Contents

          Para      Subject
          3.1       General
          3.2       Logging the tow
          3.3       Tows for Badge and record Attempts
     
          The Standard Tow
          3.4       Pre-Takeoff
          3.5       Taking Up Slack
          3.6       Takeoff
          3.7       The climb-out
          3.8       Release
          3.9       The Descent
          3.10      Joining the Circuit
          3.11      Final Approach
          3.12      Landing
          3.13      Baulked Approaches

          Non-Standard Tows
          3.14      Towing Slow Gliders
          3.15      Dual Tows

          Emergencies
          3.16      Signals
          3.17      Serious Tug Emergencies
          3.18      Engine-Related
          3.19      Airframe-Related
          3.20      ASI Failure
          3.21      Weather-Related - Poor visibility, low cloud, strong wind   
     
          3.22      Other aircraft - Wing tip vortices

3.1 GENERAL. The purpose of the tow is to launch the glider in a safe, cost-effective, and productive way on what may be a soaring, training or a trial flight. Whatever the type of flight, the tow should be as helpful as possible to the glider pilot, and should not be regarded merely as a way of gaining height. The aerotow should provide what the glider pilot needs. For a two seater training flight this could mean plenty of turns for training and staying near the airfield, whereas a water filled Nimbus needs adequate speed, a minimum number of turns, and dropping in lift even if it is a fair way (within reason) from the airfield. It is up to the tug pilot to use his skill and his gliding experience to meet each individual need.

3.2 LOGGING THE TOW. Accurate and readable tug logs are essential, they provide the only check on the launch height and an important cross check on the accuracy of the ground log and that it was being kept at all. In non radio tugs when asking for the pilots name ensure the person bringing it only approaches the tug from behind the wing. In the past because of the dangers from the propeller we did not require the tug pilot to record the glider pilots name but we lost too much money on untraceable flights. Now the rule is simple, the tug pilot is NOT allowed to take off without writing the glider pilots name on the tug log. An exception can be made during evening trial flights when Air/Exp will do.

3.3 TOWS FOR BADGE OR RECORD ATTEMPTS.

3.3.1 Silver C Distance. Silver C distance release heights are complicated by the FAI/IGC 1:100 rule. For a straight goal Silver distance, if the angle between departure (normally, release from tow) and landing is steeper than 1:100, the claim is invalid even though 50 km has been flown. Since Lasham airfield is 620 ft AMSL, out-landings will normally be on lower ground; the worst case is a bare 50 km, landing at Sea Level and in this case the 1:100 rule would invalidate the flight for Silver if release was higher than 1020 ft above Lasham! Bicester airfield is 81 km away and 270 ft AMSL, this is a much better situation and a tow to 2300 ft above Lasham is still OK (just). Old Sarum as a goal is much more critical, at only 54 km and 280 ft AMSL, a tow higher than 1430 ft above Lasham will invalidate the claim. In a North Westerly one route is to Parham, releasing upwind of Popham (BGA TP `POP', the M3/A303 junction) for 59 k, the critical release height for this is 1430 ft and as it is some way from Lasham, the glider must be dropped in lift (it lands at Popham airfield if it falls out of the sky). The moral to all this is that you must find out if there is a limiting height for release, and don't go above it.

3.3.2 Gold, Diamonds or Records. For Gold, Diamond or record attempts the tug pilot may be asked to go to a specific higher altitude, in this case the glider pilot may expect the tug to level off at this altitude and speed up a little before he releases. If the point of release is to be used as a departure point (ie a start line with Official Observers is not in use), it is important not to exceed 3280 ft (1000 m) above Lasham, since if this is done, for closed circuit distance claims the pilot will be penalised on his distance flown and for speed claims the flight will be invalid. It is equally important to fly the tow so that the pilot can release in the place that he has declared; you will normally be asked to go to a specific place such as `overhead', `the clubhouse', `Southwood Farm' (BGA TP `LA1'), or even `Alton Station' (BGA TP `ALT'). A pilot declaring a 500 km out and return to, for instance, the BGA Rotherham (`ROT') turning point, needs a departure point well South of the airfield (eg Southwood Farm or Alton); if you drop him overhead or even worse to the North, his diamond claim will fail because his distance will be less than the magic 500 k.

3.3.3 Logging Release. When a tug pilot is told the launch is for a badge or record attempt, he should put the following in the remarks column of the log sheet; The exact release height above Lasham; Precisely where the glider was released; The exact time of release; and his signature.

3.4 PRE TAKE OFF. The tug should line up in front of the glider. Avoid taxying near the winch cables, and keep your propwash away from gliders and people as far as possible, particularly if you are warming up at 1000 rpm or more. Next go through the checks, many pilots shorten their check list after the first couple of tows and provided this is a conscious decision it is OK. Pay particular attention to the fuel state and trim position and anything that may have been moved such as Carb Heat or the Canopy Latch. A reasonable check to use after your first takeoff is FFTCC, Fuel, Flaps, Trim, Carb heat, Canopy. Having decided on a shortened list stick to it. The most senseless accident you could have is running out of fuel so to avoid this, and to establish a clear rule:- NO TUG WILL TAKE OFF UNLESS IT HAS AT LEAST 5 GALLONS OF FUEL ON BOARD, AND, WHERE THERE IS MORE THAN ONE MAIN FUEL TANK, AT LEAST SOME FUEL IN EACH MAIN TANK. Before your first take off each day move your hand from the throttle to the Cable Release to help make the emergency procedure instinctive. In a non radio tug the tug pilot has discretion whether to operate without a forward signaller. Normal launch R/T procedure on 129.9 is not to reply to the usual expected transmissions of Pilots Name, Up Slack and All Out but if you are in doubt about anything, ASK. The Tug Pilot may be the most experienced pilot at the launch point, if he is unhappy about any aspect of the launch he must not hesitate to stop all flying until things are put right. Watch out for things like deteriorating weather, inexperienced signallers, pilots trying to takeoff with airbrakes still out, or runners on the wrong wing in crosswinds.

3.5 TAKING UP SLACK. When `take up slack' is given, check that the glider's airbrakes are closed, the airfield ahead is clear, and that no winch launch is in progress. The flashing lights on the Control Vehicle come on once the up slack signal lights are started and as the Winch responds to the signal, its flashing lights will also come on indicating the cable is moving. Once either of these signal lights is flashing the tug must not take off, it is OK for the tug to slowly take up slack once the winch-launched glider is climbing. Do not move before all out or a "who is going first fumble" may be caused. If the Winch suffers an actual cable break, DO NOT ATTEMPT TO TAKE OFF UNTIL THE RUNWAY HAS BEEN CHECKED AND DEFINITELY IS FREE. Once you get the Up Slack signal the tug should move forward at walking speed, as the slack comes out of the rope the inertia of the moving tug will start the glider rolling, try to use this and keep the glider moving with a little extra power if necessary while checking for the All Out signal. A gentle jerk helps get gliders with skids rolling on soft ground but if you overdo it there is a danger of the glider overrunning the cable, be particularly careful with gliders that do not have nose hooks.

3.6 THE TAKE OFF. BE ABSOLUTELY CERTAIN ABOUT THE ALL OUT SIGNAL. We have had one accident where the tug pilot was not given all out but started the take off, we must never repeat this. Take 3-4 seconds to apply full power, this is good engine handling and lessens the chances of a rich cut due to overfuelling. During the roll check for normal RPM and oil pressure while there is still time to stop if there is a problem. Check that the acceleration seems normal and that there are no unusual noises or handling which could be due, for instance, to binding brakes, a flat tyre, or loose panels. It is vital to keep straight during the take off and large control deflections may have to be used at times, particularly in a crosswind (see below) or if the glider pilot allows the glider to become off-centre.

3.6.1 Rope Breaks. If the rope breaks at this stage, it is the tug pilot's responsibility to ensure the glider does not run into the back of the tug; with heavy ballasted gliders, particularly two-seaters, there is considerable rope stretch as you initially move forward and ropes have broken at this early stage. If this does happen, you may see the glider slowing in the mirror while rolling forward and then abandoning the take off or, if the break took place at higher speeds, continuing with the take off and doing a low level circuit.

3.6.2 Crosswind Takeoffs. New tug pilots are sometimes surprised by the amount of rudder needed in a crosswind. For example, if you think about a take off with a wind from the left, 4 distinct control movements are involved.

First, right rudder to overcome the weathercocking effects at the start of the roll (ie the side pressure on the fin & rudder due to the crosswind, which tries to turn you into the crosswind).

Once moving forward, rudder back to the centre as the pull of the glider on the rope tends to keep the tug straight.

If the glider drifts downwind as it lifts off (a common event), the tug tail is pulled downwind and you will need right rudder again to keep straight.

As soon as the tug leaves the ground it too will start drifting downwind and some bank has to be applied to take up the appropriate drift angle so as to track straight over the ground.

3.6.3 Use of Wheelbrakes. Early in the roll you may need the wheelbrakes to keep straight. Soon, the propwash and airspeed will give you directional control through the rudder and the brakes will not be needed again. However, if you leave your feet even lightly on the brakes on a hot calm day you may not get airborne with a heavy glider. Make a positive movement off the brakes as soon as possible and then keep your heels on the floor.

3.6.4 Check in the Mirror. As you accelerate towards unstick, the glider will already be airborne. Have a quick check in the mirror to ensure that its position is normal (not too high) and that its airbrakes are in. This is the last time you can pull the release before the tow itself gets underway.

3.6.5 Transition into the Climb. Once the tug leaves the ground, smoothly transition to the full climb, aiming to stabilise at the correct climb speed for the glider and the conditions. Do not wait until the ASI is indicating the towing speed before pitching nose-up into the climb, this will lead to overshooting the correct speed, leading to further nose up pitch to regain it; this excessive pitch change makes it more difficult for the glider to follow you. Try to make the transition from the acceleration phase to the climb as smooth as possible, without rapid pitch changes. This is particularly important in the Regent because of its higher unstick speed and initial acceleration once airborne.

3.7.1 GLIDERS GOING INTO LOW TOW. If the tug needs nearly full down elevator, stick forward, the glider has gone into the Low Tow position. When this happens, maintain the correct airspeed by using quite a lot of forward pressure on the stick and then retrim. You will not be able to see the glider in the mirror unless he is laterally displaced as well. The rate of climb and forward stick pressure tells you it is still there and has not released. The tug will climb in a less nose up attitude with a glider in the low tow position but normal towing speeds should be used. Be careful if the glider releases without moving into high tow first, so as not to descend into it; releasing while in low tow is most undesirable because it can be very difficult for the tug pilot to tell if the glider has released. If this happens to you, note the fact in the log and make sure the pilot is briefed not to do it again. If during Low Tow training flights the stick briefly touches the forward stop this can be accepted. However, if the glider continues to descend to an excessively low position, the nose of the tug will be pulled up and the airspeed will decrease which may eventually result in a roll to the left induced by engine torque. If you ever reach this stage, release the glider, centralise the stick, but do not chop the throttle as you must avoid the glider below you.

3.8.1 Tug Procedures. Ensure you have arranged your flight path so that, after release, you can return to the airfield quickly and without using a lot of fuel; the only exceptions are in order to place gliders in lift where there isn't any closer in, and for pre-briefed release points where, if they are sufficiently far from the airfield, the glider pilot may be invited to pay more. With training two-seaters, early solo pilots, and in poor visibility, position so that the airfield can be clearly seen as you come up to release and is not too far away. As you feel the glider release, use the mirror to ensure it really has gone and to establish which way it has turned. Never descend if you are in any doubt as to whether the glider has released or not.
2.8.1.1 Flap Position Check. It is a wise precaution as you accelerate after release to develop the habit of a quick look at the wing trailing edge to double-check that the flaps are really up before you exceed flap speed on the descent. Occasionally you may have deliberately left half flap down for the tow, such as when towing slow gliders, or you may have been distracted at the time that you normally retract the flap. In any case a positive check like this is good airmanship and at the same time improves your visual scan as you turn and descend.

3.8.2 Glider Pilot's Actions. Glider pilots should be trained to release and execute a positive climbing turn so that the tug pilot can clearly see that they have gone by looking in the mirror. If the pilot does not do this, eg just pulls off and then makes it difficult for you to see the glider, make a note on the log sheet and ask an instructor to debrief the pilot on this failing. Some pilots pull off so unobtrusively that you have to continue climbing, searching for the glider in the mirror, before finally deciding that the glider has gone and starting to throttle back; this costs the club money and the pilot must be debriefed to be kinder to tug pilots. If in doubt, an increased rate of climb may be a clue as to whether the glider has pulled off.

3.9.1 Carb Heat. In humid conditions in the UK below a temperature of +10°C, carb icing is possible so use carb heat on the descent. Carb icing is insidious, it builds up in the throat of the carb and when you call for power it just is not there. Because of the pressure fall in the carb venturi, you can get carb icing at ambient temperatures well in excess of freezing. The carb heat control is there to be used!

3.9.2 Descent Speed. The most used descent speed is just short of either the rough air speed (Vra) or the maximum manoeuvre speed (Vm), whichever is the lower. For individual types, see the notes in the Annexes. Once over Vm, the aircraft is not cleared for the use of more than one third control deflection which may not be enough for collision avoidance. Slower is safer, to avoid collisions, avoid knotting the rope, and to minimise the chances of airframe damage or panels vibrating, remember tugs are rarely new aircraft!

3.9.3 General. Pilots are expected not to waste time or fuel, nor to mishandle the aeroplane. Neither overspeeding or overcooling the engine, the well executed descent will continue directly to the base leg, the exact position of which will vary according to the wind and other circuit traffic, then on to a straight final with wings level from a safe height, into a smooth landing. Expect a descent from 2000 ft to take between 3 and 4 minutes, time yourself and if you are taking longer find out why and take the necessary action.

3.10.1 Track over the ground. Try to make the path from the point of release to the circuit a smooth descent using low angles of bank to give you the best view for lookout and so collision avoidance. Spiralling or sideslipping down followed by powering around the circuit are not acceptable practices. Consider too what would happen if the engine quit, position yourself so either the airfield or a good field is always available to you.

3.10.2 Main Circuit Options. There are two main options. You can join the circuit at the upwind end, close in and under the glider circuit traffic. The alternative is to stay higher than the glider traffic which will mean going wider to avoid the traffic and a high base leg about half a mile out. Either high or low pattern is acceptable, although the higher circuit carries less risk of collision because you will above any gliders in the circuit and also since the close-in lower tug circuit means that gliders will be descending through your level and may not see you underneath. Also with the low pattern you will have to use power to fly level until finals, and it will use more fuel and take more time than a well-judged descent transitioning smoothly into a high base leg. If you have to fly a close-in downwind leg, aim to be 500 ft passing the clubhouse flying level until the base leg, then slowly descending so you start your 180 degree turn onto finals at 400 ft, and are level again lined up on finals by a minimum of 200 ft.

3.10.3 Checks. Downwind checks must be done before every landing; pilots have various personal preferences for these and any series of checks that includes FUEL, HARNESS and BRAKES OFF, is acceptable. The repetitive nature of tug flying makes it easy to forget these checks especially during a long session.

3.10.4 Base Leg. Use the base leg to reduce your speed to below flap limiting then put down half flap, then go to full flap for finals at a position appropriate to your height.

3.11.1 TRAILING ROPES. Tug pilots must accept responsibility for their trailing rope and it must not be allowed to hit anyone or anything, regardless of whether the obstacle concerned has any right to be where it is. Watch out for cars at the west end, some stop, some don't! Operating on the medium and short runways you have to be particularly careful and may have to deliberately land well up the field and then taxy back. We have had ropes damage cars parked by the trailer park North of the medium runway threshold, think of what would happen if it was a person and not a car. Although the rope only hangs down about 50 ft or so at approach speeds the aircraft may be descending, and you need a margin anyway, so for the end of the rope to clear an object on the ground the tug needs to pass over it at a minimum of 150 ft.

3.11.2 Specific Hazards. On the short runway operating to the North (35), the approach must be offset so as not to overfly the warehouse on short finals. On the main runway operating uphill (09), be aware of the power lines in the undershoot area.

3.12.1 Tug Landing Strip. Always try to land on the grass about a couple of wingspans in, parallel to the runway. Glider pilots should think of this as the tug strip. No landing run should involve crossing a runway edge at speed. Be very careful every time you taxi across a runway edge, look first and then go across slowly at 45°.

3.12.2 Obstructions. Never land towards parked gliders or similar obstructions, and allow for movement of people crossing the airfield, and gliders being moved or towed. Assume the brakes may fail, there has got to be somewhere ahead where the tug can go without causing an incident.

3.12.3 Formation Landings. Never land in formation with another tug or glider.

3.12.4 Turning at the end of the Landing Run. You can land on the left or right of other aircraft, but remember the same may be happening to you. Do not turn at the end of the landing run, keep going straight until nearly back to the launch point. Before and during turning, check for landing aircraft.

3.12.5 Aerotowing from the Grass. When aerotowing is taking place from the grass, touchdown as far into the airfield as conditions allow using light braking and slowing to walking pace before crossing the intermediate runways. When aerotowing from the runway do not use the brakes harshly during landing, taxying back is a lot cheaper than repairing brakes .

3.12.6 Crossing Runway Edges. If you slightly misjudge a landing and look like crossing a runway edge faster than walking pace always do it with NO BRAKES applied. This reduces the load on the nose leg oleo on tricycle types, giving better propeller clearance, it also reduces the risk of nosing over in taildraggers.

3.13.1 GO-AROUNDS FROM FINALS. The vital thing in this case is that the tug maintains its approach heading while starting to climb and does not turn until it absolutely clear of other traffic, and at least 1/3 up the airfield. Be aware there may be a winch cable in the air, or gliders hangar flying. Use enough power to climb whilst staying under the flap limiting speed. This should avoid having to have a very nose high attitude making lookout difficult. Raise the landing flap to half, and fly straight ahead to about 500 ft before turning onto the downwind leg.

3.13.2 ORBITS AND S-TURNS. Unless you are behind the normal glider base leg, orbits and S-turns are to be avoided whenever possible as the collision risk is increased. If an orbit seems sensible, be really thorough with your lookout before starting the turn, and only use a small angle of bank so that you can keep checking for other traffic. Orbits and S-turns should be flown with half flap, check the ball is centralised all the time as low turns, especially in strong winds, produce apparent sensations of slipping and skidding. Watch the flap limiting speed.

3.14 TOWING SLOW GLIDERS. The minimum towing speed given in the Flight Manual for a Robin Regent is 60 Kts, for a Rallye is 54 Knots, and for a Super Cub, 55 mph (48 Kts). These Flight Manual speeds are calculated so that in the event of a sudden engine failure that you have enough margin over the stall to have time to lower the nose before encountering additional handling difficulties, and at normal ambient temperatures the engine should not overheat during the tow. Both aspects are improved by towing at higher speeds and with glass gliders and water ballast this is no problem. However, the wooden `golden oldies' don't like high tow speeds which may make them difficult to handle and close to or over their tow Vne. Therefore, use the Super Cub for the slowest gliders; half flap reduces ground run but does not help the climb. After the Super Cub, use a Rallye and leave half flap down for the tow; remember to clean up after release or you will exceed the flap limit speed. Develop the habit of looking at the flap on the wings as you accelerate after release; this may save you from embarrassment one day! On tow at slow speeds, monitor the oil and cylinder head temperatures carefully for possible overheating. Also bear in mind that if you have an engine failure, because you are already slow, you may have little time to react to prevent a stall even at the `legal' minimum speeds. And the high nose attitude reduces view ahead and below; it is advisable to weave the nose more than at higher speeds to ensure that you are not flying towards another machine at the same height.

3.15 DUAL TOWS. Dual tows are allowed within the limit of the combined weights of the two gliders. Details are found in the BGA publication on dual tows and in the Flight Manuals of each tug; these documents are held in the office. The tug pilot has a responsibility for the safe and legal conduct of the flight, and so these documents should be consulted before starting any dual tows. Lasham charges each glider pilot two thirds of the normal cost of the tow. The following is an outline guide to dual towing, but it is not intended as a comprehensive set of instructions.

3.15.1 Authorization. Before setting up a dual tow, authorization must be obtained from the Tugmaster, CFI, DCFI or Manager.

3.15.2 Wind and Turbulence. No dual tows in cross winds over 5 kts, or in turbulence or strong winds.

3.15.3 Ropes. The ropes will be a normal one and one made up of two normal ones tied together with a reef knot or shackled together. This makes lengths of 150 - 170 ft and 300 - 340 ft.

3.15.4 Positioning on the Ground. Lay the ropes out on the ground at an angle of about 30 degrees, and check once the gliders are hooked up that the long rope is clear of the forward glider which conventionally is on the right hand side. Position the gliders to minimise any slack in the ropes.

3.15.5 Pilots. The more experienced pilot flies on the long rope and is responsible for ensuring that his rope stays clear of the other glider.

3.15.6 Radio. If all three machines have radio, use a common frequency, note callsigns, and do an R/T check before takeoff. Any problems can then be called on the R/T, but bear in mind that use of R/T to a glider pilot under a high workload may be a complicating factor and you may not get a reply.

3.15.7 Signalling. You need three ground signallers, one for each glider (who also may hold the wings level), and a forward signaller who is the `master signaller' and can be clearly seen by the tug pilot. The short rope wingtip holder and signaller (if different) have to be on the outside wingtip (normally, the Starboard one) for safety. As the tug moves slowly forward, the glider signallers signal normally and give `all out' once their rope is tight, but the forward signaller gives the tug pilot all out only when he sees both glider signallers giving all out. In a large field, if you can't find a third signaller, the more experienced glider pilot on the long rope can transmit `all out' to the tug by radio. This may be better in any case in a field if the wing holders and signallers are not gliding people.

3.15.8 Position on Tow - Left/Right or Low/High. The BGA notes suggest that the gliders stay in high tow but take up positions displaced left and right on either side of the tug. We have found it more successful to have the gliders go into high and low tow behind the tug, short rope high and long rope low. The advantage is that, for the short rope glider, the tow is virtually normal and requires no new flying techniques such as flying out to the right for long periods. Also, the low tow is a very comfortable position for long cross-country tows. Regardless of the method chosen, it is vital the pilots involved are fully briefed on the procedure that is going to be used; if in doubt use the Lasham low/high method.

3.15.9 After Takeoff. After take off, initially the gliders retain their small lateral offsets from the tug, normally short rope right and long rope left. The tug will continue straight ahead without turning. At an agreed height, usually about 300 ft, the forward glider gradually goes across into a normal high tow position behind the tug. Using this as a cue the long rope glider then goes into low tow in line behind the tug. Only when the gliders are in line behind the tug can it turn. Roll into all turns as gradually as possible, and use less bank than usual, to make it easier for those behind you. Even if they are experienced, they may be tired at the end of the day after a long soaring flight.

3.15.10 Release. At the release point, the forward glider releases first and does a positive climbing turn so that the tug pilot can see in his mirror that he has gone. The lower glider then comes into high tow so that the tug pilot can see him, and releases with another positive climbing turn, normally turning the opposite way from the first glider unless he can see that he is well clear.

3.15.11 After Release. The slower the tug descends after release, the less chance there is of the ropes tangling.

3.15.12 General. Dual tows usually go well while the tug is climbing but some glider pilots have little experience of long, level, cross country tows, especially in the low tow position. More dual instruction on the use of airbrakes on tow, and descending on tow, will be an advantage. It may well be worth setting up a training flight involving circling the airfield level at, say, 1500 ft, before letting some pilots go on a dual tow away from the airfield.

3.16 SIGNALS. Tug pilots must know how to signal the glider to release, and how to let the glider pilot know that his airbrakes are open. It is also important to recognise when a glider is signalling that he cannot release. These three signals can be practised and are included in the training. However these are by no means the only emergencies likely to be encountered and the following, after first covering these three signals, also offer advice on how some other problems and emergency situations could be handled. Do not forget how useful the radio can be in most emergency situations.

3.16.1 THE WAVE OFF. The signal for this from the tug to the glider is the deliberate slow rocking of the tug's wings using about 30 degrees of bank each side. On seeing this the glider must release. Use slow, deliberate control movements that cannot be mistaken for smaller amplitude bank oscillations sometimes met in turbulence. If the tug emergency is severe enough, such as an engine failure, don't signal, just release the glider and get on with dealing with the emergency.

3.16.2 GLIDER AIRBRAKES OPEN. Glider air brakes can come open in turbulence, or on take off or if the pilot fails to lock them properly. If this happens the tug pilot will first notice a poor rate of climb and may wonder wether there is anything wrong with the tug, a check on the engine gauges should confirm everything is OK at the tug end. A check in the mirror will then show the gliders brakes fully open. In this situation the tug pilot MUST use the following procedure.

1. Continue trying to climb at the correct airspeed. Try calling the glider on the radio.

2. Consider whether to signal to the glider that his brakes are open by rapid side to side movement of the rudder, use at least half the available travel and take particular care to keep the wings level, while giving this signal. The secondary effect of yaw is roll and this is particularly noticeable in aircraft with significant dihedral such as Rallyes. There is a real danger that if this signal is not done well, it can look like a wave off to a glider pilot, and this mistake could lead to an accident. Because of this danger, provided the tug is at least maintaining height, there is a good case for not giving this signal until either there are landable fields below, or the tug is approaching overhead the airfield.

3. If you are below 1000 ft, tow the glider back to the airfield, continue trying to climb but circle the airfield such that the glider can easily reach it after release even with the brakes open. Keep repeating the rudder signal to the glider pilot.

4. If the brakes stay out, repeat the signal from time to time. Most 180hp tugs can climb even when the glider brakes are open but if the tug is at risk, wave off the glider, if the situation worsens release it.

3.16.3 GLIDER CANNOT RELEASE. When a glider has release problems it will fly out to the left side of the tug, and rock its wings (ie bank first one way and then the other). This is not an emergency requiring instant action, in Australia for example, they train to descend and land on tow, so do not rush to release the glider, appraise the situation first.

Tow the glider back to the airfield.

Is the glider lower than the tug? If it is and you release the rope from the tug end, there is a danger of it going over the glider wing or breaking the canopy, than when the tug is lower than the glider.

Do not release when the cable is taut, reduce power a little first, check the glider is high in the mirror then pull the release. Check the glider is flying normally before returning to the airfield. Make a call on the Radio to inform the launch point controller of the problem.

3.18 ENGINE RELATED EMERGENCIES.

3.18.1 TOTAL POWER LOSS. Change fuel tanks, electric fuel pump on. Fly the aeroplane at the best glide speed. Check the Mixture, Carb Heat and Magnetos. Try pumping the throttle a few times. Make a Mayday call to Lasham so that they can send help. Once committed to a dead stick landing, mags off, fuel off, and if you have the height to do this safely, slow down briefly to stop the prop if you want the aeroplane to glide better. Tighten your straps and stow any loose articles such as the log sheet, if there is time. Drop the rope and if all you can reach is a field too small to land in, land in it anyway, and aim for the softest looking part of the far hedge.

3.18.2 SERIOUS ENGINE VIBRATION. Propellers can shed tips and so become unbalanced, and if a conrod breaks in the engine this will also cause severe vibration. As you definitely do not want the engine to shake out of the airframe, the only action open to you is to quickly turn the mags off, slow the aircraft until the prop stops, and carry out a forced landing.

3.18.3 ROUGH RUNNING. Less dramatic rough running may be the result of contaminated or low fuel, ignition faults or Carb icing. You might have inadvertently knocked the fuel cock, mixture lever, or mag switch. Try changing fuel tanks, try Carb Heat and keep the engine developing at least the power to stay level. Other things to try are the mixture control and turning each mag off in turn.

3.19.1 Flaps, Landing Configuration. Use flaps with caution in case you run out of trim, half flap may be OK but avoid full flap. An unusual rolling moment on lowering flap should alert you to the possibility of asymmetric flap; in this case immediately stop the flap travel, look at the flaps and, if needed, put the flap up again, making sure that you don't stall. In any event, test your proposed landing configuration at height by cautiously reducing to threshold speed before using it near the ground, stopping any further speed reduction if you encounter any problems. Land into the clearest part of the airfield at no less than the speed that you have tested at height. If the aircraft will only fly properly at about one speed, then keep that speed right down to the ground. If things have not got quite that bad but you are concerned in some way about the airframe, then fly it slowly with minimum manoeuvring down to a flapless or half flap landing, using a higher threshold speed than normal.

3.19.2 Problems in Control. In the case of problems in pitch control, try using the trimmer, and bear in mind that changes of power and flap also give effects in pitch (remember the DC 10 that lost all its primary control surfaces but was crash-landed successfully using control through secondary effects of power and flap). Problems in lateral control may be helped by judicious applications of rudder but be careful not to induce a spin, particularly in the Regent which drops a wing at the stall.

3.21 WEATHER-RELATED PROBLEMS.

3.21.1 Poor Visibility. Deteriorating visibility caused by low cloud, rain, fog, or snow demands prompt action. More light aircraft fatalities are caused by poor weather than all the other reasons added together. If the deterioration is general, do not delay a decision to land, even into a field if the airfield cannot be reached. Turn on the Turn and Slip (if fitted) if you think you are about to lose visual reference, and take up a safe escape heading. If the deterioration is localised and will blow through with the wind, provided it is not too near sunset, fly upwind into good weather and hold off at endurance speed without flap (ie minimum power) until the airfield has cleared, watching the fuel and staying within range of other airfields or large fields. Popham, Odiham, Blackbushe, Farnborough, Greenham Common or Thruxton should be borne in mind. If you have to land in really heavy rain, hail, sleet or snow, the windscreen will be obscured and you will have to look out sideways to judge your height for landing. This is not as difficult as it sounds, instructors in the rear seat of Tigers and Harvards do it all the time. The major problem is often not the landing, but seeing obstacles ahead so it is best to land well into the airfield with a slightly higher threshold speed than normal.

3.21.2 Strong Winds. Strong winds generate turbulence in the bottom layers of the atmosphere, particularly in the lee of vertical features such as lines or trees, buildings, hills etc. Turbulence can make an approach difficult. In these conditions aim to land well into the airfield as far away from downwind of trees and buildings as possible to avoid the curlover and turbulence that they generate. Land as near into wind as possible, use plenty of power on the approach, use no more than half flap, and add 10-20 knots to the normal approach speed to counter the wind gradient and help keep control. Threshold speed (Vref) needs to be higher than normal (say + 10 kts) since in effect it is the energy needed to round out, but by the time you are rounding out you should be through all the wind gradient and the majority of the turbulence. If badly rolled by turbulence, apply full power, ease the stick slightly back and convert the roll into a climbing turn. In extremis, use rudder as well as aileron to pick up a dropped wing, but only if you have a safe margin over the stall. Where you land is important, it may be better to finish your landing roll downwind of the hangar so you taxy in almost into wind rather than landing closer and having to risk turning across the wind, something it may not be possible to do due to the wind's side force on the fin and rudder.

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Last updated by John Leibacher on Friday, September 8, 1995 at 21:21