runway cleared width

[vikena]

Anyone got a source of guidance for required runway width clearance of snow for A321.

Usually the runways are cleared to a minimum of 30m . I think thats fine but what height of snowbank would you tolerate<

[tribo]

Norwegian Authorithy, Luftfartstilsynet
BSL E 4-2, Veiledning 1 (Norwegian text)
Guidance material for safety areas:
At least 50 cm clearance from a jet engine to the snow-surface.
Measured when wheels are at RWY edge.

[Max Angle]

Min. cleared width is 45m.

[tribo]

Some history from ICAO STUDY GROUP ON SNOW, SLUSH, ICE AND WATER ON AERODROMES
Memorandum No. 29, 14 August 1972 and No. 32, 17 April 1973, Attachment
Permissible snow bank height
(IATA representative)
1. One of our member Airlines has just drawn our attention to a problem of ice ingestion which resulted in extensive damage to the outer engine of a B-747 aircraft. It has been suggested that this incident was the result of inadequate clearance of snow from the areas adjacent to the edge of the runway concerned.
2. As you are aware the 6th EUM/RAN meeting recently developed guidance material on snow clearance profiles along the edges of runway, having in mind the extensive overhang of the outer engine pods of B-747 and similar types of aircraft.
3. The incident mentioned above did not occur in Europe and unfortunately the Authorities concerned did not appear to recognize or be sympathetic to the problem. For this reason it has been suggested that the development of guidance material on this aspect of snow clearance be placed on the work programme of the ICAO Study Group on Snow, Slush etc and I hope, therefore, that it is not too late to include it”
The incident:
KLM – B-747 – Captains story. (By TELEX)
Snow Clearance JFK. KL (number) Arrival feb 21 recived ATIS Runway ploughed and swept. Observed conditions 22L/22R showed clearance extended to elevated R/W lights only. At and beyond lights residual patches frozen snow one to two inches thick existed. These clearly lifted and ingested by outer engines during normal reversing. Following summarizes content discussions with (Name) and ITZ KLM. (Name) clearance policy directed at 150 ft cleared width in accordance ATA requirements. This coincides R/W light placement all JFK runways. Hard shoulder width 31R ample to accommodate machinery for additional clearance but other runways could be marginal this purpose. (Name) currently unable to commit to shoulder clearance since neither ATA or other 747 operators input indicates need thereof. Hard shoulder erosion problems from 747 operations are admitted and this CMA together with visual observations recorded above CMA were thus used as arguments in stressing need for review current policy. Note also Bermuda closure 747 operations due shoulder erosions. (Name) indicated sympathy our standpoint but cannot concede isolated incident of unproven origin is demanding of immediate remedial action. They promise early review with ATA this subject stimulated by current FAA interest.

The following report was obtained from the manufacturer: (TELEX)
Laboratory investigations revealed one fan blade had fractured transversely through the aerofoil between the part.span supports. Broken surface was characteristic of rapid tensile fracture and showed no evidence of fatigue. Leading edge was curled back in opposite direction of rotations. Damage caused by foreign object. Dissembly did not find or reveal evidence permitting identification of the foreign object. Incident could be related to (identification) 747 number four engine ingesting ice during landing on same runway 30 minutes prior to KLM.

The outcome

ICAO guidance material, with profiles, can be found in the ICAO Airport Service Manual, Part 2, Pavement Surface Conditions. ICAO Doc 9137-AN/898.

[mutt]

Max Angle,

What reference are you using for 45 meters?

Mutt

[vikena]

max angle,

you'd be doing alot of diverting in Europe if you were looking for a runway cleared to 45m.

In fact you'd run out of fuel and crash on a snowy day

Anyway I just didn't like your dogmatic single liner with no source document to back up what you stated.

On the other hand tribo, excellent response and I,ve something to go on now.

vikena

[None]

Runway Use Following Plowing Operations:
Takeoffs on runways which have been plowed are authorized if the following
conditions are satisfied:
• Usable surface has been plowed to a minimum of 50 feet (15M) either side of the centerline.
• Snow or ice outside the plowed area, but inside 75 feet (23M) either side of centerline, does not exceed 6 inches (15cm).
Note: During plowing operations, snow or ice rows may be created. Wingtip,
engine nacelle, and gear clearance may be significantly reduced.

[Max Angle]

you'd be doing a lot of diverting in Europe if you were looking for a runway cleared to 45m.The information we have from Airbus is that the minimum runway width of 45m from the AFM applies equally to contaminated runways. It's based on vmcg calculations and x-wind limits etc. They have never issued a Boeing style "snow bank height" chart. 45m (150ft in the US) is the standard runway width to the edge lights but most have quite a large area outside the lights that is weight bearing. It's true that some aerodromes only clear out to 30m to start with although major aerodromes will aim to clear the full 45m during ploughing even if they only clear the centre 30m to blacktop. If they don't you have to consider the remaining contaminant in the take-off or landing calc, if it's out limits i.e. too deep or too slippery then you can't go. Remember that even if you have blacktop on a 30m strip you could still have very shallow snow (dry 15mm or wet 4mm) out to the edge and still consider the runway as just wet for performance purposes.

Apparently we are looking at performance data to allow operations from 30m cleared width but haven’t got it yet, don't know if it's because we are behind the times (quite likely) or if Airbus haven’t issued it. If anyone has got any different info. I would be very interested to hear it.

In conclusion, roll on summer!.

[vikena]

thanks None

have you got a source for that

vikena

[None]

It's a copy/paste directly out of our FOM (FAA). I'll see what I can find from a public site. Our on-line company site requires a VPN.

[FourTrails]

To operate onto a contaminated runway we need a cleared with of 45m. However this is 45m of acceptable contaminate, ie. EWD no greater than 12.5mm. If you have a runway cleared 30m or greater with contaminant 3mm or less then you simply have a wet runway - no need to consider contaminated runway figures - its simply a wet 30m wide strip.

[vikena]

Four Tails,

My query relates to cleared widths and snowbanks. Not to contaminant depths (remaining )

vikena