Why are there no Touch Down Zone markings at UK military airfields?

[India Four Two]

I posted this on the Questions forum and received four amusing but probably incorrect replies:

The recent posting of Mount Pleasant in the "What Aerodrome" thread showed that the runway has no Touch Down Zone markings. A quick bit of Googling confirmed that UK military runways do not have these markings, but French, German, Canadian and US military runways do.

Does anyone know the reason for this and what impact that has on operations for military and civil aircraft?

I'm somewhat surprised that I had never noticed this before, since I've flown out of nine RAF airfields http://static.pprune.org/images/smilies/worry.gifSo I'm posting here in anticipation of more banter and possibly finding out the correct answer :ok:

[Vage Rot]

Because Military aircrew know that one should aim to touch town in the first 1/3 of the runway - ideally close to that big Zebra crossing?!!!!!:ok:

Mind you, they also know to overshoot should they see a big Zebra, crossing!!

[Cornerstone958]

Defence cuts no money available for the paint:O

[The Helpful Stacker]

Our growbag wearing demi-Gods are of a higher calibre than those in the air branches of colonial or other non-British military forces. As such they want not of petty markings to bring their mounts back to Earth in a correct and officer-like manner after slipping its surly bonds.

{Doffs cap at the assembled officer, stick jockey types and scurries backwards out of the room, head bowed in due reverence.}

;)

[ProM]

I think helpful stacker is half right. If we had markings, our lot would want to land anywhere EXCEPT where the markings told them to.

[PileUp Officer]

American Football is not an officers' game

[Madbob]

If you are taught properly in the first place you don't need them! I remember being taught to get the aspect right. Worked okay on a 150ft width runway but needed adjustment when the runway got wider on a landaway....

More useful than TDZ markings I found were those distance to go boards counting down the runway remaining. (And for those that got it seriously wrong there were also the RHAG markers - big yellow discs in the verge.) :ok:

MB

[flipster]

Perhaps it is something to do with the approach lane safety domains? Civ ac performance is based on them being at 50' crossing the threshold on an instrument/PAPI approach - whereas I was always taught in the mil, that if you were conducting a visual approach, the domains were safe enough for you to land 'on the numbers' from a 3 deg approach. These days I just do as I'm told and follow the PAPIs/ILS!!

Perhaps an ATCO could tell us if there is a difference between civ and mil rwy safety-domains?

[thebarrel]

"don't Dive For The Numbers Bloggs!"

[Lurking123]

I was always taught that paint was slippery. Why would you spend a fortune on some high tech non-slip tarmac to just paint huge swathes of it in shiny Dulux? ;)

[sonicstomp]

Vigilant - correct.

If you fly it down on the PAPIs (assuming they are set for the desired GP) then acquire the touchdown point, maintain a constant sight-line to the 'bit of tarmac' that the jet is now headed for..seems to work....standing by for QFI incoming!!:}

I guess that 'bit of tarmac' could usefully have some markings that may assist that visual end-game - not necessary though...

[A2QFI]

An ancient mantra for teaching ab initio pilots to do approaches was something along the lines of

In steady descending flight, anything you see that appears to be moving down the windscreen is something you going to fly over, anything moving up the windscreen is something you are not going to reach and anything stationary in the windscreen is where you will hit the ground.

[haltonapp]

Perhaps because most civilian arports are CAT II or CAT III, and at 50' decision and low vis the runway below you is at the desired touchdwn point!

[Co-Captain]

Why is it that only the inside lanes of motorways/dual carriageways have ruts worn into them?

Why do you never see baby pidgeons?

Why does my white dog have a black nose?

Oh how the mind boggles :confused:

[ProfessionalStudent]

Can you use a daysack at night...?

[India Four Two]

I have just discovered, quite by accident, that the "secret Oxonian aerodrome" does have TDZ markings (at least it does on Flash Earth, although not on Google Maps).

Standing-by for banter aimed at AT pilots.;)

[Duncan D'Sorderlee]

There's a 'box of 6' at ISK. Unfortunately, it is of little use as it is based on the centreline!

Duncs:ok:

[Brain Potter]

The markings on a runway are not related it's Cat 2/3 status but are dependant on whether it is a precision runway (ILS) or non-precison/visual runway.

As well as the centreline and threshold markings (piano keys) a precison runway has 2 other types of markings:

1. Fixed distance markings are stripes either side of the centreline at 500 feet intervals from the threshold up to 3000 feet into the runway. The first 2 sets consist of 3 stripes either side of the centreline, the next 2 sets are 2 stripes and the final 2 sets are a single stripe. Some countries, including the UK, do not use the 3/2 stripe convention but instead use thicker pair of single stripes at each point.

2. Aiming point marks are 2 long, broad stripes either side of the centreline approximately (but not necessarily exactly) co-incident with the PAPIs. On some runways these are 1000' from the threshold, but on longer runways can be at 1500'. The aiming point supplants the fixed-distance marker appropriate to that point. The UK uses a checkerboard effect, rather than a broad stripe for the aiming point.

A typical set of standard markings could be: Piano keys, 3-stripe fixed-distance mark at 500', Aiming Point at 1000', then 2 sets of 2-stripes at 1500 and 2000' followed by 2 sets of 1-stripe each at 2500' and 3000'. Continuing down the runway the first set of markings for the other end is should begin with 3000' to go, at about the same point that the centreline lights start to alternate red/white.

Slight variations on these conventions are seen around the world. However, the UK military seem to be unique amongst major nations in not providing it's precision runways with fixed-distance or aiming point markings.

I suspect that the reason the UK military is so different is that some ATC policy seems to be made without paying regard to the international conventions. As an example, major work at a large RAF transport station included fitting equipment with ultimate aim of introducing Cat 2 operations. The new airfield lighting included the standard yellow/green runway lead-off and green runway lead-on lights that are essential to low visibility operations. However, The ATC branch policymakers decided that the green lead-on lights were dangerous as they might induce pilots to line-up without clearance to enter the runway (even though the required stop-bars been fitted). Despite appeals by the operators and the SATCO that these lights were entirely in keeping with international standards and the crews were completely familar with them from worldwide operations, the lights were not connected.

The Flash Earth image of the Oxonian aerodrome shows that Satndard UK civil markings have been painted, but curiously it looks like the aiming point has been put in at 1500' rather than approxiamtely coincident with the PAPIs whch are at 1000'.

[hello1]

Slight diversion perhaps but......

Someone tell me that we are putting a Cat III ILS into the airbase now known as Futurecarterton......or are we really buying a bunch of very capable aircraft but failing to provide the necessary approach aids at their home station:

C130J = Cat II cleared at some point (but not much use for that in Bastion!)
A400M = ? but probably better than Cat I
A330 = Cat III or are we paying extra to have this taken out?
C17 = Cat II if I remeber rightly.

:D:D:D

[4Greens]

Probably a hangover from the war. Makes the runway harder to spot by the baddies. Not needed on a carrier anyway.

[Farfrompuken]

Vigilant Pilot:

The Minimum Eye Height over Threshold (MEHT), It is the lowest eye height over the runway threshold at which an on-slope
indication on the PAPIs will be seen for a given approach.:bored:

Reference Datum Height (RDH) is the height that the aircraft should pass over the threshold on a 3 degree approach (normally 50').:zzz:

Professional Stude:

A Daysack is useable at night, however it should be referred to as a Knapsack at sunset until sunrise.:ok:

Co-capt: I could answer your first question but it would see the Geek-Police go into overdrive!!

I'll get my coat...

[CirrusF]

RDH is used for JAR/OPS landing distance performance calculations.

MEHT allows calculation of landing gear clearance at threshold - only usually important on very large aircraft.

[Busta]

The touchdown zone is the long thin grey bit just after the big green bit with the lights on sticks.

Nothing matters very much, most things don't matter at all.

[HercDriver]

Hell if you cant touch down in the "Assault Zone" you suck anyway!!! :ok:

[Thud_and_Blunder]

Runways? I thought the desired landing spot was usually marked either by:

= a burning LOH (for SASless)

= a bloke with twigs in his hat / Oakley specs (delete as appropriate) holding a dayglo flashcard or an IR strobe.

[Sir George Cayley]

NOW HERE IS THE CORRECT ANSWER AFTER ALL THE DRIVEL :ok:

Regulation, regulation, regulation......

Both ICAO Annex 14 and CAP 168 require aiming point and touchdown zone markings for certain classifications of runways. It's a certification / licensing requirement.

In the UK, MOD aerodromes are not subject to ICAO/ CAA oversight and hence signals, signs and markings are as per the relevant JSP.

This may change in the future due to European Harmonisation (don't worry chaps you'll hardly feel it) but the EU have yet to decide.

Sur le incontinence, many Mil aerodromes share a civil side so Annex 14 applies.

There is a distance relationship between the ILS GP, PAPI origin and the runway markings, so even though it may work at a subliminal level they all help. Or have not yet been shown to be an hinderance:sad:

Sir George Cayley

[India Four Two]

Well, thank you, Sir George.

After all the great banter and theories, it's nice to get the answer from the Father of British Aviation. :ok:

I should have written to you in the first place.;)

BP's comment about the positioning of the markings at Brize is very interesting. I wonder what happened there. Perhaps some miscommunication along the lines of how XXIX Squadron ended up with XXX on their aircraft!

I42

[GOLF_BRAVO_ZULU]

The Breweries never made XXIX beer! Simple as that.