Introduction

Aerotow is the process of using a powered aircraft to tow a sailplane into the air. Over the past 10 years in the scale soaring community, aerotow has been growing in popularity due to the following factors: 

• It is usually safer for maiden flights than the slope
• It allows for less travelling time as most model airfields can be utilised
• Less weather dependant compared to slope flying
• When organised correctly, more people can be flying at the same time than on a slope.

With this growth in popularity, there also comes the inevitable need for better management of the events. In this article, we try and cover the main areas that affect and aerotow event and in doing so hopefully make it a fun and safe affair.  

If anyone has has comments or suggestions for additions to this article, feel free to email us here

Basic Requirements

Club affiliation and insurance

As with all events in the sport of radio control soaring, there is an expectation that you are a paid up member of a club and have current insurance with the relevant state body and the MAAA. By flying without insurance, you are putting all of the other pilots at risk. If you are new to an event, do not be offended if you are asked to show your ticket… and don’t be afraid to ask if you are not sure that someone has insurance. 

Operational Practices

1. The Pilot Briefing

To ensure that all participants have an enjoyable and safe day’s flying, a pilot’s briefing is recommended before getting under way.  The following are important items that should be covered.  Regular events could benefit from printed or on-line guidelines so that new participants and visitors can gain an understanding of the procedures in advance.

 The following areas should be clearly defined and appropriately designated:

• Launching, Landing & Pilot areas
• Glider Queue
• Tug pit area
• Glider pit area
• Frequency Control System/Transmitter Pound

The launching/landing strip (in most cases) will be defined by the location and the wind direction. In addition to the basic strip setup, procedures should be defined for queuing the models ready for launch. 

Tug and glider pits should be well away from the active runway and if possible, it is a good idea to keep glider and tug pits separate.  The glider queue will be close to the designated launch area, but a safe distance from the strip. No gliders should be in the queue unless they have a loop ready in their tow release and all glider functions have already been checked. 

Other items that should be included in the briefing include the frequency control system, specific ground operating & safety procedures, airborne procedures and emergency procedures (e.g. what is expected of a pilot if he/she experiences a loss of control etc).  

2. Key personnel & use of observers

It is highly desirable to assign one or more marshals to manage the proceedings and to provide an initial pilot’s briefing. If no marshals have been assigned then the Tug pilots, or an appropriate local club member, should take responsibility to agree appropriate operating practices and to nominate observers to assist with management of the activities. 

Wherever possible, each tow should have an observer for the glider pilot.  In all cases the tug pilots should be supported by one or more marshals who manage the active runway and provide take-off and landing clearances for the tugs.  At large meetings a dedicated safety officer is also recommended.  

3. The Tow

Hooking up – be ready and be close by

Nothing is more annoying for all pilots than a glider at the front of the queue and the glider pilot is not ready.  If your glider is in the queue;

• stay close to the queue
• have a loop inserted in your tow release ready for hook up
• have all of your controls and gear checked before you place you glider in the queue – at hook up, the only thing you should be doing is a final pre-flight check that all surfaces are working correctly
• if a token system is being used, have your token ready

Making a tug wait is making the tug’s engine get hot (and probably the other pilots in the queue!). 

Calling out your intentions

If there is a helper or marshal hooking you up they have two calls two make:

• When the line is hooked up and they are out of the way they will call to the tug pilot “take up the slack
• Holding the wing tip, they will call ”ready”

The Tug pilot will ask the glider pilot if they are ready and with a positive response, the tug pilot will call out aloud “taking off”. Some Tug pilots like to give the sailplane pilot a count down to launch “OK, 3, 2, 1….” 

Talk to the tug pilot when on tow.

Towing is joint activity between tug and glider pilots. You both need to be able to talk to each other.  With all the other ambient noise, this will require you to stand together.  Pilots are not mind readers! Notification of turns, speed and climb angle, release preparation and problems in flight all have to be communicated between each other concisely and quickly. It is a good practice to agree the direction the tug will turn immediately after release – the glider should either continue to track straight ahead or turn in the opposite direction to the tug. 

Most tugs are in high demand so a fast decent is usual after release therefore the glider pilot MUST confirm that the tow has released before advising the tug pilot that he has released. To reduce the chances of collisions, tugs should descend in agreed areas and gliders should try to remain clear of these areas.  

Pilots stay together

After your tow, make your way to the designated pilot area. Again, this will be where all pilots will be within talking proximity of each other. If someone is having trouble, all other pilots need to be aware of this. 

When in trouble!!!

The first thing to do is let everyone else know you are in trouble. That way all other pilots can clear the airspace allowing you to deal with the situation. If you are still on tow, the tug pilot may be able to assist you in regaining control or release the tow line from the tug. If there are nominated emergency procedures in place do your best to follow them.

4.  Flying

Number and type of models in the air

No matter how vast the area is that you are flying in, it can get crowded very quickly. Limit the number of gliders in the air to what is reasonable for the conditions and the size of the sailplanes or as defined by any local rules – two half scale sailplanes can take up a lot of sky! 

Observers

Aerotow by its nature means that in great conditions, your sailplane can become a spec in the sky, no matter what its scale. There are always times you may need to look away and it only takes one distraction to loose sight of your model. When flying in big air, or even better, whenever you fly aerotow, make sure you have someone who can be your second set of eyes. Too often beautiful sailplanes have been lost when the pilot accidentally starts flying someone else’s model. 

Thermaling guidelines

A lot of scale pilots do not realise that there are guidelines to follow when soaring. If a pilot is already in a thermal, and you fly into that thermal, you should start your turn in the same direction as the pilot already there. A sailplane in a thermal turn has right of way, so make sure you give them a wide birth if you are crossing their path. It is your responsibility to be aware of what is in front of your model. 

Aerobatics – where & when

Some pilots enjoy putting their sailplanes through their paces with aerobatics. As with all procedures in an aerotow event, you are required to call out your intentions to do aerobatics. Performing aerobatics in airspace where others are thermalling, or in the circuit area, can be very distracting, especially without any prior notice. 

If a designated area has not been specified in the briefing, make sure that you advise all pilots where you are doing your aerobatics. 

Beat-ups on the strip also require a call well in advance of the manoeuvre. Be aware, any landing aircraft have priority on your beat-up. If a marshal is present, do not conduct the beat-up without the marshal’s consent. When conducting the beat-up, make sure you fly to the opposite side of the strip away from the pilots and public. A large sailplane at those speeds can cover a great distance in the event of a mishap.  

5. Landing

Calling out your intentions

Wether there are marshals or just a small group of pilots, if you do not let everyone know you are landing, then no one can give you priority. Call out your intentions in advance so that last minute conflicts are avoided. 

Who has right of way?

In a properly set up strip, the sailplanes have priority in the landing circuit and tugs should hold off until the strip is clear. If a tug pilot calls dead stick, then he has priority over the sailplanes as he has less time than a sailplane to land.  If Marshals are present, they will prioritise landings so be aware of their calls. 

Retrieving your model

When you model comes to a stop, wait till the strip is clear of any other approaching aircraft, call “on the strip”, or get clearance from the marshal, and then proceed to retrieve your sailplane. DO NOT do anything to your model until you have cleared the strip. Only then should you switch off receivers or look at problems etc. 

6. Suggested Aerotow Strip Layout

The Launch Box System

The following layouts have proven to work well in most situations, and provide for an efficient and safe aerotow event. Known as the Box system, a box is outlined with witch’s hats or similar, approximately 10 meters square. The head of the box sits flush on the strip running parallel with the active runway. Depending on the wind direction, the launches are conducted on the up wind side of the box parallel with the strip. The tug and launching sailplane pilots stand on the top corner closest to the strip.

Once released, sailplane pilots move to the down wind top corner of the box for flying and landing. The Sailplane queue comes up from the bottom of the box. No pilot should leave the box other than to retrieve their sailplanes from the strip. – figure 1

 

 

If more than one tug is in operation, the box can be extended in its height to encompass a tug waiting area and two launch points – figure 2

If strip area is at a premium, then the Launch area can be angled back towards the main strip. figure 3