EI-ABI “Iolar” holds a legendary place in Irish aviation history. As Aer Lingus’ very first aircraft, the De Havilland DH.84 Dragon biplane named “Iolar” (Irish for “Eagle”) launched Ireland’s national airline in 1936. Though the original was sold and later lost, the registration EI-ABI was revived for a meticulously restored replica that continues flying today as a symbol of Aer Lingus heritage.

This article explores the full story of EI-ABI Iolar — its pioneering role, early operations, replacement, tragic fate of the original, and the creation of the current airworthy EI-ABI replica.

The Birth of Aer Lingus and Delivery of EI-ABI Iolar

Aer Lingus was founded in 1935-1936 as Ireland’s national airline (the name derives from “Aer Loingeas,” meaning air fleet). The airline received its first aircraft on May 26, 1936: a six/seven-seat De Havilland DH.84 Dragon biplane, registered EI-ABI and christened Iolar.

Based initially at Baldonnel Aerodrome (now Casement Aerodrome, home of the Irish Air Corps), this wooden biplane with two Gipsy Major engines marked the start of commercial air services for the young Irish state. The aircraft cost relatively little and suited short cross-channel routes perfectly.

Maiden Flight and Early Operations (1936–1938)

On May 27, 1936, EI-ABI Iolar operated Aer Lingus’ inaugural revenue flight from Baldonnel to Bristol (Whitchurch) Airport in the UK, carrying five passengers. This historic journey launched regular services between Ireland and Britain.

The aircraft quickly expanded operations, including Dublin to Liverpool routes. A second aircraft — the larger four-engine De Havilland DH.86 Express named Éire — joined soon after, enabling extensions to London (Croydon Airport) and the Isle of Man. Iolar served as Aer Lingus’ workhorse during these formative years, proving the viability of Irish commercial aviation despite limited infrastructure and modest passenger numbers.

Replacement of the Original EI-ABI and Its Fate

By early 1938, Aer Lingus needed larger, more capable aircraft for growing demand. In February 1938, the airline sold EI-ABI to British operator Channel Air Ferries. The Dragon was re-registered as G-ACPY (some sources note variations like G-APCY due to transcription). It was replaced in the Aer Lingus fleet by a more modern De Havilland DH.89A Dragon Rapide.

The original Iolar’s story ended tragically during World War II. Operating under its British registration, G-ACPY was shot down by a Luftwaffe Heinkel He 111 bomber on June 3, 1941, off the Scilly Isles. All aboard were lost. This wartime loss underscored the dangers faced by civilian aviation in the early 1940s.

The Current EI-ABI Iolar: Restoration and Revival

The registration EI-ABI was not forgotten. For Aer Lingus’ 50th anniversary in 1986, the airline acquired a different but period-correct DH.84 Dragon 2 (built in 1936, previously G-AECZ / EI-AFK and with RAF service history as AV982).

This airframe was restored to airworthy condition, repainted in the original Aer Lingus livery (silver/cream with green accents), and officially re-registered as EI-ABI “Iolar” in August 1985. It flew again for air displays, corporate events, and anniversaries from 1986 to 1991.

After intermittent use and grounding around 2004, a major restoration project began in 2010. On February 24, 2011, the aircraft made its first post-restoration test flight at Dublin Airport, perfectly timed for Aer Lingus’ 75th anniversary celebrations. It flew commemorative routes, including a symbolic return to Bristol.

Today, the current EI-ABI Iolar is maintained by the Aer Lingus Charitable Foundation (often associated with the Irish Historic Flight). It appears at airshows, anniversaries (such as the 80th and 85th), and educational events, keeping the pioneering spirit alive.

Technical Specifications of the DH.84 Dragon (Iolar)

Key specs (applicable to both original and replica):

• Type: Twin-engine biplane (DH.84 Dragon / Dragon 2)
• Engines: 2 × de Havilland Gipsy Major (130 hp each)
• Cruising Speed: Approx. 140-150 mph
• Range: Around 460 miles
• Capacity: 6-7 passengers + pilot
• Construction: Wooden frame with fabric covering

The replica uses authentic period details and modern safety upgrades where required for airworthiness.

Legacy and Importance in Irish Aviation

EI-ABI Iolar symbolizes the humble yet ambitious beginnings of Aer Lingus, which grew from one biplane into a major international carrier with Airbus A320/A321/A330 fleets. The replica preserves this heritage, educating new generations about Ireland’s aviation pioneers and the risks of early commercial flying.

Commemorative flights, such as the 80th anniversary trip to Bristol in 2016, evoke national pride. The story of the original’s sale, wartime loss, and the replica’s revival highlights resilience in aviation history.

EI-ABI Iolar – An Enduring Symbol

From its pioneering 1936 maiden flight to the airworthy replica flying today, EI-ABI Iolar remains one of the most cherished icons in Irish aviation. While the original was replaced after just two years of service and ultimately lost to war, the current EI-ABI keeps the legacy soaring.

For aviation enthusiasts, historians, or anyone interested in Aer Lingus history, the sight (or flight) of Iolar is unforgettable. The aircraft represents not just a plane, but the birth of modern Irish air travel.

The de Havilland Chipmunk T.Mk.20 variant was specifically built for export military customers, featuring modifications suited for training roles such as enhanced instrumentation and military-specific equipment. However, as these aircraft aged out of military service, many were converted to civilian standards for continued use in flight training, aerobatics, and recreational flying. The civilian Mk.22 standard represents a converted ex-military de Havilland Chipmunk, adapted for civil certification while retaining much of the original airframe’s integrity. This conversion process not only extends the life of these historic aircraft but also ensures they comply with modern civil aviation regulations.

Converting a T.Mk.20 to Mk.22 involves a meticulous series of inspections, modifications, and certifications, guided by established design standards like British Aerospace Drawing No. C1-G73 Issue 2.

Explores the step-by-step process, highlighting the technical details, regulatory requirements, and practical considerations for aviation enthusiasts, restorers, and operators.

Understanding the Variants: T.Mk.20 vs. Mk.22

To appreciate the conversion, it’s essential to distinguish between the variants. The T.Mk.20, produced at de Havilland’s Hatfield facility in the UK, was an export version of the RAF’s T.Mk.10. It was equipped with a 145-hp de Havilland Gipsy Major 8 engine (military designation), a two-bladed fixed-pitch propeller, and 9 Imperial gallon fuel tanks per wing. Military features included VHF radio sets, gunsight mounts (though unarmed), IMC-flying instrumentation, and sometimes anti-spin strakes for improved handling during training maneuvers.

In contrast, the Mk.22 is the civilian conversion of ex-military models like the T.Mk.10 or T.Mk.20. The de Havilland Chipmunk Mk.22 retains the original 9-gallon fuel tanks but undergoes modifications to meet civil airworthiness standards. A related variant, the Mk.22A, upgrades to 12-gallon tanks for extended range. The primary goal of the Mk.22 conversion is to remove military-specific components, restamp the engine to a civil Gipsy Major 10-2 designation, and incorporate civil avionics and safety features.

Key differences include:

• Engine Designation: Military Gipsy Major 8 becomes civil Gipsy Major 10-2 via restamping and potential overhauls.
• Fuel Capacity: Retained at 9 gallons for Mk.22, optional upgrade for Mk.22A.
• Equipment: Removal of military radios, IFF transponders, and addition of civil navigation aids.
• Canopy and Aerodynamics: Optional blown canopy for better visibility and wing luggage compartments for utility.

These changes transform the aircraft from a dedicated trainer to a versatile civil aircraft capable of aerobatics, touring, and other arial jobs including glider towing.

Regulatory Requirements and Preparation

Before commencing conversion, compliance with aviation authorities is key. In the UK, the Civil Aviation Authority (CAA) oversees the process, requiring adherence to British Civil Airworthiness Requirements (BCAR) or EASA standards for European operations. The approved design standard for converting the de Havilland Chipmunk T.Mk.20 aircraft is outlined in British Aerospace Drawing No. C1-G73, which details the necessary modifications for civil certification.

In the US, the FAA may issue a Supplemental Type Certificate (STC) for imported Chipmunks, while in Australia, the Civil Aviation Safety Authority (CASA) accepts certain unconverted military models but prefers full civil conversions.

Step-by-Step Conversion Process

The conversion, typically performed by certified maintenance organizations or specialized restorers, follows a structured approach. While exact details are proprietary to Drawing C1-G73, common steps based on historical conversions include:

1. Disassembly and Removal of Military Components

• Strip the aircraft of military equipment: Remove VHF radios, gunsight brackets, and any armament wiring.
• Inspect and replace wiring harnesses to civil standards, eliminating redundant military circuits.
• This phase ensures the aircraft meets civil weight and balance requirements, often reducing empty weight by 50–100 pounds.

2. Engine and Propeller Modifications

• Restamp the Gipsy Major 8 to Gipsy Major 10-2, involving paperwork and potential cylinder head changes.
• Upgrade the starter from Coffman cartridge to electric (Mod H.378), improving reliability.
• In some cases, changing to a constant-speed propeller for better performance, though the original fixed-pitch is often retained for cost savings.

3. Airframe and Systems Upgrades

• Fuel System: Retain 9-gallon tanks or upgrade to 12-gallon for Mk.22A variant.
• Canopy: Fit a blown Perspex canopy for enhanced visibility and aerobatic suitability.
• Undercarriage: Reinforce legs and add fairings for drag reduction.
• Avionics: Install modern civil radios, GPS, transponder, and ELT. Instrument panels are updated to civil specs.
• Aerodynamic Mods: Add anti-spin strakes (Mod H.231) and optional wingtip tanks or luggage bays.

4. Painting, Testing, and Certification

• Repaint in civil schemes, removing military markings, unless authorized to maintain military livery.
• Conduct ground runs, weight-and-balance calculations, and test flights to verify handling.
• Final inspection by authorities leads to a civil Certificate of Airworthiness.

The entire process can take 6–12+ months.

Irish Historic Flight Foundation Chipmunks

The IHFF currently operates 3 de Havilland Canada DHC-1 Chipmunks, “168” (EI-HFA), “169” (EI-HFB) & “170” (EI-HFC). These aircraft are often seen in tight formations operating at national and international events.

Two of our three DHC-1 Chipmunks originated from the RAF, with a the remaining Chipmunk being a former Irish Air Corps aircraft, all of which have gone through military to civilian conversions. The IHFF Chipmunks, whilst civil aircraft, operate in historic Irish Air Corps livery and markings.