Cargojet 727 Overrun at CYQM

[sgs233a]

Happened about 0310 local time on the morning of Mar 24, 2010:

CADORS - Welcome Page | SCREAQ - Page d'accueil (http://www.tc.gc.ca/aviation/applications/cadors/English/Reports/dailyreportresults.asp)
CADORS #: 2010A0244

Narrative: At 06:10Z, CJT620, Boeing 727-200 cargo aircraft, enroute from Hamilton (CYHM) to Moncton (CYQM), hydroplaned off the end of Runway 06 at Moncton. There was no fire. The three crewmembers were not injured. The airport Crash Fire Rescue (CFR) was not available so the Dieppe fire department was called, arriving at approximately 06:30Z. The aircraft is stuck in the mud and will take some time to remove but there does not appear to be any damage to the aircraft. Runway 06 is NOTAM’ed closed until 13:00Z. TSB Evaluating.

CYQM 240700Z 07017KT 15SM -RA BKN006 BKN008 OVC013 02/01 A2947 RERA RMK SF5SF2SC1 PRESFR SLP982
CYQM 240600Z 07008G17KT 4SM +RA BR BKN006 OVC009 02/01 A2954 RMK SF6SF2 /R17/ SLP008
CYQM 240500Z 06015G25KT 5SM -RA BR BKN006 OVC010 01/01 A2956 RERA RMK SF6SF2 PRESFR SLP015



Taken 25 Mar 2010:

http://i810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/CIMG0900.jpg (http://s810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/?action=view&current=CIMG0900.jpg)
http://i810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/CIMG0905.jpg (http://s810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/?action=view&current=CIMG0905.jpg)
http://i810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/CIMG0907.jpg (http://s810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/?action=view&current=CIMG0907.jpg)
http://i810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/CIMG0909.jpg (http://s810.photobucket.com/albums/zz30/colpaz/Cargojet%20727%20off%20Rwy%2006%20at%20CYQM%2024%20Mar%20201 0/?action=view&current=CIMG0909.jpg)

[lomapaseo]

How do you hydroplane with no standing water?

[BigHitDH]

Can only assume there was standing water at the time...no skid marks visible.

Great photos by the way. :ok:

[PJ2]

Re "no damage", if that's official then I would suspect the right-wing-low attitude the aircraft appears to be resting at is the result of a combination of slight downhill gradient (although in another photo there doesn't appear to be that much gradient), the fact that the airplane is pointed slightly left and that the right gear may be sunk a bit more than the left. The right wing appears very close to the ground. The nosegear appears to be on the surface of the overrun area. I see by the windsock there is still a strong north-ish wind, 15-20+kts.

Yes indeed, great photos - I would wish for such superb photography of every accident site so we could get a "lay of the land" so to speak.

[con-pilot]

A 727 will hydroplane, trust me on this.

[spike727]

I agree with con-pilot, B727 anti skid leaves you wondering if on rain or ice if it will really stop. I do wonder if his trust reverse were on MEL, I love them.:O

[safetypee]

The choice of landing runway appears to have been the shorter, but into-wind option. However, given the forecast gusts, the likely approach and landing speeds could have been higher than normal.

The investigation report could be interesting following recent research.
An overview of the issues is given in ‘Slippery When Wet’. (http://flightsafety.org/asw/feb10/asw_feb10_p46-51.pdf)

Re runway grooving; is runway 06 grooved? Is it a concrete surface, does it drain well?

The underlying Transport Canada research is in Joint Winter Runway Friction Measurement Program. (www.tc.gc.ca/innovation/tdc/projects/air/f/9048.htm)

The specific trials on wet runways - Aircraft landing operations on wet runways (www.tc.gc.ca/innovation/tdc/projects/air/e/8262.htm), has some interesting conclusions:-

“… using the braking coefficients obtained during the tests on wet surfaces, indicates that the current operational dispatch factor of 1.92 for turbojet aircraft does not provide an adequate safety margin for landings on wet runways, particularly those with low texture or rubber contamination.”[/i]

"… current operational dispatch factor of 1.43 for turbopropeller aircraft does not provide an adequate safety margin for landings on wet runways.”[i]

Has anyone been able to locate an on-line copy of the latest TC report - “Risk and Benefit-Cost Analyses of Procedures for Accounting for Wet Runway on Landing”?

[J.O.]

I have requested a copy of the TC document. When I receive it I will send you a PM.

[sgs233a]

Hello all,
Thanks on the photos - most were discarded - was difficult to hold a steady shot.

I'm not qualified to comment on most of the rest, but I was at the fence by the terminal within a few minutes of the overrun, and listening on the YQM ground frequency. Rain was pretty heavy, gusty, low cloud...

For the emergency services on airport, per the CFS, avail 0945-0345Z only.

As for the choice of runway, not really qualified to comment, but it does bear mentioning that 06 has an ILS and 11 has NDB and RNAV approaches only. Also, only 10 deg xwind difference between the two at the time (var 20 deg W).


Cheers,
Colin

[T18]

As mentioned previously, excellat photographs, what type of aircraft were you shooting from?

[Cater]

Sorry to be a pain but where is this airport ?? Great photos :ok:

[GarageYears]

Moncton CYQM New Bruswick, Canada

Moncton airport - Google Maps (http://maps.google.com/maps?hl=en&client=firefox-a&hs=xRU&rls=org.mozilla:en-US:official&channel=s&q=Moncton%20airport&um=1&ie=UTF-8&sa=N&tab=wl)

Indeed great pics.

- GY :ok:

[sgs233a]

T18 - it was an American Champion 8KCAB Super Decathlon. Just in the process of finishing a taildragger checkout before heading West/North looking for that first flying job. More likely to be a ramp/dock job though, unfortunately.

Cheers,
Colin

[Plectron]

Airplanes with tail mounted engines have an interesting characteristic. Just when you are having fun keeping the nose straight in a crosswind on a slippery runway, going into reverse can blank out the rudder. Slow down or go off the side? The MD-80 is particularly cute in this regard.

[safetypee]

I am still interested in runway grooving; is runway 06 grooved? Is it a concrete surface, does it drain well?
The type of runway surface is not clearly defined in the photos, but if the lengthwise marks are bitumen in-fill between blocks, then water could easily accumulate between ridges.
A recent warming spell could have thawed out (expanded) the surface, raising the in-fill forming a dam, so that with heavy rain some significant accumulation could occur.

The ATC / crew problem is then to determine the difference between a wet runway and a significant depth of water (flooded) which significantly reduces braking performance.

As a thought, who would check and report on the runway surface? If this is usually done by CFR, in their absence who determines the surface condition?

[Checkboard]

If the airport FSS was as reported "not available" does this not render the airport closed as FSS would be zero?

It depends on the local laws. In Australia RFFS (Rescue & Fire Fighting Service) coverage was only required for international operations. There was no requirement for domestic operations, so most of the airports I flew to (in jet ops, like 737s) had no coverage at all.

[sgs233a]

It's not grooved.

Taxied past the airplane, sitting on the apron plugged into a ground power cart with maintenance folks and trucks all around it. Sitting level on its gear, right wing and all its bits certainly looked intact from what I saw. I think it may have been doing engine runs later yesterday afternoon.... Certainly sounded like it!

[Storminnorm]

I hope they weren't trying to reverse it out!!!

[PJ2]

Sitting level on its gear, right wing and all its bits certainly looked intact from what I saw. Thanks, colpaz, nice to know.

[jackieofalltrades]

Great photos, interesting to see.

[sgs233a]

It flew out a few days ago, on the night of the 27th, I believe. Someone on Avcanada mentioned that it was ferried back to Cargojet's main base at Hamilton with gear down.

[pointingdog]

Here is the link for the Benefit-cost analysis of procedures for accounting for runway friction... Great Document!


http://www.tc.gc.ca/innovation/tdc/publication/pdf/14000/14082e.pdf

[safetypee]

The report at (#23) only deals with friction aspects on runways contaminated with snow and ice and specifically excludes wet runways in the definition of ‘slippery’.

The document which the FSF refers too (#7) is TP14842E “Risk and Benefit-Cost Analyses of Procedures for Accounting for Wet Runway on Landing” dated July 2008. This is not yet available on line.
This document focuses on wet runways and the importance of runway grooving. Most of the significant points are identified in the FSF article.

Although CRFI is not measured on wet / flooded runways, the background principles in ( AC 164 (www.tc.gc.ca/civilaviation/commerce/circulars/ac0164.htm) and AIM AIR Para 1.6 and table 1-4 (www.tc.gc.ca/CivilAviation/publications/tp14371/AIR/1-1.htm#1-6))) provide excellent guidance for the performance degradation on wet runways, but even this requires judgement in considering additional factors such as non grooved runway, tyre condition.
An advantage of CRFI is that it attempts to provide a similar safety margin to that required for dry operations, i.e. attempts to accommodate the variability in everyday operations.
Some of the landing distances required for low friction operations shown in the CRFI tables approximate to safety factors of 2.0 to 2.4 which are well in excess of the wet 1.92.
Unfortunately, all of the above suffer the weakness of the crew not knowing what the actual condition of the runway surface is, either through difficulties of measurement, communications, and interpretation; and even with good data, it has to be applied sensibly.

The above does little to progress an understanding of the Moncton event. However, from CRFI principles / tables, assuming that the runway was ‘very wet’, the landing distance (with reverse) on this 6000ft runway would equate to an ‘AFM’ unfactored dry landing distance of 2800-3200ft. Could any 727 pilots comment on the practicality or likelihood of this data applying to this situation.

[jimbo canuck]

Both runways at Moncton are asphalt.
Jimbo

[paulg]

This is a most constructive and instructive analysis. PPRuNe at its best methinks! :ok:

[Maurice Chavez]

Airplanes with tail mounted engines have an interesting characteristic. Just when you are having fun keeping the nose straight in a crosswind on a slippery runway, going into reverse can blank out the rudder. Slow down or go off the side? The MD-80 is particularly cute in this regard.Don't know about the MD-80, but the 727 has no problem in that regard, you get full rudder authority, BUT Boeing does say, max 1.75 EPR on pod engines on slippery runways with a crosswind. She does have a problem on a slippery/wet runway with her anti-skid.

[Maurice Chavez]

However, from CRFI principles / tables, assuming that the runway was ‘very wet’, the landing distance (with reverse) on this 6000ft runway would equate to an ‘AFM’ unfactored dry landing distance of 2800-3200ft. Could any 727 pilots comment on the practicality or likelihood of this data applying to this situation.To be honest with you, presuming Moncton is at or near sealevel, the 727 will land max landing weight at a 6000' runway with no problems. However, as I stated earlier, she has a problem with the anti-skid on wet runways. Boeing unfortunately does no longer update the manuals for the 727, last revision I hold is dated back to August 1st, 2000. Boeing is also no longer interested in supporting operational issues regarding the 727...

[safetypee]

Maurice, I think that you have missed the point which I was making with the help of the CRFI tables, and of trying to establish a rough order of landing weight which could provide a safe landing in the reported conditions.
We don’t know exactly what the runway conditions were in this event, and it is possible that the crew did not know either.

The 6000ft runway is not grooved, and on the day it was wet, very wet, and possibly ‘flooded’ with a layer of surface water.
In very wet conditions, the maximum landing weight with similar safety margins as on a dry runway would probably be equivalent to that required to stop on a 3000ft dry runway (based on CRFI interpolation – AC 164, and speculative application to a very wet runway)
If all safety margins were discarded, then assuming a 1000ft air distance (threshold to touchdown), then the landing weight could be increased to that which would stop the aircraft in approximately 2500ft ground roll; a weight which is unlikely to be available directly from aircraft data.
This approximate distance is based on the performance analysis in the TP14842E report which states that the stopping distance on a [very] wet un-grooved runway is twice that of a dry runway. Thus for the 6000ft runway, minus 1000ft air distance, the available stopping distance is equivalent to half of the remaining 5000ft.
Will a 727 stop in this (2500ft) ground distance?
Alternatively what is the max landing weight for a 3500ft dry runway, i.e. landing on a very wet 6000ft runway with no safety margin?

Perhaps some other significant findings published in report TP14842E are:-
“It would be operationally difficult to issue accurate reports of the runway being flooded during short-term transient rainstorms”.
“During the summer months the runways are reported as “bare and dry”, damp or “bare and wet”, and rarely reported as flooded unless there is pooling of water in depressions”.
And based on interviews with airfield operations managers at two major Canadian airports: -
“… airport operators do not currently make a determination of whether water on the runway is greater than 3 mm in depth during heavy rainfall, and they do not report that the runway is flooded, rather than wet, when the depth is greater than 3 mm.”

[OverRun]

I'm enjoying the discussion; almost something for Tech Log.

The mainstream of discussion is going down the path of considering performance on a very wet or flooded runway, and the side issue of grooving, which is the most logical path for the discussion to take with the information available so far.

At the same time, let's keep minimal texture and shallow surface water in the back of our minds as a possibility until we know the macrotexture and microtexture of the runway.

Most runways have reasonable macrotexture and microtexture and performance calculations assume those conditions being present. But it is possible to have a runway where the macrotexture or microtexture have been effectively destroyed by rubber build-up or by inappropriate maintenance or rehabilitation (trust me – I've seen this with my own eyes twice this year :ugh:). Under those circumstances, even a small amount of surface water can significantly affect the braking performance, and we can experience the braking problems that are normally associated with very wet or flooded conditions. One of safetypee's earlier quotes touches on this: not provide an adequate safety margin for landings on wet runways, particularly those with low texture or rubber contamination.

Because 9 times out of 10, overruns in the wet are associated with lots of rain and with poor macrotexture or lack of grooving, I've been guilty of sloppily thinking in the past that overruns always go with these conditions. Clearly I am a dynamic/viscous hydroplaning or aquaplaning sort of person – i.e. occurring when an aircraft lands fast enough on a wet runway.

I was therefore surprised recently looking at an overrun accident which occurred in only light rain. It wasn't until I measured the minimal macrotexture and virtually nil microtexture of the runway that I remembered reverted rubber skidding - akin to viscous skidding in that it occurs with a thin film of water and a smooth runway surface.

Not saying for a moment that this happened here at Moncton – we simply haven't got the data to judge yet. But while I'm enjoying the discussions here about water great than 3mm and the rest of it, I'll still keep in mind the danger represented by light rain and smooth surface.

[safetypee]

OverRun, I agree with your points about runway texture. The discussion re 3 mm water depth related to the TC report and common operational definitions; it was not intended to limit the discussion to this area.
A good research reference on the problem areas is Wet Runways (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750012279_1975012279.pdf ), but note that the information on antiskid systems and friction measurement devices have probably been overtaken by more recent information.

The operational problem might be seen as ‘how wet is a wet runway?’
In this domain, wet relates primarily to the water depth, but significantly includes runway texture, and tyre characteristics (fig 1 in the ref), noting that water depth need not necessarily be very great if either the texture and/or tyre characteristics are poor. It’s surprising how quickly we forget critical items, e.g. an 80% worn tyre is virtually ineffective in wet conditons – poor retardation and directional capability, yet in this commercially sensitive era we might allow tyre wear to the limit value.

Landing performance is published for wet conditions, but usually this is based on factored dry distances and crosschecked with computed / assumed friction levels with some measured distances.
ICAO ‘Good’ on a wet runway may be equivalent to 0.4 mu and above. The conditions are illustrated thus:- Aircraft can expect to land comfortably within the scheduled ‘wet’ distance, without undue directional control problems, but this definition might now only apply to a well drained runway with average texture.

With increasing water depth / decreasing runway texture and poor tyre characteristics, the braking friction reduces and the estimated braking characteristics can range Medium to Poor. ATM should report this estimate which is often based on their view of the runway’s ‘wet’ condition, i.e. how wet is wet – how deep is the water in relationship to the texture.
However, ATM have little knowledge of the runway texture (except when NOTAM as slippery when wet) and no knowledge of the aircraft’s tyres, thus estimates of braking action can be very poor.
Braking action PIREPS are often quoted by ATM, but due to human limitations in assessment, particularly when thrust reverse and autobrake are used, these reports can result in highly misleading information as well as a source of peer pressure.
Thus, the pilot has the burden of the assessment and landing decision, but often lacking adequate information – how much water, what’s the runway texture, and what’s the condition of the tyres (should know, but who remembers).

The majority of current operations are on good runways (grooving/texture, drainage), which reduces opportunity to experience lower than expected friction (also a problem of reverse/autobrake use); this, and the reliance on thrust reverse, can lead to complacency when assessing the conditions for landing.

Factored landing distances provide a distance margin for maintaining a safe operation against the operational variability in normal operation (speed, height, position, brakes). The additional distance does not specifically consider variability in runway condition (although some reports suggest otherwise), and thus wet factors do not necessarily provide the same degree of safety as a dry runway.
As a wet runway becomes more wet (poor runway texture and tyres) the safety margin can vanish – greater reliance on reverse or the potential for an accident. In these latter conditions, pilots are expected to change their operation – reduce the variability of normal operations – use max braking, land on-speed, correct position, etc, but even with all of these, the unknowns in the runway condition may exceed all of the distance safety margin.

Another ref: Effect of pavement texture. (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680005434_1968005434.pdf)
… a pronounced surface texture effect and a large degradation in friction coefficient as a result of the addition of a small amount of water …

[OverRun]

safetypee,

My apologies for the delay in answering; you've raised many valuable points and I only got to sit down today to think them through. Your point is very well made about:
The majority of current operations are on good runways (grooving/texture, drainage), which reduces opportunity to experience lower than expected friction (also a problem of reverse/autobrake use); this, and the reliance on thrust reverse, can lead to complacency when assessing the conditions for landing
I know a crew who fit exactly into the picture you've described, and who changed their complacent attitude (and their underpants) recently on a certain runway in the land of the verdant garden with low microtexture and low macrotexture.

Thanks very much for the links as well. The Horne paper on wet runways in particular yielded this particular gem of the inter-relationship between macro/micro-texture and fluid pressure alleviation which had been pretty much lost to most airport engineers and pilots with the passage of time. In the interests of safety and education, here it is:

http://profemery.info/aviation/surfacetexture.jpg

[50100]

It seems to me that the rigid gear is the problem. I don't believe the location of the engines are the cause. The DC-9, MD 80's and 727's all have problem with wet runways. Seldom do you see a truck gear hydroplane.