abrown532 From UK - Northern Ireland, joined Feb 2008, 144 posts, RR: 0 Posted (1 year 11 months 3 weeks 1 day 17 hours ago) and read 11308 times:
Even though the landing without gear was excellent and very smooth, surely whilst sliding to a stop, the aircraft would have severely damaged the surface of the runway. I wonder how long the runway was out of service for.
It's the same with all gear-up landings. Surely it must cost the airport considerable cost/time to repair the runway after a gear-up landing.
awthompson From United Kingdom, joined May 2005, 396 posts, RR: 0 Reply 3, posted (1 year 11 months 3 weeks 20 hours ago) and read 6591 times:
It seems few people are posting today, maybe recovering after eating/drinking too much on Christmas day! I just ate too much chocolate, that's all, so I don't feel too bad today!
I would also be interested to know more about your question. I believe part of the runway (but not all) was sprayed with foam before the emergency landing. I believe the main purpose of foam in this situation is to suppress possible sparks which could ignite any leaked fuel however foam would not prevent runway surface damage.
If the runway was in use again within a day and a half as suggested by Buyantukhaa (above) then any repairs would have been confined to replacement of damaged lights and some quick repainting of lines and markings after removel of all loose debris. This short time span would certainly not have permitted actual hard surface replacement / regrooving. Clearly there would have been some surface scrapes and damage to grooving during the event however perhaps not serious enough to prevent the runway being used until it would next be due for re-surfacing.
Perhaps someone with more knowledge than I have would elaborate from past experience in other incidents around the world.
AirlineCritic From Finland, joined Mar 2009, 667 posts, RR: 1 Reply 4, posted (1 year 11 months 3 weeks 20 hours ago) and read 6463 times:
The aircraft is made of aluminium a few millimeters thick, the runway is thick concrete or asphalt. The gear-less aircraft is in contact with the runway throughout its landing but any individual spot in the runway is in contact with the aircraft only as it passes by. I would expect there to be some scratches to the surface material, but nothing that would prevent even immediate use, as long as the aircraft and any debris was removed from the runway.
Runway lights might have suffered, however. They are in modules that can be lifted out and replaced, which I assume they did. I'd give pretty good odds for no lights being damaged either, however.
If anyone have pictures of the aftermath showing the runway surface that would be nice. But in general, I would expect runway - aircraft collisions to end up being won by the runway.
horstroad From Germany, joined Apr 2010, 209 posts, RR: 0 Reply 5, posted (1 year 11 months 3 weeks 19 hours ago) and read 5986 times:
Quoting awthompson (Reply 3): This short time span would certainly not have permitted actual hard surface replacement
a few years ago one runway at frankfurt airport was reconstructed literally over night. they had a time frame of just a little more than 7 hours to remove tranches of 15x60x0,6m of concrete each night and replace it with asphalt before the runway was fully in use the next morning.
so it actually is possible to to repair a runway in a short time span.
Runway pavement is incredibly thick and strong...we're talking equivalent to bunkers and other construction designed to withstand bombs (this is why air forces had to invent special runway cratering bombs). Sliding a bunch of aluminum and steel chunks across the surface without any particularly high pressure contact is going to mess up the lights and paint but not a whole lot else.
A388 From Netherlands Antilles, joined May 2001, 9409 posts, RR: 11 Reply 10, posted (1 year 11 months 3 weeks 4 hours ago) and read 4022 times:
Yes, I agree with the posts as well. The runway shouldn't have gotten damage other than scratches as the material used on a runway is very strong (combination of concrete and asphalt). The runway's PCN value should tell you exactly of what material the runway is built. I certainly wouldn't have expected a lot of damage to the runway or none at all.
awthompson From United Kingdom, joined May 2005, 396 posts, RR: 0 Reply 11, posted (1 year 11 months 2 weeks 6 days 20 hours ago) and read 3548 times:
Quoting horstroad (Reply 5): a few years ago one runway at frankfurt airport was reconstructed literally over night. they had a time frame of just a little more than 7 hours to remove tranches of 15x60x0,6m of concrete each night and replace it with asphalt before the runway was fully in use the next morning.
so it actually is possible to to repair a runway in a short time span.
Yes it certainly is frequent practise to relay runway in sections during night/closed hours at airports, then the next night ar a few nights later, cut the grooves. However such an operation is the culmination of (at the very least) a financial appraisal, a tendering process to select a contractor, then a planning process involving numerous meetings between contractor(s) and airport operations before the plan is put into action (you would know I work in management.) This is why I am pretty confident it did not happen at WAW in such a short notice situation.
The above said, large airports or airports with single runway operations would of course have an ongoing contract renewable every two or three years for short notice emergency type runway repairs.
pspfan From Netherlands, joined Mar 2008, 114 posts, RR: 0 Reply 13, posted (1 year 11 months 2 weeks 6 days 12 hours ago) and read 3134 times:
The most vulnerable part of the runway is the lighting. The cases I witnessed where other parts of an aircraft than the tyres made contact with the runway, it always damaged the lights. The centreline lights are almost a centimeter above the surface. And are not made of the strongest metals either.
Another thing that is probably damaged is the anti-skid layer. When applied. But that is not a critical point for closing a runway.
From what I heard the runway centre line lights were out, due to the scratching belly, and had to be replaced. Hence the closure for a day.
awthompson From United Kingdom, joined May 2005, 396 posts, RR: 0 Reply 15, posted (1 year 11 months 2 weeks 6 days 4 hours ago) and read 2774 times:
Quoting SASDC8 (Reply 14): Quoting Max Q (Reply 6):
Yes, a very smooth completely unnecessary gear up landing..
But of course.. Please enliten us why exactly.
I have not studied this in much detail yet but the following extract on Wikipedia suggests that although there was a hydraulic leak leading to a failure, a simple popped circuit breaker prevented the alternate gear extension procedure from functioning and if the crew had known about this or had been made aware of it's presence by LOT maintenance, the gear could have been lowered succesfully if the said circuit breaker had been reset by a simple press:
"Shortly after the evacuation, a team from the Polish State Commission for Aircraft Accident Investigation arrived, and discovered that the C829 circuit breaker, which protects a number of systems including the alternate landing gear extension system was "popped". The C4248 breaker for the alternate landing gear remained closed. Once the aircraft had been lifted off the runway, the C829 circuit breaker was closed, and the landing gear was able to be extended, using the alternate system. This allowed the plane to be towed to the LOT maintenance hanger for repairs and investigation."
If correct, this is indeed very unfortunate and I feel sorry for the crew and indeed passengers who had to go through this lengthy and frightening ordeal. While the crew were not aware of the circuit breaker which protected a number of other systems including alternate gear extension, I am a bit taken aback that no-one on duty in LOT maintenance (with whom the crew were in discussion by radio for many hours before the emerency landing) knew of it's presence or had relevant manuals on hand to look it up.