TWA was a frequent visitor to my airport. At some point I started to notice these wide black stripes on the wings going from the leading edge to the trailing edge. From others threads here on the Forums I have learned these are to make it easier to detect ice on the wings. They seem to be painted flat black.

Did TWA start doing this after and in response to high profile icing incidents or did it come about for some other reason?

I don't think many airlines followed TWA in placing these long and wide black stripes. Wonder why? Was TWA just being super careful? Were they placed on the wings of all the aircraft TWA operated or just some? And why do MD-80 types have smaller ice detectors on their wings.

Anyone know? Thanks for all information and guesses!

I think they installed them around 1991.

Some MD-80 have the ice detectors on the wings because upper wing surface ice would likely damage an engine if ingested. Other MD-80 have one of two different manufacturers heated pads instead of the detectors making the detectors not necessary. I believe there’s one other system as well but I can’t recall at the moment.

At Continental we had a very low tech ice detection system, the FO hauled out a ladder to the front of the wing and dragged what looked like a long pool cue across the susceptible area of the wing to make sure there was no ice


A major PITA, I know because I did it many times!

MD80's had a major problem with wing surface ice. And yes it could cause an engine out if ingested.

The inboard section of the wing could form a layer of ice just sitting at the gate on a warm humid day. The remaining fuel from the inbound fight was super cooled and was all in the inboard end of the wing. The MD80 wing is considerably thinner than say the 737. So any fuel in that section is in close contact with the upper wing surface. Condensation on the top of the wing can easily freeze.

The black stripes were one early solution. Another was piping system in the wing to move the fuel around the wing so the fuel didn't get as cold. The string attached to the top of the wing was an effective inspection method. If the string was frozen, you couldn't move it with the the stick. Then you call the deicing truck.

The best solution was the heater blanket system. I think SAS developed the STC for it. A very large panel was installed on top of the wing in the first ten feet of the wing. the panel had a heating element bonded into the middle of it. I installed many of these at Delta during the HMV visits. It took about four days to install. A couple of days of prep and then 12 quarts of sealant applied to the wing and bottom of the panel. It was fun carrying the panel up on to the wing and putting it in place. It was then vacuum bagged to the wing for 24 hours while the sealant cured.

They had two heating elements, so if one failed it would still work. Once the second failed the blanket needed to be replaced. That sealant is tough stuff. We would use the 10 ton overhead hoist, the same one that is used to install engines, to peal the blanket off.

The wing icing issue was one of many issues on the MD80, it was a really compromised design, basically a warmed up DC 9 that should have had a complete do over

Did the DC9 have the same icing issue? I know the 717 has the ice detectors on the wing.

No, the DC9 did not have that issue, MD crammed as much fuel as they could into the slightly modified -80 wing and didn’t leave enough space between the top of the fuel tank and the upper surface of the wing


Fuel would become cold soaked in cruise flight and condensation would form on this upper wing surface which could freeze in the right conditions


Since it was isolated to a fairly small area at the wing root it was hard to see and for a long time no one knew it was happening


The problem came when this ice wasn’t detected on the next take off, at rotation the wing would flex, the ice would break off and go straight into the rear mounted engines


In one case this happened to an SAS MD80, they lost power in both engines immediately after take off, however they were able to successfully dead stick into a snow covered field with no fatalities


That’s when the investigation into the wing ice problem was kicked off and different solutions put into service


The best of all were the embedded wing heaters that protected the entire area of vulnerability but not all airlines wanted to pay for this and either maintenance or flight crews had to inspect for ice before every flight in most weather conditions

In fact unless it was over 90 degrees we always had to do this physical, hands on inspection because the problem wasn’t the temperature on the ground, it was the ice that had formed on the previous flight that you couldn’t guarantee would all melt before the next take off, especially on a quick turn around


If we were in a maintenance base a mechanic would do this inspection otherwise it was up to the pilots and the FO was the lucky one who got to do this, I was in the right seat in those days and I never saw a Captain do it !

Max Q wrote:

The best of all were the embedded wing heaters that protected the entire area of vulnerability but not all airlines wanted to pay for this and either maintenance or flight crews had to inspect for ice before every flight in most weather conditions

In fact unless it was over 90 degrees we always had to do this physical, hands on inspection because the problem wasn’t the temperature on the ground, it was the ice that had formed on the previous flight that you couldn’t guarantee would all melt before the next take off, especially on a quick turn around


If we were in a maintenance base a mechanic would do this inspection otherwise it was up to the pilots and the FO was the lucky one who got to do this, I was in the right seat in those days and I never saw a Captain do it !

I watched TWA a multitude of times at STL when they used a glorified Shepherd's Pole to check for ice so they would not have to use a ladder for the check.

Okie

Okie wrote:

Max Q wrote:

The best of all were the embedded wing heaters that protected the entire area of vulnerability but not all airlines wanted to pay for this and either maintenance or flight crews had to inspect for ice before every flight in most weather conditions

In fact unless it was over 90 degrees we always had to do this physical, hands on inspection because the problem wasn’t the temperature on the ground, it was the ice that had formed on the previous flight that you couldn’t guarantee would all melt before the next take off, especially on a quick turn around


If we were in a maintenance base a mechanic would do this inspection otherwise it was up to the pilots and the FO was the lucky one who got to do this, I was in the right seat in those days and I never saw a Captain do it !

I watched TWA a multitude of times at STL when they used a glorified Shepherd's Pole to check for ice so they would not have to use a ladder for the check.

Okie

Interesting

They wanted us to actually be able to see the wing area in question, to be absolutely sure there was no ice, it was hard to see and it would surprise you how often you’d find some

Dalmd88 wrote:

MD80's had a major problem with wing surface ice. And yes it could cause an engine out if ingested.

The inboard section of the wing could form a layer of ice just sitting at the gate on a warm humid day. The remaining fuel from the inbound fight was super cooled and was all in the inboard end of the wing. The MD80 wing is considerably thinner than say the 737. So any fuel in that section is in close contact with the upper wing surface. Condensation on the top of the wing can easily freeze.

The black stripes were one early solution. Another was piping system in the wing to move the fuel around the wing so the fuel didn't get as cold. The string attached to the top of the wing was an effective inspection method. If the string was frozen, you couldn't move it with the the stick. Then you call the deicing truck.

The best solution was the heater blanket system. I think SAS developed the STC for it. A very large panel was installed on top of the wing in the first ten feet of the wing. the panel had a heating element bonded into the middle of it. I installed many of these at Delta during the HMV visits. It took about four days to install. A couple of days of prep and then 12 quarts of sealant applied to the wing and bottom of the panel. It was fun carrying the panel up on to the wing and putting it in place. It was then vacuum bagged to the wing for 24 hours while the sealant cured.

They had two heating elements, so if one failed it would still work. Once the second failed the blanket needed to be replaced. That sealant is tough stuff. We would use the 10 ton overhead hoist, the same one that is used to install engines, to peal the blanket off.

If my memory serves me right the MD-90 did away with the blankets and had and routed warmed fuel back into the taks. You're proably more familiar witht aht system than I since my MD-90 experience is a bit limited. And about twenty years old. lol

In the mid 1980's, operators were looking for last minute ways to determine if their essential lifting surfaces were contaminated with frost/ice. Several operators discovered that dark surfaces were much easier used to determine if contamination existed. Examples - outboard roll spoilers on the Dash 8's - surface paint on other types observable from the cabin, etc. In other words, phenomena observable from within the airplane prior to takeoff. Rather than an unnecessary return to the de-icing bay, these last ditch measures allow more flights to depart. Hopefully, the question raised by convair880mfan has now been answered.

I remember once in the early 90's getting deiced on the MD80 redeye to STL. From Phoenix. (And no, it wasn't the middle of winter.)