Fuel gauging system from Ametek
 Ametek's active probe fuel gauging system for the Ayres Loadmaster LM200. |
Ametek Aerospace has been awarded a contract to provide J.C. Carter Aerospace a fuel quantity gauging system for the Ayres Loadmaster LM200 aircraft under development by Ayres Corp. J.C. Carter is responsible for fuel systems integration on the LM200.
Because it offers a number of advantages over alternative fuel gauging technologies, Ametek's active probe system was chosen for the LM200. Its robust signal eliminates the effects of stray capacitance—a typical problem found in alternative gauging technologies. The signal also improves the system's immunity to electromagnetic interference, lightning, and HIRF interference. The system also features extensive built-in tests with fault isolation to individual probes.
The LM200 was specifically developed to meet the need for an efficient, versatile aircraft capable of transporting containerized and bulk freight. The aircraft is able to transport up to 8800 lb of cargo or passengers and to land at small airports.
The LM200 also features a new barometric altimeter jointly developed by Ametek and Honeywell International, Inc.
- Frank Bokulich
Study finds bleed air quality to be "excellent"
Researchers at the winter meeting of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) in January announced that concentrations of air contaminants measured in a study of commercial aircraft were found to be generally lower than those in residential or commercial buildings. Certain volatile organic compounds (VOC) and semivolatile organic compounds (SVOC) are suspected of entering aircraft through the bleed air systems that supply outdoor air to the cabin. The ASHRAE Research Project 959 identified contaminants and demonstrated the measurement methodology aboard a limited number of aircraft.
Researchers found levels of VOC, SVOC, and other contaminants to be low. In addition, they discovered that bleed air quality overall was "excellent" and was found to generally exceed desired levels of air quality for supply air in other environments, such as offices. The only exception was the very low relative humidity prevailing in high-altitude air.
"This assures that the air being brought into the aircraft is relatively clean," said Dr. Niren Nagda of ENERGEN Consulting Inc. in Germantown, MD, the firm that conducted the research. However, he did caution that the focus of the research was to measure the possible contaminants on different types of aircraft under normal operating conditions. The project was not intended to detect or measure contaminants that might occur under failure or abnormal conditions.
Air quality measurements were conducted for three different airframes during 10 flights. "Ten study flights do not provide a statistically robust sample for representing the universe of all flights," said Nagda. "A sample size of about 100 flights would be required to represent the range of conditions encountered in commercial air travel."
ASHRAE currently is developing proposed Standard 161P, Air Quality Within Commercial Aircraft, which will define the requirements for air quality in air-carrier aircraft and specify methods for compliance measurement and testing.
- Frank Bokulich
Detecting leaks at airports
Dulles International Airport in Washington, DC, has employed a new automated leak-detection system that monitors the facility's hydrant fueling system. Designed and installed by Burns & McDonnell, Hansa Consult, and Tracer Research Corp., the system collects and analyzes fuel data and alerts operators of the presence of leaks.
The Metropolitan Washington Airports Authority initiated modifications to the existing fueling system, which will meet the regulatory requirements of the Virginia Department of Environmental Quality and the operational requirements of the fuel system operator, Air BP. Servicing over 1000 aircraft per day, the hydrant system holds 400,000 gal of fuel in over 9 mi of underground piping.
Although underground point-of-use hydrant systems have replaced above-ground refueler tank trucks at most major airports, these systems demand special attention to protect the environment from potential contamination from aircraft fuel. "Because the pipes are underground, leaks cannot be visually detected," said Ward Allen, Project Manager at Burns & McDonnell. Developed by Hansa Consult, the leak-detection system installed at Dulles overcomes this problem by using data from pressure and temperature sensors to detect leaks.
Burns & McDonnell provided the designs for the piping modifications and the installation of motor-actuated valves and communication lines between the valves and the central computer. As the prime consultant, the firm also supervised the installation of the Hansa system.
- Frank Bokulich
