Terrain Watch
 

When GPS systems first began to filter into GA cockpits I noticed a sharp increase in GA aircraft being caught out by the terrain just north junction 27 of the M1. My house was situated on well camouflaged ridge, A sister property proudly supported a plaque telling one and all that 'this is the highest point in Nottinghamshire'. The plaque said 604ft and the OS map 640. As usual some oaf added a comms mast so I suppose overall 700' would be about right. Its amazing how the built environment can mask what the terrain beneath you is actually doing. In 1945 a Stirling bomber hit the ridge killing all on board and it would have been more visible then than now.

Some discussion ensued about my theory that GPS to GPS forget the map lets have a rest might not be too far off the mark.

We are now some years on and I don't live there anymore so ridge dodging GA aircraft had slipped my memory.

Until today. Driving past the 'ole homestead a light aircraft suddenly popped into view engine howling as the pilot realised the predicament he'd just flown himself into!

Unless of course he had just taken off from Watnall flying strip - which lies near J27 M1 (or was carrying out a PFL).

Alas Watnal nee Merlin Flying Club long gone. The problem arises when aircraft flying west to east cross the Erewash/Golden Valley are confronted with a ridge that in turn is masked by terrain behind it. within less than half a mile the land falls away again towards the Trent Valley. Locals always boast that the highest point is the coldest spot in Nottinghamshire. Kirkby in Ashfield library used to display a map with a bearing line running out over the Trent Valley, Lincolnshire, the North Sea, Low Countries, Baltic, Polish Plain and the steppes. The next high point was in the foothills of the Urals

Merlin flying club was at Hucknall.
The strip I mean is west of the M1. I landed there last year.

Point taken Shy Torque, the profile doesn't fit your supposition I'm only trying to illustrate just how the built environment catches folk out. Having had more than one hot air balloon wrapped round my gable end and seeing the oil streaks on the underside of a light twin as he carved his way down the street. Any lower and he'd have had to stop for the traffic lights at the top of Mutton Hill. A 1500 hour mate of mine flying from Netherthorpe and Gamston is very well aware of the gotcha presented by the feature. Nottinghamshire isn't on everyone's radar as presenting a possible terrain hazard.

"The plaque said 604ft and the OS map 640. As usual some oaf added a comms mast so I suppose overall 700'"
At what altitude do people fly in that area, leading to 700' being a threat? 800' seems unlikely to be 500' above buildings.

The problem being ; We feel too safe when flying GPS.

In the past we stopped flying because we had no visibility to navigate. Now GPS tells us position and more. We don't "care" so much about the weather as we did in the past.

That is exactly analogous to the amateur yotty community. GPS encourage you to 'go to' a point without paying attention even to where the rhumb line will take you, never mind where your actual ground track might go. When GPS without plotters first came into use there was a spate of boats hitting rocks which is closely analogous to aircraft hitting terrain.


(in a sense, boats are always in IMC! They are always flying just on top of solid overcast!)