Senior sustainability score: 50/100
Leading practice starts at 60. The highest score on SINK is 71.
Limited independent evidence: only two independent sources cover this company. The score may change as more evidence appears.
Senior designs and makes engineered components for civil aircraft, defence, land vehicles, power and energy and industrial customers. In 2025 its Aerospace division brought in £425.3 million of revenue and Flexonics £312.9 million.
More about Senior
The company was incorporated in 1933 and was named Senior Engineering Group until 1999 and Senior plc until October 2026, when Zeus UK Bidco Limited, controlled by funds advised by Tinicum and Blackstone, acquired it, took it off the London Stock Exchange and renamed it Senior Aeroflow Technologies Limited. In 2025 it had an average of 6,985 employees, including the Aerostructures business it sold on 31 December 2025, and £738.2 million revenue from continuing operations.
Founded 1933Head office Rickmansworth, United KingdomStaff ~6,985 average (2025, including Aerostructures; 4,974 at 31 December 2025 after its sale)Revenue ~£738.2M revenue (2025, continuing operations)Website ↗
Senior's footprint was 720,922 tCO2e in 2025, including the Aerostructures business it sold on 31 December 2025. 686,052 t of it is Scope 3, mostly the goods it buys (473,537 t). Scope 1 and 2 fell 8.8% in 2025 and are 39% below 2018, but there is no earlier Scope 3 total to compare. 60% of its electricity came from renewable supply, with no split between contracts and certificates. SBTi validated net zero by 2040, with a 90% absolute cut across all scopes from 2018; its near-term targets ended in 2025 and new ones are not yet published. All three scopes are independently assured, but it reports nothing on biodiversity.
Senior scores 50/100 (Making progress) on SINK's independent climate assessment, scored from public data only. Scores are free. Nobody can pay to change a score, speed it up or hide it. Last verified November 2026.
That places Senior joint 161st of 1,055 companies scored, and 1st of 10 in Aerospace.
What is Senior doing well, and where does it fall short?
Strongest on Carbon Footprint: Operations and Targets & Commitments (8/10, 8/10). Weakest on Nature & Biodiversity Impact and Energy Source (2/10, 4/10).
Where Senior lost points
For each question that lost points, the evidence our public rubric looks for that we didn't find.
What would raise this score
- Its effect on natureAssess its effect on nature and publish a basic environmental policy.
- How clean its energy isShow at least half its energy is renewable, with a transition plan.
- Its effect on waterMeasure its water footprint and set reduction targets.
Every question that lost points
- Emissions from its own operations8/10No verified figures published with their method and a falling trend.
- Emissions from its supply chain7/10No full value-chain map or supplier engagement programme.
- Whether its emissions are falling5/10No evidence of a year-on-year fall in its total emissions.
- How clean its energy is4/10Less than half its energy shown to be renewable, or no transition plan.
- Its effect on nature2/10No assessment of its effect on nature, and no basic environmental policy.
- How it uses materials and handles waste5/10No measurable waste or recycling targets reported publicly.
- Its effect on water4/10No measured water footprint with reduction targets.
- Its climate targets8/10No validated long-term net zero target.
- How openly it reports8/10No mission-locked structure, such as B Corp certification.
A score changes when the evidence does. We use new published evidence at the next rescore. Anyone can send us new evidence, free. How to send it.
How is Senior's SINK score calculated?
Same ten questions for every company. No private weighting.
SINK = (0.3 × Base + 0.7 × Performance) × ScaleWhat evidence is Senior's score based on?
12 sources used in this assessment. All publicly available. Each row shows which of the ten questions it informed.
75% of them were published by Senior itself; the rest come from independent sources.
Senior plc was taken private in October 2026 by Zeus UK Bidco Ltd, owned by funds advised by Tinicum and Blackstone, and is now Senior Aeroflow Technologies Limited. The figures are for 2025, before the change, and include the Aerostructures business sold on 31 December 2025.
“Scope 1: Combustion of fuel and operation of facilities 1,075 7,877 8,952 1,140 6,805 7,945”
“Purchased Goods & Services 2025 – 473,537 tCO2e”
“Scope 1 and 2 emissions by 39% from”
“Commitment to reach net-zero greenhouse gas emissions across the value chain by 2040.”
“Based on data reported through CDP's 2024 Climate Change questionnaire, Senior is one of a small number of companies”
“Senior was the first company in the global Aerospace & Defence sector to have its emissions reduction targets independently verified and approved by the SBTi.”
“Senior Operations, Inc., Senior Aerospace SSP (EPCRA-09-2007-0027)”
“Exposures and discharges resulting from Operations at 790 Greenfield Drive, El Cajon, CA”
“Senior is one of a small number of companies, out of over 21,000 companies scored, that achieved an 'A' rating.”
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How does Senior compare with other aerospace companies?
Senior is the highest-scoring aerospace company we've rated.
Among the 10 major aerospace brands we've scored, Senior sits 1st of 10.
Who comes next in Aerospace?
Senior leads its sector. These are the next 3 down.
Melrose has SBTi-validated near-term targets and achieved 33% absolute Scope 1+2 cuts, but excludes the largest supply chain category (purchased goods) from its reduction target.
See the breakdown →Virgin Atlantic discloses Scope 1 and 2 emissions with assurance, but absolute emissions are rising as capacity grows.
See the breakdown →GE Aerospace discloses Scope 1 and 2 emissions with third-party assurance and genuine 43% reductions, but Scope 3 — representing 99.8% of total emissions — is limited to engine use-of-life and expected to rise with travel demand.
See the breakdown →Which companies moved this week, and why.
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