Dynamic Soaring – DS

The Achievement Scheme is run by the MFNZ as a National Scheme and is open to all model flyers.

The Basic Certificate is a measure of flying ability and safety that “may be equated to a safe solo standard of flying”, and an increasing number of clubs use it as their ‘solo’ test. As an Examiner, the level of competence you should expect of a candidate should be based on that criterion; that is ‘is this person, in your opinion, fit to be allowed to fly unsupervised? A candidate wishing to take the Advanced must already have passed the Basic in that discipline.

The candidate should have studied the MFNZ Members Manual and any local site rules (if applicable) and be familiar with the ‘Safety Code for General Flying’ and the ‘Operational Guide, All Models and Radio Control’. Besides being an excellent guide to the safe flying of model aircraft, most of the questions asked at the end of the test will be from these sections of the MFNZ Members Manual.

A dynamic soaring pilot who wishes to fly above 150mph (241 kph) must also sit the HS wings certification.

The test can be performed with any unpowered slope soaring glider model, provided that the model is of sound structure to handle the loading and aerodynamic stresses put on it during dynamic soaring flight. The candidate may use a foam or a composite construction model. No pilot should attempt to fly a dynamic soaring model that is drastically out of their skill set.

The use of a gyro or autopilot is not allowed during the test. If any such system is fitted to the model, it must be disabled during the test, and you should check that this has been done.

Before any flight commencement, a first aid kit must be located on the dynamic soaring site. Due to the often remote locations where dynamic soaring occurs, a cell phone must also be onsite. The last known coverage location must be noted if there is no cell coverage. The location of the nearest Defibrillator should be identified before remote site entry.

Dynamic soaring gliders do not carry any fuel and only use small batteries and therefore only pose a small fire risk. A minimum of one dry powder fire extinguisher must be accessible onsite before flight commencement.

Due to the nature of the terrain required for dynamic soaring, every site will have slightly different characteristics. All dynamic soaring sites will have a ridgeline, but the orientation, accessibility and size may vary. It is up to the pilots involved to determine safe flight lines, active flight zones, and suitable viewing/safe areas. Most dynamic soaring sites are in remote locations away from the public and infrastructure. The examinee is responsible for ensuring that the site is suitable for the risk level of flight operation, and they should be examined on a safe site layout. Dynamic soaring should never be performed above populated or built-up areas.

The information below should be used as a guideline and discussed with all parties (pilots, examiners, flight crew, spectators, etc.) before the flight commences.

Pre-flight

Carry out pre-flight checks as required by the MFNZ safety codes.

The pre-flight checks are laid out clearly in the MFNZ Members Manual. The candidate should also go through the pre-flying session checks, also laid out in the MFNZ Members Manual. Ask the candidate to go through their checks as if the test flight was their first flight of the day. Particular attention should be given to the airframe, control linkages and surfaces.

Points to look for are the candidate’s steady and regular ground routine, which should include a pre-flight checking play and orientation of control surfaces and aircraft battery voltage. Nerves may play a part, but you should satisfy yourself that the candidate is actually in control of what they are doing when preparing their aircraft for flight.

Launching

Check that the launch area and landing area are clear on the ground and in the air prepare the model for launch.

Ideally, the candidate should launch the model. However, at the examiner’s discretion, a helper may be used for launching should one of the following conditions are met.

• High winds requiring two hands to launch the model
• It is difficult for the pilot to move from the ridge’s frontside to its backside
• The examinee is physically unable to launch the model
• Any reasonable safety argument

The candidate should perform a final surface movement test, clearly announce “launching”, and launch the model under full control. The candidate must correct deviations from the expected launch path smoothly and quickly, levelling the model into the wind without stalling. The launch should appear competent, and the glider should penetrate into the wind and fly free of the windward hill face.

Slope Soaring

Fly the model back and forth on the ridge’s front side, always turning away from the ridge. Use the slope soaring techniques to gain sufficient height for the model to enter the dynamic soaring circuit.

The pilot should be in control of the model at all times, turns should always be away from the hill and be smooth. The lifting air on the front side should be used to manoeuvre the model to a suitable altitude to clear the ridge when entering the backside and provide enough speed to ensure the model does not stall during the initial circuit.

Fly a single Lap “U circuit.”

The candidate should fly a single lap of the backside of the ridge. The model should enter from the frontside, over the crest of the ridge, through the shear layer, perform a smooth turn and exit back through the shear layer to the frontside.

Perform ten consecutive Dynamic Soaring laps.

The candidate must perform ten consecutive controlled dynamic soaring laps where each lap follows roughly the lap before. The model should pass through the shear layer on each lap. Turns should be of a consistent rate with control maintained at all times. Should the glider hit a rotor and get knocked off course, the candidate may correct and continue the circuits. Should the backside of the ridge become unsuitable for dynamic soaring, the candidate may re-enter the slope soaring circuit on the front side, wait for the backside air to clear, and then start the ten laps again.

Landing

The candidate should:

• Fly the model on the frontside to prepare the model for the landing phase.
• Call “landing” to alert other pilots of their intention.
• Land the model into wind within the predetermined landing area.

Depending on the model being flown, this can be a backside or frontside landing. You are looking for a smooth landing and not a 45-degree dive into the ground. A steep approach with strong brakes deployed is allowed, but a smooth round out and landing is expected. Things to watch out for are the pilot who realises he is too high and then dives rather than slows down (thus covering more ground, the opposite of what they want) and, conversely, the pilot who is too slow and stalls the model before arriving at the landing area. Both examples show a fundamental lack of understanding, and whilst not enough to fail the test on their own, they are a good pointer to a weak candidate.

Retrieve Model

Retrieve the model from the landing area, informing other pilots that the landing area is clear. When the model has been retrieved and returned to the launching area the transmitter should be returned to the pilot. There is no requirement to turn off the model and transmitter (and then clear frequency control, etc.) if the next flight will be made immediately. (p) Complete post-flight checks required by the MFNZ documentation. What is required here will be dependent on how smooth a landing was achieved. Any abrupt stop or collision with a fixed object would warrant a full structural and control surface check. A smooth landing will only need a visual and control movements check. As safety is the main driver the candidate may choose to perform a full check after each flight, and this should not be discouraged.

The candidate must answer a minimum of five of the Mandatory Questions correctly (Refer Mandatory Questions for all Disciplines (1-15)) on safety matters, based on the MFNZ documents for general flying and local flying rules.

The candidate must also correctly answer a minimum of five questions from the General and Specific Discipline Questions (Refer General Questions (16-29) & Dynamic Soaring Specific Questions (102-110)) on safety matters, based on the MFNZ documents for general flying and local flying rules.

It is suggested that the questions are asked before the flying test.

Prior to the flying test, the examiner should ask questions of up to three Local site rules. Such questions should query the maximum altitude models that can fly over the flying site as well as the boundaries of the site, together with site etiquette and pilot safety.

Remember, the Proficiency scheme is a test of both flying ability and knowledge.

It doesn’t matter how well the candidate can fly, if they cannot answer the safety questions, they should not pass. As an examiner, however, you should prepare yourself thoroughly for any testing you do, and you may wish to sort out your personal and private list of sensible questions. Don’t forget that you can use any local rules you know and the candidate should be aware of. Remember that the majority of questions you ask are to be BASED on the MFNZ documents; you are not expected to ask them parrot fashion and the candidate is not expected to answer that way either. This opens up the possibility of asking a candidate if they can think of reasons behind specific rules. For instance, where each of the flight areas is located, including landing and spectators viewing areas.