As electric air-taxis become a reality, you can bet any accident will be highly scrutinized. Safety and proper risk management will be keys to success. Photo: Kitty Hawk
Understanding the inherent risks in flying, combined with establishing well-founded safety principles and response planning is paramount for survival in the aviation industry. Start-ups and companies new to the aviation industry must understand that there is always risk in flying. Above all, gravity always wins. However, realizing that accidents do happen, in addition to being prepared for that possibility, will go a long way in contributing to a company’s success: that and a whole lot of cash and a stellar aircraft design.
In October 2019, one such stellar eVTOL design experienced a hard lesson – in addition to a hard landing – after logging just 4.7 hours of total flight time. According to the National Transportation Safety Board’s (NTSB) Final Report, dated March 27, 2020, on October 17, 2019, Kitty Hawk's Heaviside 2 crashed after the aircraft ground operator forgot to disable the battery charging script (computer program) prior to the accident flight. The still-running script caused multiple flight computer limits to be exceeded, affecting the aircraft’s system performance. The controllability of the aircraft degraded, resulting in substantial damage when the ground operator attempted to remotely land the aircraft.
According to the accident report form (NTSB Form 6020.1) filed by Kitty Hawk, the accident identified “small gaps” in its Standard Operating Procedures (SOPs) that contributed to the accident. Kitty Hawk, in its post-accident safety recommendations, notes that the “SOPs will be carefully evaluated routinely to ensure they represent the safe and effective operation of the system as a whole.”
During my military flight training, a ground instructor once pointed out the difference between a “WARNING,” “CAUTION,” and “NOTE” in the helicopter operations manual. It seemed excessive that almost every page of the manual had at least one (or several) such alerts, telling the flight crew not to exceed this temperature or not to exceed that operating limit – almost as if it was written by an overbearing parent concerned for the safety of his or her child. At least that was my initial impression.
My instructor, however, pointed out that each warning, caution, and note has meaning and often a story behind it. Unfortunately, many of the warnings were written in blood, cautions were the result of an expensive mistake, and notes, well because common sense is not that common.
If design risks cannot be mitigated through preferred design changes or fail-safe measures, then the appropriate procedures and warnings must be in place to minimize the risk of inherent design flaws progressing into human flights. The operating procedures and instructions should have a corresponding warning, caution, or note for the level of risk:
A WARNING, if not promptly monitored and corrective action taken, a loss of life or injury to persons or property could result. Warning: Do not approach the helicopter from the front with rotor blades turning – seems obvious, right?
A CAUTION indicates damage to the aircraft or hazard to humans could occur. Turn off the pitot tube heat after landing to prevent damage to the heating system or to prevent burn injuries to the mechanic.
A NOTE generally described an essential operating procedure. Ensure the radio power is on before attempting to transmit.
When the HH-60G Pavehawk was first introduced to the Air Force in the early 1980s, its design weight was 16,825 pounds (there are specific numbers I still recall about this helicopter, and its design weight is one of them). That was before the Pavehawk was weighed down with cabin fuel tanks and other modifications (Pavehog?). At its design weight, the Pavehawk was viewed as the "Ferrari" of helicopters. Pilots knew it, and would intentionally exceed 90 degrees bank ("overbank"), which the helicopter could do quite well with its fully-articulated rotor system and "power for days."
During a particular flight, my instructor recalls, the pilot flying kept the helicopter inverted for just a tad too long after executing a fighter-jet like overbank while crossing up and over the crest of a mountain ridge. The "extended-stay" overbank preceded with a Christmas-like show of warning lights in the cockpit, alerting the pilots to low engine oil pressure. That particular event resulted in the pilot’s need of a change of underwear, in addition to a new "WARNING" that excessive bank angles could result in a loss of oil pressure since the engine oil sumps were positioned on the bottom of the engine.
It would seem evident that a helicopter should not be inverted. "C’mon, who in their right mind would intentionally invert a helicopter in-flight!” – thought the engineer who designed the engine oil system with the oil sumps at the bottom of the engine, assuming gravity would naturally ensure continuous oil flow. In aviation, Murphy's Law prevails, and one should always expect the unexpected. Circling back to the Kitty Hawk accident, you can bet that the SOPs will be modified to include a shiny new warning concerning battery script – at least until a more robust design change to the system is implemented.
WARNING: Failure to disable the battery script prior to flight may result in degraded system performance and a loss of aircraft controllability.
Equally important is a company's response following an accident. Being prepared will make a difference as to whether the company survives following a major accident. Part of that preparation occurs during the aircraft design stage, i.e., identifying risks and accounting for the potential for human error. Additional preparation comes in the form of instilling a strong safety culture throughout the company to identify risks.
Finally, a company must have in place a well-prepared emergency response plan for when Murphy's Law comes into play (typically at the worst possible time). Airline carriers know this all too well. Every airline has in place an emergency response plan and regularly conducts drills so they are prepared for when an accident occurs.
Identifying design risks early on
A standard allegation in every product liability lawsuit is a claim for “failure to warn” – that is, the aircraft manufacturer failed to provide adequate warning to the crew or passenger of inherent risk in the design or use of the product. This liability exposure is also a reason why operational manuals are chalked full of warnings, cautions, and notes. A lack of sufficient or inadequate instructions could result in the accident and lead to liability if (hindsight being 20/20) the operator failed to warn of a potential hazard.
Kitty Hawk, like many eVTOL developers, conducts unmanned test flights (to the extent possible) to reduce the risk of injury to an on board pilot. Unmanned flights allow for rapid flight-testing but increase the potential risk to the aircraft since test-flights may shift focus to the testing of software or equipment, as opposed to the safety of aircraft. However, future test flights will be conducted with a pilot, and finally operational flights with passengers.
When developing aircraft procedures (testing or otherwise) and operating manuals, keep in mind:
- The consequence if a particular instruction is not followed. What happens if the operator fails to deactivate a particular system, and attempts to fly the aircraft?
- Foreseeable misuse of the product. Helicopters are not intended to be inverted, but it’s still possible.
- Hazards are likely obvious to an experienced flight crew, but not so apparent to the layperson. You would have to be an idiot to walk in front of the aircraft radome with the weather radar transmitting. (It’s happened before, more than once.)
A strong company safety culture
Every aviation company should (whether required by regulation or not) have a safety policy in place. Promoting a strong safety culture is not just about putting a wet floor sign in place after mopping, but also means, for example, employees know they can report safety hazards due to their own unintentional mistakes without fear of punishment for self-reporting.
An employee who understands they can report such errors without fear of losing their job is more likely to report the safety risk, as opposed to sweeping it under the rug, praying no one finds out about that tiny but expensive crack the mechanic just caused when drilling a hole in the airframe. When developing a safety policy, consider, for example, the following criteria:
- Safety objectives/goals: Set specific, measurable, and relevant safety goals/objectives, e.g., ensure all new pilots and operators are trained on operational safety checks and procedures prior to flight.
- Safety processes and procedures: Ensure proper processes and procedures are in place so that safety performance is maintained at the appropriate level (e.g., unmanned vs. manned flights) and specified objectives/goals are achieved.
- Non-punitive reporting policy: Where human errors are made without deliberate intent to cause harm or damage, then they are "normal errors." Self-reporting “normal errors” should not result in punitive action being taken against individuals.
- Safety review and audit policies: Conduct periodic reviews of operating procedures and safety measures to ensure the appropriate level of safety.
An emergency plan for when all else fails
A robust emergency response plan should be prepared well before electric generators are turning. Every emergency plan should include the following general information:
- Develop a checklist and include a list of key persons and their contact information. Include both company employees and outside contacts such as the Federal Aviation Administration, NTSB, outside counsel, and insurance representative. Identify when each should be contacted and what information must be relayed. eVTOL developers/operators should alert first responders and investigators to the presence of crash hazards, e.g., lithium-ion batteries or ballistic parachutes.
- Preserve aircraft wreckage. The operator of an aircraft is responsible for preserving aircraft wreckage, cargo, and data recorders until the NTSB takes custody of it or issues a release. (See 49 CFR § 830.10(a).) For accidents that occur in remote locations (or when a pandemic occurs), NTSB representatives may not be able to visit the accident site for several days. If so, operators may need to arrange 24-hour security (e.g., off-duty officer) for the accident wreckage.
- Identify and secure key documents. The operator of an aircraft must retain “all records, reports, internal documents, and memoranda dealing with the accident or incident until authorized by the NTSB to the contrary.” (See 49 § CFR 830.10(d).) Understand what company documents must be released to the government, and in what manner. For eVTOL developers/operators, this includes all data and related software programs.
- Brief all personnel involved in the investigation on legal ground rules and the nature of the NTSB investigative process. For example, identify whom within the company will speak with the press and government officials.
As electric air-taxis become a reality, you can bet any accident will certainly be highly scrutinized and subject to extensive media coverage. Mishap occurrences are not a matter of if, but statistically, a matter of when, and like the overbearing parent, start-ups and new entrants must understand the risks and prepare for the unlikely as part of its emergency/contingency planning.
Erin I. Rivera is an aviation attorney with Fox Rothschild LLP. He also served in the U.S. Air Force as a combat search and rescue (CSAR) flight engineer on board the Sikorsky HH-60G PaveHawk helicopter. Erin holds a private pilot license and previously interned as an air accident investigator with the National Transportation Safety Board. Erin is particularly well-versed in current developments in aircraft certification regulations, eVTOL aircraft enabling technology, and advanced air mobility/urban air mobility (UAM/AAM) initiatives.