Thursday, 24 September 2015

Hamfest HAB Launch likely to be postponed to Saturday

Given the latest flight path prediction, weather forecast and approval restrictions I will unfortunately have to likely postpone the National Hamfest high altitude balloon till Saturday.

The forecast for tomorrow is strong gusty winds at ground level which isn't ideal for launching, but that is the least of the issues.

The current flight predictions for tomorrow are not good. The prediction model used is accurate and for the size of balloon I have and the amount of helium at my disposal even a maximum fill giving the maximum ascent rate and assuming the calculated decent rate for the parachute it is still putting the likely landing right on the coast. Earlier in the week the landing wasn't quite as marginal but as the model's data set have been updated it has drifted further eastward, it is odds on it will actually land out to sea.

However the real show stopper was when I received the CAA approval for the launch this morning. They have put a restriction not permitting a launch if the balloon and payload is likely to go on a North Easterly or Easterly path that could interfere with operations on local military airfields.

This is the predicted flight path, generated by the CUSG Landing predictor at predict.habhub.org and the flight path currently goes directly over RAF Cranwell but not at a high enough altitude. 

Flight prediction for Friday
Saturday is forecast to be a much calmer day with a predicted path as shown below

Flight prediction for Saturday

There would be no issues with the airfields for that flight path and has the advantage of going almost straight up and landing close by.

Apologies to those wanting to track on Friday, but the situation is out of my control and I would be foolhardy to ignore the prediction and  it is very unlikely it will change significantly to allow a flight tomorrow so I hope you can all track on Saturday. I will still be at the Hamfest tomorrow with the equipment if you want to know more about what it is all about.


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