ALTITUDE AND GLIDE ASSESSMENT

or “Can I make it back?”

When you first open and have checked your canopy and immediate environment for other canopies then the next questions you should ask yourself are “where is the Drop Zone and do I think I can get there?”

This doesn’t change whether you are a first jump student or a jumper with 1000s of jumps.

While having fun under the canopy during descent is great, it is secondary to arriving at the DZ with enough height to complete your landing approach and landing.

With experience and on most jumps the questions can be answered with a momentary glance – “There it is and I’ll easily make it” but sometimes, following a poor spot, or on a day with tricky winds, it needs a more careful and continuous assessment of the possibilities.

So, the accuracy trick...

The Accuracy Trick

You can tell if you have enough altitude to reach a given landing site by looking at an object (eg building/tree/power pole) just in front of or near to the site.

By looking at the top of the object as you fly towards it you can see whether the ground appears to be rising or sinking behind the object.

If you are going to clear it the ground will be appearing (moving up).

But if the ground is disappearing (moving down) behind the obstacle then you know immediately that you are not going to clear it and you need to start looking in front for an alternative landing area.

As an alternative to facing the landing area, if you perform this test while side on to the wind (crabbing) it will give you a clear indication of whether you can easily clear it or not just by using the wind speed.

Then you can use your canopy drive to either hold or run to make sure you are well clear.

Of course, real life is often more complicated than that and you may encounter different winds at different heights but you have to start somewhere. (Usually the wind decreases as you get lower.)

Continue to use the accuracy trick as you get closer until you are sure you’ll make the DZ. If you find you cannot make it back then the accuracy trick lets you make the decision to land out in plenty of time to choose an alternative.

With a parachute that needs a longer runway, try to arrive at your chosen out-landing site with enough height to allow you to overfly the field, fly the landing pattern and check for obstacles. Powerlines are particularly hard to see if you fly a straight-in approach (and it is too late if you see them at 30 ft), so the few seconds spent checking an area you may never have looked at before is well worth the few more minutes of walking.

So, with a little preparation and practice there should be no more last minute decisions that aren’t really decisions - but are more like desperations.

Treat every landing as though it may be your last, then hopefully it won't be.

John Chapman, APF Technical Officer

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