AAIB Bulletin, CAA STC warning and UKACS update
5 April 2026
This week’s OnFinal briefing lands right at the start of the UK spring flying season, when the diary fills quickly and a little extra planning pays off. The headline items are squarely about staying sharp: the AAIB has issued its March bulletin and a new Bristell NG5 report, while the CAA has published a warning on mixing STCs without checking compatibility. There’s also progress on airspace coordination, plus a handy line-up of GA events coming up through April and May.
UKADS licence proposals and decision. The CAA’s page sets out its Final Decision, in CAP3225, on modifying NATS (En Route) Plc’s air traffic services licence to support the creation of the new UK Airspace Design Service. It says the decision reflects stakeholder responses to the December 2025 Final Proposals consultation and includes a notice of the licence modifications in Appendix B. The page also links the consultation trail behind the decision: CAP3164, the December 2025 final proposals; CAP3121, the June 2025 initial proposals; and CAP3063, the November 2024 illustrative proposals. For club-room readers, the key point is that the CAA has now moved from consultation to decision, with supporting spreadsheet models and the earlier consultation responses all gathered on the same page.
Before the first longer hop of the season, give your paperwork a spring tidy: check the latest AAIB safety actions, confirm any mod approvals and STC combinations, and scan short-term airspace notices before you file or depart.
The UK’s AAIB publishes monthly bulletins that gather fresh accident and incident reports in one place, making them a handy seasonal read for club briefings.
In the circuit
AAIB Bulletin 3/2026
This AAIB bulletin centres on a serious incident involving an ATR 42-500, G-LMRC, which suffered a brief but significant electrical failure during climb from Aberdeen on 27 August 2022. Multiple flight deck displays went blank, the autopilot dropped out, and the air conditioning packs shut down, but the crew brought the aircraft back to Aberdeen and landed safely. The investigation found a stuck 1PA contactor was contributory, yet the precise cause of the simultaneous loss of the emergency electrical network and a DC bus undervoltage could not be determined; the manufacturer and EASA have already taken action on failed contactors, and AAIB has issued a further safety recommendation. For readers of UK general aviation, the rest of the bulletin is notable for its mix of special-bulletin material and the absence of any GA fixed-wing, rotorcraft or UAS field investigation reports in this issue. If you like digging into electrical-system failures, crew handling, and how small faults can cascade into cockpit-wide effects, this is well worth a proper read.
AAIB: Bristell NG5 crash near Gordon prompts report
The AAIB has published its report into the fatal accident involving Bristell NG5 Speed Wing G-STEL, which occurred near Gordon, Berwickshire on 20 May 2025. According to the GOV.UK notice, the aircraft departed Nether Huntlywood Airfield for Kingsmuir Airfield, but shortly after take-off the pilot appeared to turn back, then entered cloud, lost control and the aircraft descended rapidly in a spiral before striking the ground. The pilot was fatally injured. For club pilots, the key takeaway is the familiar but sobering reminder about low-level turnbacks and the risks of continuing visual flight into deteriorating conditions. The full report is linked from the notice for anyone wanting the detailed findings and safety lessons.
AAIB March 2026 bulletin publishes a fresh round of accident and incident reports
The AAIB’s March 2026 monthly bulletin was published on 12 March 2026 and collects recent investigation outputs into one handy package. For general aviation readers, the page flags a UK GA correspondence report on a CZAW Sportcruiser forced landing after the canopy opened in flight at Firs Farm Airfield, Berkshire, alongside a Jodel D112 report covering a ground strike on go-around at Barton Aerodrome, Lancashire. It also lists a sport aviation item involving an EV-97 teamEurostar UK ground strike during an engine-failure-after-takeoff demonstration in Northumberland. The page is mainly a bulletin index rather than a narrative report, but it is useful because it shows what the AAIB is actively publishing this month and which cases have reached report stage. Club pilots and instructors will want to read the linked bulletin and the individual reports for the operational lessons, especially around canopy security, go-around handling and low-level engine failure drills.
SN-2026/002: CAA warns against mixing STCs without checking compatibility
The CAA’s latest Safety Notice reminds owners, operators and maintenance organisations to check the compatibility of every new Supplemental Type Certificate or modification against what is already fitted to the aircraft. The key message is straightforward: don’t assume two separately approved changes will work together; use the full master data set, and if there is any doubt, seek clarification from the relevant STC holder before installation. The notice uses a Beechcraft King Air B200 example to show how an aircraft can drift into an unapproved configuration if modifications are combined without proper assessment. In that case, a performance package and a later Garmin G1000 avionics STC were not inherently compatible until the G1000 was reconfigured, with the CAA warning that such mismatches can affect airworthiness documents, including the ARC and C of A.
AAIB investigation to Z-1RA Stummelflitzer, G-ZIRA
The AAIB reports a correspondence investigation into Z-1RA Stummelflitzer G-ZIRA after a forced landing due to loss of engine power at White Waltham Airfield on 3 March 2026. The listing places it in the General aviation - fixed wing category and notes it as a bulletin-style correspondence investigation. For UK GA readers, the key point is the nature of the event rather than any detailed findings: engine power loss leading to a forced landing. The page on GOV.UK is the exact AAIB reports listing, so this brief entry is all that is supported on the linked source at this stage.
Short-term airspace coordination notices
The CAA’s Short-term airspace coordination notices page is a live index of current and future notices, with 334 results listed on the page. The entries shown are predominantly aerial survey notices, each with a reference number, current status, and version date, which makes this a useful one-stop check for short-notice activity around UK airspace. ([caa.co.uk](https://www.caa.co.uk/data-and-publications/publications/publication-series/short-term-airspace-coordination-notices)) For the week covered by this briefing, the page includes multiple notices dated 23 to 29 March 2026, alongside later April and May updates, indicating that the catalogue was being actively refreshed rather than standing still. If you’re planning a trip, the club-room takeaway is simple: do a fresh look-up on the CAA page before launch, because there is a steady flow of new or revised survey activity across the country. ([caa.co.uk](https://www.caa.co.uk/data-and-publications/publications/publication-series/short-term-airspace-coordination-notices))
On the calendar
8 April 2026
Spring Weather - Free Online Seminar
On 2026-04-08, BMAA Events lists “Spring Weather - Free Online Seminar” on the BMAA events page as a free online session for UK GA and microlight pilots keen to sharpen their weather judgment before the spring flying season. The listing is useful because weather is one of the biggest go/no-go factors for light aircraft flying, making a focused online briefing especially relevant for pilots and enthusiasts planning safer, better-informed flights.
2 May 2026
BMAA AGM 2026
The BMAA’s 2026 Annual General Meeting takes place on Saturday 2026-05-02 at 13:00 in the presentation tent at the Microlight Trade Show at Popham Airfield. It’s aimed at BMAA members, with papers including the annual report, agenda, proposals, accounts and 2025 minutes available on the page; the option to attend online is also noted, though online attendees cannot vote. For UK GA pilots and microlight enthusiasts, it’s a useful chance to hear the association’s business at one of the UK’s key microlight gatherings.
17 May 2026
Ultimate High GA Safety Day
Scheduled for 2026-05-17, the Ultimate High GA Safety Day is listed by the British Microlight Aircraft Association on its events page as a general aviation safety event. The page excerpt available does not show the venue or fuller programme details, but it is clearly aimed at pilots and enthusiasts who want to sharpen their safety awareness around UK GA flying. For anyone keen on practical flying wisdom, it’s the sort of BMAA event worth flagging on the calendar.
23 May 2026
Historic Aircraft Engine Run event, Gatwick Air Museum
On 2026-05-23, Gatwick Aviation Museum in Charlwood, Gatwick is hosting a Historic Aircraft Engine Run event, with the museum running the engines of its Lightning and Shackleton aircraft. The FLYER listing says there’s also entertainment from singing trio Angel Delights and the chance to book a tank ride, making it a neat day out for UK GA enthusiasts who enjoy rare warbird sounds and museum atmosphere.