Thread Tools
This thread is privately moderated by Slider2732, who may elect to delete unwanted replies.
Jul 01, 2016, 03:31 PM
Storm Runner guy
Slider2732's Avatar
Thread OP

Hawker Hotspur and weird bubble lift

An odd flight experience of the AR6400 Hawker Hotspur.
This model is often passed up, in favour of the Hurricane, but flies very sweetly even with just rudder and elevator, as fitted to this one.
My original Blog post, with pics and build details is here:

As may have been noted, the sun sets on the road side of the small field that I fly at. However, yesterday evening saw some lightning at around 7.30pm and then reddened 'sunset' clouds in the North !
I mention that, because of the odd flights of both the Hotspur and a Nutball type aircraft up there at about 8.15pm. At that time, the temperature was about 84F and the wind was around 5mph. What may be important, is that the field grass hasn't been cut in many months, except up at the North end where there is a baseball diamond.
What am I getting at ?
Both would suddenly rise by several airframes worth of height, or occasionally drop by the same amount. Micro pockets of what I think were thermals (?). I had thought that thermals wouldn't be strong with any wind, so that is the point of my post...anyone see this sort of thing regularly ?

In the vid clip below, i'm using the elevator quite a bit to give a balanced lazy looking flight of the Hotspur. But notable moments include near the start, where she comes back far higher from the sunset direction than when going toward it, with no throttle increase or up elevator used. Also, dips and rises which should be accompanied by large changes in throttle.
A fun experience, but one that I don't yet understand !

Hawker Hotspur - Northerly sunset + bubble lift (1 min 32 sec)

Attached below, are a pic of the Hotspur and the weather conditions as reported by Wunderground for yesterday.
Sign up now
to remove ads between posts
Jul 01, 2016, 04:25 PM
Build straight - Fly twisty
Whiskers's Avatar
Thermal activity is due to temperature differences and does not need wind to make it occur.
It's the other way round. Thermal activity is the mechanism that creates the air movement we call wind.
Jul 01, 2016, 05:35 PM
Storm Runner guy
Slider2732's Avatar
Thread OP
Cheers Whiskers
It's an area I haven't delved into much over the years, with not building sailplanes.
Average winds have an average way of affecting flights, but this seemed so much stronger and i've not experienced it at that field with 7 years of flying there.
Hmm, temperature differences at ground level are something i'd not thought about, decreasing as well as increasing. But indeed, wind was always thought to be a product of thermal differences and would sort of wash out areas that birds circle (for example). The understanding that where there would be pockets of lift, would be replaced by a steady wind from a steady direction.

Quite recently i've noticed that 'morning' dew forms from around 8.30pm at the moment, which was another bit of learning.
Maybe my eyes are just open a bit more these days.
Jul 01, 2016, 06:24 PM
Build straight - Fly twisty
Whiskers's Avatar
There's always new and fascinating things to learn...

Quick Reply
Thread Tools