Tuesday, December 04, 2018

The Lion Air Crash: What You Need to Know

PK-REN from Jakarta, Indonesia [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
Lion Air B737 MAX 8 (Wikimedia Commons)

On October 29 of this year, Lion Air Flight 610 crashed into the Java Sea 11 minutes after departing Jakarta for Pangkal Pinang with the loss of all 189 souls on board. What first called special attention to this accident was that the mishap aircraft was a brand new MAX 8 version of the venerable Boeing 737, and had been delivered to the airline less than a year earlier.

Also of note has been the revelation in the wake of the ongoing accident investigation that a new safety system designed to prevent stalls had been installed on the aircraft, but had not been publicized nor documented in the flight manuals used by flight crews. The flight data recorder (FDR) from the mishap aircraft has been recovered and data from that recorder shows that an errant sensor on the aircraft may have provided bad data to this new system possibly implicating it in the accident. 

The investigation is ongoing and it is inappropriate to assign blame to any system or persons until the completion of the accident review, but as there is much misunderstanding concerning what information is already known, we can take a closer look at the circumstances surrounding this tragedy.

An Undocumented System

The new safety system installed on the MAX version of the 737 known as the Maneuvering Characteristics Augmentation System or MCAS, was designed to provide a nose-down trim input during manual flight as the aircraft approached a stall. What this means in simple terms is that if a pilot is flying the aircraft without the autopilot, and is for whatever reason flying the aircraft well below a safe speed, the aircraft will automatically run the stabilizer trim forward which will have the effect of making the controls heavier to hold.

In addition, once full power is eventually applied to recover from the stall, the forward trim assists the pilot in keeping the more powerful engines on the MAX from overpowering the recovery by exceeding elevator authority. The nose tends to want to rise during a stall recovery and forward trim lessens that effect.

Here is an excerpt from the multi-user message sent by Boeing on November 10 to all 737 MAX operators:

A pitch augmentation system function called 'Maneuvering Characteristics Augmentation System’ (MCAS) is implemented on the 737-8, -9 (MAX) to enhance pitch characteristics with flaps UP and at elevated angles of attack. The MCAS function commands nose down stabilizer to enhance pitch characteristics during steep turns with elevated load factors and during flaps up flight at airspeeds approaching stall. MCAS is activated without pilot input and only operates in manual, flaps up flight. The system is designed to allow the flight crew to use column trim switch or stabilizer aisle stand cutout switches to override MCAS input. The function is commanded by the Flight Control computer using Input data from sensors and other airplane systems.

It is also important to note that any pilot finding him or herself in this position has real problems and has already disregarded the "stick shaker" stall warning system which vibrates the control column well before reaching stall speed. The reason the system was installed on the newest MAX 8 versions of the 737 and not earlier models is apparently the discovery during flight testing of some unfavorable stall characteristics on the new aircraft that did not exist on earlier models.

Angle of Attack

Ok, so far so good. A new safety system was installed. Who can argue with a safety system? The problem that the Lion Air flight encountered, however, was some sort of malfunction in information coming from a sensor being fed to the new system. This sensor is known as the "angle of attack" or AOA sensor. The angle of attack of a wing is the angle between the chord line of a wing and the relative wind moving across that wing. A chord line is an imaginary line which runs from the leading edge to the trailing edge of a cross section of a wing. 

A wing which exceeds the critical angle of attack stalls, which is where boundary layer separation occurs and the wing stops producing lift. If you've ever stuck your hand out the window of a moving car and made a wing with it, you've experienced how changing the angle of attack changes lift. For more on AOA, see here.

The angle of attack sensor is essentially a very small wing on a hinge mounted on the fuselage which measures direction of the relative wind passing the aircraft. You can see them installed near the pitot tubes on most airliners and there are usually at least two installed for redundancy. AOA data is used by a number of systems on an airliner, but happened to be one of the primary inputs to the MCAS system on the MAX 8 aircraft. It is here where problems occurred.

Faulty Input Means Faulty Output (GIGO)

Analysis of the flight data recorder from the Lion Air flight revealed that the data from the two AOA sensors installed on the aircraft did not match. The left AOA sensor was recorded as giving erroneous information during the entire flight. An erroneous AOA information feed or some other malfunction is suspected to have caused the activation of the MCAS system resulting in the system trimming the aircraft in a nose down direction. During the entire flight the pilots trimmed in a nose up direction to keep the aircraft flyable, but at some point stopped trimming and allowed the MCAS system to trim the aircraft nose down to an unflyable condition.

The reason for this is unknown and may be determined when the cockpit voice recorder (CVR) is recovered. Also unknown is why the pilots never used the two stabilizer cutout switches located on the center stand just behind the throttles. These switches remove all electric power from the stabilizer trim motor and would thereby deactivate the MCAS trim inputs.

In fact, on the previous flight of the mishap aircraft, a failure of a similar nature also resulted in uncommanded nose down trim inputs and required the pilots of that flight to use the cutout switches to deactivate the electric trim system. The 737 has a large manual trim control wheel mounted on the center stand that can be turned to adjust the stabilizer trim. It is normally not touched but spins as the electric trim motor is engaged. The pilots on that previous flight used the manual trim wheel to adjust the trim to safely land.

The aircraft did have maintenance performed on various airspeed, AOA and other systems in the days leading up to the mishap flight in response to several defects being written up on previous flights. The exact nature of the malfunctions and degraded systems on the mishap aircraft has yet to be determined as the investigation proceeds, but an AOA sensor had been replaced in response to writeups on the previous flight. A closer look at the flight data from both the mishap flight and the previous flight can be found here.

Protecting Pilots From Themselves

There is an ongoing debate in the aviation community about the benefits and liabilities of cockpit automation. This debate has centered on the effect that highly automated cockpits have tended to make pilots rusty in their "stick and rudder" or basic flying skills. Make no mistake, automation has been a boon to both aviation economics and safety, but it is now being realized that it is not an unmitigated benefit.

At question is the design philosophy incorporated into automation. Years ago, the two main commercial airframe manufacturers, Boeing and Airbus, diverged in their approach to flight control automation. While Boeing aircraft have always incorporated the ability to disconnect all automation, Airbus on the other hand was a pioneer in designing "fly by wire" flight controls into their aircraft. This meant that pilot inputs were sent to a computer and the computer controlled the aircraft. There was no ability to completely bypass the computer and control the aircraft directly.

The revelation that a safety system designed to prevent an inattentive pilot from stalling the aircraft was surreptitiously installed will raise questions as to whether Boeing has decided to follow Airbus down the road of incorporating behind the scenes automation to prevent pilots from doing stupid things. Remember, the original anti-stall device was always the pilot. Warning systems could signal that the airplane was getting slow, but the pilot was always the backstop. Given that the MCAS system can be disabled by the trim cutout switches makes the above scenario less likely.

The alternate explanation to the installation of the MCAS system is that it is simply designed for the mitigation of unfavorable stall characteristics as mentioned above. This raises the question, though, of why the system would not be documented in the aircraft flight manual. Surely pilots would want to know of these unfavorable characteristics and also of the existence a system designed to compensate for those effects. Since the system was undocumented, the pilots of the mishap flight likely had no idea why their trim kept running forward nor were they expecting such behavior.

What's It Doing Now?

It is imperative, then, that pilots are well versed in not only the normal operation of their aircraft, but also in any possible failure mode and are ready and able to assume complete command at any time that the automation is not performing as expected.

Several high profile accidents such as Air France 447 and Asiana 214 serve to highlight the potential pitfalls of flying highly automated aircraft. Part of the problem confronting pilots of these aircraft is the danger of becoming confused about what the aircraft automation is doing. Known as "mode confusion", pilots can make the mistake of assuming that the automation will perform in a certain manner and become confused if it doesn't.

This was one of the findings in the accident review of Asiana 214 which crashed into the seawall at San Francisco. The pilots realized too late that the mode that had been selected would not do what they were expecting. They were then unable to prevent the aircraft from crashing short of the runway.

Now extrapolate mode confusion to a malfunctioning system which the pilots were unaware was even installed, and you can see the difficult situation they faced.

In Conclusion

The cause(s) for the crash of Lion Air 610 are currently unknown and will remain so until the investigation is complete. In the interim, new knowledge of the existence of an undocumented safety system installed on the 737 MAX should serve to further the debate on the appropriate role of cockpit automation.

Thursday, November 08, 2018

How Fast are We Really Going?

Airspeed is more than in interesting detail...it keeps you alive.
Airspeed is Life!

One of the most common questions we get asked by passengers is how fast we're going. Usually it is asked about takeoff or landing as it is easy to find out how fast we're going at cruise. For that, simply look at the inflight entertainment system which gives a readout from the onboard GPS system. When I give an answer to the takeoff or landing speed, I'll say it depends. On what you may ask? It depends on many factors, to include the weight of the aircraft, the wind, the airport elevation, the runway conditions (wet or dry) and even the terrain surrounding the airport.

Even after explaining all that, I have to give an approximate answer because our airspeed up front is given to us in knots and not the more familiar miles or kilometers per hour. A "knot" is a nautical measure of speed which means nautical miles per hour. A nautical mile is 6076 feet as opposed to a statute or "normal" mile which is 5280 feet. In ancient days, sailors would feed a rope over the side of their ship for a specified amount of time and then measure the number of knots (which had been tied into the rope at regular intervals) that had been pulled overboard. The number of knots pulled over was proportional to the speed of the ship.

Later on, a nautical mile was defined as one minute of arc along a meridian (north-south line) on a nautical chart. This made chart reading easier and was picked up by aviation as a standard navigation protocol since early overwater aviators would have to use the same charts as used for surface navigation.

That all sounds very interesting, but are we really using the GPS readout to determine our takeoff and landing speeds? No. We are not. Airplanes stay in the air by virtue of the wind moving over the wings. Not enough wind, the wing stalls and it drops like a rock. The question is how do we know how much wind is moving over the wing?

Wind Over the Wings

To determine how much wind is flowing over the wings we use an airspeed indicator which is simply a sensor connected by plastic tubing to those odd shaped pointy things you see attached to the fuselage near the front of any airliner. Those are called pitot tubes. The tip of a pitot tube has a small opening which is connected by tubing to a pressure sensor. A measure of the air pressure from the pitot tube when compared to the ambient pressure is proportional to the speed of the aircraft through the air.

Pitot tubes, in combination with static ports (which measure ambient pressure) and their related indicators, are collectively known as the pitot-static system, and constitute one of the most vital systems on any airplane. This is why you usually see so many pitot tubes on the front of airliners. They provide redundancy.

At this point you may be raising an objection: But isn't air a compressible fluid, and wouldn't this compressibility skew the results as, say, temperature changed or other conditions changed? Why yes, yes they would Poindexter. Move to the front row and give yourself a star.

ICE-T (Not a drink from Long Island)

Pilots of a certain age will remember the torture inflicted by their instructors by being required to perform the dreaded "ICE-T" problem using the E6B government issue "whizz wheel" circular slide rule. This usually occurred as they were struggling to realize their dream of being a jet pilot while attempting to not throw up in the flying sterno can known as the T-37 in the west Texas summer heat. ICE-T was not an exotic drink from Long Island, but rather an acronym which stood for Indicated Calibrated Equivalent True airspeed. These terms referred to an airspeed conversion from the indicated speed shown on your panel to your actual velocity through the air known as "true" airspeed.

Performing this calculation was a drawn out process using inputs such as your pressure altitude and  temperature deviation (from a standard day). It was necessary because your "true" airspeed was used in navigation calculations such as time-distance-fuel determinations.

Today, of course, those calculations are all automated by an onboard computer known as the air data inertial reference unit or ADIRU.  This system takes all the pitot static input data and combines it with attitude and position data from the inertial reference units (IRUs) to provide one stop shopping data supply to the pilots' displays, the autopilot, and even the engines which use the data to optimize things like fuel burn.

Do We Have Enough Gas?

Once you know your "true" airspeed or actual velocity through the air, you need to apply your known wind correction to determine your actual velocity across the ground. This is important, because if the headwind is, say, 30 knots stronger than what you planned for, you might not have enough fuel to reach your destination. This can ruin your day on a long overwater leg.

In years gone by, flight plans would be "winded" with the latest forecast from aviation meteorologists. The plan was only as good as the forecast, and fuel needed to be closely monitored to determine if actual headwinds were greater than forecast. INS (inertial navigation) and GPS systems have greatly increased the accuracy of fuel planning as they give real time wind readouts. You instantly know if your plan was accurate.

Wind correction data input, as you might imagine, is also automated on modern transport aircraft and fed into the aircraft's flight management system (FMS) through an automatic data upload.  This system will give you a helpful INSUFFICIENT FUEL warning if it thinks you're not going to make it. Usually this warning means that you fat-fingered your flight plan input and told the airplane that you're going back to your origination as your destination or some similar easily rectified mistake.

In Conclusion

Airspeed is important for reasons beyond satisfying the curiosity of aviation fans. In the immediate short term, it keeps airplanes aloft by informing pilots when they are getting slow, which is an unforgivable sin in aviation. In the long term, knowing ground speed, which is derived from airspeed plus wind inputs, lets pilots know that they will arrive at their destination with enough fuel.

Monday, April 09, 2018

Is the Airline Hub History?

Photo - Eric Salard CC BY-SA 2.0

A reader sent me this article from the Daily Beast (good God, man! What are you reading that for?) which foresees the denouement of the airline hub due to the arrival of a new class of commuter jets which can hop from destination to destination while skipping hubs.

Once those [smaller] jets reach the airlines they will have the same hub-killing effect in the rest of the world as here. Given the choice of flying a straight line from A to B instead of having to change airplanes on the way is a no-brainer in any language.

While the article gives a decent roundup of the recent history of the airline industry and the introduction of smaller yet longer range commuter jets, it should have been written about 15 years ago. The Canadair CRJ-200 first flew in 1991 and along with the Embraer ERJ series of regional aircraft came to dominate the regional airline market through the 2000s.

These smaller, faster jets held promise to both serve smaller markets from fortress hub airports, or to skip the hub entirely and fly point to point. Analysts thought they'd be handy in poaching passengers from a rival's hub as well. As it turned out, the hub killer commuter jet was anything but.

Primarily deployed by regional airlines which wet-leased their aircraft and crews to a major airline partner, commuter jets mostly enhanced hub operations by offering service to smaller "spoke" airports which couldn't support full narrow body service.

Airline hubs have always been inefficient in their use of crews and equipment, but very efficient in revenue generation using the ability to create many different city pairs. Point to point regional operations were never embraced by the major airlines which viewed those operations as subtracting value from sizable investments in their hubs.

The old Canadair and Embraer CRJ and ERJ jets are now being replaced by newer more comfortable "C" and "E" series jets but I don't see the economics changing much. In fact, an ongoing pilot shortage seems to be making some major airlines reconsider their relationships with their regional partners. Bringing their regional operations in-house means that they're more likely to retain the pilots they have brought onto their master seniority lists.

For instance, both United and Delta have recently purchased regional aircraft directly, though United may still have their regional aircraft flown by one of their regional partners.

However it shakes out, it doesn't appear, though, that the airline hub will be going anywhere soon.

Thursday, April 05, 2018

The Deadly Flaw Hiding in Self Driving Cars and Pilotless Airplanes (Hint: It's Humans)

Photo: Timtempleton  CC BY-SA 4.0

A common theme on this blog has been about the promise—and pitfalls, of automation in aviation. Pilotless airplanes have been trumpeted simultaneously as the final nail in the coffin of aviation accidents and as the solution to the ongoing worldwide pilot shortage.

Not to be outdone in the hyperbole of the future department, driverless cars are heralded as the end of everything from traffic jams and fatalities to the need to even own an automobile. Simply summon one on your smartphone and away you go to the opera or to work.

The reality of the future, while not thwarting all those dreams outright, may be riding the brakes a bit.

The fatal collision between a driverless Uber car and a pedestrian last month is calling into question the idea that driverless technology is ready for prime time. And the interesting part is that Uber, for their part, thought the same thing. Their driverless car wasn't really driverless, but had a driver hired for the purpose of sitting behind the wheel to take over if the machine made a mistake.

Well, the machine made a mistake when a woman crossed the road outside of a crosswalk and was hit and later died of her injuries. Tragic as that was, it is inevitable that these types of accidents are going to occur. Sensor technology, while good and getting better, still has a long way to go. If you find it difficult to drive in heavy rain or snow, machines have even more difficulty.

These problems will eventually be solved, but in the interim, it will be up to humans, whether in the car, or at a remote facility, to monitor the machines. In this case, the human monitor was not able to avert the crash. This, then, is the flaw in the system: humans make lousy monitors of machines, be it an autonomous car or an automation flown airliner.

A recent article in the WSJ highlighted the stressful nature of the job for which Uber's monitor/drivers were responsible:

“The computer is fallible, so it’s the human who is supposed to be perfect,” one former Uber test driver said. “It’s kind of the reverse of what you think about computers.”
 Also, as autonomous technology improves, the need for drivers to take action diminishes, making it harder to stay focused, test drivers said.

Humans, being human, become bored and distracted after a very short period of time. Well, then, you might say, we should employ other machines to watch the machines. This begs the question of what the monitor machine (or more likely software) should watch and why couldn't this functionality be incorporated into the primary control software.

This also gets to the nature of how machines think versus how humans think. Humans are better than machines at processing ambiguous information and confronting situations which are new to them. AI, or artificial intelligence, is how software engineers hope to emulate the human ability to make decisions when confronted with novel situations which haven't been pre-programmed.

This capability is getting better all the time, but has a way to go before humans can be completely written out of the equation. In the meantime, humans will need to be somewhere in the control loop. We should all hope that the human monitor isn't dozing when the sun gets in the eyes of the computer driven car while we're crossing the street.

Wednesday, April 04, 2018

Air Force Reserve Adds New Commitment for Pilots and Maintainers

U.S. Air Force photo/Tech. Sgt. Shane A. Cuomo

The Air Force Reserve just added an additional six month commitment for pilots and maintainers who wish to separate or retire.

While being careful to not call this new requirement a "stop-loss", the AF Reserve is adding on six months of involuntary service in addition to whatever service requirements were previously imposed. The military typically adds mandatory service requirements for things like aircraft qualification courses, professional development courses, and permanent change of station moves.

I find it interesting that the AF Reserve has to implement controls like this as membership as a traditional reservist typically requires as little as a few days per month up to about a week and a half per month for combat ready flight crews. In addition, reservists are protected from discrimination or firing by their civilian employers by a law known as USERRA.

What this telegraphs is that as the commitments, deployments, and tasking of the reserve forces increases, reservists, who already have a civilian career as a pilot or maintainer, are calling it quits.

What military planners seem to fail to realize is that pushing on the combined active/reserve water balloon in one place will result in a bulge in another place. That is to say that there is no free lunch. Higher tasking and deployments for the guard and reserves, most of whose members came from the active forces, will force an exodus from those organizations as well.

The military should either accept higher personnel loss rates in a good economy and spend the money and resources on training replacements, or, here is a novel idea: just start to say no to increased tasking, though that would require a higher degree of testicular fortitude than is normally displayed in the flag ranks.

Monday, April 02, 2018

The Dominoes Fall: Goodbye Great Lakes Airlines

By Quintin Soloviev - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=58727240
Photo - Quintin Soloviev 

Great Lakes Airlines, a regional airline serving the upper midwest part of the US has shut down operations as of  last week.

In a statement released, the management of the airline blamed their woes on the 1500 minimum hour for pilots rule imposed by Congress in the wake of the 2009 crash of a Colgan commuter aircraft. Great Lakes management has had trouble finding pilots to fly their Beech 1900 aircraft.

A lively debate currently continues as to the efficacy of the 1500 hr rule which mandates that all pilots have a minimum of 1500 hours of experience before being able to serve as a pilot on a commercial passenger carrying aircraft. It has been noted by opponents of the rule that both pilots on the fated Colgan airliner had the minimum 1500 hours and that the rule would not have prevented that crash. The accident review blamed fatigue and training issues with the captain of that flight.

I am personally agnostic about this rule noting that the USAF and other military services can produce competent pilots with about 200 hours of experience. On the other hand, their training is estimated to cost about $1 million per pilot.

Also, there is an ongoing worldwide pilot shortage occurring in many countries without such an onerous hours requirement. The pilot shortage is a multi-faceted problem which will not likely be solved with the repeal of the 1500 hour rule.

Thursday, March 22, 2018

Boeing 737 MAX 8 Pilot Report

The Boeing 737 first flew in 1967 and since then has become the world's best selling airliner with Boeing just recently delivering the 10,000th 737 to Southwest Airlines. Major updates and enhancements over the decades mean that the newest generation of 737s, the MAX series, while bearing a family resemblance to the earliest models, is packed with the latest technology in avionics and propulsion.

I recently had the opportunity to fly a 737 MAX 8 for the first time. We had been scheduled to fly a 737-800 for the sequence, so when a MAX 8 showed up I was quite pleasantly surprised. My next concern was whether I'd remember anything about the new features of the airplane. Our differences training had been accomplished months earlier through an online course. As it turned out, there was little to be concerned about as the cockpit displays, while larger, incorporate all of the familiar elements from the NexGen series with a few welcome additions. (The NexGen 737s consist of the 600-900 series first introduced in the late 90s) I felt at home in the MAX cockpit right away.

Pilot's primary NAV display with terrain mode selected

The MAX 8 in our configuration has a 175 seat single class capacity with a standard crew complement of four flight attendants and two pilots. The layout and galleys are very similar to our -800s. There are two lavs aft and one forward. The MAX comes equipped with Boeing's new Sky Interior which features programmable LED lighting and mood music for boarding and deplaning. The seats themselves have adjustable headrests and a generous 32" seat pitch and 17.6" width, the widest of any 737 variant.

Boeing Sky Interior with programmable LED lighting

Moving back up front, the most dramatic feature of the MAX is the cockpit displays. The six 7 inch square display units in the NexGen (NG) aircraft have been replaced by four 15 inch wide display units. Separate mechanical features of the NG such as the flap indicators and clock are now displayed on these larger units. The gear handle and standby flight instruments have been relocated between the center displays and are now equidistant from both pilots.

Preflight, Engine Start, and Taxi Out

We were scheduled to operate as WN 5599 from DCA (Washington Reagan) to MCO (Orlando). The enroute burn was planned at 1+59 and 9000 lbs at an altitude of FL400 or 40,000 ft. The aircraft was carrying two deferred maintenance items, the onboard network system, and the first officer's ILS system resulting in a downgrade to CAT I ILS status. As the weather was VMC at both our departure and destination, this was not a concern.

Our takeoff weight was planned at 144,400 lbs, well below our max allowable of 159,800 lbs departing from runway 1 in DCA. Our maximum takeoff weight was determined by the maximum allowable structural landing weight of 150,800 lbs plus our planned burn of 9000 lbs. The planned fuel was 14,900 lbs which included 2000 lbs of contingency fuel in addition to the standard 45 minutes of  FAR reserve or 3200 lbs. I was immediately impressed in how little fuel it was going to take us to get to Florida.

The LEAP-1B engines deployed on the MAX are 15% more fuel efficient than the CFM56 series engines on the NG aircraft. These efficiencies are the result of an increase in the bypass ratio from five on the CFM56 to nine on the LEAP-1B and an internal pressure ratio increase from 11:1 to 22:1. A significant weight reduction in the rotor of the LEAP-1B adds to the fuel efficiency of the engine but also adds some restrictions on start and shutdown which I'll address later.

Fan blades of the LEAP-1B

Our preflight checks and flows were nearly identical to our NG aircraft. Our clearance from DCA was on the Boock2 RNAV departure. Departing to the north from DC always requires extra vigilance due to the proximity of the prohibited areas around the White House and the Naval Observatory where the vice president's residence is located. The authorities have an extreme lack of understanding and humor should an airliner even brush into one of these areas. The departure requires an immediate left turn after liftoff to track the Potomac. As the wind was gusting out of the northwest, I elected to engage LNAV lateral navigation on the ground to have lateral guidance immediately after takeoff.

Once we were loaded and had clearance from ground control, we started the pushback and start sequence. The restrictions on starting which I noted above now came into play. The rotor, or the spinning center shaft of the engine, had so much weight shaved off that it could have a tendency to bow when hot after shutdown. This bowing could cause the compressor blades to rub against the engine housing resulting in excess wear and possible compressor stalls on start due to air leaking around the gaps.

A view from the wheel well

To mitigate against this thermal bow effect, the computer will motor the engine before introducing fuel during the start sequence. The amount of anti-bow motoring is determined by the computer but can be up to several minutes before the fuel lever can be raised to start each engine. Once started, there is an additional three minute warm up period before takeoff thrust can be applied. This restriction is five minutes when the engine is started cold. There is also a firm three minute cool down period required before shut down as well. These restrictions will most likely not pose a problem except perhaps when you've pushed back onto a taxiway where other aircraft have to wait for you.

The quietness of the aircraft became immediately apparent as soon as the engines were started. It is truly a quiet airplane. I fly with a Bose noise cancelling headset and didn't notice until we were nearly level at 40,000 ft that I hadn't turned on the noise cancelling feature. It was that quiet. The LEAP-1B engine employs the same scalloped or saw tooth pattern on the trailing edge of the cowling that is evident on the 787. This design smooths the mixing of the core and fan airflows, significantly reducing turbulent flow and noise.

Scalloped cowling decreases engine noise (and looks cool)

The aircraft steering had a nice tight feel to it, but any new aircraft should. I won't miss the wobbly shopping-cart nosewheel steering of our old -300s, which were retired last year. We were cleared for takeoff with little delay and were on our way.

Takeoff and Climbout

The takeoff roll was unremarkable save for the quietness of the engines. We had calculated a reduced thrust takeoff power setting, but the aircraft accelerated and lifted off smartly. The LNAV course became active almost immediately and we started our left turnout on the departure. I hand flew the aircraft up to about 18,000 ft before engaging the autopilot. I thought the aircraft responded to manual controls similarly to our 800 series aircraft.

Pilot's inboard display with vertical situation and enhanced engine instrument display

The Boock2 departure tracks north and then makes a right turn for a nice view of the city...from the right seat! We quickly arrived at our cruise altitude of 40,000 ft, turned off the seat belt sign, and had some time to look at the new features on the displays. Other than being nearly twice as large as the NG displays, some new features such as a vertical situation display are included. When activated, this feature displays a side view of the aircraft's altitude and planned vertical navigation. It should come in handy for keeping situational awareness during complicated arrivals or when given a "descend via" clearance.

Descent and Approach

Our flight plan had us flying the Cwrld4 arrival from over Ormond Beach. This arrival set us up nicely for a VFR downwind arrival to Orlando's Rwy 35R. The arrival went smoothly with the autopilot easily staying on path in VNAV. Our arrival weight was very close to the planned 135,400 lbs and we had planned for a flaps 30 visual approach. We were just about abeam the field at perhaps 3000 ft when we got the clearance for a visual approach, my favorite kind of clearance.

Depending on controller preferences and traffic load, some controllers will call your every turn around the pattern. This type of hand holding can be annoying, especially if there is no other traffic in the pattern. Other controllers will just let you go to turn your own base and final. This was one of the other guys and he cut us loose. The key is to not screw it up and fly a bomber (wide) pattern or to cut in so tight that you end up going around.  I disengaged the autopilot and autothrottles, and proceeded to fly the pattern by hand to get a feel for how the MAX flew in the slow speed regime.

The engine instruments display can be selected for either side 

Flying a visual approach cross cockpit can have its own challenges as you can't readily see the runway, which is the primary reference in any visual pattern. Inside cockpit references can be used such as the FMC glidepath, wind arrow, runway DME (distance), and of course the best resource, the guy or gal sitting on that side of the airplane.

I'd been descending on downwind with flaps at position 1 for extra drag. While I'll use the speedbrakes if I need them, my preference is to avoid using them if possible. Pulling the nose up, dropping the gear and extending flaps on schedule is my preferred technique for getting configured quickly. The MAX went through her paces brilliantly and we were lined up on glidepath about three miles out when I brought the power up. While I had to take a second look or two to see the electronic flap gauge and newly positioned gear indicator lights, I quickly adjusted to their new locations.

Landing and Taxi In

The landing was uneventful and rather smooth if I do say so myself. The aircraft decelerated smoothly with the reversers and auto-brakes while the quietness of the engines again made itself apparent. We exited on the high speed and taxied to our gate. We had to start the timer after leaving the runway to ensure that we complied with the mandatory three minute cool down period before shutting down the engines. It wasn't a factor in this case as the taxi time was longer than three minutes.

The LEAP-1B engines are eight inches in diameter larger than the CFM engines on the NG, so in order to maintain the same ground clearance, the nose gear was lengthened about eight inches. This gives a slightly different picture while taxiing, but I found the landing picture to be very similar to the -800. The longer nose strut becomes apparent after lowering the nose to the runway but it was not disconcerting.

APU fairing

After shut down, we had a 45 or so minute turn at the gate before our next leg which was to Philadelphia. I took this time to walk outside and take a few photos of the jet. The most obvious difference in the MAX is the larger engines and slightly different looking winglets than those installed on our -800s. Also different is the APU fairing which resembles that of the 767 or 787 more so than earlier model 737s. Other than that, there are not a lot of obvious tells to set a MAX apart from its NG sistren.

The Mighty MAX Strikes Out

Our flight to Philly was completely full at 175 passengers plus crew. Once loaded and ready to go, we pushed back and went through the lengthened start up process. It was on taxi out to the runway that the MAX let us down. Shortly after leaving the ramp and joining the parallel taxiway to Rwy 35L, the Master Caution and the L Elev Pitot heat light came on. This meant that a fault had occurred in the heating element for the elevator pitot tube which provides airspeed inputs to the elevator feel system.

As Orlando is a maintenance base for us, I made the decision to return to the gate and have our mechanics look at the problem. As it turns out, this malfunction can be deferred through the use of the minimum equipment list (MEL). There are two of these systems installed and only one is required for flight with some restrictions. It was this restriction that sank us.

The mechanics noted that this tail number had a history of this particular malfunction, but they had the deferral paperwork done very quickly and we were ready to go...or so I thought. The next thing we heard over the gate agent's radio was that the airplane was being taken out of service. I quickly called dispatch and our dispatcher didn't even know what was happening. A phone call to the supervisor of dispatch revealed that while the flight to Philly was fine, it was the subsequent flight to Chicago that was the problem.

The restriction for this maintenance deferral was that the aircraft couldn't be operated in forecast or actual icing conditions. And it turns out that the forecast for Chicago was a broken cloud layer with temperatures below freezing. The supervisor of dispatch didn't want the airplane stuck in Philly, so we lost our beautiful MAX. Luckily for us (and 175 passengers), another airplane was available. Tail swapping a full airplane took about an hour, but we were glad to be going again, only this time in an 800 series.

The author in the corner office

In Conclusion

The 737 MAX is loaded with new technology which makes it a pleasure to fly and saves a bunch of money in fuel costs which should make airline managements happy. But even with all the new technology, the airplane is still a 737 at heart and was quite easy to fly. The LEAP-1B engines are whisper quiet and the large displays present data in an elegant and easy to understand format. Of course, as we discovered, there will always be some bugs that need to be squashed in a new system, but I am quite confident that the MAX has a long and productive future in front of her.

Captain Rob Graves is a veteran airline pilot and retired Air Force officer. He currently flies a Boeing 737 for a major American airline where he has over 25 years of experience. His Air Force career included instructing future USAF pilots in the T-37 primary jet trainer, aerial refueling in the KC-135 Stratotanker, and conducting worldwide logistics in the C-5 Galaxy cargo aircraft. He is the author of This is Your Captain Speaking, an aviation blog. It can be found at robertgraves.com. He also writes for Avgeekery.com. All photos by Robert Graves.

Friday, March 16, 2018

Will the Air Force Ever Get Their New Tanker Aircraft?

Image result for kc-46
KC-46 [Official USAF illustration]
The Air Force has been trying to replace their aging KC-135 tanker aircraft...for decades. There is a replacement aircraft, the KC-46, which is nearly ready to go, but the program has been plagued by scandal and delays for many years. And now, on the eve of the new aircraft's introduction into operational service, more delays have been announced. Let's take a look at the long and sorry history of this program.

First fielded in the late 1950s, the KC-135 Stratotanker has been the mainstay of the Air Force's aerial tanker fleet. Supplemented by the addition of the KC-10 tanker variant of the DC-10 airliner in the early 80s, USAF's tanker fleet has grown advanced in age and maintenance requirements to stay mission ready. A re-engining program which replaced the original Pratt and Whitney J-57 turbojets with modern CFM-56 high bypass turbofans did help to extend the life of the KC-135, but these 1950s era aircraft are entering their seventh decade of service and are in need of replacement.

Enter the KC-767

Starting in 2002, the Air Force explored the replacement of the KC-135 with a tanker variant of the Boeing 767 airliner to be known as the KC-767. Other potential aircraft considered to be used as a platform for the new tanker were the 747, the MD-11, the A-310, which had already been converted into a tanker in Germany, and the C-17. An Airbus version of the A-330 airliner to be known as the KC-330 was also evaluated with the decision eventually made to go with the Boeing KC-767 plane.

After the decision awarding the contract to Boeing was announced, allegations of corruption surfaced. A resulting congressional investigation turned up evidence that the competition had been rigged in favor of Boeing. An Air Force program manager and Boeing executive were eventually convicted and served jail time for their roles in the scandal.  KC-767 aircraft went on to be built by Boeing and sold to the Italian Air Force and Japanese Self Defense Force.

The KC-767 acquisition program was cancelled by the Air Force in 2006 followed by a request for proposals for a new tanker replacement program to be known as the KC-X. Boeing offered a different variant of the 767 airliner after deciding against a 777 version. Airbus partnered with Northrup Grumman to propose an A-330 based tanker now known as the KC-30.

This time the contract was awarded to the Airbus tanker over the Boeing entry. Alleging bidding improprieties, Boeing started a public relations campaign to have the decision reversed. After the GAO confirmed Boeing's allegations, the program was opened for a rebid with Boeing winning the award over Airbus in February of 2011, nearly 10 years after the start of the process.

The KC-46 Pegasus Comes to Life (Sort of)

Design work began on the new aircraft immediately with the contract calling for the first deliveries of operational aircraft in 2017. Snafus in the program followed shortly thereafter. In 2014 it was discovered that a significant amount of wiring had to be redesigned due to safety concerns. Boeing took a $425 million charge in 2014 due to the delays and extra costs essentially guaranteeing that the program would be unprofitable for the company after winning the contract on a fixed cost basis. 

More delays and charges were taken in 2015 due to problems identified in the fuel system. The first flight of the aircraft in its final configuration occurred on September 25th of that year, but delays nearly ensured that an already aggressive test flight program would be difficult to achieve in the allotted time. In May of 2016, another six month delay was announced due to supply chain problems. By that time Boeing had already taken nearly $1.5 billion in cost overruns against the program.

By mid 2016 it became apparent that there was a growing likelihood that Boeing would not be able to deliver the first 18 KC-46 aircraft to the Air Force by the agreed upon date of August 2017. At that point discussions were started as to what sort of penalties would be levied against Boeing. Additional cost overruns by this time had raised Boeing's out of pocket costs for the program to about $1.9 billion.

New technical problems with the boom refueling system and delays in the certification of the centerline drogue and wing refueling pods pushed the projected delivery of the first 18 aircraft into the first half of 2018.

As the program currently stands, ongoing boom refueling control problems, lack of a supplemental FAA certification, and problems with the HF radio system which may result in arcing on the skin of the aircraft (generally bad in a refueling aircraft) are pushing initial delivery well into 2018, over a year late.

In Conclusion

The military procurement system has always been somewhat of  slow motion train wreck resulting in weapons systems designed by committee and costing taxpayers billions of dollars over what they should, but this program should win an award for dragging a simple tanker replacement out decades.

Many times the delivered systems then do not work as advertised or are so laden down with useless features so as to be worse than the systems they replace. Expensive fixes then need to be designed and installed to fix poor initial design. There has to be a better way.

Add to this the overly aggressive bidding and promises made by Boeing in order to ensure that they got the contract and it seems like this decades long disaster will leave no winners on the field. 

Thursday, March 08, 2018

Do I Talk Too Much? A Primer on Airline PA Announcements

The chapter in Tom Wolfe's novel, The Right Stuff, which introduces us to Chuck Yeager, starts with this vignette:

Anyone who travels very much on airlines in the United States soon gets to know the voice of the airline pilot—coming over the intercom with a particular drawl, a particular folksiness, a particular down-home calmness that is so exaggerated it begins to parody itself (nevertheless!-it's reassuring) the voice that tells you, as the airliner is caught in thunderheads and goes bolting up and down a thousand feet at a single gulp, to check your seat belts because "it might get a little choppy"...

Wolfe went on to describe how that drawl, which characterizes the "pilot voice", had its genesis in Chuck Yeager's West Virginia cool-as-a-cucumber mein and delivery.

That southern drawl style of voice can still occasionally be heard over an airline PA, but it seems to have been eclipsed in recent years by the nondescript mid-Atlantic patois of most television news anchors. And that is too bad. A certain cachet has been lost in my opinion, but then again, a fake accent is probably worse than no accent.

My real problem with airline PA announcements, however, has nothing to do with the delivery, but rather the content and timeliness. We actually do talk too much when we should probably shut up and not enough when something needs to be said. Let me explain:

Mandatory versus Optional

Pilot PA announcements are prescribed in our manuals as either customer service announcements, which are mostly optional, or required safety announcements, which are mandatory. There is little that can be done about the mandatory safety announcements such as those required when the seat belt sign is cycled on or off, but it is the customer service announcements which can probably use the most improvement.

We are encouraged to give an opening PA to introduce ourselves and to give some information about the flight. My problem starts right away when pilots introduce themselves using first names only such as  "Bob and Tom". Perhaps I'm just old school, but when I hear that, I can't help but think I've tapped into the Wiggles channel, or perhaps wandered into a birthday party at a Chuck E. Cheese joint. Our informality infection has progressed just a bit far. Professionals should try to look and sound the part.

After the introduction comes a several minute soliloquy about the length of the flight, the filed altitude, the expected ride enroute, the destination weather, and those super gals and guys serving you in the back. Perhaps there was a time in years past when this information was not publicly available to anyone who cared to know, but that time has long since passed. Nearly all that information is now easily available on the iPad that every passenger will now have to put down while Captain America, er, Bob, rambles on for interminable minutes.

Opening PAs should be short, to the point, and only offer information that is not already available through the internet or the airplane's entertainment center. If the destination weather must be given, "partly cloudy and breezy" will suffice rather than well, folks, there's a scattered layer at 3000 ft and a broken layer at 12,000 ft with 8 miles of visibility and the winds at 320 degrees at 8 gust 15 knots. Passengers' heads often cock when hearing such details much in the same way as your dog's head does when you try to explain the theory of relativity. Passengers aren't trained in pilot jargon.

Silence is Not Always Golden

Now if things are going to be out of the ordinary, such as being so turbulent that the flight attendants won't be getting out of their seats, or there's an ATC departure delay, then that is worth passing along. This brings us to the times when something needs to be said and yet only golden silence prevails. If the push time is 0900 and it's, say, 0905 and we haven't pushed, a PA should be made to inform the customers that, yes, we know that we're now late, and here's the reason, and here, also, is when we expect to be moving. Not announcing those things makes it seem like the pilots are hoping that no one notices. They do.

This is especially important during lengthy ATC or maintenance delays. If we're stuck at the gate for an extended period of time, I personally like to give an update every 10 to 15 minutes. This won't be a long announcement but rather something along the lines of yes, the mechanics are still working the problem, but we expect that we will eventually be under way in so many minutes.

Honesty is (Usually) the Best Policy

Many pilots prefer to use euphemisms when describing things like turbulence or maintenance issues. I personally prefer an honest but not too detailed description of weather and mechanical issues. If we're expecting moderate turbulence, I'll use that term instead of "really bumpy". If there is a line of thunderstorms ahead, I'll say that. If those terms scramble someone's eggs, perhaps they should not be flying. 

Likewise, if we have a mechanical issue, I'll mention the system that is affected without going into unnecessary detail. "Folks, we have an electrical problem" is probably better understood rather than the number 2 transformer/rectifier is showing zero amperage (usually followed by a detailed discussion of what a T/R even is).

One thing to be careful about concerning maintenance announcements is the subject of deferrals. Most people expect that their airplane is perfectly functional all the time and will likely not understand the concept of redundant systems and deferred maintenance. In those cases, I'll usually announce that the mechanic has the problem squared away and we'll be departing soon.


Is there anything more annoying than modern day customer care speak? Endless apologies followed by assurances that your experience and well being are of the highest concern have become a ubiquitous soundtrack to life in our deracinated corporate infused existence. A bit of real talk is a great antidote and is usually well appreciated by people trapped in an aluminum tube for extended periods of time. 

If we (the airline) screwed something up, I like to say so, but if that's not the case, I'll say that as well such as "our good friends at the FAA have instituted a flow control program".  Another annoying tic that I hear occasionally on the PA is the airing of dirty internal laundry such as "well, folks, we're ready to go but the ground ops folks are dragging their feet getting the plane serviced." When speaking to customers, you are the voice of the corporation. They don't know or care about internecine tribal spats.

Flight Attendant Announcements

Admittedly, most of the announcements you hear on an airliner come from the flight attendants. Cut them some slack because most of what they say is mandated by either the corporation or the FAA. And I wholly approve of pre-recorded safety videos that are now becoming common. I'd much rather watch a professionally produced safety video than listen to a harried flight attendant rush through a safety demo for the fourth time that day.  Other announcements such as the mandatory seatbelt sign notification are also being automated on newer aircraft.

Humor of course always has its place in airline PAs, but like wearing Spandex, only certain people can pull it off. Unfortunately, most of those that do, probably shouldn't. Perhaps there should be an audition where aspiring comedians can go through their schtick and get feedback before inflicting their routine on a captive public.

 In Conclusion

Airline PAs should convey valuable and timely information to customers who have no other means of gaining that information. Redundant, rambling, or lengthy announcements merely add insult to the injury of modern air travel. And of course, don't forget to bring your noise cancelling headset.

Wednesday, March 07, 2018

When Choosing an Airline, Choose Wisely!

It should not be news to anyone working as a pilot that the airlines are hiring. With many thousands of pilots retiring in the next decade, the major airlines need to hire thousands of pilots just to maintain their current manning levels. Any growth will mean hiring even more.

This hiring binge is causing headaches for the traditional sources of pilots, the commuter airlines and the military. For various reasons I've written about in recent posts, fewer young people are opting for a career in aviation, meaning that as the major airlines hire pilots away from the commuter airlines and the military, those organizations are having trouble maintaining their manning levels.

For the young pilot who has his or her ratings and is ready to make a move to a major airline, times could not be better. All the major airlines are currently hiring and are offering long and lucrative careers as an airline pilot. The question is, which airline is the best to work for?

The simple answer, of course, is that the best airline is the one that hires you. If you only have one offer from a major, then your choice is an easy one. All the major airlines will provide a secure and comfortable flying career. Should you be lucky enough to have offers from multiple carriers, which is increasingly likely, your choice becomes more complicated.

Seniority is Life

Seniority, or the order in which you get hired, determines your quality of life for the next several decades. That guy or gal sitting in front of you in new hire class? He or she will be senior to you until one of you retires and there's nothing you can do to change that. Seniority will determine the days you fly, the quality of your layovers, which base you can hold, and the equipment you will operate. These all add up to quality of life and pay.

Being senior means you get both quality of life and better pay (by flying larger equipment or bidding better trips). Mid level seniority means you can have one of these or the other but not both, and being junior means you get nothing (and like it)! Obviously, being senior is better, but you can choose the airline at which you will gain the most seniority in the least amount of time by doing a little homework before accepting an offer.

The most important thing you will need to ascertain is the number of expected retirements of pilots senior to you when you get hired. For instance, if your prospective airline has not hired for a long while and is now just getting started, that means many of the pilots working there will retire after a short while, thereby clearing the way for you to become senior.

Conversely, if you are getting hired near the end of a long hiring binge, that means the relatively young pilots who were just hired, but are senior to you, will be there a long time before retiring, keeping you in the right seat or working weekends and holidays for a large part of your career. Getting hired at an airline full of old pilots is best.

Other Considerations

You should consider the overall financial health of any carrier you wish to join. Currently, the big four US major airlines, Delta, American, United, and Southwest, make up about 80% of airline capacity and are all in great financial shape. But then again, they should be with a good economy and cheap fuel. You will want to consider what happens when the economy goes south or fuel gets expensive.

Smaller carriers such as Alaska and JetBlue may be positioned less well to weather a substantial economic downturn. Then there are the ultra low cost carriers such as Spirit and Frontier that have carved out niches with a bare bones product. They are small, but at least in the case of Spirit, they are growing fast. I've had several Spirit pilots on my jumpseat say that they are there for the long haul and not considering looking elsewhere.

You will also want to consider the equipment that your prospective airline flies. Widebody international flying will generally provide a better quality of life in terms of days worked and length of layovers, but back side of the clock flying can take its toll on your health over time. Many pilots consider being a widebody F/O as a career destination as the pay is close to narrow body captain pay and the schedules and layovers are good.

Take into account the type of bidding system your prospective airline employs. Preferential bid systems are generally reviled, but being senior under such a system means you always get everything you want. As an example, a good friend of mine, who is the number nine 737 captain at his airline with a PBS system, routinely gets four or more 30 hr Maui layovers monthly because he likes them. I, on the other hand am the number fourteen 737 captain at my airline with a traditional bidding system and can only bid the lines that the company publishes. To get longer layovers in warm locales, I have to suck up things like four day trips and 11 hour layovers in DTW.

In Conclusion

There has never been a better time to be starting a career in aviation. There is a world wide pilot shortage and airlines are hiring pilots as fast as they can. Make sure to project your career aspirations at any carrier you are considering with an eye towards your seniority attainment to make the best decision. Good Luck!

Important Information from the TSA!!

Airport Full Body Scan Status Report
Finally, some useful facts
are coming out about all of those airport full body scans!
TSA disclosed the following
Airport Screening Results
2016 Statistics On Airport Full Body Screening From TSA :
Terrorists Discovered
Hemorrhoid Cases
Enlarged Prostates
Breast Implants
Natural Blondes
It was also discovered that 308 politicians had no balls.