DEVELOPMENT AND EVALUATION OF AN ENHANCED AIRFIELD SIGNAGE FOR TEMPORARY

INFORMATION

November 15, 2016

5,336 words

8 figures and tables

Gaël LE BRIS

Airside Development Manager, Groupe ADP

Batiment 7300, Zone Technique, BP81007, 95931 Roissy-Charles de Gaulle Cedex

+1 (407) 818-6879 (phone)

gael.lebris@gmail.com (e-mail)

Gaël LE BRIS 2

Abstract 1 2 The aviation community have faced several accidents and incidents on infrastructures and procedures temporarily 3 modified for the purpose of construction works. The analysis of these events show that usual means of 4 communication to the air crews are the weak link of the safety chain. 5

In order to address the key challenge of situational awareness during construction works, the Airport 6 Construction Advisory Council (ACAC) of the Federal Aviation Administration (FAA) and Paris-Charles de 7 Gaulle (CDG) developed and evaluated with the airfield community, from 2011 to 2016, an innovative aviation 8 signage. Parallel and complementary studies in human factors lead to the definition of standards for a temporary 9 information signage, also called Orange Construction Signs (OCS). Paris-CDG focused on the development of 10 specific messages for each one of the major hazards that could require an increased situational awareness of the 11 air crews during the taxiing and takeoff. 12

The results of the evaluation conducted by the Federal Aviation Administration were published in 13 September 2015. The purpose of this paper is to present the parallel study performed by the author at Paris-CDG 14 with the coalition of the stakeholders of the airside operations. Both research projects are convergent and confirm 15 the relevance of the orange sign concept for increasing the situational awareness and preventing safety events 16 during airfield construction. 17

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INTRODUCTION 1 During the past years, aviation accidents and incidents regularly happened on airfield infrastructures and air 2 operation procedures modified for the purpose of airport construction works. The analysis of these events shows 3 that usual means of communication to the air crews are not always sufficient (1). For instance, publishing a 4 compliant aeronautical information is not the guarantee that this information reaches the cockpit, or that it will 5 prevent the accident when it does. In 2008 at Paris-Charles de Gaulle (CDG), an aircraft took off from a shortened 6 runway without being aware of the reduction. The aircraft performances were estimated by the crew using the 7 full runway lengths, despite a compliant Aeronautical Information Publication (AIP) Supplement and vocal 8 reminders from the controller (2). Similar events have been notified all around the world (3). 9

Consequently, the key challenge of operational safety during construction works is situational awareness. 10 From 2012 to 2016, the Airport Construction Advisory Council (ACAC) of the Federal Aviation Administration 11 (FAA) and Paris-Charles de Gaulle (CDG) had developed with the stakeholders of the airfield operations, and 12 evaluated on the field, an innovative signage for enhancing the situational awareness. Based on parallel and 13 complementary studies in human factors, specifications were defined for a temporary information signage, also 14 called Orange Construction Signs (OCS). Paris-CDG particularly focused on the development of specific 15 messages for each one of the major hazards that could require an increased situational awareness during the 16 taxiing and takeoff. 17 18 METHODOLOGY 19 In September 2012, the Airport Construction Advisory Council (ACAC) of the FAA and Groupe ADP met in 20 order to share their best practices for ensuring the safety of the aviation operations on temporarily relocated 21 runway thresholds. Both entities observed that they had identified the information to the air crews as the weak 22 link of the Reason's model for airfield works. Specific signs based on the International Civil Aviation 23 Organization (ICAO) standard for the airfield information were previously tried during runway works in 2009 at 24 Chicago O'Hare (4) and 2012 at Paris-CDG (5). However, feedback from the field and an incident at Singapore 25 Changi in 2007 called for research on a variant of the standards in airfield information. In Singapore, yellow 26 signs comparable to these installed in Paris-CDG and Chicago O'Hare failed in preventing aircraft to takeoff 27 based on full runway lengths while it was shortened (6)(7). 28 29

30 FIGURE 1 Signs of reduced runway length at Chicago O'Hare (2009) and Paris-CDG (2012) 31 32

The first step of this project was the development of the overall concept. The goal was to be closed 33 enough to the existing standards for avoiding a breach in the visual habitudes of the pilots, but it was also to be 34 distinguished from the regular information signs in order to catch the attention and increase the situational 35 awareness. 36

The hazards generated by the different airfield construction configurations and these which could be 37 mitigated by regular ground airfield signs, were identified (e.g. takeoff on a shortened runway towards the 38 construction without using reduced lengths). This excludes for instance the case of the landings. This step was 39 supported by a preliminary research of accidents and incidents during construction. This research used a selection 40 of online databases and other governmental sources. 41

The next step was the characterization of these hazards by their risks on the aviation operations (e.g. 42 high speed collision with the construction). They were then grouped depending on the information that could be 43 used by the crew for preventing such risks to come true (e.g. the takeoff run available is reduced). This step and 44 the ones to follow were completed with the involvement of pilots, air traffic controllers and airfield drivers. 45 Specific, efficient and straight-to-the-point messages were developed for increasing the situational awareness 46

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without confusing the air crews. A selection of these messages were evaluated on the field. This fifth step had 1 been completed from June to September 2015. 2

The results of the evaluation were then compared with the study performed in the United States by the 3 Federal Aviation Administration at the William J. Hugues Technical Center and at six different airports, and 4 published in September 2015 (8). 5 6 ACCIDENTS AND INCIDENTS RELATED TO AIRFIELD CONSTRUCTION 7 Table 1 presents the accidents and incidents selected for the research project. The events at Paris-CDG were 8 extracted from the records of the airport Safety Management System (SMS). For the occurrences outside Paris-9 CDG, the primary sources were FAA's Aviation Safety Information Analysis and Sharing (ASIAS), Transport 10 Canada's Civil Aviation Daily Occurrence Report System (CADORS), regular official accident digests (French 11 BEA, Spanish CIAIAC, etc.), and technical publications (e.g. AeroSafety World). 12 13 TABLE 1 Airfield accidents and incidents during construction 14

Date ICAO

Code

ACFT Description

2015 LFPG – Two trucks do not give the priority to aircraft while crossing a taxiway.

08/06/2015 EDDM A319 Take off from a runway entrance closed for construction.

2015 LFPG – 21 incursions in a temporary dead end while intending to transit by.

2014-2015 LFPG – Two towed large aircraft on a taxiway with a limited wingspan.

07/04/2012 LKPR A319 Takeoff RWY12 without taking into account the reduced TORA.

2012 LFPG – At least 3 entries on the shortened runway by closed access taxiways.

2011-2013 LFPG – 13 vehicle/pedestrian incursions on taxiways.

2009 KORD – 2 takeoffs of HEAVY ACFT without being aware of the DTHR.

08/16/2008 LFPG B738 Takeoff RWY27L without taking into account the reduced TORA.

02/06/2007 WSSS B743 Takeoff based on full runway length and collision with markers.

05/30/2007 WSSS A340 Takeoff facing construction using full runway length.

03/22/2007 NZAA B777 Takeoff with configuration and thrust incompatible with shortened RWY.

07/16/2003 EGCC B738 Takeoff facing works based on full runway length. Site cleared by 56 ft.

10/31/2000 RCTP B744 Takeoff from wrong runway and catastrophic collision with constructions.

09/27/1999 KLAX B747 Incursion on a taxiway closed for construction and collision with trucks.

1997 LOWW B747 Too long takeoff. Blast fences cleared by 5m.

ACFT Aircraft. DTHR Displaced Threshold. RWY Runway. TORA Takeoff Run Available. 15 16 HAZARDS AND RISK ANALYSIS 17 18 Takeoff toward the construction works based on full runway distances 19 When a runway is shortened for the purpose of constructions, using aircraft performances (V-speeds) based on 20 full runway lengths for takeoff can lead to near-collision with obstacles beyond the end of the shortened runway. 21 Many safety events of this type have been observed all around the world. At Vienna in 1997, a 747 took off too 22 long and cleared jet blast fences by 5 meters (16.4 feet) only (9). At Paris-CDG in 2008, a 737-800 took off long, 23 damaged plastic delineators, but without sustaining critical damages, and then flew low over jet blast fences (10). 24 At Chicago O'Hare in 2009, two wide-bodies took off without being aware of the declared distances in force. At 25 Prague V. Havel in 2012, an Airbus A320 initiated a takeoff with V-speeds calculated on the basis of full runway 26 lengths. The crew realized its mistake when they saw the construction works appearing beyond the end of the 27 available runway (11). These events occurred on airports where the shortened runway and the related aeronautical 28 information were compliant to the standards. 29 A high speed collision between aircraft and vehicles or excavations is typically catastrophic. In Taipei, 30 Taiwan in October 2000, an aircraft aligned and accelerated on a runway closed for maintenance (12). The aircraft 31 was destroyed by the collision with heavy machines. When the constructions are not directly on the runway, the 32 likelihood of a collision is lowered if there is no non-frangible obstacle (e.g. jet blast fences and heavy machines) 33 on the runway itself. However, this is not always possible, especially when the purpose of the works is the 34

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refurbishment of the runway pavement. Banning the aircraft requiring the longest distances, for taking off as 1 performing an accelerate-stop, is a method for reducing the likelihood of the risk of a collision (Paris-CDG, 2012). 2 Only the suspension of all operations facing the works removes the hazard (Paris-Orly, 2009). However, when 3 this is not possible, an appropriate signage could decrease the likelihood of a takeoff with erroneous V-speeds by 4 increasing the situational awareness and providing direct information to the crews. 5 6 Takeoff from a closed runway 7 The hazard in this situation is when an aircraft is aligning a runway closed for construction works and accelerating 8 for taking off. The most critical risk is the destruction of the aircraft after colliding vehicles. The typical case is 9 the accident of October 2000 in Taipei. During adverse weather conditions with poor visibility, a 747 aligned a 10 temporary runway, partially closed for construction and parallel to the active runway. The aircraft initiated the 11 takeoff and collided with heavy vehicles (12). Specific signs may have alerted the pilots on the status of this 12 closed runway. Other takeoffs from temporarily closed runway have been reported, especially during short term 13 closure when the visual indication are usually reduced to a lighted X installed for preventing landings (13). 14 15 Incursion on a taxiway closed or with a restricted access 16 Taxiways closed to the operations should be visibly blocked with barricades, markers and lights. Sometimes, 17 taxiways are restricted only in one direction for the purpose of runway operation safety. At Paris-CDG from April 18 to June 2012 when Threshold 08L was temporarily relocated, the access to Runway 26R for takeoff was restricted 19 to the only Taxiway R1 offering the maximum Takeoff Run Available (TORA) to the aircraft. Intermediary 20 taxiways were used only for exiting the runway. Stop bars of these taxiways were lit so to be seen when taxiing 21 towards the runway. Still, an aircraft entered onto the runway by these taxiways. Lighted mandatory signs (lit 22 wrong way signs) were installed. At least another incursion occurred. 23

This hazard includes catastrophic risks when workers are exposed to potential casualties (Los Angeles 24 International, 1999) or because the restriction of the taxiway access is itself in force for preventing catastrophic 25 consequences (Paris-CDG, 2012). 26 27 Incursion on a taxiway with a temporary reduced allowable wingspan 28 If construction works are conducted within the taxiway strip, the separation distance between the taxiway 29 centerline and the construction site cannot be enough for ensuring an acceptable level of safety regarding the risk 30 of a catastrophic collision between an aircraft and construction equipment or vehicles. Consequently, the 31 allowable wingspan must be reduced. 32 The sign used at Paris-CDG mentions "MAXSPAN [temporary maximum wingspan] m". This message 33 was evaluated as satisfying by the pilots, but new specifications on the visual elements could increase the 34 visibility of the sign and the identification of the modified and temporary maximum allowable wingspan. 35 36 Incursion in a temporary dead end 37 During the reconfiguration of taxiways in the vicinity of Threshold 08L between 2011 and 2014 at Paris-CDG, 38 Taxiway UNIFORM had a dead end for a limited period of time. A ground marking "ONLY M06 TO M09" 39 (name of the stands served by the reduced taxiway) was painted in order to remind the crews about this 40 configuration. No misrouting or incursion was observed. 41 During pavement rehabilitation on Taxiway ALPHA along Satellite VICTOR of Terminal 1 on summer 42 2015, 15 incursions of aircraft expecting to transit occurred. The same marking than previously was in place, and 43 it was even doubled by a second marking closer to the last intersection before the temporarily restricted section. 44 Yet, it did not avoid new incursions. A more efficient message seems relevant for mitigating the risk of misrouting. 45 This message should be more specific on the presence of a dead end, instead of being focus on an inventory of 46 the stands still served by the taxiway. 47 48 Incursion of a vehicle or a pedestrian within the object free area of an active taxiway 49 Such vehicle/pedestrian deviation (V/PD) are not rare at major airports. They are not usually accompanied with 50 injuries, but they can be potentially fatal to the pedestrian or vehicle infringing the taxiway strip. 51

A specific sign could increase the vigilance of the crews on the environment when there is an increased 52 risk of incursions (proximity with constructions, temporary taxiway/roadway intersection). 53

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Priority refused by a construction vehicle to an aircraft 1 Because contractors are not necessarily used to drive on the airfield, they are not always familiar with the aircraft 2 speeds and the distances on the airfield. Also, a heavy truck does not have the same mobility than a light car. 3 Consequently, the risk of a near-collision between a construction vehicle crossing an active taxiway on a service 4 road and an aircraft taxiing is higher when works are in progress. 5 6 Temporary signage not understood by the crews 7 From 2011 to 2014, different messages were tested at Paris-CDG for informing the crews about the reduction of 8 the taxiway strip width or the wingtip margins. These indications were considered by the crews as too long, 9 confusing, and not directly usable. 10 11 DEVELOPMENT OF THE NEW SIGNAGE CONCEPT 12 13 Design principles 14 Eight "golden rules" were defined with pilots, air traffic controllers and airfield drivers for designing the signage: 15

The overall concept should be simple and cheap to implement (feasibility and acceptance by the project 16 and construction managers). 17

The overall concept should be the closest possible to the standards (pilot environment). 18

The overall concept must be compliant with the ICAO specifications for the luminance and colors 19 (visibility). 20

The sign must be visible and readable. The letters must contrast on the background (visibility). 21

The messages must be short and simple (understanding). 22

The messages must be straight to the point (efficiency). 23

The messages must be understood by all the airside users: crews and drivers (representativeness). 24

Only a small set of different messages should be allowed (habitudes and efficiency). 25 26 General layout 27 The regular color for the background of the information signs is yellow in the ICAO (14) and FAA standards. 28 Consequently, the variant of the standard for temporary information should be different. The ACAC brought the 29 idea of using safety orange, since this is the standard color for the roadway construction signs for the U.S. Federal 30 Highway Administration (FHWA) (15), and in other countries such as Canada, Belgium, Brazil, New Zealand 31 and Ireland. Also, this color is recognized all around the world as related to safety and construction works. 32 Moreover, the Vienna Convention on Road Traffic of 1968 which defines the international standards for roadway 33 signage recognize both the yellow and the orange as color for temporary signs (16). 34 35

36 FIGURE 1 Roadway construction signs in different countries 37 38 The standard color for the lettering of the information signs is black (or possibly yellow against a black 39 background). This color is visible on the orange background, but the participants in the workgroups in the U.S. 40 and France proposed to evaluate a white lettering in order to test a different color than the standard. The police 41 and the size of the lettering should be compliant with the standards, as the requirements in luminance (17)(18). 42 43 Reduced TORA sign 44 The sign "REDUCED [runway designation] TAKEOFF RUN AVAILABLE [reduced TORA] m" is the most 45 important development of this project. By providing a clear information to the crews on the reduction of the 46 runway length, it also reduces the likelihood of a takeoff toward the construction works based on full runway 47

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distances. It prevents the most critical accident possible for a departing aircraft: the collision at high speed with 1 constructions. It was developed with air carrier pilots based on the experience of the temporary displaced 2 thresholds at Chicago O'Hare in 2009 and Paris-CDG in 2012. This sign should be located at each taxiway with 3 a reduced TORA or TODA, in place of the lighted sign displaying the non-reduced value of the TORA. 4 5 Sign for diffused or non-specific risks 6 So far, there is no standard for informing the crews about diffused risks such as an increased likelihood of vehicle 7 or pedestrian incursion on an active taxiway. The "CONSTRUCTION AHEAD" sign is proposed, as on the road, 8 for situations where the risks are diffused and not precisely located. For instance, this sign should be used when 9 there is an increased risk of vehicle/pedestrian incursion from a construction site on operative taxiways. When 10 the end of the section under construction is not clear, an "END CONSTRUCTION" sign should be added. These 11 signs should be installed when a runway or a taxiway is closed, and that the consequent configuration of the 12 airfield is not clear and requires a specific attention. 13 14 Reduced allowable wingspan 15 "MAX SPAN [maximum wingspan] m" is a text that has been used for more than eight years at Paris-CDG with 16 only two incursions (on erroneous clearances) when the maximum allowable wingspan was reduced. It should 17 be installed at each entrance of the taxiway with a reduced allowed wingspan. 18 19 Taxiway with a temporary dead end 20 "DEAD END" is a message used for advising the crews that a taxiway is temporarily with a dead end. It can be 21 supplemented with the name of the taxiway and a directional arrow when the intersection configuration is 22 confusing. It should be located at each intersection offering an alternate route that to the dead end. Previous 23 messages including "FROM X TO Y ONLY", with X and Y the names of the closest and farthest accessible 24 stands were not always successful. Taxiway incursions occurred since this information did not specifically point 25 out the configuration in dead end. It just implied that certain stands were not accessible. 26 27 28

29 Figure 2 Temporary information signs 30

31 EVALUATION ON THE FIELD 32 33 Description of the phasing 34 In order to validate the final concept, comprehensive field evaluations were conducted in 2015. Paris-CDG 35 benefited from the FAA's campaign performed in 2013 and 2014. Based on this feedback, a three-phase 36 evaluation was prepared. 37

The tests were conducted along real-scale taxiway construction works on Taxiway QUEBEC northward 38 Terminal 1. A questionnaire was prepared and sent to the airfield drivers, the aircraft towing providers, and airline 39 pilots with the support and collaboration of Air France, EasyJet, FedEx, SAS and Singapore Airlines. After 40

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passing in front of the orange signage, the participants had to fill out the questionnaire on paper or online. They 1 were available in both French and English. 2 3

4 Figure 3 Orange construction signs evaluated at Paris-CDG in 2015 5

This phase-by-phase process was iterative: the results of a phase were analyzed with the stakeholders in order to 6 adjust the next phase if appropriate. Phase 1 evaluated an orange background with 300 mm-high letters from June 7 15 to July 15. The text was "CONSTRUCTION AHEAD". Since many participants mentioned the letters were 8 too small, and the conspicuity of the white lettering was poor against the orange background, Phase 2 replaced 9 the white lettering by a 400 mm-high black lettering and the same message from July 16 to August 15. Phase 3 10 evaluated the marking variant with the text "DEAD END" from September 06 to October 27. 11 12 Questionnaire 13 11 questions were asked to the airline pilots, airfield drivers and tow-tractors: 14

1. Do you prefer the white letters [phase 1] / black letters [phase 2] on an orange sign OR the standard 15 black letters on a yellow board? 16

2. How would you rate the visibility of this orange sign? (POOR = 0 1 2 3 4 5 = EXCELLENT) 17 3. Do you perceive the orange color of this sign as related to a temporary information? YES/NO 18 4. Do you perceive the orange color of this sign as related to ongoing construction works? YES/NO 19 5. Do you clearly understand the meaning of "CONSTRUCTION AHEAD"? (I DO NOT UNDERSTAND 20

= 0 1 2 3 4 5 = I CLEARLY UNDERSTAND) 21 6. Before taxiing in this area, were you aware of the construction works on TWY ALPHA and QUEBEC? 22

YES/NO 23 7. Is this sign improving the situation awareness in the vicinity of the construction works? YES/NO 24 8. Day and time (UTC) when crossing the sign: _________________________________ 25 9. Aircraft type and name of the airline: ____________________________________________ 26 10. Weather conditions (example: CAVOK and night): __________________________________ 27 11. Observations: _______________________________________________________________ 28

29 Descriptive statistics 30 110 respondents participated in phases 1 and 2 of the evaluation, with respectively 90 and 20 answers for each 31 phase. 20% were airline pilots, 36% were tow-tractor drivers, and the remaining 44% were airfield drivers. Phase 32 3 only received 11 questionnaires back, with an overall positive feedback. Because of the small set of data, the 33 results will not be analyzed further in this paper. 34 35 The different amounts of respondents between phase 1 and phase 2 can be explained by: 36

A cultural bias: the solution proposed for phase 2 addressed most of the concerns expressed during phase 37 1 (poor contrast of the white lettering, letters to be enlarged, etc.). The potential contributors may have 38 not felt the need to fill out a second questionnaire. 39

Cumulative requests: phase 2 came after a 4-week phase 1 supported by an intense promotion by 40 different channels to the operational stakeholders. 41

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Summer vacations: the switch from phases 1 to 2 occurred at the end of July. In France, the end of July 1 is typically a crossover period between workers taking vacations in July and those leaving in August. 2 The information on phase 2 may have not reached the stakeholders so efficiently than for phase 1. 3

4 Weather conditions 5 Most of the evaluations were performed during the daylight under excellent weather conditions. However, 14% 6 of 99 observations were made during nighttime, and 11% on 107 observations were performed under rain or 7 cloud cover. No observation was made during Low Visibility Operation. 8 9 RESULTS AND ANALYSIS 10 11 Influence of the category of respondent 12 The respondents included airline pilots, airfield drivers and aircraft towing service providers. The population 13 who is most exposed to the most critical hazards are the pilots. However, they account for 20% of the population 14 of the respondents. Only 3 crews participated in phase 2. 15 16 It is possible to establish if the answers to each one of the question depend on the category of participant, or if 17 the perception and experience of the signage are the same. This verification was performed using the data from 18 phase 1, in order to have a set of answers based on the same exact questions on the same sign. Also, phase 1 has 19 the biggest population. 20 21 For each question, the following was calculated: 22

Correlation coefficients between the variable "answers" and the variable "category of respondent" ; 23

Under the null hypothesis H0 (no correlation), the value of function t of the Student test ; 24

The related p-value. 25 26 TABLE 2 Study of the independence between the category of respondent and the answers of Phase 1 27

Question Correlation

coefficient

t-stat

under H0 p-value

1 – Preferred color 9.0 x 10-3 0.83 0.411

2 – Visibility 2.5 x 10-4 2.4 x 10-3 0.998

3 – Relation orange/construction -3.1 x 10-2 -0.30 0.768

4 – Relation orange/temporary -0.17 -1.62 0.108

5 – Understanding of "CONSTRUCTION AHEAD" -2.5 x 10-2 -0.23 0.817

6 – Aware of works on QUEBEC 0.076 0.71 0.479

7 – The sign enhance the situational awareness -8.8 x 10-2 -0.83 0.407

The H0 hypothesis is here an absence of correlation. 28 29 It is noticeable that: 30

The correlation coefficient is within [-0.5 ; 0.5] for all the questions, and far from the limits (indicator 31 of a poor correlation) ; 32

The null hypothesis is rejected for high values of p, and it is always higher than typical values such as 33 0.05 or 0.10. Only for one question (association between orange and the temporary aspect of the 34 information), the rejection value is relatively low (0.108). 35

36 So, it is reasonable to state that being a pilot, a tow tractor driver or an airfield driver does not influence the 37 answer to any of the questions asked for this evaluation. 38 39 Preferred color 40 During phase 1, 58% of the respondents (on 90) preferred the black lettering against the yellow background to 41 the white lettering against an orange background. The respondents noticed the poor visibility of the white lettering 42 on the orange background. 43

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During Phase 2, 95% of the respondents (on 20) preferred the black lettering against the orange 1 background instead of the standard black lettering against a yellow background. The alternative to the standard 2 is clearly preferred to the black and yellow standard for temporary information. 3 4 Visibility 5 On 90 answers, more than half of them rated the visibility of the white lettering against an orange background 6 under 3/5 (the median is 3). A fourth of the answers is between 0/5 and 1/5 (included). The comments clearly 7 show that this poor visibility is mainly due to the lack of contrast between the white letters and the background. 8 The letters were also mentioned as too small. 9 On the 20 answers collected during phase 2, more than half of them rated the visibility of the black 10 lettering against an orange background from 4/5 to 5/5 (the median is 4). Three quarters of the answers are 11 between 3/5 and 5/5. All the answers were higher than 1/5. The enlarged black letters with an orange background 12 have an enhanced visibility. 13 14 Orange color and temporary construction information 15 The results of questions n°3 and n°4 are similar. For phase 1, respectively 72% and 71% of the respondents (on 16 90 answers) understand the orange color as related to a temporary information or constructions. For phase 2, 100% 17 of the respondents understand this link. 18 19 Understanding of "CONSTRUCTION AHEAD" 20 During phase 1, 50% of the respondents (on 89 answers) rated the understanding of "CONSTRUCTION 21 AHEAD" from 4/5. 75% of the respondents rated the text beyond 3/5. Note that "CONSTRUCTION AHEAD" 22 is not a standard message in France and in many other European country. 23

During phase 2, after a month of information on the evaluation, a 5/5 rate is given by half of the 24 respondents (20). 75% of them rated beyond 4/5. 25 26 Aeronautical information 27 During phase 1, 64% of the respondents only (on 89 answers), and 78% of the responding pilots were aware of 28 works in progress on the taxiway where the sign was installed. During phase 2, they were 90% of the respondents 29 (100% of the three pilots of the set). 30 31 Enhancement of the situational awareness 32 66% of the respondents (on 90 answers) stated that the orange sign with a white lettering enhanced the situational 33 awareness in the vicinity of construction works. They were 100% of the respondents (on 20 answers) during 34 phase 2 for the orange sign with a black lettering. 35 The temporary information sign with a black lettering and an orange background increase the situational 36 awareness, especially after a period of information. 37 38 COMPARISON WITH THE RESULTS OF THE U.S. EVALUATION 39 In the United States, evaluations were conducted at the following airports in 2013 and 2014: Chicago O’Hare 40 International Airport (ORD) in Chicago, Illinois; Portland International Airport (PDX) in Portland, Oregon; 41 Theodore Francis Green State Airport (PVD) in Warwick, Rhode Island; Long Island MacArthur Airport (ISP) 42 in Ronkonkoma, New York; Orlando Sanford International Airport (SFB) in Sanford, Florida; and John F. 43 Kennedy International Airport (JFK) in New York, New York (8). 44

At the U.S. airports, on a total of 131 respondents (98 drivers and 33 pilots), 114 of them (87%), strongly 45 agreed or agreed that the "CONSTRUCTION AHEAD" sign was conspicuous. 116 of the respondents (88%) 46 agreed or strongly agreed that the sign was comprehensible at an adequate distance. At the six U.S. airports, 117 47 (89%) of the combined respondents agreed or strongly agreed that the "CONSTRUCTION AHEAD" sign 48 provided adequate notification of the existing construction. 49

For the "CONSTRUCTION ON RAMP" sign, on 51 respondents, 47 (92%) of them agreed or strongly 50 agreed that the sign was conspicuous 45 (88%) agreed or strongly agreed that the sign was comprehensible at an 51 adequate distance. 48 of them (94%) strongly agreed or agreed that the sign provided adequate notification of the 52 existing construction. 53

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A total of 27 pilots and vehicle operators in the U.S. evaluated TORA signs providing takeoff run 1 available information. Overall, 25 respondents (92%) agreed or strongly agreed that these signs were conspicuous; 2 22 respondents (81%) agreed or strongly agreed the signs were comprehensible at an adequate distance; and 24 3 respondents (89%) agreed or strongly agreed the signs adequately notified them of existing construction. 4

These results are comparable with the figures observed at Paris-CDG. 5 6 TABLE 3 Results of the OCS evaluation in the United States (number of respondents in parenthesis) 7

Agree or Strongly Agree with: CONSTRUCTION

AHEAD

CONSTRUCTION

ON RAMP

RWY XX

TORA Y,YYY FT

The sign is conspicuous 87% (131) 92% (51) 92% (25)

The sign is comprehensible at an adequate

distance 88% (116) 88% (45) 81% (22)

The sign adequately notified of the existing

construction 89% (116) 94% (48) 89% (24)

8 TABLE 4 Results of the OCS evaluation at Paris-CDG (number of respondents in parenthesis) 9

Rates higher than 3/5 or « Yes » on: CONSTRUCTION

AHEAD (Ph. 1+2)

CONSTRUCTION

AHEAD (Phase 2)

The sign is visible (Poor=0 to Excellent=5) N/A 75% (20)

I understand "CONSTRUCTION AHEAD"

(I did not=0 to I clearly do=5) 80% (109) 100% (20)

The sign improves the situational awareness

(Y/N) 72% (110) 100% (17)

10 FINAL RECOMMENDATIONS 11 Safety Risk Managers should carefully consider using the new temporary information signage for mitigating the 12 following hazards during construction: 13

Infringement of the obstacle limitations during works within the taxiway strip 14 ("CONSTRUCTION AHEAD") 15

Vehicle/pedestrian deviations (V/PD) and especially incursions on the taxiway 16 ("CONSTRUCTION AHEAD") 17

Hazards related to strong modifications of the usual ground routing ("CONSTRUCTION 18 AHEAD") 19

Unexpected incursion of an aircraft in a temporary dead end ("DEAD END") 20

Maximum wingspan reduction ("MAXSPAN XX M") 21

Modification of the runway lengths (reduced TORA sign) 22 23

Most of the other situations requiring a temporary sign should fall into one of these four categories of 24 sign. If not, it may not be relevant to provide a specific information to the crews (provide only data with an 25 operational interest). Temporary signs and markings should be located 100 m (328 feet) to 200 m (656 feet) 26 before the beginning of the hazard as far as possible, as on the road. 27

Temporary signs shall be equipped with flashing lights for a better identification. The lights should flash 28 simultaneously in order to avoid confusion with Runway Guard Lights (RGL). 29

The temporary signs should not be lit during the night. Instead, it should have a highly retroreflective 30 background meeting roadway standards for non-lighted signs. Indeed observations and measurements confirm 31

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that externally illuminated temporary signs are often difficult to read because of the poor installation of the 1 projectors and unappropriated devices (halos and overlighting). Preliminary assessments by the author and field 2 evaluations in the United States, proved that optical performances of aircraft and car lights are sufficient to 3 provide a proper lighting for the signs. If the location of the signs and especially their distance to the taxiway 4 centerline is unusual, requiring them to be lit, then this light should be external, and provide a compliant reflected 5 light meeting the ICAO requirements in term of luminance homogeneity. 6

Training programs for airfield drivers should include a description of these signs. 7 8

CONCLUSION 9 At Paris-CDG, the set of orange signs was adopted as best practice to be included in the safety risk assessments 10 (SRA) of the airfield construction works. Each situation requiring a reinforcement of the visual information has 11 now a specific orange sign, with variants adapting the concept to the local airfield geometry (including a marking 12 version when there is no space for a vertical sign). Other airports in Europe have been adopting this orange 13 construction signage: Oslo Gardenmoen (reduced TORA sign, 2015), Paris-Orly ("DEAD END", 2016) and 14 London Heathrow ("CONSTRUCTION AHEAD", 2016). 15 The results of the research efforts at Paris-CDG and in the United States were presented to technical 16 workgroups of the European Aviation Safety Agency (EASA) with the support of the French Aviation Authority 17 (DGAC). A submission to the Visual Aids Working Group (VAWG) of the ICAO is presently envisaged. 18

Following the publication of the FAA study, an amendment of Advisory Circular 150/5370-2 19 Operational Safety on Airports During Construction was submitted to the industry for comments. It includes 20 safety orange construction signage as a visual aid to alert pilots and vehicle operators of existing airport 21 construction works. 22 23 REFERENCES 24

1. "Safety of the runway operations with a temporary displaced threshold during construction works", 25

Gaël Le Bris, TRB/TRIS, 15 November 2013. 26 2. "Serious incident on 16 August 2008 on take-off from Paris Charles de Gaulle Airport (95) to the Boeing 27

737-800 registered SU-BPZ operated by AMC Airlines", BEA, 2011. 28

3. "Safety of Runway Operations during Construction Works", TRB Straight to Recording for All, 29

http://www.trb.org/Main/Blurbs/173568.aspx 30

4. "What’s on Your Runway? (Expanded Version)", Lessons Learned During Runway 28 Threshold 31

Relocation — Chicago O’Hare International Airport (ORD) in 2009, Wayne Rosenkrans, 32

AeroSafety World, July 2012. 33 5. "Working Safely on an Operative Runway", AeroSafety World, Flight Safety Foundation, August 2013, 34

pp. 12-16. 35 6. "Runway take-off incident involving Airbus A340, Registration A40-LH, Singapore Changi Airport, 30 36

May 2007", AIB/AAI/CAS.039, AAIB, December 2008 37 7. "Take-off incident involving Boeing 747-300, Registration HZ-AIT, Singapore Changi, 02 June 2007", 38

AIB/AAI/CAS.040, AAIB, August 2008 39 8. “Development and Evaluation of Safety Orange Airport Construction Signage, Bassey, Robert, FAA, 40

2015 41 9. "What's on Your Runway? Mitigating Hazards Associated with Airport Construction", FAA ATO, p. 3. 42 10. "Serious incident on 16 August 2008 on take-off from Paris Charles de Gaulle Airport (95) to the Boeing 43

737-800 registered SU-BPZ operated by AMC Airlines", BEA, 2011. 44 11. "AAIB Bulletin 2/2013", EW/G2012/07/23, AAIB, 2013, pp. 51-52. 45 12. "Crashed on a partially closed runway during takeoff, Singapore Airlines Flight 006, Boeing 747-400, 46

9V-SPK, CKS Airport, Taoyuan, Taiwan, October 31, 2000", Aircraft Accident Report ASC-AAR-02-47 04-001, ASC, 2002. 48

13. "Quasi collision de nuit avec un véhicule de balisage lors du décollage autorisé sur une piste fermée", 49 Report f-pn130905, BEA, December 2015. 50

14. "Annex 14", Volume I – Aerodrome Design and Operations, §5.2.17 – information signs, 6th edition, 51 ICAO, pp. 5-23/5-24, November 2013. 52

15. "Manual on Uniform Traffic Control Devices (MUTCD)", Revision 2, FHWA, May 2012. 53

Gaël LE BRIS 13

16. "Vienna Convention on Road Traffic of 1968", section G §I.4, version of 28 February 2012. 1 17. "Annex 14", Volume I – Aerodrome Design and Operations, Appendix 3 – Mandatory Instruction 2

Markings and Information Signs, 6th edition, ICAO, pp. APP 3-1/APP 3-3, July 2013 3 18. "Annex 14", Volume I – Aerodrome Design and Operations, Appendix 4 – Requirements concerning 4

design of taxiing guidance signs, 6th edition, ICAO, pp. APP 4-1/APP 4-11, November 2013 5