Propeller and / or engine separation from an aircraft in flight are rare and unusual occurrences, with the risk of possibly fatal consequences. An ANA DC-2 VH-USY had its shut down right engine drop off whilst about to land at Nhill, Victoria in 1940 with no casualties, after the engine mounts had failed following an inflight engine fire. When the aircraft in question is a large four-engined airliner, the threat of imminent peril is multiplied because of the number of people involved. Such an incident, unique in the annals of Australian aviation, occurred in April 1964. The following article is believed to be the fullest account of this event yet to be published.

Born at Warracknabeal, Victoria in 1924, Cyril Keith Hants was educated at Mont Albert Central School, Melbourne. In 1942 at age 18 years, Keith volunteered for RAAF aircrew, and after acceptance began pilot training at Western Junction aerodrome near Launceston, Tasmania, where he completed his first solo in a Tiger Moth.

The following year at age 19 he was awarded his pilot wings brevet at Point Cook after qualifying on the Airspeed Oxford multi-engined trainer. He was posted to England to fly bombers, first Wellingtons and then Lancasters. In mid-1946 Keith returned to Australia for demobilisation at age 22. He joined Australian National Airways in 1947 as a First Officer on DC-3 aircraft based at Melbourne’s Essendon Airport. Subsequent advancement saw him flying DC-4 and DC-6 aircraft before returning to fly DC-3 aircraft as a check captain. On 3rd October 1957 A.N.A. was taken over by the much smaller Ansett Airways and Keith was now flying with the new combined airline, Ansett-ANA.

Mostly uneventful airline route flying followed until that fateful day in April 1964, when Keith was pilot in command of a Douglas DC-6B scheduled to operate a flight from Melbourne’s Essendon Airport to Adelaide and Perth. At 1.21 pm EST on Tuesday 14/4/64, just after take-off from Runway 17 at Essendon and at about 200 feet altitude, Ansett-ANA DC-6B VH-INA operating as Flight AN216, bound for Adelaide, lost the complete propeller assembly from N° 3 engine. Initially one blade separated due to fatigue fracture, with the other two blades wrenching themselves off soon afterwards still attached to the hub. Due to the massive torque loads generated by this event, the engine, weighing just over a ton, almost wrenched itself off its mountings but remained hanging at angle, lower than the main undercarriage would be when extended. All this caused a severe directional disturbance, much aerodynamic drag and a major power loss, all requiring immediate action.

A considerable quantity of oil was being lost from the No. 3 engine area due no doubt to oil tanks and lines being ruptured and some had sprayed on the side of the fuselage and windows. The propeller debris dropped onto the suburb of North Essendon, fortunately causing no loss of life or injury. The first blade punctured the roof of a private home whilst the other two blades and propeller dome landed as one unit in the backyard of another house. This 3-bladed Hamilton Standard propeller assembly was fitted as standard equipment to the 18-cylinder supercharged 2,500 h.p. Pratt & Whitney R-2800 aero engine, powering both the DC-6B and the Convair 440 – both types in Ansett-ANA airline service at the time.

The technical crew on AN216 was Captain Keith Hants, First Officer Bob Gordon, Flight Engineer Bert Clarke and Supernumerary First Officer Murray Bax. Cabin staff was Senior Hostess Judy Murphy & Hostess Margaret Harper with 57 revenue passengers (20 First Class & 37 Economy) plus luggage, mail and freight for both Adelaide and Perth, the final destination.

At 1.23 pm Capt. Hants advised Essendon control tower that a major part of N° 3 engine had dislodged & a large part of the propeller had landed somewhere in North Essendon. The resulting out-of-balance forces had left the engine barely hanging below the wing, creating considerable aerodynamic drag with marked reduction in aircraft performance. The big Douglas propliner struggled to gain enough height to safely clear the built up areas whilst maintaining approximate runway heading taking it over the mouth of the Yarra River and out over Port Phillip Bay.

The DC-6B manufacturer’s flight manual states that the power-on stall speed at VH-INA's estimated gross after take-off would be just over 100 knots, and that the probable climb rate available in this unique condition was about 100 feet per minute at a cruise-climb airspeed of about 140 knots up to 1500 feet altitude. This was in reality the best performance that could be obtained given the dire situation the aircraft was in. It can be seen that margins were not great and turns had be made gently at a shallow angle to offset the increased banked stall speed. A clockwise circular flight pattern over the bay of about 30 kilometres in diameter was then taken up embracing points abeam Williamstown, Dromana, Mud Island and Point Cook.

This was to consume and also dump fuel to reduce the aircraft’s weight before attempting the planned emergency landing back at Essendon, and to prepare for a possible ditching in the event of further complications. Fortunately being an autumn weekday, the number of pleasure watercraft on the bay below the stricken airliner was minimal. At 1.30 pm the crew began jettisoning fuel over the bay. At 2 pm, DC-3 VH-ING took-off from Essendon, with Capts. John Blair & Peter Gibbes (the latter being the Ansett-ANA Director of Operations), certain D.C.A. experts & Ansett-ANA maintenance engineers J. Stubbs & M. Webber. The DC-3 was flown alongside VH-INA to examine the damage.

It was decided that the engine should be dislodged as soon as possible as it would be too dangerous to attempt to land with the damaged engine still attached so precariously. After much manoeuvering by Capt. Hants (shallow dives & sharp pull-ups, making the cabin occupants decidedly uncomfortable), the engine finally dropped off into Port Phillip Bay in about 12 metres of water some 5 kilometres East of Point Cook, from about 1200 feet altitude, at 2.44 pm. This position was noted by Air Traffic Control radar and then located and marked with buoys by a Point Cook-based RAAF crash launch. The aircraft then returned to Essendon Airport and landed safely on Runway 26 at 2.55 pm, exactly one hour and thirty four minutes after take-off.

A huge crowd of onlookers including press, airline, Department of Civil Aviation and emergency personnel and vehicles had assembled to watch this epic arrival. Red Cross workers met the passengers to attend to their possible needs whilst the fire crew checked the aircraft. Reginald Ansett himself came out to see the fortunate conclusion to the 94-minute air drama over Melbourne, and congratulated all crewmembers on a sterling effort.

VH-INA was then towed back to the hangar for inspection and fitted with a new No. 3 engine and propeller overnight. Following satisfactory checks, it was soon back in revenue service. Subsequent investigations found that one blade of the failed No. 3 propeller had suffered a catastrophic fracture some 21 centimetres from the blade root, caused by a metal fatigue crack originating from a point beneath the de-icer boot. The reason for the crack occurring was that a small portion of the blade surface in that area had been subjected to unplanned heating in excess of 500 degrees centigrade several thousand flight hours prior to the incident.

It was considered that the most likely source of this heating would have been from an electrical breakdown or short in a previous de-icer boot fitted to the blade and changed prior to the last 4200 flight hours. The particular propeller at the No. 3 engine position on DC-6B VH-INA at the time of the incident was a certified overhauled and fully airworthy component drawn from the Ansett-ANA spares inventory and was fitted prior to the aircraft entering Australian RPT service.

For his exemplary airmanship and skilful handling of a most difficult and unique hazard to life and limb as experienced by his passenger-laden DC-6B aircraft, Captain Hants was awarded the Queens Commendation for Valuable Service in the Air by the Governor of Victoria on 18th June 1964. Keith continued domestic airline flying with Ansett-ANA, serving a total of 26 years, achieving the senior rank of Flight Captain Viscount and then Flight Captain Electra, until medical problems ended his flying career in 1973. For twenty years from 1974, he operated a ground simulator school at Essendon Airport until he retired in 1994 at age 70.

After Keith’s first wife Christine passed away he married Helen, whose own husband had died and the couple live comfortably at Gisborne in pleasant surroundings. Now aged 82 Keith still has some ongoing medical difficulties.

Douglas DC-6B constructor’s number 44893 was built in late 1955 at Santa Monica, California for United Airlines, USA - the world’s largest civil operator of the type with a fleet total of no less than 99 DC-6s in a variety of versions. It was delivered on 11th January 1956 as “Mainliner Diamond Head”, reflecting United’s heavily patronised route from the U.S. West Coast to Hawaii. A smaller American operator acquired the aircraft in May 1960, onselling it to Ansett-ANA on 22nd November 1963 as VH-INA, when it had already logged 18,325 flight hours.

New DC-6Bs were no longer available as the type had ceased production five years earlier in 1958. On arrival at Ansett-ANA’s Essendon Airport workshops the aircraft was given a full Australian Certificate of Airworthiness check and fitted with four newly overhauled engines and propellers. In the period 28th-31st December 1965, VH-INA was chartered by the Australian Defence Department for the Royal Australian Air Force, flying from Perth via Cocos Island to RAAF Base Butterworth, Northern Malaysia.

Returning via the reverse route the round trip crew were Capts. Alan Ramsay & W. Parker, F/O Neville Baker, Navigator W.C. ‘Bill’ Kennedy & F/E Joe Crago. VH-INAs last Ansett-ANA revenue service operated on 29th May 1966, after which it was withdrawn from service in open storage in the “graveyard” at Essendon Airport until being sold to Taiwan in March 1967. This grand old propliner’s last known activity was as a firebomber in Canada commencing in the early seventies.