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Quick Turns

Meeting the New RVSM Monitoring Requirement

November 18 is the deadline for compliance with revised reduced vertical separation minimum (RVSM) monitoring requirements, and if your operation doesn’t comply by the deadline, you may be subject to enforcement action.

According to the new standard, operators wishing to fly in RVSM airspace must verify height-keeping performance for two airplanes of each aircraft type in their fleet – or each airplane within a single type – at least once every two years, or within intervals of 1,000 flight hours per airplane, whichever is longer.

There’s a reason for the strict requirements: During a recent webinar hosted by NBAA, Federal Aviation Administration (FAA) officials noted a variety of aircraft, including airliners, have already had non-compliant altitude-keeping performance identified.

How to Comply

Operators may use one of three methods to demonstrate compliance. Operators of a Mode S-equipped aircraft within North American airspace may overfly an active aircraft geometric height measurement element (AGHME) site or “constellation” so the aircraft’s actual flight altitude may be recorded, and any discrepancies between indicated and true altitude noted. Eventually, up to seven constellations will be located in the U.S. and Canada. At this writing, four AGHMEs were active along common instrument flight rules (IFR) flight routes near Atlantic City, NJ; Cleveland, OH; Wichita, KS ; Phoenix, AZ; and Ottawa, Ontario.

Another method to record altitude is using a carry-on GPS monitoring unit (GMU) to monitor the aircraft during normal operations. This method does not require flight over a specific track or portion of airspace to monitor the aircraft’s performance.

Operators flying to Europe may also employ one of three ground-based height monitoring unit (HMU) locations to record and compare secondary surveillance radar returns against an aircraft’s Mode S, Mode C or Mode A transponder signal. This data is collated to create a track history of the aircraft passing through the coverage area, which is then compared with ambient atmospheric conditions to determine the aircraft’s total vertical error. The FAA and European authorities share monitoring data, meaning that operators may utilize an HMU to comply with FAA requirements.

Ensure Accuracy

Each method requires operators to submit notice of an altitude-monitoring flight to the appropriate authority 24 hours before takeoff. A successful AGHME monitoring flight is documented in the FAA’s monitoring status results, and this may be used as proof of compliance with monitoring requirements.

To ensure that your aircraft maintains compliance between the required recording intervals, one operator suggested carrying a simple form in the aircraft to record altimeter readings during pre-departure check and while in cruise flight within RVSM airspace. This enables operators to note altimeter correlation over time, as well as provide early detection of possible discrepancies that might lead to altimetry system error or other non-compliance events.

For More Information

Visit the RVSM section of NBAA’s web site at

Operators Expand Use of Risk Assessments

The question of how to properly assess the potential risks involved in various aspects of an operation can provoke strong opinions.

A recent NBAA Air Mail discussion revealed differing schools of thought about the need for risk assessment in certain situations, and how detailed those assessments should be.

“The safety management system (SMS) approach requires that risk assessments be conducted by design and intent,” explained Eli Cotti, NBAA’s director, technical operations. “As I read these e-mails, I came away with the thought that the risk assessment (RA) process is being used by some for more than original SMS intent.”

Implications of Overuse

While some fear that the overuse of the RA process could potentially minimize its impact, overall, Cotti views it as a positive step. He noted the intent of human factors guidance, and the subsequent development of SMS, is for RAs to be conducted whenever a potential hazard is identified.

Other situations calling for an RA include situations when the operator doesn’t have a standard policy or procedure in place for a particular situation, or when a management decision is required. “The trend has been to increase emphasis on the SMS approach,” Cotti noted. “The SMS approach is responding to the requirements from regulators and the general public for organizations to assess, manage and demonstrate their overall safety to a declared tolerable level.

“In addition, SMS exists to assist an organization in better understanding its current level of safety, to communicate this level to stakeholders, prevent incidents and accidents, and improve communication, morale and productivity within the organization,” he added.

Creating a Method

So, when should a risk assessment be performed? Cotti believes that’s up to the individual operator and situation. “When designing, implementing or operating a safety system, those responsible should put the considerations of the people in the system ahead of procedural or technological considerations. It is the people in the SMS that ultimately provide the safety function, supported by any technologies or procedures.”

Kevin Smith, chief of aircraft maintenance at Progress Energy, noted his company implemented a standardized risk-assessment document for its flight operations, and that led to greater RA awareness throughout its operations.

“One of our pilots developed what we call the Flight Risk Assessment Program,” he said. “It assigns values to various factors of the flight. This allows us to assess risk as low, medium or high. Basically, it helps us identify what can hurt us. If we can mitigate that, or at least be aware of it, it makes it a safer environment and helps keep us on our toes.”

Smith added that this pilot also helped develop a similar methodology for the maintenance department. “ Behind the scenes, the document also feeds another database that tabulates everything and allows us to review that data and target higher-risk areas.”

For More Information

To get more information on safety management systems, visit

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