ACRP-Problem-No-10-10-09.pdf

ACRP Problem No. 10-10-09 Recommended: No Standardization of Runway Braking Action Assessment (snow covered runways TRB Aviation Group Aircraft/Airport Compatibility Cmte: combine with 10-10-03. reduce amount to $ 400,000. ACRP Screening Panel This scope is currently being addressed by the TALPA rule-making committee by FAA Flight Standards Office. A AC CR RP P Problem Number Problem Number 10-10-09 I. PROBLEM TITLE: “Standardization of Runway Braking Action Assessment (snow covered runways)” II. RESEARCH PROBLEM STATEMENT: In the United States today, methods of determining coefficient of friction on snow and ice covered runways runs the gamat from personal assessment in light weight vehicles, to mu meters, Saab Skidometers, diagonal braking vehicles, James de-acceleration meters (Canadian Runway friction index), and in some cases where the agency is fearful of the legal consequences of inaccurate reporting, leaving assessment of runway conditions to aircraft already having landed or taken off. In any case, the airport community is derelict in its duties to provide “standardized” condition assessment to crews using the airport. It should be pointed out many countries, as well as the United States Military, have adopted one standardized system for reporting, presumably concluding that one system, albeit somewhat imperfect, is better than a hodgepodge of assessment techniques scattered throughout the country. III. OBJECTIVE: Select one system and metric for reporting that all United States airports will adopt for determining coefficient of friction for snow packed and icy runway conditions. It should be noted that determining actual braking actions on wet runways would be beyond the scope of this study. Recognizing that hydroplaning (viscous, dynamic, and reverted rubber) is a condition primarily experienced by larger vehicles operating at weights and speeds that would be difficult or impossible to duplicate by runway vehicles, and such an attempt would likely prove to be futile. As a former pilot as well as an airport operator, it has been my belief that too much emphasis has been placed on attempting to correlate a measurement taken by a runway vehicle with the myriad of aircraft that might subsequently be landing or taking off from the facility. Rather, the emphasis for the study should be directed at correlating the condition of the runway with the braking characteristics of the measuring vehicle. For example, an objective might be to confirm that by using a Ford F150 vehicle on a grooved runway with two inches of snow, the specific metric measurement selected would always be close to the same. Thus the measurement of a truck in Denver would correlate to a reading taken in Buffalo given similar weather conditions. From the standpoint of the crew member, he or she would over time develop a correlation between the airports reading and how his or her particular aircraft with its unique weight and braking system, as well as their personal skill level would translate into a stopping distance. This is currently very difficult for crews since airports use so many different techniques for measurement purposes. An additional advantage of such an approach relating coefficient of friction to the device making the measurement rather than the aircraft provides comfort to airports legal council, who now would recognized that the report represents the performance of its vehicles, but not necessarily the aircraft. IV RESEACH PROPOSED Enough analysis has already been conducted by the FAA, the Canadians, and others regarding the effectiveness of devices to measure braking action of ground based vehicles on snow covered runways. Research now should be focused on which device most accurately can determine coefficient of friction on runways during winter weather conditions, again, without attempting to correlate these determinations to aircraft performance. The study should take into consideration the cost and maintenance of the device recognizing that many small airports have limited budgets for sophisticated apparatus. When I was actively engaged in airport operations, we used a half-ton pick-up truck to report runway conditions during winter conditions. I was always impressed how closely the reading taken by myself in a small truck correlated with those reports coming from crews after landing on the same runway. Incidentally, the truck was used year round by the airport for traditional airport related activities. The study should also settle on a standard metric, say for example, “nil, poor, fair, or good”, or “0-10”, that all commercial and private airports would adopt. In time such standards would be incorporated into appropriate “Advisory Circulars” or possible FAR 139. Manufacturers would be invited to provide data regarding their equipment and its effectiveness in generating consistent readings for a standard set of runway conditions. It should be recognized such a research effort will produce only one winner and many losers, which in turn might result in political complications. Given the importance of the effort, this should be accepted as a “cost of doing business”. V. ESTIMATE OF THE PROBLEM FUNDING AND RESEACH PERIOD The FAA has spent millions, and studied this off and on, for some thirty years. Since the scope of this study takes a different tack, and will benefit from all the studies that preceded it, the task should be completed in less than eighteen months at a cost not to exceed $500,000-$650,000. VI. URGENCY AND PAYOFF POTENTIAL One only has to study past accidents involving aircraft and winter conditions to appreciate the importance of a standardized system for reporting runway conditions. Lives can and will be saved if this effort proves successful. VII. RELATED RESEARCH FAA in concert with Transport Canada and NASA has accomplished the “Joint Winter Runway Friction Test Program”. Numerous reports are available regarding this study. Additionally, the FAA has published “Advisory Circular 150/5200-30A” that discusses runway assessment during inclement weather conditions. VIII. PERSON DEVELOPING THE PROBLEM Jim DeLong 3751 Castle Butte Drive Castle Rock, CO 80109 Tel: 303 681 2555, cell 720 232 4664 FAX: 303 681 2634 IX. PROCESS USED TO DEVELOP PROBLEM STATEMENT Concept and process evolved from my individual experiences serving not only as a Chief Operating Officer at a large hub airport, past Chairman of the ACI Technical Committee, but also as a former pilot with over 7000 hours of jet flight time. X. DATE AND SUBMITTED BY 10 April, 2009 Jim DeLong