Xplorer Ultraflight
Performance Paramotors
for powered paragliding

Articles of Interest

Dealing with Turbulence in flight
I often receive questions from relatively new PPG pilots regarding handling turbulence, deflations and the like.

There are a number of aspects to this.

First, avoiding a deflation is far better than sorting one out.

The best way to prevent a collapse is not to fly in such conditions that are condusive to this type of turbulence.

    Major causes of turbulence:
  • Mechanical turbulence, downwind of obstacles (aka rotor generators such as buildings, mountains, etc)
  • High instability of the air due to Super-Adiabatic Lapse-Rate
  • Shear Layers due to friction between differing air masses
  • High gust factor due to mixing air

If you are not aware of these scenario's, then your instruction was seriously lacking.

Meteorology should be a major part of your training. Without detailed insight, you are asking for trouble - sooner or later you will find yourself airborne in suicidal conditions; perhaps so turbulent that you cannot execute a safe landing at all! I have seen this, where a pilot launched in what he thaught was ideal weather, only to get totally trashed and fought for his life for about 20 minutes before being dumped into the ground - thankfully not injured, but motor was seriously damaged - not that it mattered, as he promptly gave up flying right there... this all on a day we had foreseen the conditions and decided to fly kites instead.

OK, not flying in rotor nor highly unstable air-mass is your first stage of avoidance. But what happpens if you are airborne and then either accidentally fly into rotor area, or the wind suddenly changes and you find yourself in severe turbulence?

For the first part, you must be constantly aware of your upwind geographic layout. Always think about where the wind is comming from. Sometimes you can safely fly higher OVER rotor areas. The height and downwind extent of the rotor will depend for the most part on wind strength and the lapse-rate. A safe guideline is to be at least twice as high as the wind obstacle (rotor generator) and/or 10 times its height behind (downwind of) it.

For the second instance, of wind changing and weather deteriorating:-

    Wind can change in a few manners:
  • drops off - no problem, flying gets better.
  • picks up - may cause penetration problems and will probably increase gust factor.
  • Get gustier - possibly associated with stronger peaks - will lead to turbulence increase and could cause dynamic stall complications.
  • Veers or Backs - direction changes (Clockwise or anti-C, respectively). May be associated with change in wind speed - either milder, stronger, or gustier. Primary concern of changing direction will be changing upwind turbulence generators. An obstacle that was not throwing rotors your way earlier, may now be aiming straight at you!

Keep an eye on telltale signs of wind changes. These may include amongst others: ripples on water, smoke from fires or BBQ, windsocks, flags, weathercocks, laundry on lines, trees and bushes, pedestrians' clothing, birds taking off and landing, boats at anchor, etc. Look out for these BEFORE takeoff, and all the time during flight.

The earlier you spot changes happening, the quicker you can evaluate the threat factor, make decisions and formulate plan a of action.

Plan of Action may include such ideas as: Land immediately, anywhere that looks safe. Start looking for suitable landing. Start flying back to intended landing (takeoff area?) and re-evaluate along the way. Change intended route to avoid new danger areas. Climb higher to increase options and get over rotors. Turn directly into wind to better handle increased turbulence, while seeking a suitable landing.

Remember that you are unlikely to be suddenly struck down by a dragon out of no-where. There will be telltale signs if you look out for them. You may already be aware of a manageable amount of turbulence and quite content to deal with it, but be on the lookout for noticable increases. You may have flown into an area of increased turbulance (start turning away) or the conditions may have deteriorated.

Assuming you cannot avoid the turbulence, or it catches you completely by surprise, then you modify your flight as follows:

If at all possible without sacrificing landing options or flying into no-go areas, try to face into the wind. This does a number of things - reducing your groundspeed, - upwind obstacles are in your direct line of vision, - gusts are easier handled head-on.

This last bears embellishment. A sudden gust or blast of air from the front of the wing will cause it to pitch-back and gain some height. From the rear, you will temporarily lose airspeed and lose some height - hopefully you have surplus height when this happens. From the side, you are likeley to suffer an assymetric deflation or minor collapse. In any event, you are more likely to be able to anticipate the gust or turbulenace and pre-empt with the correct action, if you are facing the wind.

Most collapses (outside of doing extreme maneauvers), are from downward blasts of air, e.g. the downward edge of a horizonatally rotating eddie of air. Even in this scenario, you are better off facing the wind than any other attitude.

While flying into wind in turbulence, chose a safe height, and start looking out for wind-obstacles ahead which may throw rotors at you, while at the same time start evaluating your flight plan and decide whether you would prefer to land, or continue, or divert to another route. If you chose the latter, make gradual changes to your flightpath and try not to turn more than 90 degrees from the wind. If you need to turn downwind, first climb to a safe altitude, say 1500 feet (or more), then turn downwind gradually.

Beware of the downwind demon. Flying into strong wind, if you do a rapid turn to face downwind, you may rapidly lose some considerable height due to a variety of factors.

If everything fails, and you get a major deflation, then you need to revert to your paragliding training. Dealing with a collapse under power is no different from soaring flight, with one exception - Do NOT suddenly dump the power. If you let go of the throttle, you will have a worse situation to deal with - instead, if you have enough height, gradually back off the power until you are in flat glide mode, at the same time take the standard procedures to deal with the deflated wing. This is not the place for me to tell you how to deal with a collapsed wing - you should have thoroughly covered this in your training, BEFORE converting to flying with power!!!!!!

I seldom fly a motor with an emergency parachute. I always paraglide with a reserve, but then thermals and mountains are a constant threat and deliver much turbulance.

When I fly with a motor, I chose a location free from mountains upwind, free of excessive thermic activity, free of excessive wind, and with a safe lapse-rate. Best times are early morning until the thermals start popping, and again late afternoon when the thermal activity has died down somewhat.

Flying in mid-summer, at mid-day, is asking for trouble, even near the coast.

I always insist that my students are first 100% capable of handling their wing in all conditions without a motor, before they start converting to powered flight. Most of my students are paraglider pilots converting to powered flight, so this is easy enough. When Joe Public wants to fly paramotors, I first send them on a full paragliding course with an instructor I trust (preferably one that also flies motors, but not essential). Then, when they have completed, I test their practical ground-handling and flying skills. If they are not yet up to scratch, I will start on the theory and ground-handling, but will not start them flying until they get their canopy handling skills sorted out.

Let me emphasise this:

Canopy Handling Skills are the primary skills required to fly paramotors !!!!!!!!!

Converting to power should be straightforward for someone whom is already capable of handling his canopy well.

Then the student only needs to grasp the fundamentals of propeller forces, thrust/speed/AOA problems, and modify takeoff and landing techniques.

Handling all the new forces introduced by the motor and spinning propeller, is enough workload, without still battling to control the wing in adverse conditions.

If you have not completed a full paragliding course, I strongly urge you to enroll in one with a reputable instructor, even if you do not intend paragliding without a motor after you get your paraglider license. You will find the skills and knowledge taught there to be an eye-opener and will be shocked at how dangerous your flying was before.

OK, so how would I handle a typical severe collapse?
I must assume that a sufficiently safe altitude was being maintained just prior to the collapse.

I would not even think of throwing a reserve yet (even if I had one), and would first see if I could sort out the collapse.

I would simultanously start backing off the power, while counter-steering to maintain flight into wind, then start pumping out the collapse. Even if the wing is badly tangled up, I would rather land with it collapsed, as long as I could maintain into wind.

Even a badly trashed wing still offers significant drag to soften your impact, provided you are facing the wind. If you come in fast downwind with a high descent rate, you will very likely strike some object and get seriously injured.

If the collapse starts with you facing to one side of the wind, up to 90 degrees away, and the collapse is on the windward side, then there is no great hurry to counter steer, at least until the collapse has caused you to turn into wind, by which time you need to have recovered sufficient steerage to stop the rotation and maintain that heading.

If the collapse happens on your downwind (leeside) wing, you need to establish if you can turn the wing away from the collapsed side without stalling, or start counter steering to reduce any rapid rotation, and if high enough, let the wing turn slowly through 270 degrees and then stop the rotation facing the wind. This does not mean you should not be trying to pump out the collapse while doing all this.

Some collapses recover without any pilot input, some need minor input, some need major recovery technique from the pilot, and a very few may be uncorrectable. Only in the last case, and only as a very last resort, should you even think of throwing your reserve.

A lot depends on your wing, your height, your experience level and training received, and the extent of the collapse and your rotation rate.

There is no simple answer, unless specific details are considered.

If you are flying a wing with a Basic or Standard rating, and the wing behaves well with a motor, then you should not experience unmanagable situations, unless you are inexperienced or have insufficient training, or find yourself in EXTREME turbulence.

It is up to YOU to get PROPER training, specifically CANOPY HANDLING SKILLS as tought in a Paragliding Course, and it up to YOU to avoid extreme turbulence. Your selection of wing may also be critical.

Write to keith@xplorer.co.za