ministry, a submission from Westland was also requested.
The Westland design, internally designated P. 8, was the work of Arthur Davenport under the direction of “Teddy” Petter.
It was Petter’s second aircraft design, and he spent considerable time interviewing Royal Air Force pilots to determine their requirements for such an aircraft.
The army sought a tactical and artillery reconnaissance aircraft to provide photographic reconnaissance and observation of artillery fire in daylight, up to approximately 15,000 yards (14 km) behind the enemy front.
The result of Petter’s pilot enquiries suggested that field of view, low-speed handling characteristics, and STOL performance were the important requirements.
Davenport and Petter designed an aircraft to incorporate these features.
The Lysander was to be powered by a Bristol Mercury air-cooled radial engine and had high wings and a fixed conventional landing gear mounted on an innovative inverted U square-section tube that supported wing struts at the apex and contained internal springs for the faired wheels.
The wings had a reverse taper towards the root, which gave the impression of a bent gull wing from some angles, although the spars were straight.
It had a girder type construction faired with light wood stringers to give the aerodynamic shape.
The forward fuselage was duralumin tube joined with brackets and plates, and the after part was welded stainless steel tubes.
Plates and brackets were cut from channel extrusions rather than being formed from sheet steel. The front spar and lift struts were extrusions.
The wing itself was fabric covered, and its thickness was greatest at the strut anchorage, similar to that of later marks of the Stinson Reliant high-winged transport monoplane.
Despite its appearance, the Lysander was aerodynamically advanced, being equipped with fully automatic wing slats and slotted flaps and a variable incidence tailplane.
These refinements gave the Lysander a stalling speed of only 65 mph (56 kn; 105 km/h).
The tube that supported the wings and wheels was the largest Elektron alloy extrusion made at the time.
Due to the difficulties involved in manufacturing such a large extrusion, Canadian-built machines had a conventionally fabricated assembly.
The Air Ministry requested two prototypes of the P.8 and the competing Bristol Type 148, quickly selecting the Westland aircraft for production and issuing a contract in September 1936.
The high-lift devices gave the Lysander a short take-off and landing (STOL) performance much appreciated by the Special Duties pilots such as Squadron Leader Hugh Verity.
The wings were equipped with automatic slats which lifted away from the leading edge as the airspeed decreased towards stalling speed.
These slats controlled automatic flaps. Slow speed flight was therefore greatly simplified, “and it was possible to bring a Lysander down to land, if not like a lift, at least like an escalator”.
The inboard slats were connected to the flaps and to an air damper in the port wing which governed the speed at which the slats operated.
The outboard slats operated independently and were not connected, and each was fitted with an air damper.
On a normal approach, the inboard slats and the flaps would begin to open when the airspeed had dropped to about 85 mph (74 kn; 137 km/h) and be approximately half down at 80 mph (70 kn; 130 km/h).
The only control that the pilot has is a locking lever which he can set to lock the flaps down once they have been lowered automatically.
Variants
Lysander Mk.I
Powered by an 890 hp (660 kW) Bristol Mercury XII radial piston engine.
Two forward-firing 0.303 in (7.7 mm) Browning machine guns in wheel fairings and one pintle-mounted 0.303 in (7.7 mm) Lewis or Vickers K machine gun in rear cockpit.
Optional spat-mounted stub wings carried 500 lb (230 kg) of bombs.
Four 20 lb (9.1 kg) bombs could be carried under rear fuselage.
Lysander TT Mk.I
Lysander Mk.Is converted into target tugs.
Lysander Mk.II
Powered by one 905 hp (675 kW) Bristol Perseus XII sleeve valve radial piston engine.
Lysander TT Mk.II
Target tug conversion of the Lysander Mk.II.
Lysander Mk.III
Powered by an 870 hp (650 kW) Bristol Mercury XX
Or
30 radial piston engines, 350 delivered from July 1940.
Twin 0.303 in (7.7 mm) Browning guns in rear cockpit.
Lysander Mk.IIIA
As Lysander Mk.I, with Mercury 20 engine.
Twin 0.303 in (7.7 mm) Lewis guns in rear cockpit.
Lysander Mk.III SCW
(Special Contract Westland)
Special version for clandestine operations.
No armament, long-range 150-gallon fuel tank, fixed external ladder.
Lysander TT Mk.III
Lysander Mk.Is, Mk.IIs and Mk.IIIs converted into target tugs.
Lysander TT Mk.IIIA
100 purpose-built target tugs.
P.12 Lysander Delanne
Unofficially referred to as the “Westland Wendover” Modification of the prototype Lysander K6127 to carry a 4-gun turret power-operated tail gun turret at the rearmost end of the fuselage for “beach strafing” in case of invasion of the UK.
It was fitted with a new constant section rear fuselage and a much larger tail plane with twin tails, making it a Delanne-type tandem wing, to support the additional weight of the turret aft.
Both Frazer Nash and Boulton-Paul turrets were considered but neither electrical (for the BP turret) nor hydraulic lines (for the FN turret) were installed.
The wing and forward fuselage remained unchanged.
Although it flew well, trials were still underway when the threat of invasion disappeared and it did not proceed past trials, most of which were carried out with a dummy turret.
“Pregnant Perch”
L6473 adapted with a ventral gun position, again for beach strafing.
Crashed during testing after engine failure.
In 1940 K6127 was tested with a pair of 20 mms (0.79 in) Oerlikon cannon mounted on top of the wheel fairings, and the stub wings removed, the intention was to use the aircraft against invasion barges in the threatened German invasion of Britain.
Specifications
Crew
2
Length
30 ft 6 in (9.30 m)
Wingspan
50 ft 0 in (15.24 m)
Height
14 ft 6 in (4.42 m)
Wing area
260 sq ft (24 m2)
Airfoil
RAF 34 modified
Empty weight
4,365 lb (1,980 kg)
Max take-off weight
6,330 lb (2,871 kg)
Powerplant
1 × Bristol Mercury XX,
9-cylinder air-cooled radial piston engine,
870 hp (650 kW)
Propellers
3-bladed
Performance
Maximum speed
212 mph (341 km/h, 184 kn) at 5,000 ft (1,524 m)
Stall speed
65 mph (105 km/h, 56 kn)
Range
600 mi (970 km, 520 nmi)
Service ceiling
21,500 ft (6,600 m)
Time to altitude
10,000 ft (3,048 m) in 8 minutes
Take-off distance to 50 ft (15 m)
915 ft (279 m)
Armament
Guns
2 x forward-firing .303 in (7.7 mm) Browning machine guns in wheel fairings
&
Two more for the observer.
Bombs
4× 20 lb (9 kg) bombs
Or
1x drop tank (fuel or cargo) under rear fuselage and/or 500 lb (227 kg) of bombs or drop tanks on undercarriage stub wing hard points (if fitted).
Sources Westland Aircraft Since 1915-Derek N. James. The Book of Westland Aircraft-A H Lukins. Westland, Plane Makers 2-David Mondey. Westland Lysander-Profile Publications 159. Westland Lysander Warpaint 48-Alan W Hall. The Westland Lysander, A Technical Guide-Richards A Franks. Westland Lysander Mks. I, II, II / IIIA, III(SD) / IIIA(SD), TT Mks. I, II, III-Michal Ovcacik & Karel Susa.
