Concrete rectangles at the ends of runways.

'Safe Bar 6' is an abbreviation of 'Safeland Barrier Mk 6' which was the standard RAF arrestor barrier system until the 'Type A' was introduced in the late '70s.
They were intended for use by all jet aircraft in the RAF inventory from JPs upwards but are not suitable for propellor aircraft hence have been withdrawn from places like Cranwell after years of operating JPs.
SOP at Farnborough was to raise the upwind barrier for all jet takeoffs and landings (apart from the Comet and BAC 1-11) and advise the pilot 'barrier up' when clearing them to takeoff or land.

Ossington_2008 wrote:

My guess is footings for VASI's. Variable Angle Slope Indicator. Low rectangular boxes containing coloured lights visible to a landing pilot. Green if on the glideslope, red, if too low. That kind of thing. More on how it works on google, but few images of the lights.

'VASI' stands for 'Visual Approach Slope Indicator' which showed either red or white; there was no 'green' light in this system but there was in an earlier system called 'AAI' or 'Angle of Approach Indicator'.
VASIs superceded AAIs and have now been superceded by PAPIs or 'Precision Approach Path Indicators' and all these systems were installed adjacent to the runway threshold/displaced threshold and not at the end of the runway.

TerryClark wrote:

'Safe Bar 6' is an abbreviation of 'Safeland Barrier Mk 6' which was the standard RAF arrestor barrier system until the 'Type A' was introduced in the late '70s.
They were intended for use by all jet aircraft in the RAF inventory from JPs upwards but are not suitable for propellor aircraft hence have been withdrawn from places like Cranwell after years of operating JPs.
SOP at Farnborough was to raise the upwind barrier for all jet takeoffs and landings (apart from the Comet and BAC 1-11) and advise the pilot 'barrier up' when clearing them to takeoff or land.

Thanks for the reply its is most enlightening, I would have never figured that places like Duxford would have had this equipment as I have always considered it relatively recent.
A google of the Safeland MK6 brings up an image of a Canberra which has apparently engaged it so it was capable of adsorbing a fair bit of energy.

I would be interested to know why on some airfields the barriers were not placed right on the threshold as, apparently, the aircraft would have to run a moderate distance over what looks like grass?
In the case of Linton this would have been 200ft from the threshold on the main runway (but at the end of the overrun on the cross)
I am guessing that the barrier would not bring an aircraft to a dead halt but 'expand' a fair distance slowing it down so the undercarriage would run on grass.

698 wrote:

[
Thanks for the reply its is most enlightening, I would have never figured that places like Duxford would have had this equipment as I have always considered it relatively recent.
A google of the Safeland MK6 brings up an image of a Canberra which has apparently engaged it so it was capable of adsorbing a fair bit of energy.

I would be interested to know why on some airfields the barriers were not placed right on the threshold as, apparently, the aircraft would have to run a moderate distance over what looks like grass?
In the case of Linton this would have been 200ft from the threshold on the main runway (but at the end of the overrun on the cross)
I am guessing that the barrier would not bring an aircraft to a dead halt but 'expand' a fair distance slowing it down so the undercarriage would run on grass.

I can only guess that there was a 'bit of grass' between the end of the paved surface and the barrier in the expectation the aircraft might be slowed by its wheels sinking into the ground and thus slowing the aircraft down before it engaged the barrier; the barrier net had to be fairly robust and engaging at high speed could cause airframe damage.
When the aircraft engaged the barrier, the net would break free of the stanchions and would pull out about 200ft (I think; can't remember the exact figure)

Yes, that must have been the case.
I wonder what the criteria was for an airfield have them fitted as GE and the 1975 ERS seem to tie up together and not all were so fitted.

Anyway, another one of my little curiosities has been solved !

698 wrote:

Yes, that must have been the case.
I wonder what the criteria was for an airfield have them fitted as GE and the 1975 ERS seem to tie up together and not all were so fitted.

Anyway, another one of my little curiosities has been solved !

Basically if miitary fast jets (up to Canberra size) were operated from that airfield; other airfields eg Woodvale, Colerne, Hullavington did not have fast jets based there (apart from Hullavington when they filmed the TV series 'The Squadron; now how many of you remember that eh?) plus of course V bomber airfields and heavy transport airfields; Victors and Belfasts in particular were a 'bit critical' on takeoff and if there was a barrier where they were taking off, the crew would make sure to request it was down for their departure!

698 wrote:

Thanks for the reply its is most enlightening, I would have never figured that places like Duxford would have had this equipment as I have always considered it relatively recent.

Duxford was a fighter station until it closed in July 1961 operating Javelins and Hunters.
Not sure if Javelins had brake 'chutes but Hunter F6s didn't and on a 6,000ft runway, an arrestor barrier was needed in case of hydraulic failures.

Llanbedr had three arrester barriers on rwy 36/18 as it was then and rwy 33, for the use of Valley touch and go practice and Llanbedr unmanned aircraft, ie Meteor U15 U16 and Jindivik

www.google.com/maps/@52.795152,-4.122686,282m/data=!3m1!1e3

www.google.com/maps/@52.814553,-4.1286535,282m/data=!3m1!1e3

www.google.com/maps/@52.8072304,-4.1187387,196m/data=!3m1!1e3

Regards Ian

I've had a very quick flick through my copy of Gloster Javelin An Operational History by Michael Napier, bought for me at Christmas but I've not got round to reading it yet, and there are no photos that I've found that show a Javelin deploying a chute.
There are two photos of interest to this topic , one is on page 137 showing a Javelin in the barrier at Leuchars in December 1962 ( apparently a 'trial') and on page 231 a Javelin touching down at Tengah (I think) and in the fore ground can be seen what I assume to be part of the barrier assembly.

I could quite imagine the effects of a barrier trying to stop a Vulcan, bit like a rugby tackle by the legs on a giant and also the effect of the barrier catching those legs if the aircraft was airborne but only just.

Yes, I remember that TV series and recall that the first program was the best with Jaguars and Phantoms in the action, which in the rest of the series was 'cut back' to Harriers. So there is nothing new under the sun in defence spending!

ianbache wrote:

Llanbedr had three arrester barriers on rwy 36/18 as it was then and rwy 33, for the use of Valley touch and go practice and Llanbedr unmanned aircraft, ie Meteor U15 U16 and Jindivik

www.google.com/maps/@52.795152,-4.122686,282m/data=!3m1!1e3

www.google.com/maps/@52.814553,-4.1286535,282m/data=!3m1!1e3

www.google.com/maps/@52.8072304,-4.1187387,196m/data=!3m1!1e3

Regards Ian

To be pedantic, the third barrier was on runway 15 not 33!!