In the wake of several recent airliner losses, talk in the media once again turns to the futuristic concept of remotely piloted passenger jets.
A very bad idea, as I explain on Mashable.com. Just click here to read, or use the link below.
The media response and the social media firestorm after the Germanwings tragedy has prompted ill-advised, reckless “solutions” that in many cases, only makes air travel less safe.
Click here for my commentary on Mashable that has ignited its own firestorm of reaction.
Can YOU stop a jet on a winter runway?
Whenever an airliner slides off a taxiway or runway in winter conditions, the public and the media asks dozens of questions related to one overriding concern: how could this happen?
But for every other flight that lands on a winter-affected runway without incident, there were dozens of questions correctly answered by pilots related to THIS overriding concern: how can we assure that DOESN’T happen?
I’ve been flying in and out of LaGuardia and Washington Reagan all winter, accommodating ice, low visibility and contaminated surfaces in what has been an exceptionally vigorous winter storm season. The questions and correct answers required to assure a safe flight under such conditions are neither straightforward nor simple. Here’s the decision process–YOU decide what to do.
First, before we even depart for an airport affected by winter weather, we think about the factors that affect our landing: weight, wind, landing distance required, and runway surface conditions. And there are no easy answers any of these questions.
Weight comes first: considering stopping, you’d want weight to be the lowest possible, right? If only it were that simple: the primary, most variable weight in flight is fuel–if you reduce fuel weight to the bare minimum, you also reduce flying time to the bare minimum. The facts of life when flying into a major metropolitan airport include delays–demanding MORE flying time, thus more fuel and thus more weight. If you have only the minimum fuel aboard required to fly the distance, you are screwed: at the first delay (and airborne holding assignments of up to 30 minutes are typical) you must divert.
What you need to do is carry enough fuel to fly the miles AND accommodate typical, historically predictable enroute holding. We’ll have to be sure that we can still accommodate that weight on landing (checking landing distance charts) but that’s a separate question to be dealt with: for now, tank as much fuel as required to fly the distance and hold for a reasonable duration enroute.
We don’t leave the rest of the questions for arrival, but we do answer them late in the flight when the variables have been sorted out: once we’re in the terminal area, we finally can predict an accurate landing weight.
So we request the data-linked landing distance chart for our specific weight which is calculated by computers back at our tech center and sent to our on-board printer. Problem for you is this: the chart also has variables you must resolve: what is the runway condition, and what is the braking effectiveness?
Those two variables can not be definitely determined because the informational reports are both very subjective: the “runway condition” must be determined in reference to varying standards. Our airline calls a runway “contaminated” when 25% of the landing surfaces is contaminated by ice, standing water or snow.
Another airline may allow 30%, another 60%, so there’s never any “contaminated” determination available other than reports from previous company aircraft. But even those are subjective–how do you eyeball 75%–and in winter storms, conditions can worsen by the minute.
Braking effectiveness is another subjective report: what I consider “fair” braking for my jet (and I report this to the tower after landing based on what I just experienced) might be “good” for a lighter regional jet or “poor” for a heavier aircraft or and aircraft with less effective brakes. And, in heavy precip, that can change drastically in just minutes.
The landing distance charts reference “good” or “fair” in the conditional determination of braking effectiveness–but you now know that “report” is vague at best. Still, you must decide which calculation to use.
There’s also more than one chart for landing distance. The first one assumes that you touch down at the Visual Approach Slope Indicator (VASI) aimpoint which is about 1,500 feet from the runway threshold. There’s another chart that computes stopping distance from the visual touchdown markings on the runway some 500 feet prior to the VASI aimpoint. That chart, with the additional distance from the earlier touchdown point, may allow you to land based on stopping distance.
But can you accomplish that? The “you” is key–no one on the ground can answer that. Ultimately, the captain decides, and here’s what he’s thinking: what are the winds? A tailwind will make that very difficult, a headwind will help. But can you count on either wind report? Those reports, like “braking effectiveness,” have a very short shelf life–winds change minute by minute. Do you think your landing wind is reliably a headwind, or at least not a tailwind? Again, YOU have to answer that based on subjective reports.
As far as the visual touchdown aimpoint, are you going to be transitioning to this new, shorter target from an instrument approach, which has a more distant touchdown point more like the VASIs? If so, do you have adequate distance, time and visibility to do so? And the skill?
Finally, landing rollout must be done exactly right: spoilers deployed, reverse thrust promptly initiated at the proper level, and brakes applied promptly and correctly. That sounds easier than it is.
First, spoilers normally are automatically deployed–but that deployment needs certain prompts: main wheel spin-up is a primary trigger, and patchy ice may keep wheels from spinning, delaying auto deployment, even as you eat up critical landing distance. Or, like last month, I landed my 737-800 on a wintery DCA runway without the auto-spoiler system working. I agreed before dispatch on the flight that I could and would do so manually. My judgmental call, a fact of life in airline flight operations.
Regardless, the point is, the crew must assure spoiler deployment and effective reverse thrust AND full braking–all in a millisecond when landing distance is critical.
As crucial, you must put the jet down on the exact spot–neither before nor absolutely, not beyond–and put it down firmly to ensure wheel spin-up, essential for traction and auto-spoilers. If you’re the ignorant smartass getting off the plane after that trying to be witty by saying “You must be a Navy pilot, that was a carrier landing” or “I guess the brakes work,” I’ll ignore you–but the crew will write you off as an ignorant smartass just the same.
There’s no feeling worse in the cockpit than the anti-skid system releasing the brakes on rollout, even if you’ve done everything correctly, but that’s essential too: the system applies braking force to the very brink of a skid, beyond which there’s no braking, just sliding. If you’ve calculated your stopping distance based on “fair” reports, you can expect some releasing as the brakes do their job. All the more reason for a firm and accurate touchdown.
I expect and require every landing to be on the correct speed (faster makes stopping more difficult) and on the right spot, even at DFW Airport with miles of runway to spare, simply because it must be (for me) the rule rather than the exception when I fly to LaGauardia, Washington Reagan or Santa Ana-Orange County with shorter runways. “Pretty” landings are a Hollywood contrivance and have no place in the actual profession.
When we stop safely and exit the runway, that’s because we correctly solved the puzzle: weights, speed, touchdown point, winds, and braking distance. For passengers, that means a safe trip completed. For the cockpit crew, the work is only beginning: all of these variables must be dealt with successfully again in order to execute a safe take-off or abort on that same winter-affected runway.
The airline industry in the United States has an enviable safety record, which is why the very rare incident gets so many media headlines. The real news is, overall, airline pilots are doing their job very well.
Network news media love a screaming headline, even if they have to fudge the facts to suit the rhetoric. But here is the reality behind the wailing and gnashing of teeth regarding recent ice-related delays at major airports: the airlines did a damn good job given the challenges heaped on them in this storm.
As a captain, I flew a 737 trip in the middle of the week in the slush and snow out of DFW. Here is your chance to bypass the media frenzy (NBC News carefully crafted “9 hour delay for passengers”–quietly admitting later that it wasn’t on-board) and watch the flight evolve despite the weather interference.
At 06:10, a phone call from crew schedule woke me up. I had volunteered to fly a trip that day and they offered one, a turn to John Wayne Orange County (SNA) scheduled to depart at 10:10. I agreed to fly the trip.
Normally, it takes me 35 minutes to drive to DFW. I left my house at 6:45 to allow extra time for the slush and snow snarling the highways.
I arrived at DFW an hour later, an hour and twenty minutes early. The jet was parked at the gate, had been all night in the freezing precip, so I went aboard and started powering up systems. A quick check of the wings and fuselage confirmed what I assumed driving in: we’ll need a good de-icing on the wings, control surfaces and fuselage.
Let’s get more specific about aircraft icing. First, we need to remove the accumulated ice. Second, we need to prevent more ice from re-forming on aircraft surfaces. De-icing can be accomplished by a number of different fluids under pressure. “Anti-icing” is provided by a different, specifically designed fluid that chemically inhibits the adherence of ice on aircraft surfaces.
In our case, the ceiling was low and visibility limited by ice fog, confirming the critical temperature-dew point spread that leads to condensation which of course would freeze on any cold surface. That means both de-ice and anti-ice will be required.
Anti-ice fluid effectiveness varies with temperature, and rate and type of precipitation. The duration of anti-ice protection declines as various forms of moisture increase. So, gauging the time–called “holdover time”–is a call that must be made by the flight crew based on observation of conditions actually occurring.
You can tell when anti-ice fluid has been applied to a jet because it will be colored either brick red-ish or lime green. The intensity of the color cues the cockpit crew as to the fluids declining effectiveness–it fades as the fluid loses the ability to inhibit icing. We actually check visually that from inside the aircraft prior to takeoff.
A side note about the fluid color. Most airlines now use the green fluid because the red was difficult to distinguish from hydraulic fluid as it dripped from crevices and bays on the aircraft, sometimes several flights downline from the original de-icing treatment. I learned long ago how to differentiate the two: propylene glycol, the main ingredient in anti-icing fluid, smells and tastes sweet. Skydrol hydraulic fluid is bitter. Yes, I’ve tasted both in the thirty years (and counting) I’ve been flying jets and laugh if you want, but it saves all aboard a needless and probably lengthy maintenance delay.
Another unseen complication that adds to the icing mix is jet fuel. The worst case is with fuel remaining in wing tanks after a flight at high altitude. The fuel in the tanks become super cold due to the temperature at altitude (often -50C or less) and as a result, the wing surfaces both upper and lower are super-chilled, causing any moisture in the air to freeze on contact. Explain that to the guy sitting next to you griping as we de-ice on a sunny, clear day: humidity plus ice-cold metal surfaces can add up to wing icing that must be removed: we can tolerate no more than 1/8″ of mere frost on the underside of the wing only. Any other airfoil contamination must be removed before flight.
Clear ice on wings is not easy to see from the cabin, particularly the area near the wing root, which is critical on aircraft with tail mounted engines like the MD-80 and -717, because upon wing flex as rotation and liftoff occur, any wing root ice that breaks loose into the slipstream could easily fly back along the fuselage to be ingested by either or both engines, with potentially disastrous results.
So why don’t aircraft have heated wing surfaces? Actually, most MD-80 upper wing surfaces do have an electrically heated thermal blanket on top of the inboard-most portion of the wing surface. But, not the curved wing root joint which is not visible from the cabin. So, you’ll notice a lot of MD-80 aircraft having to de-ice in even the slightest icing conditions.
In our case, I knew the fuel pumped aboard for our flight would have the opposite effect. At DFW, the fuel is stored underground and pumped aboard from a hydrant, not a truck. The effect would be to warm, not freeze the wing surfaces. That would help with de-icing, but we’d still require a thorough dose of Type-2 de-icing fluid to clean ice off the jet.
By 9:10, the official crew check-in time, there was no sign of a first officer. I started the process of printing a flight release and agreeing on a fuel burn, as well as the complex process of determining takeoff speeds, made more complicated due to the presence of slush and snow on the runway. Any type of contamination, from pooled water to slush to ice can impede both acceleration and deceleration. Both maximums (takeoff and stopping) must be accurately calculated and while there is a published “runway condition,” the actual calculations are very much a realtime, eyeballs-verified assessment: I’ve broken through an undercast during an ice storm as we approached DFW only to find that just the first two-thirds of the runway had been cleared–a fact not noted on the official field report. That lopped off about four thousand feet of useable braking surface.
At 9:30, forty minutes prior to pushback, still no sign of a first officer. The roads are awful, as is the traffic, so I’m not surprised and I’m glad I left home as early as I did. I called Crew Tracking, catching them by surprise as well: in this winter storm, there were plenty of stuck, stranded or missing crewmembers. They hadn’t noticed.
I resigned myself to going out into the sleet to do the exterior inspection myself, planning to have all preflight duties complete in case the first officer should show up at the last minute. Here’s an up close look at the leading edge icing:
and the ice on the wing trailing edge:
Engine covers were installed, a very smart preventative measure to prevent icing, but which would require maintenance removal and documentation. I radioed maintenance to get in the cue for this required maintenance and fortunately, American Airlines had well-staffed maintenance for this shift. But again, they too had technicians who, like my F/O, were stuck in the ice storm snarled traffic, slowing things down.
With the exterior preflight complete, I requested the upload of navigation and performance data as well as our clearances. And I took a minute to call the Crew Scheduling Manager on Duty to suggest that they grab the deadheading 737 first officer sitting in row 20 and reassign him to fly the trip. He said if the duty legality limits worked, that’s what he’d do.
By 10:00, the conscripted first officer was in the right seat, having agreed to the reassignment: he’d fly the leg to the west coast, his home base, and rather than going home, he’d also fly the leg back to DFW and only then deadhead home, if possible. Just one more crewmember going the extra mile to make the flight operation work.
We pushed back nearly on time (10:21 vs. 10:10) , but the ramp was congested with ice and slush, slowing everyone down even further. The precip had stopped, the ceiling had lifted to a thousand feet and the temperature-dew point spread had widened, all of which meant less chance of ice formation. Our holdover time would expand, allowing us to de-ice on the ramp rather than at the end of the runway. Essentially, that made for a shorter wait for all aircraft: if there is freezing precip, or any precip in freezing temps, all de-icing would have to be done at the end of the runway, meaning long takeoff delays.
Taxiing a seventy-five ton tricycle on ice and slush is tricky, requiring slower speeds and a critical energy management: too slow and you’ll have to add excessive power to restart movement, slinging ice and slush at other aircraft. But you also need almost zero forward inertia to maintain nose gear traction in any turn, aided by asymmetric braking on the main gear into the turn. It’s a dicey operation that takes extra time.
We kept the flaps retracted on taxi-out so as to not accumulate any slush or freezing water on the underside of the flaps, a potential problem during flap retraction. Our miles-long taxi from the east side terminal to the west side runway gave us plenty of time to assess the surface conditions and fine-tune our power and speed plans.
We finally lifted off nearly fifty minutes after taxi-out. Through route shortcuts and favorable winds, we made up some of the lost time, arriving twenty-eight minutes behind schedule.
I believe my flight was more typical of all flights during an unrelenting ice storm, but mine isn’t the one craftily worded into a horror story by the media. Regardless, the fact is that icing makes flight operations complex, difficult and challenging. Yet more flight operated in the same way mine did–slow, careful, successful–than the media version of a few unfortunate cases. I take it as a compliment that the reality of these winter flights was a success story leaving the media very few flights to turn into their typically overblown horror stories.
By the time I got home nearly fourteen hours after voluntarily accepting the challenging flight assignment, the network news was already sensationalizing the “impossible” travel situation created by SnoMIGOD 2015 which dumped an unprecedented amount of snow and ice on DFW and Dallas Love Field. At least I knew the facts were not as they’d have us believe–and now you do too.
Travel smarter, with this insider air travel field manual and survival guide. Check it out on Amazon.com, or just click this link to order from Amazon.
The crash video is horrendous, as is the most of the speculation in the media. Here’s my discussion of the video with Fox News:
To to watch, simply click here.
The direct link:
Sidelong cross-cockpit glance: yep, it’s a flat top, ex-USMC style, and the bushy but gone gray Magnum PI mustache suggests a time warp. Better times? Easier times? He laughs a lot for a guy on the razor’s edge of disaster. I say nothing.
Ahead cumulus knots itself into towering stacks, each with a cirrus blow-off pointing like a banner to where the fleet’s headed. Same place we are, or so the anvils point. I’m thinking an upwind end run around the billowing, full-sail armada. He’s talking about our Chicago layover tonight.
His wife, a flight attendant, met us at our connecting gate as she passed through the airport. Something in her eyes matched the foreboding that weighed heavy as the tide on my mind. Pleading? Hurt? Wary? I couldn’t tell–yet I know what I know: My Darling Bride, also a flight attendant, flew with her yesterday. And I knew his wife–flew with her many times–before they were married. Then she was bright in the sense of Christmas lights, tiny scattered points of happiness gleaming everywhere. Not any more.
“Takes two to tango,” his words tumble in a snippet from what is more of a forced chatter, or so it seems. I guess if you’re talking you never have to listen. But in the tango of time and fuel, in the dance altitude and storm clearance, may I cut in?
“I’d say left,” my mouth says. It’s his flight leg, but my jet. He’s flying the plane, but I signed for the damages. Upwind is longer, but smoother, safer. The shorter way is too uncertain, could put someone through the ceiling.
“We can top it,” he suggests, sweeping a hand out flat, as if showing a planar space between our altitude and the boiling cumulus rising ahead. Ah, there’s a thought. Climb another two thousand feet to max habitable altitude for the weight–which puts you into the coffin corner where the difference between high-speed buffet and low speed stall is a handful of capricious knots. If there’s any turbulence, those knots stop the tango and freestyle. Good luck.
His wife had mechanically recited to mine the all-too-familiar litany. “We just bought our ‘captain’s house’ … he wants me to quit flying … he can hold captain in Chicago … get a crash pad there …” In the jumpseat confessional, all is forgiven, but there will be penance nonetheless. Ahead, lightning licked the bruised-blue cloud bases, promising a fresh evening hell for Kansas and eventually, Illinois.
“Let’s take it over the top, direct,” he says with finality. “Stay on time.” Unsaid, but mentioned earlier: “she gets in an hour ahead of us.” Gentleman that he is, he doesn’t want her waiting. She flies for a different airline, but even after working her way over to our terminal, she’ll still have time to kill.
The thing about fiery cumulus and boiling sky is this: you really don’t know how it’s going to turn out. Never mind about the paper algorithm of options and assets, timing, clearance and margins, in real life, you just never know.
I key the hand mike. “Center, we need twenty left for weather.”
He slumped a little. Peeved? The perfect plan set back a few minutes? Can’t tell. Doesn’t matter. We swung wide upwind.
I glance at the cloud tops, anvils aglow with the molten sunset. Some storms seem to fade, to lose their fire when the heat of the sun goes away. But this towering mess seemed the type that would thunder ahead regardless.
“Some things,” I say, “Some things you just can’t get over.”
Deaf ears. He was already hundreds of miles ahead, prattling on about Geno’s and where they’d watch the mind-numbing circularity of NASCAR (“She gets it–and me!”) inside The Loop.
Shouldn’t be in too much of a hurry, too far down the road, I thought to myself. Some things you just never get over, and really, you probably shouldn’t try.
Some you’ve read here, many have yet to appear and the last essay, unpublished and several years in the writing, I consider to be my best writing effort yet.
Own a piece of JetHead, from Amazon Books and also on Kindle.