During 1911 Willows moved his business from Cardiff to Birmingham, from where the Willows No.4 was launched in June 1912. The completed ship being 110 ft in length with a 24,000 cu.ft capacity envelope of oiled cotton, carrying a small car mounted on a long boom containing the crew of two or three and a 35 hp Anzani engine driving swivelling airscrews. Simple cruciform fin and rudder planes were affixed to the rear of the envelope.

This airship was inspected and appraised by the newly formed Royal Flying Corps and the navy, where the quality of workmanship involved in its construction was praised and the craft adjudged to be suitable for traing purposes for the two services. In July 1912 the Willows No.4 was purchased by the Admiralty and after modification, which included the fitting of new envelope, she became naval airship HMA No.2.
Willows built several other airships including a further order for the navy. This was to become the prototypr for the early Sea Scout class of airship used for convey protection during the war.

On August 19, 1913, “Naval Airship No.2” (the re-constructed “Willows No.4” – under the command of Lieut. Neville Usborne, R.N.) experienced engine failure due to a broken crankshaft near Odiham in Hampshire. In order to save the hydrogen in the disabled airship, it was decided to try and tow it home employing the airship “Eta” – newly-constructed by the Royal Aircraft Factory and currently undergoing its acceptance trials. Accordingly, a tow-line was attached and the two airships ascended, the “Eta” keeping about 600 feet above the towed ship so as to avoid all chances of fouling the rudder gear. The approximate 8-mile trip back to the airfield at Farnborough (the exact distance to the town of Odiham being 7.4 miles) was made at a groundspeed of 25 mph against a 5 mph headwind. The “Eta” was in all probability skippered by Army Capt. Waterlow at the time.

The Willow 3 was the outcome of five years of experimental work on the simple steering mechanism. The elevation of the dirigible is accomplished by the same set of propellers that produce the forward drive, and by this means it is possible to rise in the vertical plane to any desired altitude even with the whole system heavier than air, and also to rise diagonally in any angle between the vertical and horizontal.

One instance when this direct lift would prove of great value would be in the case of a machine becoming rainsoaked and unable to raise itself by the lifting power of the gas, as occurred at the Crystal Palace when the
“Nulli Secundus” was docked there.

In practice the machine is ballasted, so as to have just sufficient buoyancy to lift the 150 ft. trail-rope, and is then driven to the desired altitude, or driven downwards, by the propellers as required.

It has taken some considerable time to perfect this device, because the control of this movement, when applied to a bevel-driven propeller-shaft revolving at high speed, becomes most difficult in practice where ease and quickness of operation are essential.

Other features of this airship are its symmetrical appearance and the ease with which it can be dismantled; in fact it is possible to pack the whole apparatus upon a one-horse trolley for transport.

The system upon which the dirigible has been built is rigid, and quite small, having been constructed for demonstration purposes, it is possible with a few modifications to lay down a dirigible on the same lines of any size.

The following are the leading dimensions and details:—Envelope length, 86 ft.; diameter, 22 ft.; fish-shaped, having the greatest diameter about one-third in from the nose, capacity 21,000 cubic ft. The usual valves are fitted; top gas valve, automatic gas and air valves, and ripping panel; a ballonette of one-tenth capacity is placed in centre of lower half of balloon. The suspension is taken by ropes from a canvas band, sewn round the envelope, to a boom 58 ft. in length, built up of 3 in. bamboos and a light 3 in. steel tube.

The car containing the motor, propelling gear, and operator’s seat is hung below the boom by steel cables. A balanced rudder of 56 sq. ft. area is carried at the extremity of the boom also a vertical vane, which has a steadying effect upon the forward motion of the airship. The car is of triangular section and 10 ft. in length, built of steel tube braced with steel wire; the motor, a 30-h.p. 8-cylinder J.A.P., drives a right and left hand propeller placed one on either side of car, through belting and bevel gear.

The propellers are of steel tube with aluminium blades; a guard is fitted to prevent any possibility of damage to the balloon by fracture of a propeller.

The control consists of a steering wheel, which by rotary movement operates the rudder and by a sliding movement alters the position of the propellers for ascending or descending.

A clutch lever and throttle completes the control, so that the machine can be driven single handed, the operator also having the balloon valve lines within reach, which enables a passenger, or for military purposes an observer, to be carried. The weight of the complete car is 550 lbs., the suspension boom 100 lbs., gas-bag 350 lbs. and rudder and vane 21 lbs.

The erecting of the machine and most of the construction has been carried out at Cardiff, the whole of the airship being British built.

The trials which took place during November and December 1909 from the East Moors, Cardiff, were satisfactory in every way, and the airship was overhauled in preparation for some tests of a more severe nature.

The Willows No.3, named City of Cardiff, of 33,000 cu.ft capacity was completed in November 1910 and, with Willows on board, left from Wormwood Scrubs to undertake the first flight from London to Paris, a distance of 218 miles. During this voyage, after a trouble free Channel crossing, a forced landing due to engine trouble necessitated a diversion for repairs. These repairs were carried out at the workshops of Clement-Bayard airship company at Levallois-Peret. After repairs the airship continued to Paris the next day, arriving to much acclaim and earning the distinction of being the first British airship to cross the Channel.

The Willows airships were a series of pioneering non-rigid airships designed and built in Wales by Ernest Thompson Willows. The larger Willows No. 2 first flew on 26 November 1909. It was 86 ft long and 22 ft in diameter with a 29,000 cubic feet (820 m³) volume.

On 4 June 1910 Willows landed the No. 2 outside of Cardiff City Hall and then flew back to his shed at East Moors. On 11 July 1910 it flew from Cheltenham to Cardiff and the following month on 6 August it returned to London. The trip included navigating by night and landing a Crystal Palace at dawn. The 122-mile (196 km) flight was a record for a cross-country flight in Britain and Willows was the first aviator to cross the Bristol Channel in a powered aircraft. No. 2 was powered by a JAP 30 hp air-cooled V8 engine and had two swivelling propellers mounted either side of the suspended car. It was also fitted with a rudder for directional control. After six flights it was rebuilt and lengthened and became No. 3, which was named “City of Cardiff”.