Hilda Beatrice Herbert was born in Vauxhall, London, England, on 17 February 1864, one of nine children of Louisa Hopgood and her husband, George William Herbert, an Anglican vicar. Artistic from an early age, she attended a branch of the National Art Training School, South Kensington, and later exhibited her work. She spent time in Egypt with her parents when she was 19 and then at 21 trained as a nurse for a year at a hospital in Berlin.
On 3 January 1888 Hilda Herbert married Maurice Henry Hewlett in her father's church, St Peter's, in Vauxhall. The couple, who were to have a son and a daughter, were known as eccentric characters. Hilda was short, with a ruddy complexion and a determined countenance. Maurice had been a partner in his family's law firm and keeper of land revenue records. However, in 1901, three years after writing a successful romantic novel, he gave up his profession for a literary career.
Hilda Hewlett was a pioneer motoring enthusiast, and, in 1909, when she attended the first English flying meeting at Blackpool, she yearned to fly. She adopted the pseudonym Grace Bird and with a Frenchman, Gustave Blondeau, went to the Mourmelon-le-Grand aerodrome in France to study aeronautics. Hewlett and Blondeau were equally dedicated to the future of aviation, and their partnership was to last 10 years. When she returned to England with an Henri Farman biplane, The Blue Bird, they opened the Hewlett and Blondeau flying school, one of Britain's first, at Brooklands, Surrey, in 1910.
In August 1911 Hilda Hewlett became the first British woman to obtain a pilot's certificate, No 122. Soon after, she assisted in teaching her son, Francis, to fly. He was to have a distinguished military flying career in England and New Zealand. In 1912 Hewlett cemented her place in aviation history when she won a quick-start competition.
As interest in aviation grew, the firm of Hewlett and Blondeau Limited was formed to manufacture aeroplanes, first at Brooklands, then at Clapham, and finally in 1914 on a 10-acre site at Leagrave, Bedfordshire. Here Hilda was a familiar sight driving her large car with a big dog in the back. She wore unusual clothes and a masculine Eton hair-style. The firm developed a good reputation and was very successful. Managed by Hewlett, who was described as an 'indefatigable worker, good organiser and shrewd business woman', by August 1914 it employed 700 workers and was producing 10 different types of planes. During the First World War it supplied over 800 military aircraft. Around this time Hilda and Maurice 'politely' separated; he died in 1923.
When the war ended in 1918 the company diversified into farming equipment, but it closed in late 1920. During this period Hewlett spent nine months visiting New Zealand, Rarotonga and the United States. After the Leagrave factory and site were finally sold in 1926 she moved to Tauranga with her daughter Pia Richards, and Pia's family. As Hilda explained, 'the urge to escape from the three C's, crowds, convention and civilization became strong'. New Zealand also offered opportunities to camp and fish, other long-time interests. Now 62, she was always addressed as 'Old Bird' by family members.
Two aircraft manufactured by Hewlett and Blondeau had preceded her to New Zealand: a Caudron biplane had been purchased by the pioneer aviator Will Scotland in 1914; and an Avro 504K, a post-war imperial gift aircraft, had arrived in 1920. Several years after settling in New Zealand Hewlett and a partner purchased Southern Cross Airways and its solitary plane, but the company closed before any flights were made.
In 1928–29 Hilda Hewlett bought four sections on Edgecumbe Road in Tauranga, overlooking the Waikareao tidal estuary, which had served as the town's flying field for eight years. Landing and take-off could take place only for an hour or so either side of low tide. She had been welcomed into Tauranga's society and was present, along with the mayor, B. C. Robbins, and 18 other civic leaders, at a meeting in June 1932 to establish the Tauranga Aero and Gliding Club. She was elected its inaugural president the following month.
The aero club soon obtained land at the western end of Elizabeth Street to build a hangar and clubroom. Members pressed for the draining of the estuary so it could be used continuously, but Hewlett promoted the search for a permanent non-tidal airfield; she realised the importance of such a facility if Tauranga were to be included in regular air services. Her son, Francis, the club's third president, was later instrumental in selecting the 140-acre airport site at Whareroa.
In 1934 Jean Batten, touring New Zealand after her celebrated flight from England to Australia, was welcomed to Tauranga and hosted by Hewlett. The meeting of the two pioneers from different eras was said to have 'caused quite a stir'. At the opening of the new Tauranga aerodrome in January 1939 the minister of defence, Frederick Jones, named an adjacent road after Hilda and her son in recognition of their services to aviation.
Whatever Hilda Hewlett wanted to do, she did and did well. With her adventurous spirit, determination, energy and ability she could have pursued a variety of careers, but it was in aviation that she made her mark. She died in Tauranga on 21 August 1943, survived by her children. After a service on the railway wharf she was buried at sea as she had requested.