Distance to Run Marker Boards

[Belgique]

LINK (http://www.dft.gov.uk/stellent/groups/dft_avsafety/documents/page/dft_avsafety_023891.hcsp)

1. Reference this Report (Cessna Citation C560 overrun at Leeds Bradford) and its mention of "distance to run marker boards", does anybody know what the
UKCAA
IFALPA
US ALPA
FAA
NTSB
CASA
ICAO
etc
position on these seemingly useful devices actually is.

2. Can anybody cite runways

a. where they'd be a "nice to have"

b. where they are currently in use (military or civil) - lit or unlit

[Dan Winterland]

Common in the military, esp in UK. Have seen them at a few civil airports (can't remember where) but they are rare.

I'd like to see more. I spend my working life landing large aircraft with steel brakes close to MLW, often in hot climes. Something other than the red CL lighting at 900 and 300M would be useful.

[Ex Douglas Driver]

They are standard at military fields and are positioned either side of the runway and show a single figure giving distance to run in '000s of feet. They are illuminated for night ops here in Australia.

I agree that they are great for awareness on speed vs runway remaining, especially when trying to stop your skitterish little jet on a slick runway at night.:ok:

From the FAA website http://www1.faa.gov/atpubs/AIM/Chap2/aim0203.html
2-3-13. Runway Distance Remaining Signs

Runway distance remaining signs have a black background with a white numeral inscription and may be installed along one or both side(s) of the runway. The number on the signs indicates the distance (in thousands of feet) of landing runway remaining. The last sign, i.e., the sign with the numeral "1," will be located at least 950 feet from the runway end. FIG 2-3-41 shows an example of a runway distance remaining sign.

Runway Distance Remaining Sign Indicating
3,000 feet of Runway Remaining
http://www1.faa.gov/atpubs/AIM/Chap2/F0203041_small.GIF

[PAXboy]

This reply is not entirely tongue in cheek!

If you see the '1' board go by and your lightning fast brain computes that you wished it had been '2' ... what do you do?

Or to put it in a more practical way: If the runway is wet and you are a bit heavy and the '1' goes by and you are still going faster than you would like, what do you do? As an outsider, I presume that, if you are already at max braking for the conditions, there is not a lot more that can be done?

[Onan the Clumsy]

We had an MU300 (?) overrun 31R at KDAL and as he started down the banking and towards Bachman Lake, he looked up at the localiser array - mounted on about twenty telephone poles. He fed in some hard rudder and collapsed the gear - at least that's what it said in the NTSB report. Everyone walked away unhurt. :ok:

I got some cool pictures of them hoisting up the airplane on a sling.

[Genghis the Engineer]

There is a very much simpler version with much going for it in-use at many private strips. Essentially markers are placed at thirds - so there are only two markers (well 4, usually placed both sides of the runway).

The principle is very simple - if not at half-take-off speed or better by first marker, abort. If not airborne by second marker - abort.

Crude, but if you check the calcs, it makes good sense.

G

[forget]

There’s a novel and very effective way of advising Runway remaining at www.airspecinc.com Take a look at Reduced Runway Occupancy.

[Spitoon]

There's a commonly cited problem with countdown type boards - is it metres or feet?

It only takes a belief that it's metres when it's really feet and boards could do more to induce an overrun than to prevent it. Take the UK - we measure runways in metres these days - but it looks like Australia works in feet. Before you tell me that pilots are professionals that would check etc., just think about how many fuel exhaustion incidents there have been over the years.

[alf5071h]

An interesting initial post, but how would you use marker boards?
In the referenced accident the captain judged that the runway remaining after a late touchdown was sufficient to stop, unfortunately he was wrong.
So even with comprehensive knowledge of exactly how much distance is required to stop an aircraft with full reverse using max braking on a dry runway, considering slope, wind, wt, etc, how can marker boards of distance remaining help the crew decide to land? I doubt that few if any pilots, even those with vast experience, will be able to make such a judgement for every landing; thus for this particular judgement marker boards are of little value. However they may give a guide to the expected touchdown point, which if excessively long should prompt a go around, an issue that the AAIB considered but did not emphasise. Clear information as to the expected and actual touch down point should be available from the runway fixed distance markings (paint lines) positioned relative to the landing threshold; thus if you land at the correct point (and correct speed, configuration, into wind, wt, etc) the landing ground roll should be accomplished within the generous margins allowed by certification rules.
It is more likely that marker boards are used as a ‘how goes it’ during a normal landing i.e. to judge whether more of less retardation is required for the conditions encountered in order to make the planned turn off point. An astute captain will always retain a margin for error.

Also from the AAIB report, where is a 3.5 deg approach defined as unusually steep, in my book steep approaches start at 4 deg or higher. 5.5 deg is unusually steep, see LCY, (and a Citation operates into that airfield).

The Citation overrun accident involved human error, but the AAIB report only scratches the surface in seeking the underlying reasons for these errors. Until these reasons from this or similar accidents are aired we are unlikely to make significant improvements to flight safety. The suggestion to use marker boards is a diversion from the real issues that require addressing in landing accidents (also see http://www.pprune.org/forums/showthread.php?s=&threadid=102014). Not to knock the usual high standard of reporting from the AAIB, but when you slip from the pinnacle the only way is down!

[Pub User]

Who measures runways in metres?

I've never heard anyone refer to a runway length in metres in the UK, and all the perf' tables I've seen are in feet.

That said, it doesn't really make any difference what units the boards use. If they're still flashing past by the time one of them says "1", than you're probably in the brown stuff. If you're lucky, some weirdo may have used metres.

[GlueBall]

alf... I think that when you land at places as on the 10236' sloped pavement of Quito, (SEQU), (Elev 9228'), you'll very much appreciate knowing how much pavement is left because you won't see the end of it until you pass the 3000' marker! It will certainly assist your deccelaration technique. So when the pavement is dry and when you're light and when you see the 5000' marker, but not yet the end of the runway, then you won't necessarily have to "stand" on the brakes and use max reverse, eh?

[Ex Douglas Driver]

The idea of the marker boards is not to detect that in the last 1000FT you're about to run off the end. They allow deceleration to be compared to runway remaining over the entire landing roll.

From my background we use the rule of thumb of 30kts G/S per 1000FT remaining e.g. 90 Kts G/S at the 3000FT board. Slightly faster than that then start pushing the brakes harder, a heap faster than that then call for the barrier or the arrestor cable.

Where the boards are also useful is if aerodynamic braking or a delayed braking technique is utilised, then effectiveness can be judged and a wheel braking point nominated. ie aerodynamic brake to below 120Kts G/S by the 4000FT markers then start on the wheel braking.

[QAVION]

Some commercial glass cockpit aircraft are now being fitted with an aural warning system tied in with GPS which actually gives a verbal countdown of remaining runway length (especially when you're approaching the end of the runway). This is, assuming your particular runway is actually in the Nav Database ;)

Regards.
Q.

[Onan the Clumsy]

Another use for the countdown board could be if you were still too fast at the "1" - you could run right through it. That might slow you down a little :p

[alf5071h]

Glue Ball … You may have misinterpreted one of my points. In no way was I suggesting that a captain stands on the brakes and uses max reverse for every landing. These non-normal actions should only be used where the captain judges that the conditions are not as advertised or that he has made a mistake (and we all do), normally by not going around. The judgement that landing conditions have changed may be aided by marker boards; but that judgement and the decision to act, are taken on the ground. Whereas the judgement to avoid a costly overrun by flying a go-around is made in the air.
One of the underlying human issues in the referenced accident was the lack of input from the non-flying pilot. In any commercial operation one would expect that the NFP would at least say something. He would not require great training, experience, or judgement to alert the captain that the aircraft was fast, not correctly configured, and GPWS warnings given; a clear cut case for a go around. The Flight Safety Foundation’s Approach and Landing Accident Reduction Tool Kit includes the definition of a stabilised approach and the actions to be taken if the conditions are not met. The video on the CD shows the important role undertaken by the NFP. Many of the approach and landing (and particularly CFIT) accidents involve issues of judgement, not just by the captain, but by the crew. Thus these are crew, team, or organisational accidents.
Perhaps instead of marker boards the industry should adopt a policy for a mandated go around if the appropriate conditions are not met at a suitable approach gate. This does not imply that the conditions should be as defined by the FSF, but that each operator should have at least a policy and a set of conditions that can be referenced by the NFP and adhered to by the captain. The accident report did not comment on company procedures, thus I conclude that if they did exist they may only have been in the captain’s mind, and on that particular day for whatever un-established reason he did not follow ‘his’ procedures. (No blame policy)

[safetypee]

Honeywell are proposing to use voice call outs for distance remaining in their new Runway Awareness Advisory System (RAAS); these calls can be programmed for feet or metres as required by the operator. I understand that calls will be available for RTOs and ‘long’ landings; thus in the latter case there are an additional alert to the crew that an error has already occurred. I think that this was part of alf’s argument.
Honeywell are also investigating an airborne alert for high-energy approaches; if such a system is viable then it would be an additional alert to the handling pilot that the approach was unstable. Furthermore if the co-pilot did not alert the captain to the errors then there would be an automatic backup.