The Bluenose Soaring Winch Operation Dick Vine Free Flight page 16 1982 Sept/Oct (5/82) The Bluenose Soaring Club has enjoyed remarkable growth in the last three years. Membership has climbed and the number of flights has gone up: 1979— 765; 1980— 1444; 1981 — 2000; and this year we are 100 ahead of last year. Our club fleet — 2-22, Ka7 and private owner ships Ka6E, Skylark 4, Open Cirrus and Stand- ard Austria — expanded with the addition of the Ka8 and a single-seat Astir, and it appears that we are able to finance their purchase over five years, still keeping fees and flight charges low. There are several reasons for all this, of course, but the main one is our inexpensive winch. We have developed a workable and productive technique for dealing with the various issues involved in winch launching from maintenance, cable repair and driving skill to safety and sig- naling procedures. And that is one of the most important factors for our progress. THE WINCH The winch was built several years ago by members of the club and was recently mounted on an old truck (see photo by Lloyd Bungey). It can now be driven into position and the field can be reversed to accommodate a wind direction change in twelve minutes. We used a single drum 5 inches wide, with an 18 inch barrel diameter, and 48 inch diameter flanges with no level wind. A 310 HP Ford V8 engine of great age with automatic transmis- sion is the power source. An azimuth pulley guide is mounted about 5 feet from the drum with 12 inch grooved pulleys and side rollers of one-and-a-half inch SC8O pipe. This assembly is very heavy, but has enough inertia that it smoothly adjusts to the desired angle of the cable. CROSS-WINDS Quite strong cross-winds of 20 mph at 90 degree to the launch direction can be tolerated provided the pilot lays off for drift. However, if there is a downwind component we change ends since high revolutions are required to maintain speed and the wire would descend onto the winch — all very hard on winch, wire and driver’s nerves (not to mention the pilot). We use .135 inch diameter piano wire. It is much stronger than necessary, and some care is required to avoid kinks. After a while it bends at the point where it touches the drum at release. Last year we managed 1100 launches before a break and this year we hope to do better. After the first break, others happen more often, probably because people are less cautious. CABLE REPAIRS Once we suffer a break, the wire receives a careful DAILY INSPECTION and doubtful joints are fixed before flying begins. Of course, this saves climbing trees and wading through swamps and loss of time, all associated with cable breaks. We repair breaks by passing the broken ends through three 5/32 inch Nicopress sleeves, heat the bare ends of the wire and peen it into a mushroom end about 1/4 inch diameter. We then draw the joint together so that all sleeves are touching with 3/8 inch between the mush- room and the end sleeve. The sleeves are then crimped into the wire. Such joined wire lasts about 200 launches before it wears away on retrieves, so that it is no longer strong enough. It takes about 5 minutes to do a joint if the crew is experienced. The joint can carry about 1900 pounds load plus/minus 10% and is repeatable by anyone so we haven’t worked on any other system. PRECISION ORGANIZATION Our field at Stanley, Nova Scotia, is 5500 feet long, running north/south. We share it with EAA 305. When they aren’t flying we use a 90 degree runway to land if the wind is suitable, thus improving our cycle time. Training cycles are about 12 to 15 minutes due to briefings and long landings, etc. But once soaring conditions develop, we can cycle in 6 1/2 minutes. We retrieve at 18 to 20 mph with a beat-up truck. It has a small gantry to tow the wire to one side so that the truck can stay on the pavement (avoid- ing much shaking to wire and driver) and the wire is pulled over the grass. PERFORMANCE The 5300 foot cable give us an average of 1400 feet release height. Of course, the Ka7 is a very heavy bird (900 lbs), thus students with instruc- tor on board reach only 1100 feet, and at solo stage at least 1400 feet. The Ka8 and the Open Cirrus are super-winchers and generally reach 2000 feet; a 1800 feet release height is very common for all our single seaters. In order to achieve fast cycle times, all must work together: both winch and retrieve driver must be efficient at their end of the field and the field manager at the launch site must see that the correct aircraft is pushed up with crew ready (parachutes on and strapped in) as soon as the cable is on hand. We don’t rush the pilot through the flight preparation stage, but if he is not ready another aircraft waiting with crew receives preference. SUMMARY Any club can run a winch operation, provided the field is long enough so that good height can be achieved without too steep a pull-up, and safe landings straight ahead can be made from faulty launches. This requires about 5000 feet of runway, but a little less is OK. To be successful you must commit yourself to the winch process. Considerable practice and skill are required to consistently achieve fast cycle times, Don’t expect an efficient operation if the winch is only used in case of an unser- viceable towplane. If clubs want to continue to operate over a long term, there is no doubt in my mind that a more economical launch system will become necessary. And for once, I think, Nova Scotia is the wave of the future. 0 INCLUDES A PHOTO - The BSC Winch.