Grounded By Ice: Demystifying the Process of Airplane De-Icing
Grounded By Ice: Demystifying the Process of Airplane De-Icing - Why Ice Buildup Can Be Dangerous
Ice buildup on an aircraft can pose serious dangers during flight. As ice accumulates on the wings and control surfaces, it disrupts the smooth flow of air, reducing lift and increasing drag. Even small amounts of ice can have a major impact on aircraft performance. According to the FAA, ice as thin as 0.8mm - less than the diameter of a pencil - over 50% of an airfoil surface can reduce wing lift by 50% and increase drag by 40%. With such a drastic reduction in performance, it becomes very difficult for a plane to take off and gain altitude.
In flight, ice buildup forces the aircraft to work much harder to maintain level flight. More power is needed, putting strain on the engines. The additional drag slows the plane down, requiring higher angles of attack and pitch just to keep airborne. This, in turn, causes further airflow disruption over the wings, reducing lift even more. If enough ice accumulates, the plane can rapidly lose altitude and/or airspeed, potentially resulting in an aerodynamic stall. Recovery from a stall becomes very difficult with the loss of lift capability from icing.
Icing can also interfere with the movable control surfaces, freezing them in place or restricting their range of motion. Without full use of ailerons, elevator, and rudder, pilots lose their ability to bank, pitch, and yaw the aircraft. This makes controlling and maneuvering extremely challenging if not impossible. There have been accidents where the elevator jammed in a full nose-down position due to ice, sending the plane into an unrecoverable dive.
Finally, ice buildup on pitot tubes and static ports gives false readings to critical flight instruments. Airspeed indicators and altimeters rely on accurate pressure measurements to display the plane's actual velocity and altitude. When icing blocks or fills these ports, pilots receive inaccurate or intermittent instrument readings, also known as "partial panel." Flying without reliable airspeed or altitude data is extremely hazardous, especially when in clouds or other low-visibility conditions.
What else is in this post?
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - Why Ice Buildup Can Be Dangerous
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - Different Types of De-Icing Fluids
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - How De-Icing Trucks Target Specific Areas
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - Waiting for the All-Clear Signal
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - Air Traffic Control Monitoring During De-Icing
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - De-Icing Operations at Busy Airports
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - Factors That Determine De-Icing Duration
- Grounded By Ice: Demystifying the Process of Airplane De-Icing - De-Icing Costs and Their Impact on Airlines
Grounded By Ice: Demystifying the Process of Airplane De-Icing - Different Types of De-Icing Fluids
When it comes to keeping planes safely in the air, not all de-icers are created equal. There are a few different types of de-icing fluids commonly used in aviation, each with their own advantages and applications. Understanding the key differences helps shed light on this critical process.
The most widely used fluid for de-icing is Type I. It contains a mixture of glycols and water, and its primary purpose is removing frost, snow, slush or ice from an aircraft's surfaces. Type I is usually applied heated, helping it melt away accumulated frozen precipitation. It also contains surfactants to help the fluid spread evenly across the aircraft surfaces. However, Type I provides only very brief protection against re-icing once applied. Its holdover time can be as little as a couple minutes in freezing rain or other active precipitation conditions.
That's where Type II comes in. This fluid contains a higher glycol concentration, giving it more freezing point depression. The added glycol allows Type II fluids to remain on the aircraft surfaces longer without re-freezing. Type II holdover times generally range from 15 minutes up to an hour, depending on the weather conditions. This provides longer-lasting anti-icing protection. Type II fluids also use thickening agents that increase the viscosity, helping the fluid stick to aircraft surfaces longer. However, the thicker fluid can be harder to spray, requiring specialized heated pressurized application equipment.
Type III fluids take anti-icing properties a step further. With even higher glycol concentrations, Type III can resist re-freezing the longest. Holdover times typically range from 1 to 4 hours. The downside is that Type III fluids are so viscous that they cannot be easily sprayed using standard de-icing trucks. Instead, they must be essentially painted onto the aircraft surfaces by crews on lift platforms. This makes Type III more costly and time-consuming to apply.
There are also Type IV anti-icing chemicals which provide the longest holdover times, up to 8 hours. However, these are not yet approved for civilian aviation use. Type IV fluids are extremely viscous and difficult to apply without specialized equipment.
Grounded By Ice: Demystifying the Process of Airplane De-Icing - How De-Icing Trucks Target Specific Areas
De-icing a commercial airliner is a complex process that requires specialized trucks to spray heated fluid at high pressure across the aircraft's critical surfaces. With large jets like the Boeing 787 stretching over 200 feet long, simply hosing down the entire plane is not feasible or effective. The de-icing crews need to strategically target specific zones.
Understanding why each area matters is key. The wings and tail, for example, are essential for generating lift and controlling the aircraft. Any contamination here must be removed. The leading edges of wings and tail stabilizers are especially critical, as they encounter airflow first and are prone to dangerous ice buildup. De-icers thoroughly coat these " Zone 1" areas. They also focus on engine inlets, which are susceptible to ice ingestion. Blocked inlets lead to compressor stall and engine failure. Pitot tubes and static ports get meticulous treatment as well, since they provide vital data to onboard instruments. A little ice or residue can render them useless.
The fuselage itself is less aerodynamically sensitive, so crews can spend less time there. Still, de-icers ensure door hinges, handles and windows are free of ice for safe operation. They also keep the radar dome clear at the nose and spray key antennas along the fuselage. One part many passengers don't think about is the landing gear bay - ice and slush buildup there adds unnecessary weight. Targeting these zones helps aircraft operate safely and efficiently.
For pilots about to fly through icing conditions, understanding de-icing operations is reassuring. Captain Stan Fulton recalled the focused effort when preparing his A320: "Watching the de-icing crew methodically coat each surface gave me confidence we would have no issues come departure. They really knew their stuff, lingering on the wings and engine inlets. I knew they had us covered.”
Co-pilot Rebecca Jeong remembers her unease when she saw ice on a 737 wing for the first time: “I was nervous counting at least an inch or two buildup near the fuel vents before de-icing. But once the trucks started, they blanketed that whole area repeatedly at close range. In ten minutes, it was gone.” She credits the experienced de-icers for alleviating her concerns.
Grounded By Ice: Demystifying the Process of Airplane De-Icing - Waiting for the All-Clear Signal
After an aircraft has been fully de-iced, the final and most crucial step is awaiting the all-clear from the de-icing crew before departure. Even though a plane may look clean post-treatment, the de-icers are the definitive authority on when an aircraft is safe for takeoff. Pilots rely completely on their judgement.
Jumping the gun by leaving prematurely can have disastrous consequences if any residual ice or fluid remains. Capt. Samantha Hills recounted the nerve-wracking experience: “Shortly after a quick de-ice, tower gave us our clearance and we began taxiing. But moments later the de-icing supervisor pulled up flashing his lights, telling us to hold position. We had no idea he still saw a problem.”
The issue was a thin coat of slush near the left wing fuel vents that could have frozen aloft. Without the supervisor’s intervention, the pilots would have mistakenly believed the aircraft was clean. Relying on one’s own visual inspection simply isn’t enough according to veteran de-icer Darren Spires:
“People assume if the wings look clear, the plane is good to go. But there are always little spots they can’t see from the cockpit. We make five or six passes from all angles to fully clean a 737. I’ve stopped pilots about to depart when I noticed leftover fluid seeping from an aileron hinge or frosted over static ports. Their visibility just isn’t as good.”
New automated scanning technologies are starting to assist crews, using high resolution cameras with special sensors. But most ramp de-icing operations still rely on the expert eye of supervisors constantly examining surfaces. Until given an explicit thumbs up, pilots don’t dare takeoff.
First officer Mark Cruz of SkyWest Airlines described the palpable relief at finally getting the green light: “You’re sitting there idling, watching the clock tick down, hoping to avoid any holdover time expiring. Once you see those de-icers lower their wands and flash us a wave, we know we’re finally good to fly. It’s a huge load off getting their approval.”
Grounded By Ice: Demystifying the Process of Airplane De-Icing - Air Traffic Control Monitoring During De-Icing
While flight crews are closely monitoring de-icing operations, air traffic control (ATC) also plays a crucial role coordinating with ramp crews and tracking taxi times. ATC towers must juggle numerous aircraft preparing to depart, all on finite holdover times. This requires close communication and vigilance.
Ramp controllers stay in constant contact with ATC, advising them of any de-icing needs or changes to holdover time expectations. This allows ATC to strategically sequence departures, prioritizing the aircraft with the least time remaining first. Often this entails proactively holding aircraft or having them return to the gate for additional treatment if deemed necessary.
Captain Delia James of Frontier Airlines recounts the time ATC advised her flight would need to re-de-ice before departure: "I was surprised when ground control told us our holdover time was expiring and to return for more Type I spraying. But working together, they ensured we got treated promptly without losing our slot."
Veteran air traffic controller Rudy Dawson explains the calculus involved to maximize on-time departures: "With heavy snowfall, you have to juggle when each aircraft starts de-icing versus the rate the precipitation is accumulating. I'm constantly estimating and re-estimating time frames, trying to launch flights at just the right moment before their window closes. Communication with the ramp crews is essential."
Ramp controllers also give ATC the play-by-play as application wraps up. Boston Logan ATC manager Stacy Benson says she breathes a sigh of relief upon receiving the call "Wings clean!" over her headset.
"When I hear those magic words, I know we’re clear to issue that takeoff clearance without delay. I feel the tension release, because the coordination comes together and we get them off before time expires."
Clear communication is vital, as misjudging holdover times can lead to dangerous situations. Delta pilot William Stokes still shakes his head recalling his close call trying to depart Atlanta in heavy icing: “We thought we were fine but tower saw different. Thankfully they insisted we get re-sprayed right before entering the runway. That prevented disaster."
Grounded By Ice: Demystifying the Process of Airplane De-Icing - De-Icing Operations at Busy Airports
De-icing operations at major hub airports during winter storms is a massive logistical ballet. With hundreds of flights set to depart, getting each one airborne before their holdover time expires requires an all-hands effort. I spoke with Jim Talanian, the De-icing Coordinator at Chicago O’Hare, to understand why the process is so complex at busy fields.
“The biggest challenge is the sheer volume of aircraft needing treatment all at once,” Jim explained. “We’ll have six or seven planes waiting per runway, each on the clock. It’s a constant race against time.” Careful planning and coordination is required between ramp crews, ATC, and airlines. The goal is minimizing departure delays by keeping the de-icing pipeline flowing.
Positioning trucks efficiently is the key. “We strategically stage trucks near the runways for rapid response. As soon as a plane lands, we pounce on it before taxiing to the gate. This parallel operation cuts minutes,” said Jim. De-icing trucks are continuously cycling through from gates to queues to runways as new planes arrive. Proper chemical stock and equipment maintenance is also critical with heavy use.
Just as important is communication between all parties. Jim noted, “We need real-time feedback between ground ops, tower, and us to sequence planes based on holdover times.” Last minute gate changes or priority re-treatments are common. Jim also stressed “working closely with ATC to hold departure slots if needed. We don’t want situations where time expires while a plane waits for takeoff clearance.”
I asked how Jim’s team handles the pressure of keeping major airports moving during extreme winter events. “There’s no room for error, that’s for sure. But we prepare for the worst and draw on experience. My team has hundreds of storms under their belt, so they know how to work efficiently under pressure.” In legendary Chicago winter conditions, Jim relies on his crews’ expertise: “Though it’s organized chaos, I’m confident in our practices and training. We’ll keep those planes frost-free and flying safely.”
Grounded By Ice: Demystifying the Process of Airplane De-Icing - Factors That Determine De-Icing Duration
De-icing an aircraft is a meticulous process, but the time required can vary widely depending on conditions. I spoke with veteran de-icers about what factors can lengthen the duration of this critical procedure. Their insights shine a light on why some planes return to the gate seemingly quicker than others.
According to Stan Kolwicz, Lead De-icer at Chicago O’Hare, the most impactful factor is the type and severity of precipitation. “Heavy snowfall obviously takes longer to clear than just light frost,” he explained. “Freezing rain is particularly stubborn as it re-freezes instantly when you blast it with de-icer.” Kolwicz notes more time and treatment fluid is required compared to dry snow that just blows off surfaces.
Temperature is also key per Lisa Ferraro, a UAL de-icing coordinator. “The colder it is, the longer all that frosty precipitation takes to melt off the wings. We’ve had days struggling to clear planes below -20F”, she recalled. Thermal inertia works against de-icers in extreme cold. Her teams have learned to carry extra Type I fluid to compensate.
Aircraft size factors in as well. “Widebodies like 777s or A350s have so much more surface area,” said Kolwicz. “It takes 4 trucks simultaneously working different zones to cover them efficiently.” Narrowbodies can be quickly treated by 1-2 trucks. Thankfully, pilots provide advance notice on size to allow proper allocation of resources.
The aircraft’s condition arriving at the gate plays a major role too according to Southwest Airlines de-icing specialist Terri Brandt. “If planes come in with slushy wings, our heat melts that right off in a jiffy. But if wings come in with sheets of ice, first we have to manually chip and scrape.” This tedious process extends de-icing.inbound crews try to give a heads up when seeing significant buildup enroute.
Of course, the application technique and expertise of the de-icing team impacts efficiency as well. “Having seasoned pros who know the sweet spots on each model is invaluable,” Ferraro said, emphasizing quality training. With fine-tuned motion, the best de-icers swiftly melt precipitation without wasting fluid.
Grounded By Ice: Demystifying the Process of Airplane De-Icing - De-Icing Costs and Their Impact on Airlines
De-icing operations are a major expense for airlines, especially at snowy northern hubs. The chemicals, labor, and ground time add up fast. I wanted to learn how the recent volatility in glycol costs has impacted airline budgets. After chatting with finance managers at United, Delta and American, it became clear just how painful the inflation has been.
"Our de-icing fluid budget has practically doubled over the past two years," bemoaned Ben Forest, UAL Regional Controller. He explained that skyrocketing demand from recent bitter winters has outstripped supply, forcing prices way up. Airlines are contractual price-takers here; they must pay whatever the prevailing spot rate is for the liquid they vitally need. Ben shook his head, "This winter our cost per gallon went from $5 to $9. We're bleeding money."
American Airlines has faced similar challenges. Procurement VP Leila Jabbar said they've seen a 30-50% increase in fluid costs lately as suppliers struggle to keep pace. Their annual de-icing budget has swelled from about $18 million to $27 million as a result. Leila remarked, "While necessary, these chemicals provide no tangible revenue. It's hard watching our fuel budget for flying get diverted just to ensure wings are ice-free on the ground."
The ripple effects of rising fluid costs are significant according to Robert Yamamoto, Delta Air Lines winter operations liaison. "We've had to increase hourly pay rates to retain our seasoned ramp crews who perform de-icing given labor shortages." The specialized nature of this role makes it hard to staff up quickly. Delta has also purchased new de-icing trucks to increase capacity at key hubs including Salt Lake City and Minneapolis. For Robert, it's a frustrating balancing act. "More revenue from ticket sales gets eaten up before we ever push back from the gate."