mesaflyguy From United States of America, joined Dec 2012, 2348 posts, RR: 2
Reply 3, posted (1 year 2 months 2 weeks 1 day 16 hours ago) and read 3859 times:
I see the ice (I think I do) on the close engine. It can reach upwards of -60 degrees farenheit at that altitude, so it is likely that any condensation would instantly melt. As the aircraft started to descend, the temperature would rise, causing the ice to melt,cwhich is what you observed.
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N243NW From United States of America, joined Jul 2003, 1598 posts, RR: 21
Reply 4, posted (1 year 2 months 2 weeks 1 day 16 hours ago) and read 3859 times:
It looks to me that it may have just been the absence of a shadow on that part of the engine that makes it look like icing. Perhaps as you descended the angle of the sun gradually changed and that was what caused the apparent ice to disappear...?
Unless you were cruising inside clouds (with visible moisture around the aircraft), it seems somewhat unlikely that ice would build up in this fashion. I'd be happy to be proven wrong, though.
eugegall From United Kingdom, joined Dec 2009, 93 posts, RR: 0
Reply 15, posted (1 year 2 months 2 weeks 1 day 12 hours ago) and read 3664 times:
That is exactly my point for posting this. I thought it was very, very odd to see.
Guys of course I could be wrong and obviously I am in the minority in thinking its ice or frozen condensation but I too have a pilots licence. Yes its only a PPL but I do have a very good basic knowledge of the main principles of flight.
I watched it form and I watched it dissolve. It did not change shape through aircraft turns which is why I am sticking to my guns and stating its not light. Even the pictures back my story up. The light glare/shade/shadow on the outside engine is completely difference place to the inside engine. IF it was light the shapes on both engines would be in the same place, or at least very close. On the images the light on the outside engine is on the far right hand side. On the inside engine the light is on the very bottom. Unless there is a second sun that I am unaware of I guess its not light causing that.
CosmicCruiser From United States of America, joined Feb 2005, 2254 posts, RR: 16
Reply 16, posted (1 year 2 months 2 weeks 1 day 11 hours ago) and read 3599 times:
man if you saw all the weird shadows and light combos that can happen you would be surprised. light can be in all sorts of weird places and that can create some awesome sights but ice no. Ice forming that much should be around the whole inlet and as someone said it's probably too cold anyway.
What you are seeing is the shadow of the front of the fuselage with the sun relatively low and to the right of the aircraft. The give away is how well the light reaches the fan and under side of the pylon of #1. If the sun was higher, the rear of teh inlet and the pylon of #1 would have a shadow.
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26point2 From United States of America, joined Mar 2010, 782 posts, RR: 0
Reply 18, posted (1 year 2 months 2 weeks 23 hours ago) and read 3387 times:
Yes. Clearly flying toward the sunrise. Shadow on the wing looks like the front of the plane/hump and with a bit of shadow on engine 1 one can imagine the shape of the rest of the nose within the shadow.
Any inflight structural ice would accumulate evenly on the entire engine inlet...all the inlets as amateur of fact.
Structural ice can form at these altitudes under unusual conditions but is rare. The GLEX has reports of inflight engine TAT probe icing causing engine rollback. Didn't the AF crash over the Pacific encounter probe ice before they lost control?
CaptCufflinks From UK - England, joined Dec 2012, 92 posts, RR: 0
Reply 19, posted (1 year 2 months 2 weeks 15 hours ago) and read 3210 times:
It's got to be an optical illusion, rather than ice - in fact, if you take a look at this picture (same aircraft) you'll notice that the outboard engine has an identical look to it. It's a tiny bit brighter in this image, so you can see the same "shiny" effect on other parts of the engine.
akiss20 From United States of America, joined Sep 2007, 570 posts, RR: 5
Reply 20, posted (1 year 2 months 2 weeks 12 hours ago) and read 3111 times:
Engine's are required to go through very stringent icing tests to pass certification. Icing tests are one of the most difficult tests they must pass as they represent icing conditions almost NEVER seen (engine manufacturers are always arguing with the FAA as to whether the tests should be as stringent as they are).
This past summer I worked with GE on some ice accretion modelling as well as reviewing videos of icing tests to better ice shedding models. I can't show any of the images as it is all highly proprietary, but there were some tests where I was damn amazed that the engine could keep going. Thing looked practically like a block of ice.
Change will not come if we wait for some other person or some other time. We are the ones we've been waiting for. We are
If it's sufficiently high, yes. However, weather conditions necessary to generate enough rain/snow are so severe that you should never be operating an airplane in them in the first place. Taca Flight 110 is the cannonical case for preciptation leading to an engine shutdown: http://en.wikipedia.org/wiki/TACA_Flight_110
Both the engine OEM and the airframer test for water and icing ingestion and those tests are *far* more severe than anything observed in what's supposed to be normal operation.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 81
Reply 25, posted (1 year 2 months 1 week 4 days 22 hours ago) and read 2331 times:
Quoting Aaron747 (Reply 24): It is simply inconceivable that ice would accumulate in that particular location only.
Although I agree it's most likely a lighting effect in this particular case, it's not inconceivable to have ice only in that particular location...for many nacelle anti-ice systems, the piccolo tubes that distribute hot air inside the nacelle leading edge are shaped like a "C" with the opening pointed down (air comes in at the top in the "middle" of the C and exits small holes all along the C). As a result, if you had a marginal/failing anti-ice valve that wasn't providing full flow, the first part of the nacelle that would get cold and start to ice (assuming icing conditions were present) is the bottom center.
CALTECH From Poland, joined May 2007, 1942 posts, RR: 25
Reply 26, posted (1 year 2 months 1 week 3 days 22 hours ago) and read 2107 times:
Quoting eugegall (Reply 6): I'm 99% sure its ice and not shadow or condensation.
Quoting zeke (Reply 5): The lighter area is just sunlight, the fuselage is blocking the sun, the round shadow is on the wing.
Quoting zeke (Reply 17): What you are seeing is the shadow of the front of the fuselage with the sun relatively low and to the right of the aircraft. The give away is how well the light reaches the fan and under side of the pylon of #1. If the sun was higher, the rear of teh inlet and the pylon of #1 would have a shadow.
Not ice, just some sunshine. Pretty clear air there at cruise altitude, typical for the mid-Atlantic. Not a lot of moisture there.
Quoting tdscanuck (Reply 25): Although I agree it's most likely a lighting effect in this particular case, it's not inconceivable to have ice only in that particular location...for many nacelle anti-ice systems, the piccolo tubes that distribute hot air inside the nacelle leading edge are shaped like a "C" with the opening pointed down (air comes in at the top in the "middle" of the C and exits small holes all along the C). As a result, if you had a marginal/failing anti-ice valve that wasn't providing full flow, the first part of the nacelle that would get cold and start to ice (assuming icing conditions were present) is the bottom center.
Not on any of our engine inlets. On all of our GE, Pratts and Rolls engines, the anti-ice spray tube is a "O" shaped tube. No "C" shape, and the tube is a complete circle. The hot air enters from the left side of the nacelle or looking at the fan face, at about the 2 - 3 o'clock position, and exits through a tap off the spray tube that blows overboard at or very near the bottom of the inlet.
Looking at your photos provided, the engine anti ice would have been selected off with that clear air at altitude, and any build up of ice on just that one engine inlet would have been much more uniform around the entire inlet, not just at that bottom area. The number 1 outboard engine would have had some ice build up as well. Just some sunshine and shadows making a optical illusion.