Clean aircraft concept?

dasleben said:
I would be interested in seeing research related to this. Until then, this crew was operating as test pilots; Airbus requires all surfaces be clear prior to departure, and this crew departed with a fair amount of wet snow. I don't believe that a lack of accidents is any sort of conclusive evidence that this can be done safely on aircraft with LEDs. How is single-engine performance affected by contaminated surfaces? Are there any adverse handling characteristics specific to that aircraft (aileron flutter, etc.)? These are just two of the many questions that need to be answered before anyone can call this video safe.
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All very true, and you really hit the nail on the head with the line about the lack of accidents. I follow all the regulations, however, I believe all the evidence shows that we do not have to do more than that if you have LEDs. If you don't, as I wrote previously, you might want to consider being more cautious than the regulations require.
 
Blackhawk said:
http://www.ntsb.gov/investigations/fulltext/AAB0603.html
"The Board concludes that the probable cause of this accident was the flight crew's failure to ensure that the airplane’s wings were free of ice or snow contamination that accumulated while the airplane was on the ground, which resulted in an attempted takeoff with upper wing contamination that induced the subsequent stall and collision with the ground. "
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001211X14270&key=1
"THE ICE CONTAMINATION ON THE WINGS RESULTED IN AN AERODYNAMIC STALL AND LOSS OF CONTROL AFTER LIFTOFF. "
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001213X32505&key=1
"The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
ICE/FROST REMOVAL FROM AIRCRAFT..NOT PERFORMED..PILOT IN COMMAND"
http://aviation-safety.net/database/record.php?id=19910217-2
"PROBABLE CAUSE: "The failure of the flight crew to detect and remove ice contamination on the airplane's wings, which was largely a result of a lack of appropriate response by the Federal Aviation Administration, Douglas Aircraft Company, and Ryan International Airlines to the known effect that a minute amount of contamination has on the stall characteristics of the DC-9 series 10 airplane. The ice contamination led to wing stall and loss of control during the attempted takeoff."
http://aviation-safety.net/database/record.php?id=20020104-0
CAUSAL FACTORS: "1. The crew did not ensure that N90AG's wings were clear of frost prior to takeoff.; 2. Reduction of the wing stall angle of attack, due to the surface roughness associated with frost contamination, to below that at which the stall protection system was effective.; 3. Possible impairment of crew performance by the combined effects of a non-prescription drug, jet-lag and fatigue."

http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=bca&id=news/bca1010p2.xml&headline=Fine-Grain Icing on Aircraft&next=0
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I have no time or training in jets and can only speculate that the performance envelope is such that you don't want to take off without anything other than clean flying surfaces using correct hold over times. Play it conservatively in this hostile flying situation.

With that disclaimer out of the way, I see a lot of other factors on these flights as well as ice contamination factoring into these crashes.

  • Montrose: sounds like they had to use creative math to get the performance numbers for takeoff and was still willing to try it with a wet slush covered airplane.
  • Early call outs and rotation
  • Letting a low time F/O with marginal training record fly in crappy conditions.
  • Fatigued, possibly drug impaired pilots.

In icing conditions you should properly inspect the plane, de-ice and re-de-ice as often as needed. Add to this you should bring your A-game to the cockpit, when you are flying in challenging conditions.
 
dasleben said:
Airbus requires all surfaces be clear prior to departure, .
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When I was on the freight ramp the UPS airbuses would be doused in deicing fluids before take off when we had no contaminants on any of the feeder planes. I can't remember the exact reasoning now but it was some sort of preventative measure against accumulation on climb out.
 
FlyingScot said:
I have no time or training in jets and can only speculate that the performance envelope is such that you don't want to take off without anything other than clean flying surfaces using correct hold over times. Play it conservatively in this hostile flying situation.

With that disclaimer out of the way, I see a lot of other factors on these flights as well as ice contamination factoring into these crashes.

  • Montrose: sounds like they had to use creative math to get the performance numbers for takeoff and was still willing to try it with a wet slush covered airplane.
  • Early call outs and rotation
  • Letting a low time F/O with marginal training record fly in crappy conditions.
  • Fatigued, possibly drug impaired pilots.

In icing conditions you should properly inspect the plane, de-ice and re-de-ice as often as needed. Add to this you should bring your A-game to the cockpit, when you are flying in challenging conditions.
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You are confusing contributing factors with probable causes.
 
FlyingScot said:
When I was on the freight ramp the UPS airbuses would be doused in deicing fluids before take off when we had no contaminants on any of the feeder planes. I can't remember the exact reasoning now but it was some sort of preventative measure against accumulation on climb out.
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That's pretty interesting. Hadn't come across that before.
 
Seagull, what difference does a heated leading edge make if it is not designed to de-ice an entire wing? I don't see how a heated leading edge provides any safety in ground icing conditions hence the reliance on fluids.
 
It is the issue of boots in flight that makes the difference, but the key issue is not de-ice, it is leading edge high lift devices, leading edge slats and flaps.
 
Also, regarding the DC-8, it has neither leading edge flaps or slats, it does have slots, but that is a bit different.
 
I think the bottom image here sheds some light on why it might make a difference. Think of how the wing profile looks with them retracted. Even if you get flow on the leading edge that is disrupted, it would not (as much) adversely impact the flow with the slat extended.

The other side is that accumulation on the top of the wing will likely blow off at the speeds the larger jet aircraft fly at, so that might be a player also. Not sure of all the reasons, this is really just speculation. Follow the regulation and get deiced when the rules require it, regardless.
 
FlyingScot said:
When I was on the freight ramp the UPS airbuses would be doused in deicing fluids before take off when we had no contaminants on any of the feeder planes. I can't remember the exact reasoning now but it was some sort of preventative measure against accumulation on climb out.
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I haven't heard of this before either. Type IV is supposed to protect against accumulation up until shearing off during the takeoff roll, and Type I is just a contaminant remover. As far as I know, no current de-ice fluid that isn't a part of the aircraft (TKS), is designed to protect the wings or body in flight.
 
Other question- you're the pax sitting at the window over the wing watching this situation shape up. Your response?
 
Not much you can do. If it has LED's, you're very likely ok. If not, the answer is highly non-linear and too dependent on unknown variables to make any sort of reasonable prediction.
 
cencal83406 said:
I haven't heard of this before either. Type IV is supposed to protect against accumulation up until shearing off during the takeoff roll, and Type I is just a contaminant remover. As far as I know, no current de-ice fluid that isn't a part of the aircraft (TKS), is designed to protect the wings or body in flight.
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I was hoping that someone who knew for sure would explain. I will have to rely on what I was told whether it was right or wrong, hopefully someone will correct me. I was told it had to do with issues of fuel vent icing up and spraying helped prevent it. My thought each day watching this, was how much cheaper were the airbuses to purchase or operate that offset the cost and delay of having to spray the airplane in what I considered non-icing conditions.
 
Could it have been frost due to cold fuel? Upper surface frost will require de-icing per the regulation.

Another possible explanation could be that the pilots wanted to increase the costs to their employer?
 
FlyingScot said:
I was hoping that someone who knew for sure would explain. I will have to rely on what I was told whether it was right or wrong, hopefully someone will correct me. I was told it had to do with issues of fuel vent icing up and spraying helped prevent it. My thought each day watching this, was how much cheaper were the airbuses to purchase or operate that offset the cost and delay of having to spray the airplane in what I considered non-icing conditions.
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I've heard that some stations will hose down aircraft prior to the pilots getting there so they won't have to lose any time getting deiced for contaminates such as frost. If it's snowing, obviously you're in a different situation.

Don, or one of the other UPS guys, could back that up or shoot it down.
 
FlyingScot said:
I was hoping that someone who knew for sure would explain. I will have to rely on what I was told whether it was right or wrong, hopefully someone will correct me. I was told it had to do with issues of fuel vent icing up and spraying helped prevent it. My thought each day watching this, was how much cheaper were the airbuses to purchase or operate that offset the cost and delay of having to spray the airplane in what I considered non-icing conditions.
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seagull said:
Could it have been frost due to cold fuel? Upper surface frost will require de-icing per the regulation.
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I believe seagull hit it. Its only on the Bus that they do this and its not only UPS IIRC FedEx does it also on the Bus that continues to BOI but not the MD11. Its amazing as a feeder freight dawg the mentality between brown and purple. If I took off with this snow as in the video on the 1900 on purple side there is a good chance I will get fired, well never even that never make it out of the chocks, than flight canceled than fired. Its amazing the difference in regards to safety. When I had smoke in the cockpit the other month and returned to land they didn't care the packages made the PM sort the first thing they wanted to know was if I was ok!
 
jtrain609 said:
I've heard that some stations will hose down aircraft prior to the pilots getting there so they won't have to lose any time getting deiced for contaminates such as frost. If it's snowing, obviously you're in a different situation.

Don, or one of the other UPS guys, could back that up or shoot it down.
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They tried this on the UPS ramp in SLC on the feeder planes. Lasted on day when they found out the pilot must be present to supervise
 
JayAre said:
I believe seagull hit it. Its only on the Bus that they do this and its not only UPS IIRC FedEx does it also on the Bus that continues to BOI but not the MD11. Its amazing as a feeder freight dawg the mentality between brown and purple. If I took off with this snow as in the video on the 1900 on purple side there is a good chance I will get fired, well never even that never make it out of the chocks, than flight canceled than fired. Its amazing the difference in regards to safety. When I had smoke in the cockpit the other month and returned to land they didn't care the packages made the PM sort the first thing they wanted to know was if I was ok!
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Could you elaborate on this? Not clear which company you're talking about and whether you are saying something positive or negative about either one?
 
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