View Full Version : Help with VFR scanning techniques

30th Jun 2002, 14:22

Just want to know about good scanning techniques. Where can I learn them?

Any help appreciated.


30th Jun 2002, 22:48
Umm....what exactly would you like to scan....Trevor Thom says a bit about this.

When looking out never keep your eyes still....you must be looking at all parts of the sky all the time....even if its only for other traffic and not for ground features. Head down time should be kept to a minimum. Scan the map (always keep the map pointing the way you are going it makes things easier :D). And just go over the instruments on the way back up...thats how i do it. Oh and a FREDA check now and then.

Hope that helps


1st Jul 2002, 04:12
FREDA ??:confused:

1st Jul 2002, 09:13
I checked her out once... :D

The Nr Fairy
1st Jul 2002, 10:40
411A :

Mnemonic for "Fuel / Radios / Engines / DI / Altimeter".

Commonly taught in UK for leaving circuit, en-route and post-joining circuit checks at PPL level.

1st Jul 2002, 10:41
Well dont you always have a really fit co-pilot!!! :D No seriously....FREDA = Fuel Radios Engine DI Altitmeter.....just so everything stays how you want it to stay...Enroute checks if you like.


1st Jul 2002, 11:59
FEDRA - There's one school that teaches that...:rolleyes:

and there's FEDRNA - For instrument flight. :cool:

1st Jul 2002, 12:19
I like the humour:)

Just really want to know the best way to "rubberneck" short of having eyes in the back of my head.


2nd Jul 2002, 06:38
For a visual scan for traffic aircraft that are on a collision course remain at a constant relative bearing only increasing in size not moving across the visual field.

The eye is constructed so that the field of view is around 120 horizontally and 150 vertically, however only the centre of the vision area (the fovea) can detect the sort of detail we need to see aircraft - the rest is designed to detect movement (like big nasty predators!).

In addition to this without anything to focus on (i.e. looking at an empty sky), an eye will relax to its natural focus point of around one to two metres. This makes the pilot short sighted (known as empty field myopia) so that aircraft out the window are out of focus, and even harder to detect.

Finally, the eye doesn't move in a smooth scan, but "jerks" from poistion to position (known as "saccades"), which each "jerk" taking about a third of a second.

Given these points, for a good visual scan you need to: Move your scan from point to point, covering about 10 of the field of view with each movement. regularly focus on distant objects (like hills or clouds) to avoid empty field myopia. and hope you have a good radar service / TCAS :D

2nd Jul 2002, 08:35
One scanning technique that was taught to me by a cousin who used to fly F-4's for the Navy during my PPL training works very well and has served me thru the years. If you have VFR flight following services (always nice to have,but DON'T be overly reliant on it!),i.e. "traffic 5 miles...." first focus out at 5 miles distance and THEN look for the target. This method helps to alleviate the empty field myopia affect mentioned in an earlier post.