As stated in the section titled “BEAH Gatwick”, Jock Cameron, Managing Director of BEAH, had somehow persuaded the Board of BEA to purchase two S61N helicopters from Sikorsky in Connecticut, USA. One of these was destined for a new helicopter service linking the mainland to the Isles of Scilly. Hitherto, this service had been operated by a De Havilland Rapide flying from Lands End aerodrome to St. Mary’s aerodrome in the Scillies. The only other means of travelling between the mainland and Scillies was via the “Scillonian”, a relatively small motor vessel based in Penzance harbour. Due to the shallow harbour, this boat had a relatively small water draft (small depth of keel) and was thus subject to unpleasant rolling motion in anything but good sea states. A specialised heliport was built on East Green just to the east of Penzance and the service commenced operations in 1964 under the management of Captain Ron Dibb. It soon became successful and became an intrinsic part of the local scene. The demand for seats and therefore flights was limited in Winter but in Summer the helicopter flew from dawn to dusk on its 20 minute per sector operation.
Although I had found the job of Manager and Chief Pilot in Shetland both demanding and, at times, very rewarding, it had its limitations. The three children enjoyed living there but for my wife, Margaret, it lacked many of the advantages to be found on the mainland. Jock Cameron wanted me to extend my two years to four. I agreed to make it three at the end of which my high seniority in the company guaranteed me the first vacancy at the choice posting of Penzance. We sold our bungalow in Shetland to BAH for a residence for the new manager, Robin Zingel, the first non-pilot manager in BEAH or BAH, and moved south to a bungalow just west of Penzance.
I suppose it could be said that if Shetland was the most demanding of operations, Penzance was the most exotic! There were even palm trees growing around the terminal building. In Winter the passengers were normally locals and others with business interests but during the Summer the service transformed into a holiday run with holidaymakers with accommodation booked on the Scillies or day-trippers, many of whom would experience their first ever helicopter flight. The clearance from the cabin attendant that all the passengers were seated and strapped in was “All is proper in this chopper”, spoken with a strong Cornish dialect.
The operation had been under VFR (Visual Flight Rules) but with the advent of the IFR (Instrument Flight Rules) capability pioneered for helicopters by BAH, Captain Mike Perkis, the manager of the operation, asked me to develop a cloud break procedure to permit us to fly in low cloud yet achieve a safe approach and landing to St Mary’s airport in the Scillies. Such a procedure was developed using the Decca Navigation moving map display as installed as standard on the helicopter, combined with the Lands End VOR (a radio beacon on the airfield at Lands End providing signals giving bearing and range to an instrument on the dashboard of the helicopter). Once approval had been received from the CAA, we were able to take off from Penzance and disappear into low cloud, fly safely towards the Scillies and then descend to the minimum descent altitude of 200 feet above the sea for a landing at St Mary’s. Returning to Penzance employed a similar procedure descending over the bay by St Michael’s Mount with descent to 300 feet above the sea.
We flew in just about all weather conditions, sometimes in rough conditions with strong winds. It was amusing to read a local newspaper article praising “Royal Navy heroes” referring to a flight carried out in stormy weather from the nearby Royal Navy station at Culdrose. We had been airborne at the same time flying our service with numerous passengers on board!
I have to confess to a certain mischievous practice. When flying over the Scillonian one would announce on the cabin address “…we apologise for the slight vibration but if those on the right hand side of the aircraft would care to look down you will see the alternative means of travel – the Scillonian.” They would see the Scillonian plunging up and down as it battled through the waves. There was a not funny side to this as, on occasion, the boat passengers could suffer various injuries and would then be ferried back to the mainland by helicopter!
Article from Shell Aviation News 1976 (reproduced by kind permission)
British Airways Helicopters Ltd., formerly BEA Helicopters, provides a scheduled service linking the Isles of Scilly with Penzance in the far south-west of England*. This operation, with its regularity factor of 98%, can claim to be one of the most reliable airline services in the world and now carries more than 80,000 passengers a year in a single Sikorsky S61NM.
Such results have been achieved under VFR Visual Contact conditions during the twelve years of the service’s existence, viz. en route weather minima of 300 ft cloud ceiling and visibility of 900 metres. However, there are certain situations when en route weather is below limits even though weather at both ends of the route is above VFR minima. Sea fog is a particular nuisance in this respect. It was therefore considered worthwhile to investigate an IFR capability to overcome the en route problem. As BAHL pioneered the introduction of commercial helicopter instrument flight in Britain, the considerable experience gained on North Sea operations for the oil companies encouraged the prospect at Penzance.
The VFR minima at Penzance (elev. 14 ft) are 300 ft cloud ceiling and 900 metres visibility, while at St Mary’s, Isles of Scilly (elev. 116 ft) they are 200 ft and 900 m. A feasible IFR operation would need to have minima equal to or less than these. In order to achieve maximum utilization of the one aircraft, the daily schedule packs up to 24 sectors, each of about 20 minutes, totalling 11 hours and 15 minutes elapsed time including 8 rotors running refuels and 3 rotors stopped refuels/turnrounds. Any innovation could not be allowed to increase sector times significantly and so, ideally, the approach at both ends should approximate to the direct track between Penzance and Scilly.
St Mary’s has only a VDF facility, thus a Decca approach along the 249o radial from the Lands End VOR (LND) was favoured, using airborne radar for an extra check on range and azimuth. At Penzance an approach from the Lands End VOR down to Mounts Bay on a radial of 125oM was most convenient. In precise terms both of these approaches are ‘cloud break procedures’ and the aircraft must have completed the instrument descent at three miles prior to touchdown.
The draw-back to IFR procedures as opposed to VFR is the extra fuel required and therefore the reduced payload available. The S61NM, a partially amphibious conversion of an S61L, has 30 passenger seats and a maximum all-up weight of 20,500 lb.
On this route, the minimum VFR fuel of 1200 lb ex Penzance allows flight to St Mary’s and return to Penzance with 400 lb loiter fuel remaining in the tanks. Fuel for IFR would be this 1200 lb plus an extra 320 lb, giving a total of 45 minutes loiter, plus diversion and approach fuel to St Mawgan of between 450 lb and 780 lb dependent upon wind. This could be reduced if fuel were made available at St Mary’s but so far this has not been considered worthwhile.
St Mawgan (elev. 392 ft) is a Master Diversion airfield on the North coast of the Cornish peninsula, and has an NDB, ILS and PAR. It is the only suitable diversion airfield available to the S6INM with its limited fuel capacity of 2550 lb. The only other airfields within range are R.N.A.S. Culdrose and the small civil airport at St Just (Lands End). Culdrose, a mere seven minutes Hying from Penzance, has PAR; however, with an elevation of 268 ft it rarely experiences better weather than Penzance and is not available for diversion at weekends or holidays, our busiest periods. St Just has no approach aid and weather disadvantages similar to Culdrose.
Despite the reduced payload with IFR fuel, equivalent to as many as six passengers, the ability to fly on time far outweighs the consideration of a poorer load factor. On peak days, such as a Wednesday or a Saturday in summer, there are frequently more than 700 passengers to be flown, nearly all of whom are starting or finishing a holiday on the Isles of Scilly. If helicopter flights are cancelled, these passengers have to be accommodated overnight, which can prove impossible. Over the twelve month period, some 22% of the passengers are day-returns who usually book at short notice; should there be a payload problem, it is these who would be invited to spend their day elsewhere.
A typical IFR flight could be as follows. After the initial climb-out at 20 kt from the Penzance Heliport, the aircraft is rotated at Decision Point to 80 kt, and shortly afterwards enters cloud. A climbing turn is made over the sea to a cruising altitude of 2000 ft (Reg. QNH) on to a track to cross the LND VOR. Deccometers and Flight Log are checked and up-dated overhead the VOR, after which a QDR of 249oM is maintained towards Scilly. Decca Flight Log and VOR indicators are cross checked and should agree within one Decca Lane. When the Eastern Isles of Scilly are shown by the airborne radar to lie at a range of 12 miles, the Decca Flight Log is checked to agree.
Some eight miles from touchdown, with all approach checks completed, a descent is initiated according to the track and heights as shown in the Decca Flight Log. These provide a 3o glide slope. The pilot handling the controls responds to corrections in height and heading as given by the other pilot from the Decca Flight Log and radar picture. The Decca is used as the primary aid with the radar and VOR as confirmatory aids.
At three miles from touchdown, at a height of 200 ft (QFE), visual contact is made with the sea and the aircraft is flown level, holding the decision height. Continuing to read information from the flight log, radar and VOR the pilots maintain decision height until either sufficient visual cues for a landing become available or an overshoot is initiated. During these final stages of the approach airspeed is reduced to 70 kt. The continuing of an approach at low level and low airspeed, even after decision height has been reached, allows the extreme manoeuvrability of the helicopter to be exploited in complete safety. With the variety of aids in use there is no possibility of collision with the only significant obstacle on Scilly (a radio mast). Familiarity with the radar picture gives confident identification of the island of St Mary’s and even the airfield itself. Another bonus with the radar is the knowledge that the QE2 passenger liner, or a supertanker, is not parked in the undershoot.
After five minutes on the ground at St Mary’s, during which time perhaps 30 passengers have disembarked and another 30 climbed on board, the aircraft lifts off again. Passing through a decision point of 50 ft (the take-off area at St Mary’s permits a different take-off technique from that used within the confines of Penzance), the aircraft climbs to 2,000 ft (Reg. QNH) on a direct track for the LND VOR.
A few miles short of LND track is adjusted to bring the aircraft 3 n miles from the VOR on to a QDM of 125o. This QDM is maintained over the VOR and thereafter a QDR of 125o. For the 3 n miles before the VOR and 1 n mile after, height is maintained at 2000 ft (Penzance QFE); this allows the tracking accuracy of the Decca to be checked against the VOR. In addition, the radar picture is scrutinised to check the range of Cudden Point in order to confirm the fix. The duties of the pilots during this approach arc similar to those for the Isles of Scilly approach. Visual contact with the sea is made by the Decision Height of 300 ft, following which the aircraft is turned on to a Northerly heading for a visual approach to the Heliport.
CAA approval to begin commercial IFR operation was granted at the end of May 1976 for the Penzance/Scilly helicopter service. The procedures at both ends arc straightforward, and are enjoyed by the five resident Penzance pilots. Since neither involves undue extension of flying times, pilots can practise instrument approaches more frequently than would otherwise be commercially desirable. Instrument flight adds another dimension to the repetiveness of the VFR operation.
For many years now, some military helicopters have had the capability for hands-off zero visibility approach and landing. So far such a capability has not been developed for and taken up by commercial aviation. BAHL has conducted trials on MADGE (a microwave approach guidance system)** with great success, but the installation of such equipment cannot yet be justified commercially. It would probably require MADGE and high intensity lighting to allow us to complete manual approaches in fog. Probably the most likely improvement that could be made to our IFR operation would be an NDB located on the Penzance Heliport and one on St Mary’s Airfield. These, together with the experience gained during several hundred instrument approaches, might encourage CAA approval of a slight reduction in the IFR weather minima.
•See SAN 404 & 405/1972. ‘West Country Airline” by British Airways Helicopter* Ltd’s Managing Director Captain j. A. Cameron.
**See SAN 429/1975 Tor an evaluation of this system by F. W. Free, Project & Performance Engineer, British Airways Helicopters Ltd.