Aerodynamics for Naval Aviators was written by Harry Hurt in 1959 and published by the US Navy in 1960. It is still in print and is still in use as an authoritative handbook for pilots to learn the aerodynamics behind the safe operation of aircraft through all areas of the flight envelope. Whether going very fast, or very slow, whether going very high in the sky or flying low to land, the aerodynamic principles explained in this book have helped many aviators fly safely in all manner and variety of aircraft.
On stall recovery in Chapter One, Basic Aerodynamics, Hurt states, “Recovery from stall involves a very simple concept. Since stall is precipitated by an excessive angle of attack, the angle of attack must be decreased. This is a fundamental principle which is common to any airplane.” (See Aerodynamics for Naval Aviators, Ch 1, Effect of High Lift Devices, pg 29).
In my flying experience, there are two ways to reduce the angle of attack (AoA) and a third step in the stall recovery procedure. The first way to reduce AoA is to lower the nose of the aircraft with the elevator towards or even below the horizon. The second way is to add all the power you have and accelerate the aircraft. The third step is to roll wings level. While this does not directly influence the AoA, this step does re-direct the lift force vertical and opposite the weight of the aircraft.
In Chapter Four, Stability and Control, Hurt writes, “The initial tendency to continue in the displacement direction is evidence of static instability and increasing amplitude is proof of dynamic instability.” He writes further, “In most cases, the contribution of the fuselage and the nacelles is destabilizing.” Under the topic of Longitudinal Dynamic Stability, Hurt writes, “dynamic instability will exist when the amplitude of motion increases.”
(See Ch 4,, ibid, Dynamic Stability, pg 245, 256, 279).
According to public media reports of various B737 MAX mishap investigations, the Maneuvering Characteristics Augmentation System or MCAS moves the elevator trim relatively rapidly and to a large displacement angle, in much the same manner that a pilot, hand flying a stall recovery would move the elevator. (See: https://news.yahoo.com/ethiopian-airlines-crash-mcas-system-boeing-737-max-194126559.html). Interestingly enough however, the MCAS does not engage the auto throttle system to add full power. Not sure why?
So while the concept that the MCAS is improving the longitudinal stability of the B737 MAX, most likely due to engine nacelle longitudinal destabilization factors, this is the engineering argument offered for the MCAS system not being a pilot procedural controlled stability control, such as an elevator, in actuality the MCAS acts very similar to the control inputs of a pilot recovering from a high AoA induced stall, by moving the elevator due to input of a high AoA.
In that regard, it might be a very good idea to:
-first rely on several AoA probe inputs to validate the high AoA data input is in fact a high AoA
-second to display that reading in the cockpit for all to see
– and third let everyone in on what appears to be both a longitudinal stability augmentation system and stall recovery system, so that the owners and operators can maintain it well and operate it safely.
Is the discussion about the optional equipment of B737MAX angle of attack AoA data comparator systems diverting the discussion from two of the most central safety issues, safety hazard reporting and rapid response, and the full extent of flight crew training?
Why ask that question? First, the specific hazard of a malfunctioning AoA probe and/or data value input to the flight control system computers, ordering an erroneous massive nose down stab trim control input, was reportedly known to exist on the B737MAX acft before both the Lion Air mishap or the Ethiopian Air mishap. Who knew and who reported it? According to reports from pilot groups, 3-5 US based passenger carrier flight crews experienced a similar malfunction and reportedly entered same in the acft maintenance log book, and may have written an airline safety event report as well. Thus at least one or more US certificated airlines may have known of this hazard, meaning that their FAA (principal operating or operations inspector (POI) and their principal maintenance inspector (PMI) either knew or should have known of this hazard, and thus through their Boeing reps, the manufacturer knew or should have known of the hazard. This is to some degree speculation based on reports and the reported procedures for reporting and sharing flight safety hazards between flight crew members, the airlines, the regulators and the manufacturers.
This could mean that FAA and Boeing, if knowing of the hazard, should have immediately and rapidly issued a safety of flight notice to all B737MAX certificated operators, informing of: A. the flight hazard B. the maintenance fix C. the aircraft operators procedures, either standard, supplemental, non-normal or emergency, as appropriate to respond to this hazard if encountered in operations.
Did FAA or Boeing do this? It is not clear yet how far along this path the FAA and Boeing proceeded. News reports of the Boeing fix underway in January 2019 show that some action was underway prior to the Ethiopian mishap.
Second, and more specifically, a Lion Air flight crew reportedly experienced this hazardous malfunction, on the mishap acft, during the flight previous to the mishap flight. How did Lion Air respond to the reported hazard? Was the hazard reported? Why did Lion Air maint management and flight ops management assign that acft to fly again, knowing it had experienced the hazardous malfunction on the previous flight? Had that hazard had been resolved? Was the event entered in the aircraft maint discrepancy log book? What possible justification was used to clear the maint discrepancy? Was the airline’s Boeing maint rep asked what to do in this case? Why or why not?
If an additional crew member (ACM), [ACM because he was on the flight deck vs in a passenger seat in the cabin, where he would have been a dead heading crew member DH], a qualified and certificated airman was on the flight deck, assisted the operating crew members by either moving the horizontal stab motor cutoff switches or recommending the same to the operating crew, was that event recorded by Lion Air Flight Safety Manager, investigated and this information promulgated immediately by Lion Air Safety to all Lion Air flight crew members and to their CAA regulators and the manufacturer Boeing? Why or why not?
Why did one flight crew member, the ACM, know how to turn off power to the trim motors with the horizontal trim cutoff switches, and know to turn off the power at that time as a response to the malfunction, but other crew members, and the operating crew members did not? Boeing B737 Runaway Horizontal Stabilizer Trim Emergency Procedures are published in the Boeing Aircraft Operating Manual or AOM, and Quick Reference Handbook or QRH, and are very similar to the procedures on most or all Boeing passenger acft, such as the B757 and B767. Why did some certified and trained Lion Air crew members know that and others seemed to not know that? Why did the Ethiopian Air flight crew apparently not know that? How is that possible?
Would have having an AoA comparator and disagreement warning system have made a difference if the system did not automatically disengage the horizontal stab automatic trim system known now reportedly as the MCAS Maneuvering Control Augmentation System? If the flight crew was not trained on MCAS, how would a comparator system have helped them? Even without a comparator, merely knowing to flip the horizontal stab trim cutoff switches at the first instance of uncommanded horizontal stab trim movement, should have resolved the runaway stab trim issue enough to allow the flight crew to land the aircraft, in our opinion.
So, in our opinion, these mishaps reveal two massively glaring safety of flight issues: First, why are known and reported equipment hazards and procedural short falls not resolved quickly, rapidly and universally by the airline, their CAA, EASA or FAA regulators and the equipment manufacturers such as Boeing or Airbus? Why does the hazard reporting system seem to work most of the time but not all of the time? Is there a regulator difference in hazard reporting system and resolution? If so, why? Second, why are some flight crew members trained, qualified and certified to operate with only a bare minimum FAA type rating training at some airlines in the global commercial scheduled airline community, and then little or nothing else further, while flight crew members at the three major US based airlines are given four to five times more training subject-wise, twice as deep training hands-on sim-wise, trained to competence and then regularly receive repetitive in the cockpit line oriented safety audits, line checks with immediate feedback, Advanced Qualification Program or AQP reviews, plus take home systems and procedural tests, exposures to safety forums, monthly or weekly ASAP Event Review Team reports and FOQA training reports? Why is there such an enormous difference in flight crew procedural training? Do you think that flight crew training and flight safety are closely related and perhaps that is an unaddressed global or international commercial scheduled airline safety issue?
In the opinion of SafetyForecast, two issues may be being ignored here, two issues which are literally the foundation elements for mishap -free commercial scheduled airline flight operations: [Yes we believe that mishap free commercial scheduled flight operations can be achieved by constantly reporting and resolving flight safety hazards and by training flight crew members on all procedures, equipment , limitations available and repeating and refreshing that training regularly.]
First, where is the flight hazard reporting and resolution safety program in non-US based airlines? Does it exist and how robust is it? Does it seek to both report safety of flight hazards and rapidly resolve these hazards? “All safety is local.” Citation: Paul Miller, SafetyForecast.com Better Safe Inc.
Where is the hazard reporting and resolution interface joint safety program between the manufacturer, regulator, certificated commercial scheduled airline and the certified flight crwe member?
Remembering that “All Safety Is Joint”, (Citation Paul Miller, SafetyForecast.com Better Safe Inc.) meaning that safety is really a joint effort between the certificated airmen, the certificated airline, the CAA regulator and the equipment manufacturer.
Second, where is the highly developed, broad based and in depth flight crew procedural based training program, above and way beyond type training, globally, in many non-US based airlines? Why are some operating flight crew certified in type and then given little if any additional training? “If you seek one level of safety in commercial airline operations, should you seek one level of training?” (Citation: Paul Miller and David Williams, SafetyForecast, Better Safe Inc and Safety Net Inc.)
There is a much bigger flight safety story here, in our opinion and it involves both safety hazard and resolution programs and flight crew training programs.
Paul Miller, int’l B757/767 captain, retired, 43 years of line and instructional flying David Williams, US FAA designated airline check airman and airline captain, retired
In my opinion, the issue is not that the flight crew received “aircraft differences training” (systems, limits and operating procedures differences between the B737-800 and B737-900, and the B737 MAX) on an iPad. Don’t shoot the messenger. The use of an iPad as a syllabus media is not invalid and may be likened to reading a book on a computer tablet.
From the point of safety management, the real first issue is that the Maneuver Control Augmentation System (MCAS) may not have been included in the aircraft differences training syllabus. The differences training syllabus may have been created by Boeing as an FAA certification requirement. The MCAS had been engineered, tested, installed and delivered on the new B737 MAX by Boeing, as a flight control system on the B737 MAX, a system different from the flight controls on B737 -800 and -900.
The second issue is that the FAA signed off on both the B737 MAX aircraft as certified safe for flight and signed off on Boeing’s B737 MAX “aircraft differneces training syllabus” as sufficient for flight crew training for passenger airline flight crew members certified to operate the B737-800 and B737-900 passenger aircraft.
The third issue is that neither Boeing nor the FAA informed passenger carrier airlines about this different, new and additional B737 MAX flight control system.
The fourth issue is that, after airline pilots reportedly submitted flight hazard incidents of apparent uncommanded pitch trim movements to their airlines, and the airlines reported these flight hazard incidents to Boeing and the FAA, that neither the manufacturer Boeing nor the regulator the FAA apparently took any actions to resolve the flight hazard or inform other airlines of the occurrence of the reported flight hazards.. This allowed a known flight hazard to exist unresolved amongst airline operators of the B737 MAX, which then apparently and eventually resulted in two fatal passenger airline disaster mishaps, when the hazard reoccurred.
As with many airline disasters, both the hazard and the failure to rapidly respond to the known and reported hazard has resulted in what could be considered two totally preventable fatal mishap disasters.
Effective commercial flight safety programs of Safety Forecasts and Plans should not only have both the ability to detect and report flight hazards, but also have the ability to rapidly respond with an immediate hazard procedural response, an interim hazard policy remediation and a long term hazard resolution.
Contact SafetyForecast Director of Safety Policy Captain Paul Miller today for further consult and assistance. Our goal is to save your operation from fatal mishaps, costly material losses and the diversion of time, talent and resources away from the main goals of safe and profitable flight operations. PaulMiller@safetyforecast.com
In fact three aircraft have been destroyed by fires caused by lithium ion batteries, one in 2006, two in 2010. But the FAA, NTSB and other government and official agencies categorize safety as related to passenger safety or a cargo acft only hazard and of no interest to passenger airline safety, such as the current FAA and EASA Cargo Carve-out Exemption of new Flight Duty and Rest Regulations. However, by summarily ignoring the distinct ties in safety that nevertheless may validly exist between cargo airlines, passenger airlines and their respective pilots safety, FAA, EASA and others may have gravely missed the most valuable of all safety principles, that of early warning.
The early warning evidence in this case was the two cargo fires caused by lithium-ion batteries. The fire dangers of lithium ion batteries have been amply noted, the information on this hazard has been widely available and mishap reports by FAA and EASA have identified a clear and present danger since at least 2006.
Instead of keeping lithium-ion batteries away from commercial aviation however, FAA, EASA and others have made a clear choice to allow industry lobbyist lawyers to influence safety decisions when it came to lithium ion battery carriage regulation and by that same process, have kept the safety experts themselves at arms length.
No greater illustration of inverted safety logic is present in aviation government regulatory administration today than this example.
When will the FAA, EASA and other government aviation safety agencies place aviation safety experts in charge of making important public safety and industry regulatory safety decisions?
When will the direct, clear connection in commercial aviation safety between passenger and cargo airline operations be recognized by FAA, EASA and others? It is obvious that attorneys themselves appear unable to make that connection. Wouldn’t the industry be better served by placing safety experts in charge of safety decisions and regulations?
Passengers on domestic US airlines are now at an increased risk of being crashed into by sleepy cargo pilots. Lawyers at the FAA used case law, negligence reasoning and other historically based legal records to reach a regulatory milestone, aligning with lawyers at large US based package express and airborne freight haulers. The FAA pointed out that so far, when cargo pilots have had fatal crashes, they have only killed themselves. But is the regulation a millstone around the necks of cargo pilots? Industry safety experts say the risk to the passenger flying public is very real. Fatigue caused human errors can lead to massive passenger casualties. Take for instance one of the worst commercial aviation passenger disasters in history. 583 people were killed when two heavily laden B747s collided in Tenerife in 1977. It is believed that some of the crew members who may have been on duty in excess of 15 hours, in my opinion, misunderstood ATC communications. The KLM captain was very near the end of his official duty day, but believed that if he could get airborne before the end of his duty day, that he could complete the flight to Amsterdam with his load of passengers. A good man, a man dedicated to his company, a man with a great record at the company as a captain, under the fatigue caused misconception that he had been cleared to take off, although he had not, began his takeoff roll, colliding just moments later with a Pan Am jet on a fog shrouded runway.
Now imagine hundreds of fatigued cargo pilots operating around the clock due to this FAA ruling. Imagine a sleepy cargo crew misunderstanding an ATC radio call and ramming 850,000 pounds of plane, cargo and fuel into your family in a passenger plane innocently waiting to takeoff, albeit by accident, while seated on a passenger jet, one tightly regulated by the FAA. One thing will be for sure. The lawyers from the FAA and the cargo industry will be saying, “We need to do something about this.”
So, we have a chance right now to “do something about this,” and we ought to do it before we witness another tragedy such as Tenerife. The FAA should let the law of the people speak for the people. After all, it is their safety that is really the first priority, is it not? Cargo carriers have prospered under FAA safety regulations, countering the claims by their lawyers that safety would cost them business losses. Check their financial records. Now check the FAA and NTSB accident records. In fact the records show that many if not most of the cargo crashes were the result of fatigue and other human factors, and not safety regulations. The ruinous losses of these accidents is in the hundreds of millions of dollars. And these are fully documented losses of property and lives, they are not suppositions, arguments or cases put together in a law office.
This other “study” of potential business losses due to safety regulations is purely speculative, oppositional and entirely hypothetical. There doesn’t appear to be a shred of real evidence in the entire argument. So, I think that it is time that we base our decisions of safety, of life and death on reality, on data, on facts and on history and not on the unsubstantiated claims of lawyers, accountants and other business professionals.
Air Transport Association (ATA), or now Airlines for America (A4A) and the FAA can not claim all of the credit for the huge improvement in airline safety over the last decade in my opinion. As a matter of fact and record, both the FAA and ATA now A4A, opposed, and opposed with great vigor, virtually every safety of flight recommendation from pilot groups and pilot associations, from individual pilot recommendations directly to the FAA and/or the employer company, from the NTSB and from just about every safety foundation, association and organization, not just in the last decade, but in the rememberable history of this writer. It has only been after sustained high levels of Washington lobbying, high profile professional papers delivered, public relations campaigns and other dedicated efforts that the FAA has agreed to any safety regulatory or legislative improvements and on the part of commercial companies, after very tough pilot associations legal negotiations for contractual safety improvements.
Examples? Collision Avoidance Systems (TCAS) for Cargo, Flight Duty and Rest Regulations, Improved Flight Crew Training Requirements, Cockpit Smoke Equipment, improved security, higher ATC standards for aircraft handling and routing around severe convective weather, Aircraft Rescue and Firefighting (ARFF), Crash Fire and Rescue (CFR) at airport equipment and manning requirements and training, hazardous materials air cargo handling rules, regulations and laws.
Again, these are but a few of the many safety improvements worked for by commercial pilot associations, pilot trade groups, as well as various global flight safety oriented foundations.
Now let’s talk ASAP, the Aviation Safety Action Program. The joint commercial pilot working group worked 1993 to Sept 1995 on the Proposed Draft FAA Advisory Circular for Airline ASAP, based on the prototype successful program established by American, Allied Pilots Assn and the FAA Southwest Region. The FAA however sat on that AC, until publishing their first draft in Oct 1998 . The Final ASAP Advisory Circular appeared I believe in 2001. Many airlines then fought ASAP participation until finally agreeing and adopted ASAP in the mid 2000’s, fully ten years after it was recommended.
So I would challenge anything stated about safety by the FAA and A4A in terms of their advocacy and management thereof. In fact the FAA and A4A opposed ASAP and virtually all of these safety programs that eventually became very valuable programs. Could it be argued that FAA and A4A are anything but an impediment to airline safety?
Oh, one more important point. All of the safety recommendations made by pilot associations and adopted as regulation, rule or law, have worked!! I would argue that this is why the commercial airline industry is safer today than 10 years ago. That is why we are safer today than ten years ago, not because the FAA and A4A have argued the supposed “Cost and Benefit Analysis” at every safety program proposed.
It is my opinion that lawyers for the FAA and A4A have used “Cost and Benefit Analysis” in some cases to delay safety programs and have not, in so doing, protected the industry from costs. Quite the opposite is true in my opinion. This delay may have actually led to repeated human factorsmishaps of the same type being suffered throughout the industry again and again without resolution.
These costs related to commercial aviation disasters have wreaked financial havoc in the commercial airline industry by allowing hundreds of millions of dollars and hundreds of lives to be wasted, while substituting legal wrangling and administrative procedures to take precedence over safety.
For safety, look to the person with a personal stake in the argument and improvement. Do not look to the supposed “Cost Benefit Analysis” argument for any value in safety.
Why does the FAA not take immediate and rapid action on safety issues when a flight crew member, the NTSB or anyone else for that matter brings the issue and a solution to their attention? Quite a simple answer really: the FAA is run by lawyers and not safety professionals. Lawyers deny that there is a problem of their own origin, because to “admit a problem” ( lawyerspeak, not safetyspeak) would be to admit fault and therefore legal liability in a tort court. Instead of safety resolutions, the FAA maintains deniablity until pressure from the press and the public is so great that they cannot deny “something has to be changed!”, usually the result of a press grabbing major air disaster, such as Continental/Colgan 3407. A safety professional, on the otherhand, would have been looking at the problem, in this case, flight crew training, as soon as the first evidence of a problem was revealed. The sad part about the lawyer approach of the FAA is that hundreds of innocent people have to die and grab headlines in order for a change to be made. If the FAA were instead run by safety professionals, changes would occur without a lot of needless loss of life. As far as comments such as, “Regulation created in a knee jerk reaction can do more damage to the commercial air industry than the industry (or passengers) can afford. Is it worthwhile to ground perfectly safe aircraft and aircraft operations on the basis that if there are no aircraft flying or no-one can afford to travel by air no crashes can happen…” frankly, I do not even know where to categorize this illogical line of reasoning.
As far as I know, there has never been a recommendation by a safety professional that said no aircraft should be flying or make flying so expensive that no one can travel. These kind of statements are known as “make up an outlandish course of action, pretend that a safety professional said it, and see how many people you can fool,” type of statement, also know as “red herrings.” Safety on the other hand is good for business.