Flight Safety Information - August 25, 2022 No.163 In This Issue : Incident: Jazz DH8D at Toronto on Aug 20th 2022, propeller overspeed : Incident: Swiss BCS1 at Zurich on Aug 24th 2022, engine shut down in flight : Incident: VivaAeroBus A320 at Guadalajara on Aug 23rd 2022, engine shut down in flight : Incident: Cathay A35K at Manchester on Aug 23rd 2022, gear problem after departure : Jet carrying staff who work in New Hampshire congressional offices makes emergency landing : Airline staffing crisis raises concerns about pilot fatigue : ExpressJet Files Chapter 11 Bankruptcy, Furloughs 1,300 Pilots : Australia Offers VFR Pilots ADS-B Avionics Subsidy : Aerodynamic Phenomenon: A Detailed Look At the Coffin Corner : ALPA - 66th Air Safety Forum - September 12-15, 2022 - JOIN US! Incident: Jazz DH8D at Toronto on Aug 20th 2022, propeller overspeed A Jazz de Havilland Dash 8-400, registration C-GGMZ performing flight QK-8201 from Toronto,ON to Sault Ste. Marie,ON (Canada) with 39 passengers and 4 crew, was climbing out of Toronto when at about 14,000 feet the crew received indication the left hand propeller was overspeeding. The crew worked the related checklists and shut the left engine (PW150A) down. The aircraft returned to Toronto for a safe landing on runway 23 about 50 minutes after departure. The Canadian TSB reported maintenance replaced the #1 pitch control unit. https://avherald.com/h?article=4fd51d15&opt=0 Incident: Swiss BCS1 at Zurich on Aug 24th 2022, engine shut down in flight A Swiss International Airlines Bombardier C-Series CS-100, registration HB-JBH performing flight LX-1210 from Zurich (Switzerland) to Oslo (Norway) with 105 people on board, was climbing out of Zurich's runway 28 when the aircraft was about to be handed off to Rhein Radar while level at FL200. The crew responded to the hand off "Stand by, will call you later". The crew subsequently transmitted "Mayday Mayday, engine failure, call you back" The crew maintaining FL200 shut the left hand engine (PW1524G) down, the aircraft returned to Zurich for a safe landing on runway 14 about 35 minutes after departure. The airline reported the crew detected irregularities with one of the engines. According to information The Aviation Herald received Switzerland's SUST is looking into the occurrence. https://avherald.com/h?article=4fd51b2e&opt=0 Incident: VivaAeroBus A320 at Guadalajara on Aug 23rd 2022, engine shut down in flight A VivaAeroBus Airbus A320-200, registration XA-VAJ performing flight VB-518 from Guadalajara (Mexico) to Los Angeles,CA (USA), was climbing out of Guadalajara's runway 10 when a loud boom was heard from the right hand engine (V2527) and streaks of flames and sparks were emitted by the engine. The crew stopped the climb at 13,000 feet, shut the engine down and returned to Guadalajara for a safe landing on runway 10 about 40 minutes after departure. The aircraft is still on the ground in Guadalajara about 6 hours after landing. https://avherald.com/h?article=4fd4c781&opt=0 Incident: Cathay A35K at Manchester on Aug 23rd 2022, gear problem after departure A Cathay Pacific Airbus A350-1000, registration B-LXN performing flight CX-216 from Manchester,EN (UK) to Hong Kong (China), was climbing out of Manchester's runway 23L when the crew did not receive normal gear up and locked indications and stopped the climb at FL120. The aircraft entered a hold and returned to Manchester for a safe landing on runway 23L about 85 minutes after departure. The flight had been scheduled to depart on Aug 22nd 2022, but was delayed despite the aircraft arriving on time and took off with a delay of 24.5 hours. The airline reported the aircraft made a precautionary procedural return when there was an abnormal gear indication. https://avherald.com/h?article=4fd4bbad&opt=0 Jet carrying staff who work in New Hampshire congressional offices makes emergency landing No one hurt; Sens. Hassan, Shaheen, Reps. Kuster, Pappas not on board aircraft PORTSMOUTH, N.H. — The New Hampshire National Guard is confirming that a KC-46 refueling jet had to make an emergency landing on Tuesday. Two jets embarking on an orientation flight were flying with 16 staffers from the offices of Sens. Jeanne Shaheen and Maggie Hassan and Reps. Annie Kuster and Chris Pappas when one aircraft had an issue with its refueling boom hoist cable, officials said. Officials said the jet had to land with the boom extended at Joint Base McGuire Dix Lakehurst in New Jersey after leaving Pease. The second aircraft was diverted to the Manchester-Boston Regional Airport. Both jets landed safely. A third jet that was on its way to Florida from Pease diverted to the New Jersey base and transported the staffers back to Pease. Shaheen, Hassan, Kuster and Pappas were not on board on the jets. https://www.wmur.com/article/kc-46-jet-emergency-landings-new-hampshire/40977790# Airline staffing crisis raises concerns about pilot fatigue A new report that two airline pilots fell asleep mid-flight and missed the plane's landing has given the public a rare glimpse at life behind the cockpit doors in the era of COVID-19. A pair of Ethiopian Airlines pilots were napping simultaneously when they were supposed to be landing the plane, according to industry news site Aviation Herald. They woke up once the autopilot disengaged and set off an alarm. While investigators are looking into exactly what happened during the flight, one thing is already well-known: Airlines around the world are facing a shortage of pilots and other flight crew members, which can lead to worker exhaustion and burnout. "I think it's reflective of an increasing concern that pilots have across the globe of just being overworked, need to work more overtime, because of those pilot shortages," Lindsey Roeschke, a travel and hospitality analyst for Morning Consult, told CBS News. What's behind the pilot shortage? As COVID-19 was spreading in 2020 and 2021, when airline operations came to a near standstill, carriers offered early retirement to thousands of pilots in an effort to slash costs. An aging workforce has also led significant numbers of older pilots to retire as scheduled, further reducing the number of available flyers. Meanwhile, there is no quick fix, Roeschke said, noting that even raising wages is ineffective because it simply spurs pilots to move to higher-paying airlines rather than expanding the pilot pool. "Airlines can hire as much staff as they want to hire, but it takes a long time for pilots to be trained, certified. It's not only a time commitment but a financial commitment to invest for pilots when they're initially going through those steps," Roeschke said. "So it does have a long tail unfortunately, everything that happened during the pandemic." The best way to stem pilot fatigue, as well as reduce the onerous flight delays and cancellations that have plagued the airline industry of late, is for airlines to trim their schedules, experts say. Along those lines, London's Heathrow Airport this summer said it would cap the number of daily passengers at 100,000 and also told airlines to stop selling tickets on summer flights. "That's not what we want to hear as travelers, but at the same time cutting back on some of those routes and tamping down expectations of how many flights airlines are actually going to be able to actually execute will help to avoid those last-minute delays and cancellations," she said. Added Roeschke, "In the short term, it might make flights a little bit harder to come by, maybe a little bit more expensive, maybe a little bit more crowded, which of course is frustrating to hear as passengers. But will help to deter those showing up to the airport and finding out 'your flight is cancelled' those types of experience, which are worse than the alternative." https://www.cbsnews.com/news/pilots-fall-asleep-cockpit-airline-delays-cancellations-staffing/ ExpressJet Files Chapter 11 Bankruptcy, Furloughs 1,300 Pilots The airline has ceased operations after failing to turn a profit. The company rebranded itself as “Aha!” Based in Reno, Nevada, the airline started with only four airplanes, targeting the boom in leisure travel. [Courtesy: Aha! Airlines] Regional carrier ExpressJet Airlines, once among the fastest-growing airlines in the western U.S., announced Tuesday it has filed for Chapter 11 bankruptcy protection, planning to cease all flight operations and furlough approximately 1,300 pilots. Despite reporting “exceptional operating performance for July 2022” earlier this month, the airline has done an about-face. In a statement, ExpressJet chairman and CEO Subodh Karnik said, “A combination of conditions led us to this decision,” in which, despite their best efforts, “termination of operations was in the best interest of our stakeholders.” The 1,300 furloughed pilots are protected under a collective bargaining agreement that the Air Line Pilots Association (ALPA), the largest pilot union, established with the airline. A provision in the agreement allows the furloughed ExpressJet pilots to be hired by another airline so that they can begin flying again with reduced training. How We Got Here When travel disruptions caused by the pandemic in 2020 forced United Airlines (NASDAQ: UAL) to end its United Express contract with ExpressJet and transfer those operations to CommutAir, ExpressJet’s operation was severely damaged by the loss of business. That September, ExpressJet operated its last revenue flight from Memphis International Airport (KMEM) to George Bush Intercontinental Airport (KIAH) in Houston, after which approximately 3,000 people lost their jobs. Introducing ‘Aha!’ However, a year later, in July 2021, ExpressJet gained approval from the Department of Transportation to restart commercial flights. The company rebranded itself as “Aha!” Based in Reno, Nevada, the airline started with only four airplanes, targeting the boom in leisure travel. At its peak, ExpressJet operated more than 450 aircraft. As Aha!, it would focus on 11 regional routes affected by the pandemic and offer ad-hoc charter services. Using its ERJ-145 fleet, it restarted under the Aha! brand in October 2021, with its first flight being a charter flight. No Path to Profitability In a July 2022 press release, the airline stated that it completed 100 percent of its flights with a 95.6 percent on-time arrival rate; but in its bankruptcy court filing, the airline said that in July, it operated at a $17 million loss. Moreover, it said it couldn’t foresee a path toward profitability. Effective August 23, the airline ended service and filed for Chapter 11 bankruptcy in Delaware. Typically, Chapter 11 bankruptcy gives a company some wiggle room to reset itself under government supervision, while Chapter 7 bankruptcy is usually reserved for closing shop altogether. In a court document, the company said in this case, its objective is to liquidate its assets and auction them off. The airline said it deliberately filed for Chapter 11 so that it could pay back its creditors. CEO Points to a Number of Factors Karnik cited a lack of growth due to limited aircraft availability, as well as the company’s failure to quickly establish a passenger servicing infrastructure at smaller airports. Moreover, despite a widespread post-pandemic rebound in travel that helped most U.S. airlines return to profitability, Karnik said ExpressJet’s revenue was poor. He attributed the low revenue to the impact of COVID-19 variants and management’s inability to establish hotel bundles to attract customers. Finally, despite larger airlines being able to rake in record profits by passing higher fuel prices on to customers, the ExpressJet CEO said fuel and other costs took an unexpected toll on his airline’s finances. ExpressJet To Repay Creditors Before Closing Shop With operations coming to a halt, the airline has begun laying off employees and plans to return its leased airplanes to its parent companies. In its court filing, the airline said its largest creditor, the Small Business Administration (SBA), is owed $10 million for a PPP loan. The airline also owes the Department of Treasury $3.9 million for a Cares Act Loan the airline received to protect wages at the height of the pandemic. The airline listed 18 more of its largest creditors. They range from insurance companies to maintenance providers. https://www.flyingmag.com/expressjet-files-chapter-11-bankruptcy-furloughs-1300-pilots/ Australia Offers VFR Pilots ADS-B Avionics Subsidy For a limited time, the Australian government is offering a subsidy of up to AUS$5,000 for ADS-B equipment on crewed VFR aircraft. The government's Civil Aviation Safety Authority (CASA) is hoping the grant program will encourage more VFR aircraft owners to use ADS-B. Currently, ADS-B in Australia is mandatory only for IFR operations. These rebates can cover as much as 50 percent of the cost of purchasing and installing eligible ADS-B transceivers, said CASA. To apply for the subsidy, the aircraft must be in either the CASA Australian aircraft register or a register of an approved Australian sport aviation organization. Applications will be accepted until May 31, 2023, or until funding is exhausted, whichever occurs first. CASA said that for VFR pilots, ADS-B will provide: better situational awareness through improved electronic visibility of nearby airborne VFR aircraft; enhanced search and rescue capabilities through improved air traffic information; and ATC with additional and accurate automated aircraft position information. Operators should note that the selection process is competitive. "Make sure you include enough detail and supporting evidence in your application to help us decide whether to award you the grant," said CASA. "Understanding the entire process will help you be grant-ready and may improve your chances of getting funding." https://www.ainonline.com/aviation-news/general-aviation/2022-08-24/australia-offers-vfr-pilots-ads-b-avionics-subsidy Aerodynamic Phenomenon: A Detailed Look At the Coffin Corner Explanations about the coffin corner are sometimes vague or lacking in detail. The coffin corner is one of those phenomena which is talked about a lot both within and outside the aviation industry. However, most of the explanations about the coffin corner are many times vague and not explained in that much detail. In this article, we are going to dig deep into the topic and discuss what the coffin corner actually is. High-speed flight and compressibility effects Most of the jet transports in the world travel in the transonic region. On average, a typical jetliner cruises at speeds ranging from 78% to 85% speed of sound. Or, in technical terms, 0.78 to 0.85 Mach number. So, what does the Mach number mean? Mach is the speed of an object relative to the speed of sound. For instance, if an object is traveling at 0.1 Mach, that simply means that the object has a speed that is 10% of the speed of sound. If the same object moves at Mach 1, that implies that it is traveling at 100% the speed of the sound, or it has the same speed as the speed of sound. When an object reaches Mach 1, it is said to be supersonic, and when the speed goes beyond Mach 1, the object moves into the supersonic regime. So, why is the Mach number so important? To understand this, visualize an aircraft sitting on the ground. If you hit its nose with a hammer, you hear a sound. This sound is carried by pressure waves that travel at the speed of sound on the ground, which is about 340 m/s. Now imagine the aircraft moving at a certain speed. If you hit the aircraft while it is on the move, the pressure wave will still travel at the speed of sound. However, this time because of the movement of the aircraft, the distance between the leading pressure wave and the aircraft decreases. As the aircraft speed increases more and more, this distance further reduces. In real life, as an aircraft approaches Mach 0.4, the compressibility of the air becomes a factor. As mentioned before, as the aircraft speeds up, it starts to catch up with its pressure waves. Below 0.4 Mach, the pressure wave acts like a police car that clears up the traffic for the President. The pressure waves warn the air molecules ahead of the aircraft to make way for it. But as the aircraft moves closer to its pressure wave, it can no longer warn the air particles. As there is no warning, the air is suddenly made to undergo big changes which increase its density, temperature, and pressure. At some point, if the aircraft speeds up to Mach 1, it finally catches up with its pressure waves. This causes the pressure waves to bunch up, forming shockwaves. During a climb, the True Air Speed (TAS) of an aircraft increases due to the reducing density. Together with the TAS, the speed of sound also reduces because the speed of sound is directly proportional to the temperature. As temperature decreases with altitude, it reduces the speed of sound. What this means is that as an aircraft climbs higher and higher, its Mach number increases. The formula for Mach number is as follows: Mach = TAS/ LSS, where TAS is the True Air Speed, and LSS is the Local Speed of Sound. As an aircraft climbs, its TAS increases which increases its Mach number. This is important because if an aircraft that is not designed to go above the speed of sound goes above it, undesirable things can happen, such as loss of control. In an aircraft, the flow velocity is the highest on the wings, and thus, it is the most likely part of it that can go beyond the speed of sound the quickest. So, now let me introduce a new term. The Critical Mach number. The Critical Mach number, or Mcrit for short, is the speed shown on the aircraft speed indicator when a part of an aircraft goes sonic. In a typical aircraft, the wing will reach Mach 1 way before any other part of the aircraft, and if the aircraft is designed for subsonic flight, its critical Mach number plays a major role in the highest speed it can attain. So, designers have come up with wing designs that can slow down the Mcrit, including the use of swept wings and supercritical airfoils. High-speed stall and Low-speed stall A high-speed stall is caused by shockwave formation. Because of the drastic changes that are brought to the airflow by the presence of a shockwave, it causes flow separation right behind it. A shock that is attached to the wing consequently causes the airflow to separate from the wing, and this leads to loss of lift. This is called a high-speed stall. With an increase in altitude, the aircraft approaches Mach 1, and due to this reason with an increase in altitude, the speed for high-speed stall decreases. Shockwaves can cause flow separation which can lead to a high-speed stall. On the other side of things, the increased altitude causes the low-speed stall to increase. Please refer to this article for a detailed explanation of the low-speed stall phenomenon. The low-speed stall increases with altitude because of the compressibility. As explained previously, as the aircraft's speed increases, the airflow is no longer warned of it. Due to this reason, as the wing's leading edge hits the airflow, it is made to curve over the wing at a steeper angle. At normal speeds, the airflow begins to diverge and upwash way ahead of the wing leading edge. Due to the steep approach angle of the airflow, the region of the lowest pressure on the wing occurs much closer to the leading edge, causing the adverse pressure gradient to affect a larger area of the wing. This causes the wing to stall at a lower angle of attack due to early flow separation. An increase in altitude increases the low-speed stall speed. Now, it is understood that with an increase in altitude and speed, the high-speed and low-speed stall gets closer. One increases while the other decreases. At some altitude, these two speeds become one single speed. This altitude is called the Aerodynamic ceiling of the aircraft. Once you reach this ceiling, congratulations, you have officially reached the coffin corner. How close to the coffin corner do airliners fly at? For airliners, there are regulations that govern their certification standards. One of them is that at the highest ceiling, the aircraft must be able to maneuver with at least 0.3 gs. This means that the aircraft must have enough margin for pilot maneuvering without encountering either a high-speed buffet or the low-speed buffet. The buffet is the shaking of the aircraft that is experienced in a stall due to separated airflow hitting the tail surfaces of the aircraft. Most aircraft manufacturers provide buffet onset charts in the flight manuals, which the pilots can use to determine the altitude, speed, and weight at which low and high-speed buffet can occur. Below is the buffet onset chart of an Airbus A320 with a worked example. First, let us look at the yellow line. When the line from a load factor of 1.0 with an aircraft weight of 60 Tonnes is extended to an altitude of 41,000 ft, it can be seen that the low-speed buffet occurs at 0.65 Mach. To check the high-speed buffet, cruising at 0.80 Mach, we can see that it happens at a load factor of about 1.2 g. Now, look at the red line, which is set up for an altitude of 37,000 ft. In the same manner as before, at a load factor of 1.0 and a weight of 60 Tonnes, the low-speed buffet occurs this time at a lower speed of 0.62 Mach and at the same speed of 0.80 Mach, the high-speed buffet occurs at a load factor of 1.4 g. It can be seen from this example that with an increase in altitude, the low-speed and high-speed buffet margin reduces. Moving away from the airliners, the military reconnaissance aircraft, the very famous U2 Dragonfly flies close to its coffin corner. When at cruise, the difference between its low-speed and high-speed stall buffet is a mere 5 knots. https://simpleflying.com/coffin-corner-guide/ 66th Air Safety Forum – Join Us! PERSEVERANCE THROUGH STRENGTH AND UNITY September 12 – September 15, 2022 | Omni Shoreham Hotel | Washington, DC safetyforum.alpa.org CONFIRMED KEYNOTES INCLUDE • Capt. Joe DePete – President, Air Line Pilots Association, Int’l • The Honorable Jennifer Homendy – Chair, National Transportation Safety Board • The Honorable David Pekoske – Acting Administrator, Transportation Security Administration • Mr. Nick Robinson, Director General Civil Aviation, Transport Canada • Capt. “Sully” Sullenberger – Former U.S. Ambassador to ICAO • Mr. Dieudonne Kazzembe, Aero Club Foundation Scholarship Recipient Agenda and registration information can be found at safetyforum.alpa.org THANK YOU, SPONSORS & EXHIBITORS! Sponsorship and exhibitor opportunities are available. Email airsafetyforum@alpa.org for more information. Curt Lewis