Name This Optical Phenomenon

Earlier this month, I observed a sunset that I couldn’t quite explain. While an occasional solar halo or a pair of sun dogs are known to entertain us pilots at higher altitudes, this wasn’t one of those. This sunset was accompanied by two perfectly vertical rainbow-colored columns of light.

The best photo I took was the right side of the sunset with one of the vertical features.

I tried to find any other example of this phenomenon and didn’t find a good one with a technical description. A rainbow or a halo would be obviously round. A sun dog would be parallel to the horizon instead of vertical. A sun pillar would be above the sun instead of on the sides.

For a guess, this vertical rainbow phenomenon might be a partial halo at the top end with a reflected image below, creating an illusion of a vertical beam.

Are We Established?

When the approach controller issues a clearance, “maintain 3,000 feet until established,” what does it mean to be established?

The specific meaning of this phrase is a bit more involved than a short definition, and it is critically relevant in avoiding Controlled Flight Into Terrain (CFIT) accidents.

Maintain the last altitude assigned by ATC until the aircraft is established on a published segment of a transition route, or approach procedure segment, or other published route, for which a lower altitude is published on the chart.

AIM 5-4-6 (e)(1)

In the first example of how this works, assume an airplane is vectored to the ILS 23L at KIND on a heading between the CLANG and LLARY waypoints.

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Boeing MAX Safety Report Widely Misunderstood

Headlines about the recent NTSB Safety Recommendation Report on the 737 MAX design are focusing all attention on the report’s cover page. But is the report really about pilots reacting to emergencies in unexpected ways?

I found the most relevant part of the report on page 5. This is where the NTSB described Boeing’s use of an engineering simulator in testing the severity of MCAS malfunctions.

Failure modes that could lead to uncommanded MCAS activation (such as an erroneous high AOA input to the MCAS) were not simulated.

In other words, Boeing never simulated MCAS sensor failures while evaluating pilot responses to MCAS malfunctions. If you thought this report was about bad assumptions on pilot behavior, you missed the fact that Boeing only used a scenario where the MCAS sensors were working just fine, and the MCAS silently went mad.

So the NTSB isn’t just telling Boeing and the FAA to adjust their metrics for pilot behavior. They are asking for a top-down review of pilot reactions to all realistic problems, such as sensor damage, when approving any new design as airworthy.

Flight Themes in the Four Realms

A Balloon Basket in the Land of Sweets

For a pop culture moment, let’s consider the mysterious flight elements of Disney’s movie from last winter, The Nutcracker and the Four Realms.

I say “mysterious” because there are some hidden clues as to why several flight-related themes appear, mostly very subtle, throughout the movie.  For the most part, there is no clear metaphor, no overt allusion, and very little background information that points to this in the story.  As an aviator, these things simply catch my attention.


Birds are portrayed in almost every scene.  Look for this when you watch the movie.  Drosselmeyer’s owl appears every so often as a sort of creepy non-speaking narrator or family member that helps to connect some of the scenes together, but never contributes to the story.  This is one clear flight theme with no greater purpose.  And as I said, the other elements are subtle.  There are birds on the walls, birds in the furniture, birds as lawn ornaments, and less pervasively in the costumes.  But look at the hats.  They all have swans.

Another live bird, a raven, is employed to call out a sense of foreboding as Clara leads an army into the Land of Amusements.

One of the rare acknowledgements of the bird “motif” comes from an interview of the production designer, Guy Dyas.  In his description of Clara’s peacock-and-angel-wings princess throne, he mentions that, “Peacocks, traditionally, are a sign of good luck and goodwill.”  The throne itself is “one of those winks or nudges to the audience to look just a little bit closer behind the meaning behind the visuals that they’re looking at.”

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Airlines Still Selling Boeing MAX Tickets

Southwest Airlines 737 MAX Tickets

More than three months after the accidents and worldwide emergency grounding of Boeing’s 737 MAX airplane model, airlines in the USA are still selling tickets to fly on these airplanes.  This contradictory market for disreputable flights exists amid frequent press releases about rolling cancellations of the same flights month after month.  Why are these airplanes still scheduled at all?  Are these airlines in such a hurry to have the 737 MAX return to service that they will honor these tickets the moment the government allows it?

Yesterday, the FAA announced that they “recently found a potential risk that Boeing must mitigate.”  This has been widely reported with alarmist spin as a “new” safety concern that will delay the 737 MAX certification review.  However, no official source actually described the risk as “new” or otherwise unique from the original design flaws.  Boeing described the risk as “a specific condition of flight, which the planned software changes do not presently address.”  Some of the more sober news articles later this afternoon described the specific condition as a stabilizer trim runaway in which the manual electric trim switches are unresponsive or slow due to a computer malfunction.  Travelers and industry experts alike must consider this as an ongoing process that may have revealed more information about the original design, rather than creating new or worse problems.

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On the Ethiopian Crash Report

The crash of Ethiopian Airlines flight 302 is certainly the most important event being discussed in the aviation industry today.

Having read the just-released investigation report, I now see several pieces of new information that will profoundly change the direction of this discussion.  For my part, I am making an armchair analysis of a preliminary, though official, report.  My expertise in some areas of aviation should not be taken as authoritative nor anything more than added speculation toward a very large media frenzy.

Critique of the Report Summary

While the latest Executive Summary seemed careful to avoid drawing conclusions, I was dismayed about the focus on details such as the Angle of Attack values and the crew’s request to return for landing.

Here was an opportunity to accurately summarize the content of the report while still remaining impartial.  For example, the summary simply stated, “The crew lost control of the aircraft,” but this is hardly an accurate summary of the reported data.  In fact, it appears the crew was struggling but did have control of the aircraft during the first four minutes of the emergency.

Similarly, the summary mentions stick shaker activation and, vaguely, “flight control problems”, when the only glaring control problem in the flight data recording was a series of Automatic Trim Down Commands that created a heavy control bias for the pilots to fight against.

The Elephant in the Room – Missed Opportunities

In retrospect, the Boeing Max fleet should not have been in operation after the previous Lion Air crash.  I can’t say this is easy for the aviation industry to accept, even now.  Before the second crash, there was simply not enough attention on the design flaws in these aircraft, and those in the industry who should have been made aware of the underlying risk were not made aware.  Possibly worse, the traveling public had no idea the severity of the problem.  I am not immune from this lack of oversight, as I found myself on the flight deck of one of these aircraft hitching a ride to work a few months ago.  Knowing what I know now, I would not have taken that flight.

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R-ATP Exemption Follow-Up

Back in 2014, I wrote about six different universities and a community college that were all petitioning the FAA to become exempt from the requirement to hold a ground school certification so that they could participate in the R-ATP program.

That post had become somewhat stale, so here is a look back at what happened in the past few years.

Petitions Denied

Chandler-Gilbert Community College was denied its exemption in November 2017 and as of May 2018 was not authorized to certify R-ATP applicants.

Metropolitan State University of Denver was denied its exemption in July 2014 and as of May 2018 was not authorized to certify R-ATP applicants.

Denied and Then Authorized

Baylor University was denied its exemption in December 2014 and later gained R-ATP authorization in February 2016.

Eastern Michigan University was denied its exemption in August 2015 and later gained R-ATP authorization in July 2016.

Jacksonville University formally withdrew its petition for exemption in September 2016 and gained R-ATP authorization later that same month.

Petitions Granted

Auburn University was granted its exemption in November 2015, allowing Part 61 students who graduated between August 2010 and December 2016 to apply for R-ATP.

Purdue University was granted its exemption in July 2014, allowing Part 61 students who graduated between January 2009 and December 2016 to apply for R-ATP.

R-ATP Cross Country Time

ATP Qualifications Job AidI previously wrote about a regulatory boo boo that made it impossible to determine how much cross country flying experience was required to obtain a restricted ATP certificate.  The regulation that allowed students to apply for the rating with 30 college credit hours was never included in the nearby paragraph authorizing reduced cross-country time requirements.

To bring some clarity to this issue, I can now point you to this official checklist: FAA ATP Qualifications

Although this checklist is not regulatory, it is published by the FAA and so shows the original intent of the R-ATP regulation to allow anyone with 200 hours of cross-country time to apply for reduced minimums.

Since FAR § 61.160(e) contradicts the above checklist, I still anticipate a future amendment to fix this regulation.

Update: After 8 years, the FAA corrected paragraphs (d) and (e) as follows.

The FAA is also making a clarifying amendment to § 61.160(e) by adding a cross-reference that was inadvertently omitted in the Pilot Certification and Qualification Requirements for Air Carrier Operations final rule. As evident from the preamble to that final rule, § 61.160(e) was intended to “reduce the cross-country flight time required for all applicants for an R-ATP [airline transport pilot certificate with restricted privileges] certificate to 200 hours.” However, the express language of the rule provided relief only to those categories of applicants listed in paragraphs (a), (b), and (c). Because the relief in § 61.160(e) was intended for all eligible applicants, including persons eligible under § 61.160(d), the FAA is amending § 61.160 by adding a cross-reference to paragraph (d).

86 FR 62084

R-ATP Denied at Eastern Michigan University

Letter of denial from FAA to EMU.A search on federal websites revealed the FAA denied Eastern Michigan University’s exemption petition for R-ATP flight training last month.  “The FAA has fully considered the petitioner’s supporting information and has determined the relief requested is not in the public interest and would adversely affect safety.”  This decision is not surprising in light of the two-year delay and similar decisions preventing other Part 141 flight students from obtaining eligibility certification for a Restricted ATP check ride.

In its letter, the FAA gives this official response:

Based on the FAA’s records, EMU does not hold a part 141 ground school certificate. The FAA reviewed the description that EMU provided of its arrangement with EFC for the ground and flight training of students enrolled in its Aviation Flight Technology program. The arrangement does not meet the intent of having the ground training integrated with the broader academic curriculum. EMU does not have control over the curriculum provided by EFC and the FAA would have no oversight responsibilities with EMU because it does not hold a part 141 pilot school certificate. Therefore, the FAA has determined that EMU’s aviation degree program does not meet the minimum level of integrating its pilot ground training with its broader academic curriculum of an aviation degree program.

Update: R-ATP Exemption Follow-Up

Flight Range Ring is Always a Circle

Concentric flight range rings with wind.
Even with a strong wind, the range ring is a perfect circle.

I found an interesting error in Flying Magazine today, in which the author described an airplane’s range as being “anywhere from a perfect circle to an egg shape based on the wind conditions.”  Wrong!

Remember, one should think in the most simple terms about the effect of wind on an airplane.  Wind is just motion of the air.  After an airplane leaves the ground during takeoff, it experiences no relative influence from a steady wind because the airplane is flying into the air in a manner that is constant relative to that air.  From any given point in the air mass, the airplane’s range is a perfect circle within that mass.

Wind is important in flight, of course, because it modifies the ground track and speed relative to the Earth’s surface.  This changes fuel requirements, and ultimately the cost and efficiency of flight between points on the surface.  But what the wind does not do is create “eggs” or “semi-oval shapes”.  When the wind is calm, the range circle in the air mass is identical on the ground.  When the wind is 20 kt, the center of the range circle moves 20 NM away from the airplane’s initial position on the surface for each one hour of flight.

The slight asymmetry of two or more range circles is created by the fact that concentric “range rings” will be centered in different positions on the surface.  As described above, if a 1-hour range ring is offset by 20 NM, then a 2-hour range ring must be offset by 40 NM, and so on.  When these range rings are plotted simultaneously, they give a slight illusion of being oblong, when in fact they are still perfectly circular.

If that explanation is too simple, you can verify the wind calculations using some basic high school trigonometry.

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