UFC 4-211-01 Aircraft Maintenance Hangars.pdf

UFC 4-211-01

13 April 2017

Change 3, April 20, 2021

UNIFIED FACILITIES CRITERIA (UFC)

APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED

AIRCRAFT MAINTENANCE

HANGARS

AIRCRAFT MAINTENANCE HANGARS

Any copyrighted material included in this UFC is identified at its point of use.

Use of the copyrighted material apart from this UFC requires the permission of the copyright holder.

U.S. ARMY CORPS OF ENGINEERS

NAVAL FACILITIES ENGINEERING COMMAND (Preparing Activity)

AIR FORCE CIVIL ENGINEER CENTER

Record of Changes (changes are indicated by \1\ ... /1/)

Change No. Date Location

1 November 2017 See UFC Summary Sheet 2 May 11, 2020 See UFC Summary Sheet 3 April 20, 2021 See UFC Summary Sheet

This UFC supersedes UFC 4-211-01N dated 25 October 2004 with Change 3, dated 16 December 2009.

FOREWORD

The Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and provides planning, design, construction, sustainment, restoration, and modernization criteria, and applies to the Military Departments, the Defense Agencies, and the DoD Field Activities in accordance with USD (AT&L) Memorandum dated 29 May 2002. UFC will be used for all DoD projects and work for other customers where appropriate. All construction outside of the United States is also governed by Status of Forces Agreements (SOFA), Host Nation Funded Construction Agreements (HNFA), and in some instances, Bilateral Infrastructure Agreements (BIA.)

Therefore, the acquisition team must ensure compliance with the most stringent of the UFC, the SOFA, the HNFA, and the BIA, as applicable.

UFC are living documents and will be periodically reviewed, updated, and made available to users as part of the Services’ responsibility for providing technical criteria for military construction. Headquarters, U.S. Army Corps of Engineers (HQUSACE), Naval Facilities Engineering Command (NAVFAC), and Air Force Civil Engineer Center (AFCEC) are responsible for administration of the UFC system. Defense agencies should contact the preparing service for document interpretation and improvements. Technical content of UFC is the responsibility of the cognizant DoD working group. Recommended changes with supporting rationale should be sent to the respective service proponent office by the following electronic form: Criteria Change Request. The form is also accessible from the Internet sites listed below.

UFC are effective upon issuance and are distributed only in electronic media from the following source:

• Whole Building Design Guide web site http://dod.wbdg.org/.

Refer to UFC 1-200-01, DoD Building Code (General Building Requirements), for implementation of new issuances on projects.

AUTHORIZED BY:

LARRY D. McCALLISTER, PhD, PE, PMP, SES

JOSEPH E. GOTT, P.E.

Chief Engineer

Acting Chief, Engineering and Construction Directorate of Civil Works

Naval Facilities Engineering Command

U.S. Army Corps of Engineers

EDWIN H. OSHIBA, SES, DAF MICHAEL McANDREW Deputy Director of Civil Engineers DCS/Logistics, Engineering & Force Protection

Deputy Assistant Secretary of Defense (Facilities Investment and Management) Office of the Assistant Secretary of Defense (Energy, Installations, and Environment) http://www.wbdg.org/pdfs/ufc_implementation.pdf http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4 http://dod.wbdg.org/

NEW DOCUMENT SUMMARY SHEET

Document: UFC 4-211-01, Aircraft Maintenance Hangars

Superseding: UFC 4-211-01N, Aircraft Maintenance Hangars: Type I, Type II and Type III dated 25 October 2004 with Change 3 dated 16 December 2009, NAVFAC Interim Technical Guidance (ITG 2010-01) - Maintenance Hangar Design and Planning Guidance for F35B or C, and Engineering Technical Letter (ETL) 02-15: Fire Protection Engineering Criteria New Aircraft Facilities, 3 December 2002.

Description: This UFC provides criteria for planning and design of Aircraft Maintenance Hangars for the aircraft of the combined DoD United States Armed Forces.

Reasons for Document: This is a new Joint Service document. This new document represents another step in the Joint Services effort to bring uniformity to the planning, design and construction of military facilities. The UFC was developed to provide design requirements to accomplish the following:

• Assist planners in understanding the facility requirements to ensure accurate space programs budgets.

• Provide architects, engineers, and construction surveillance personnel with essential, minimum (min) requirements for the design and construction of Aircraft Maintenance Hangars.

• Clarify the operational intent of the facility design.

Impact: The following will result from the publication of this UFC:

• This UFC creates a single source for common DoD Aircraft Maintenance Hangar criteria and an accurate reference to individual Service-specific documents.

• This UFC facilitates updates and revisions and promotes agreement and uniformity of design and construction between the Services.

Unification Issues: Non-unified content is mainly a result of operational differences among the Services and is addressed in the Service-specific chapters including:

• The Navy included Functional Data Sheets (FDS) in this UFC. The Army keeps their Room Data Sheets with the Army Standard and the Air Force keeps these specific requirements with their Dynamic Prototypes.

• The Army and Navy perform fuel cell operations in the Aircraft Maintenance Bay per operational guidelines. The Air Force has specific construction criteria for the design of fuel cell maintenance hangars.

• Service differences in various subjects are noted in this UFC:

o Aircraft Clearance Tables o Design of the Aircraft Maintenance Bay slab on ground o Ordnance grounding o Fire suppression and detection o High intensity overhead radiant heaters in the Aircraft Maintenance

Bay o Aircraft power distribution servicing aircraft o Aircraft Maintenance Bay floor finish options

\1\ Reasons for Document Change 1:

Revised paragraphs 3-4.2 Ground Floors, 3-4.2.3.1Aircraft Maintenance Bay - Slab on Ground Design, and 7-4.1Aircraft Maintenance Bay - Slab on Ground Loading.

Previously, the UFC did not allow for slab on ground variable thickness in the hangar bay for areas not subject to aircraft loading. Generally, the reasoning was that the hangar bay may experience different aircraft during its lifespan due to change in mission or during special circumstances such as airshows or storms where aircraft may be “dense packed” into every available slab space or just to maintain future flexibility of use. However, it was recognized that this could result in substantial savings in a very large hangar bay. The governing rationale to revise was to continue to prohibit variable thickness in multiple aircraft hangar bays since these hangars generally house smaller aircraft and are less likely to maintain dedicated aircraft parking locations in perpetuity, but to allow slab thickness variation for single aircraft hangar bays where a very large aircraft dedicated to one single parking spot was envisioned. In any case, the designer should validate the requirements with the user. For standard hangars, such as Navy Type I, II, III, and IV, this is prohibited since the intention for these is to maintain hangar bay flexibility in accommodating multiple aircraft platforms or repurposing the hangar.

Revised paragraph 5-6.7.4 Existing Water Only Delue Systems.

Paragraph revised due to error in intent.

Deleted old bullet under paragraph 3-5.8.2.1 Preconditioned Air Systems relating to portable units being used for backup since later paragraph describes two units tied together with manifold for redundancy. /1/

\2\ Reasons for Document Change 2:

Revised paragraphs:

• General o Incorporated Navy FY 19-01 ITG and other F-35 cooling air system lessons learned in 3-5.8 Process Systems and 4-2.2 Mechanical Systems.

o Upgraded compressed air hangar bay and shop requirements to reflect new equipment needs of cabin pressure testing and fuel cell evacuators.

o Removed AFFF specific fire protection requirements o Other general fire protection system changes o Additional references added for battery maintenance shops

• Chapter 1 o 1-4 Scope of Facility revised to clarify applicability to all aircraft hangars.

• Chapter 2 o 2-1.6 Solar Glare Hazard Analysis revised.

o Paragraph 2-2.1.3 Heavy Maintenance Shops revised.

• Chapter 3 o Figures 3-1, 3-1-1, 3-1-2, 3-1-3 revised.

o Revised typographical errors in column labels.

o 3-3.4.1.1 Aircraft Maintenance Bay and 3-3.4.1.3 Heavy

Maintenance Shops revised to generalize light-colored floor coatings o Paragraph 3-5.3.1.7 Specialized or Localized Exhaust revised.

o 3-5.8.1Compressed Air, Table 7-4: Hangar Bay (OH), and

Table 7-19: Hangar Bay (OH) (F-35 Only) revised to include minimum requirements o Paragraph 3-7.1 Hazardous (Classified) Locations revised.

o 3-7.4 Renewable Energy Sources o 3-7.13 \2\ Aerospace Ground Equipment (AGE) Electrical Power

Provisions added for safety.

o Revised paragraph 3-10 Hangar Doors for reference to structural prohibition on vertical lift fabric doors in high wind areas.

o 3-10.1.3 Catwalk revised to emphasize importance and need.

o 3-11.3.1Trench Design revised to emphasize ductile iron trench covers o Fire Protection

◊ Removed AFFF specific requirements

◊ Clarified fire protection requirements variation between services.

◊ Updated separation drawing and section details.

◊ Unified pump redundancy requirements between services.

◊ Updated positioning of high-expansion generators in relation to helicopters.

◊ Clarified allowable location for fire protection system controls.

◊ Added additional guidance on zoned systems

◊ Revised guidance on testing of optical detectors.

◊ Added clarifying note on electrical classified locations.

◊ 3-6.4 Fire Water Supply AFFF deleted and replaced with Low Level Water only

◊ 3-6.8.1 Fire Suppression Pipe Labeling AFFF bullet for label deleted.

◊ 3-6.8.2 Fire Suppression Drainage AFFF deleted.

◊ 3-6.9 \2\ Foam/Water or Water Only Flow Control Valves Paragraph title change to include Water Only flow control valves and deleted last sentence regarding AFFF.

◊ 3-6.10 Foam/Water Proportioning System 3rd bullet modified to replace “AFFF” with “concentrate”.

◊ 3-6.11.2 \2\ Deleted Paragraph retained to avoid numbering issues for references. /2/ paragraph deleted regarding AFFF.

◊ 3-6.12 \2\ Foam/Water Solution and Low Level Water Only Piping /2/ Edited to include Low Level Water systems.

◊ 3-6.12.1 \2\ Low Level Water Only Piping AFFF replaced with Low Level Water

◊ 3-6.16 \2\ Low Level Water Trench Nozzle System and 3-

6.16.1 Low Level Water System Performance AFFF/foam

replaced with Low Level Water.

◊ 3-6.18 Hydraulic Calculations AFFF/foam replaced with Low Level Water.

◊ 3-6.19.1 \2\ Fire Alarm Control Unit/Autonomous Control Unit (FACU/ACU) through 3-6.19.2.3 Foam/Water, Low Level Water Only, and Preaction Supervised Solenoid Disconnect AFFF/foam replaced with Low Level Water.

◊ 3-6.19.5.1 \2\ Conduit and Enclosure Installation within the Hangar Bay through Figure 3-10: Start Foam System Signage AFFF/foam replaced with Low Level Water.

◊ Revised and added: Figure 3-10: Start Foam System Signage, Figure 3-11: Stop Low Level System Signage, Figure 3-12: Stop Foam System Signage, Figure 3-13: Stop Low Level System Signage

• Chapter 4 o 4-2.2 Mechanical Systems \2\ revised.

• Chapter 5 o 5-3.2 Aircraft Maintenance Bay Striping Requirements and Figure

5-1 Notes revised allowing matching of center line from outside.

o 5-1.2\2\ US Air Force Standard Designs for Aircraft Maintenance

Hangars o 5-12.3.4 Fuel Foam/Cell Repair Room o 5-12.5.3 Washing Facilities O 5-12.7.1Hazardous (Classified) Locations o 5-14 Facilities for Unfueled Aircraft to 5-15 Hangars for Fuel Servicing added.

o General Fire Protection

◊ Clarified requirements for fire protection releasing controls.

◊ Clarified requirements for fire protection optical detectors.

◊ Clarified requirements for auxiliary notification devices.

◊ Clarified requirements for HAS/PAS electrical classified locations.

◊ Deleted requirements of HAS/PAS AFFF systems.

◊ Added modernization requirements for existing high-expansion foam protected hangars.

◊ Added modernization requirements for existing unprotected hangars.

◊ Revised drain requirements to unify with NAVY and support F-35 cooling requirements.

◊ Added requirements for unfueled aircraft hangars at Air Logistics Centers and at government owned contractor operated plants.

◊ Added guidance for aircraft fuel servicing in hangars.

• Chapter 6 o 6-1 INTRODUCTION Clarified Army UAS hangar applicability.

o 6-1.1 US Army Aircraft Maintenance Strategy revised.

o 6-3.1.2 UAS Aircraft revised.

o Figure 6-1: Typical Maintenance Bay Configuration andFigure 6-2

Maintenance Bay Pavement Markings revised.

o 6-4.1.1\2\ UAS Hangars – Group 3 and Group 4 /2/clarified for

Group 3 and Group 4 o 6-5.1 Heating revised o 6-5.3 Plumbing revised o 6-6.2 Fire Pumps Revised o 6-11.1.2 Location and Spacing

• Chapter 7 o Table 7-1: \3\ Standard Hangar Bay Module Dimensions and

Crane Capacities* Type I F-35B (USMC) width revised for Iintermediate Maintenance Program (IMP) maintenance and renamed to Navy and USMC Type I vs. F-35B and F-35C.

o 7-2.4 \2\ Low Level System Containment to 7-11.1.6 \2\ Low Level Discharge Devices AFFF term removed generally o 7-7.3 Power Service Points bullet added for Triton hangar GSE o 7-3.2 Aircraft Maintenance Bay Striping Requirements and Figure

7-1 Notes revised allowing matching of center line from outside.

o 7-14.5 Functional Data Sheets “cfm” changed to “scfm” throughout.

• Appendix o APPENDIX B: GLOSSARY SCFM added o C-6.5 \2\ Trench Drain Location to C-6.6 Alternate Foam/Water

Discharge Notification AFFF term deleted.

/2/

\3\ Reasons for Document Change 3:

• Chapter 1 o 1-5 Commentary added to this document per UFC 1-300-01.

• Chapter 3 o 2-1.7 and 2-1.7.1 added for lighting impacts.

o 3-3.2.3 revised.

o Figure 3-4 revised.

o 3-5.1 and 3-5.2 revised.

o 3-5.8.2.6 and 3-5.8.2.7 revised.

o 3-6.3.2 revised.

o 3-6.17.2 revised.

o 3-6.19.2.4 Optical Flame Detection Inhibit Switch clarified.

o 3-6.19.4 revised.

o 3-7.6.1 Typo corrected.

o 3-6.10 bullet added.

o 3-6.17.3 revised.

o 3-7.1 revised.

o 3-7.5.2 revised.

o 3-7.14 added.

o 3-9.3 revised.

o 3-10.1.1 revised.

o 3-10.2 revised.

o Table 3-3 title and notes revised.

• Chapter 4 o Title Change and 4-1 Title revised.

o 4-2.2 Mechanical requirements modified.

• Chapter 5 o Table 5-1 title and table revised.

o 5-2.2 reviesed.

o 5-6.1 revised.

o 5-6.5 revised.

o 5-6.6 through 5-6.7.9 relocated to 5-15, 5-16, 5-17 and revised.

o 5-11.1 revised.

o 5-12.7.1 revised.

o 5-12.6.2 revised.

o 5-15, 5-16, 5-17 relocated and revised from 5-6.6 through 5-6.7.9.

• Chapter 6 o 6-1.3 Applicability added.

o 6-6.3.1 revised.

o 6-6.6 revised.

o 6-6.7 revised.

o Table 6-1 Title and notes revised.

• Chapter 7 o 7-3.1.3 corrected o 7-3.1.5 revised.

o 7-9 and 7-9.3 revised to clarify Navy crane hazardous environment.

o Table 7-1 revised. Table 7-2 Title and notes revised.

o 7-7.5 revised.

• Appendix o C-7.4 Hazardous (Classified) Locations added. /3/

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Change 3, April 20, 2021

TABLE OF CONTENTS

Change 3, April 20, 2021

FIGURES

Figure 2-1: Minimum Aircraft Maintenance Bay Clearances Figure 2-2: Alternate Corner Configuration Figure 2-3: Vertical Hangar Clearances Figure 2-4: Vertical Hangar Clearances with Sloped Roofs Figure 2-5: Space Requirements for Vertical Lift Fabric Doors Figure 2-6: Space Requirements for Sliding Steel Hangar Doors Figure 3-1: Internal Fire Rated Separations Figure 3-2: Air Force and Navy Hangar Bay Egress Figure 3-3: Army Hangar Bay Egress Figure 3-4: Typical Aircraft Maintenance Bay Slab on Ground Cross-Section Figure 3-5: Concrete Slab on Ground Construction Joint Figure 3-6: Concrete Slab on Ground Contraction Joint Figure 3-7: Concrete Slab on Ground Expansion Joint Figure 3-8: Joint Sealant Details for Concrete Slabs on Ground Figure 3-9: Inductor and Concentrate Tank Installation Figure 3-10: Start Foam System Signage Figure 3-11: Stop Low Level System Signage Figure 3-12: Stop Foam System Signage Figure 3-13: Stop Low Level System Signage Figure 3-14: Adjacent Space Electrical Hazardous Classifications Figure 5-1: Aircraft Maintenance Bay Striping Requirements Figure 5-2: ANSI Warning Sign Figure 6-1: Typical Maintenance Bay Configuration Figure 6-2: Maintenance Bay Pavement Markings Figure 6-3: Army Foam Pump Detail Figure 7-1: Aircraft Maintenance Bay Striping Requirements Figure 7-2: Drive-Through Hangar Figure 7-3: Pull-In Hangar Figure 7-4: OH/O1 Level Adjacency Diagram Figure 7-5: O2 Level Adjacency Diagram Figure 7-6: Type I & II OH/O1 Level Hangar Adjacency Diagram Figure 7-7: Type I (F-35) O2 Level Adjacency Diagram Figure 7-8: Type III OH/O1 Hangar Adjacency Diagram Figure 7-9: Section Showing Header Truss Figure 7-10: Section Showing Cantilever Truss Figure 7-11: Section through Type II Hangar Crane Configuration and Vertical

Clearances Figure C-1: Considerations for Aircraft Maintenance Bays for Large Aircraft ction through Type II Hangar Crane Configuration and Vertical Clearances .. 258 Figure C-1: Considerations for Aircraft Maintenance Bays for Large Aircraft Figure E-1 to E-17 Various Photos: ………………….………………………………287

Change 3, April 20, 2021

TABLES

Table 2-1: Minimum Aircraft Maintenance Bay Clearances Table 3-1: Aircraft Maintenance Bay Slab on Ground Joint Spacing Table 3-2: Concrete Slab on Ground Dowel Size and Spacing Table 3-3: \3\ Sample FACU Functional Matrix /3/ Table 3-4: Sliding Hangar Door Pockets Table 5-1: \3\ Sample Air Force RSFACU Functional Matrix Table 6-1: \3\ Sample Army RSFACU Functional Matrix Table 6-2: Aviation Platform Ground Service Baseline Requirements Table 7-1: \3\ Standard Hangar Bay Module Dimensions and Crane Capacities* .. 182 Table 7-2: \3\ Sample Navy RSFACU Functional Matrix Table 7-3: Hangar Space Table Table 7-4: Hangar Bay (OH) Table 7-5: Air Frames (Shop) Table 7-6: Aviation Ordnance (Shop) Table 7-7: Avionics Space (Shop) Table 7-8: Corrosion Control/Coating Shop Table 7-9: Detachment (Shop) Table 7-10: Flight Gear/Paraloft (Shop) Table 7-11: Flight Line (Shop) Table 7-12: Night Vision Goggles (NVG) Storage (Shop) Table 7-13: Phase Crew (Shop) Table 7-14: Power Plant (Shop) Table 7-15: Seat Shop (Shop) Table 7-16: Tool Room (Shop) Table 7-17: Division Office Table 7-18: Maintenance Control Table 7-19: Hangar Bay (OH) (F-35 Only) Table 7-20: Seat and Canopy Maintenance/AME Maintenance (Shop) (F-35 Only) . 219 Table 7-21: Airframe Hydraulic Clean Room (Shop) (MV-22 Only)

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INTRODUCTION

PURPOSE AND SCOPE

This UFC provides requirements for Aircraft Maintenance Hangars. This UFC is not intended as a substitution for thorough review during design by individual Program Managers and Operations Staff in the appropriate Service.

This UFC is organized with general requirements and Service-specific requirements.

Apply Chapters 1, 2, 3, 4 and Appendices to all Services. Additionally, apply Chapters 5, 6, and 7 to Air Force, Army, and Navy respectively for Service-specific requirements.

Applicability

The information in this UFC applies to the design of all new construction projects, to include additions, alterations, and renovation projects within the United States and its territories and possessions and outside of the United States and its territories and possessions.

References

APPENDIX A: REFERENCES contains a list of references used in this UFC.

USERS OF THIS UFC

This UFC is intended as a source of basic architectural and engineering information for all individuals involved in the planning, design and construction of Aircraft Maintenance Hangars.

Specific users of the UFC include the following:

Architects and Engineers

Architects and Engineers (A/E) who will provide design services under the direction of the individual Service design agencies.

Planning Personnel

Planning personnel will use this UFC for programming new or replacement facilities, pre-design planning, or assessing the extent of improvements required in an existing Aircraft Maintenance Hangar in order to achieve the standard established herein.

Additional Users

Additional users may include entities for operational or other purposes. The respective users should refer to this UFC from their own policy documents as appropriate and may include:

• Headquarters Staff and Field Operating Agencies, Change 3, April 20, 2021

• Major Command (MAJCOM) Staff/Regions,

• Base, Installation and Garrison Commanders,

• Installation Facilities Management,

• Installation Technical Proponents.

GENERAL BUILDING REQUIREMENTS

Comply with UFC 1-200-01. UFC 1-200-01 provides applicability of model building codes and government unique criteria for typical design disciplines and building systems, as well as for accessibility, antiterrorism, security, high performance and sustainability requirements, and safety. Use this UFC in addition to UFC 1-200-01 and government criteria referenced therein.

Facility Requirements Document (FRD)

The airframe manufacturer's FRD or equivalent document is an integral requirement of hangar design that contains additional airframe specific facilities requirements that must be considered and satisfied in addition to this UFC.

FRDs are typically authored by the airframe manufacturer and contain many specific details, are often quite voluminous and difficult to obtain. The FRD may have additional technical facility requirements, special spaces, special clearances, special maintenance procedures, systems, data or other items that may impact the hangar design. This UFC is not a substitute for the FRD of the design airframe(s) being hangared.

SCOPE OF FACILITY

This UFC specifies requirements for aircraft hangars that support all types of fixed wing, rotary wing, and hybrid aircraft of the Army, Air Force, Navy, Marine Corps, and Reserves. The UFC additionally applies to hangars for select Unmanned Aircraft Systems (UAS)/Remotely Piloted Aircraft (RPA).

\2\ This UFC applies to all aircraft hangars including maintenance hangars and also to other specialized hangar types. Additional study is required to identify unique requirements, functional areas or systems based on mission or aircraft. /2/ Some specialized hangars include but are not limited to depot, transient, special operations, research, fuel-cell maintenance, and prototype hangars. For aircraft corrosion control and paint facility hangar design requirements, refer to UFC 4-211-02 and this UFC where incorporated by specific reference. Maintenance hangars support ongoing day to day functions of the aviation squadron, wing or brigade and facilitate routine, preventative, basic aircraft upkeep to sustain aircraft operations. Maintenance activities are generally short-term and minor in nature compared to those that might be performed in more intensive intermediate maintenance level or depot-level hangars that facilitate extensive breakdown and rebuilding of components. Maintenance hangars are typically characterized by large obstruction-free hangar bays surrounded by various configurations of supporting trade shop and administrative spaces. Extra value has been placed on facility safety, continuity of mission operations, flexibility, maximizing

Change 3, April 20, 2021 hangar bay utilization, and minimizing life-cycle costs of materials and systems. For these reasons, the UFC limits options on certain requirements, ranging from structural systems and hangar doors, to proven systems for the expected large-scale aircraft and operations common in military maintenance hangars. Exemptions to certain requirements may be submitted for consideration where supported and warranted by the mission requirements. \2\ See Mil-STD 3007G. /2/

Service Specific Information

Refer to Chapters 5, 6, and 7 for Air Force, Army, and Navy, respectively, for Service-specific information.

\3\

COMMENTARY

Limited commentary has been added to the chapters. Section designations for such commentary are preceded by a “[C]” and the commentary narrative is highlighted with light gray. Below is an example:

[C] 1-2.3 EXAMPLE TEXT

This is an example of how commentary appears in this document.

/3/

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PLANNING AND LAYOUT

SITE ISSUES

Coordinate the design and construction of Aircraft Maintenance Hangars adjacent to an airfield with airfield operations, civil engineering master planning, existing Air Traffic control Tower site lines, and the Federal Aviation Administration (FAA) (when applicable) to confirm the new facility will not conflict with airspace, ground operations or required unobstructed clearances. Review safety and security prior to commencement of design or construction. Refer to UFC 3-260-01 for further requirements.

Airport Operations Area (AOA) Safety

The planning and design of an Aircraft Maintenance Hangar will emphasize AOA safety.

AOA safety includes unobstructed airspace and safe and efficient ground movements per UFC 3-260-01.

The Airport Operations Area is any area of an airport, installation, or station used or intended to be used for the landing, takeoff or surface maneuvering of aircraft. The AOA includes such paved areas or unpaved areas that are used or intended to be used for the unobstructed movement of aircraft in addition to its associated runway, taxiway or aprons.

Construction Phasing Plan

Prior to Construction, provide notification of construction by issuing notices as required by Federal Aviation Administration Advisory Circular (FAAAC) 150/5200-28, latest edition. Include a construction phasing plan in the contract documents. The purpose of a phasing plan is to establish guidelines and constraints for the contractor to follow during construction. Submit the construction phasing plan for coordination and review at the concept stage and all design stages. Coordinate the plan with airfield management, airfield operations, communications, ground and flight safety, environmental, emergency services, security forces, and logistics. Include the extent of fencing required to keep personnel out of the construction area and to keep Foreign Object Damage (FOD) off the airfield. Include crane restrictions, required FAA permits, flight line access requirements for personnel and equipment, hours of operations within the AOA, haul routes for materials (especially concrete trucks), stockpile locations, details for closing portions of the airfield, and airfield barricades. Refer to UFC 3-260-01 ABBREVIATIONS Section 14 for further guidance on phasing and operational safety plans.

Safety Clearances

Apply all horizontal and vertical operational safety clearances to Aircraft Maintenance Hangars that dictate the general arrangement and sizing of hangars and their relationship to airfield and airside facilities. There are, however, general considerations that apply in most cases, such as:

• Adherence to required unobstructed clear zones

Change 3, April 20, 2021

• Adherence to standards in support of safety in aircraft operations

• Non-interference with line of sight or other operational restrictions

• Use of existing facilities

• Flexibility in being able to accommodate changes in aircraft types or missions

• Efficiency in ground access

• Priority accorded aeronautical activities where available land is limited

• Security

• DoD and Military Service-level explosive safety quantity distances when applicable

Airport Operations Area Security

Regulatory requirements for security of assets can have a significant impact on the planning and layout associated with aircraft, as well as the aircraft themselves, requiring varying types and levels of protection. Operational security of the airfield is also a consideration. Collocate maintenance buildings to inhibit or prevent unauthorized access and enhance facility and airfield security.

Integration of Security Measures

Integrate protective features such as barriers, fences, lighting, access control, intrusion detection, and assessment into the site and facility planning and design process to minimize problems with aircraft operations and safety requirements. Include the protective measures in the design, based on risk and threat analyses, with an appropriate level of protection, and comply with security-related requirements.

Solar Glare Hazard Analysis

If any new photovoltaic and glass-enclosed solar-hot water systems are proposed, provide solar glare hazard analysis as required by FAA policy. Refer to Interim Policy, FAA Review of Solar Energy System Projects on Federally Obligated Airports. FAA policy on Glint/Glare Impacts on DoD Aviation Operations requires Glint/Glare analysis of photovoltaic and glass-enclosed solar-hot water systems that are on military airfields and within 2 miles of military airfield control towers, active runways thresholds, and helicopter landing zones. FAA policy requires the use of FAA's Solar Glare Hazard Analysis Tool (SGHAT) for Glint/Glare analysis found on website:

https://share.sandia.gov/phlux. This analysis is required for eliminating the potential for ocular impact to pilots and/or air traffic control facilities due to glare from solar photovoltaic (PV) and solar hot water (SHW) systems on airports.

To prevent mirror-like reflections from building surfaces to aircraft in flight, provide roofs and other external surfaces with a specular reflectance compatible with the location of the building on the airfield. If the building is located so that glare is an operational hazard, provide surfaces of the building with a light reflectance of not more than 10, https://share.sandia.gov/phlux

Change 3, April 20, 2021 measured at an angle of 85 degrees in accordance with American Society of Testing and Materials (ASTM) D523, Specular Gloss at critical surfaces of the building.

\2\ Solar PC or SHW systems should not block, reflect, or disrupt NAVAIDS, and other equipment required for safe aviation operations. Designer must coordinate with appropriate authorities to insure no impact to NAVAIDS system operations./2/

2-1.6.1 Airfield Manager Approval for Solar Energy System Projects

Provide the results of the SGHAT to the Airfield Manager for evaluation of any possible adverse effects to the airfield daily operations prior to approving new photovoltaic and glass-enclosed solar-hot water systems on the military airport.

\3\

Nightime Light Hazard Analysis

Nighttime light pollution impacts both airfield operations and flight operations when Night Vision Goggles are in use. Minimize operational hazards due to nighttime light pollution emanating from both interior and exterior of facility by minimizing and orienting glazed openings and exterior lighting fixtures. Provide cutoff shielding on exterior lighting fixtures. Consider impacts from any major interior light sources such as hangar bay lights with open hangar door or through translucent panels of fabric hangar doors.

During conceptual design, perform computer rendering lighting studies from point of view of Control Tower and Ground Control stations to ensure no hazards exist.

2-1.7.1 Airfield Manager Approval

During review of the concept phase submission, provide the results of the nighttime light hazard analysis to the Airfield Manager for evaluation of any possible adverse effects to airfield operations. Obtain approval of Airfield Manager prior to executing projects on the military airport or heliport. Resubmit and obtain approval of Airfield Manager of any proposed design modifications that deviate from previous approved solution.

/3/

FACILITY FUNCTIONS AND ADJACENCIES

Maintenance hangars are required to provide weather-protected shelter for the servicing and repair of aircraft at the organizational level.

Ground Level

The following spaces are typically provided on the ground level of a two story hangar.

Locate these rooms with consideration of the access requirements described in each Paragraph, regardless of the number of levels in the hangar.

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2-2.1.1 Aircraft Maintenance Bay

Aircraft Maintenance Bays are sized to accommodate aircraft as well as the maintenance activities around the aircraft. The Aircraft Maintenance Bays require direct access to a component of the flight line, preferably a peripheral taxi or tow-way.

2-2.1.2 Maintenance Administration

Maintenance administration spaces include maintenance control, quality control, rooms to access maintenance records and manuals on computers, as well as office space for manufacturers' representative personnel. Most of these spaces need direct or nearly direct access to the Aircraft Maintenance Bay.

2-2.1.3 Heavy Maintenance Shops

These industrial spaces house shops for maintaining large heavy parts and equipment such as engines, sheet metal and composites. All of these spaces require direct or nearly direct access to the Aircraft Maintenance Bay. Provide an overhead door or a pair of personnel doors to the Aircraft Maintenance Bay for movement of large equipment. \2\ If a battery maintenance shop is required, see UFC 3-520-05 for additional requirements. Lithium-Ion battery maintenance requires significant space and mechanical systems. /2/

2-2.1.4 Light Maintenance Shops

These spaces house shops for maintaining parts from the aircraft such as electronics, avionics, or weapons systems. Direct access to the Aircraft Maintenance Bay is preferred but not required because these parts are more portable than those in the heavy maintenance shops.

2-2.1.5 Storage

Ground level storage includes spaces for storing and issuing parts and tools for the maintenance of the aircraft. Direct access to both the Aircraft Maintenance Bay and to the exterior are preferred, but direct access to the exterior is more important to allow for deliveries.

2-2.1.6 Personnel Support

Break rooms, restrooms, showers and locker rooms should be located to support ground level personnel.

2-2.1.7 Building Support

Building support spaces includes areas used for maintaining the building and areas that house building utilities. Facility maintenance rooms have a low priority for adjacency, but they are typically located near the utility rooms. Utility spaces include mechanical rooms, compressor rooms, electrical rooms, communication rooms, fire protection rooms, and janitor closets. Provide major utility rooms with direct exterior access and locate them close to exterior equipment related to the space. Communication rooms

Change 3, April 20, 2021 typically require interior access. Provide separate general, secure and unit-managed communications rooms. Confirm access with the installation. Account for equipment and access space for maintaining equipment in Utility space sizing. Consider user access for user-owned and operated equipment such as a compressor that may be in a shared utility room. Mechanical rooms in hangars are typically larger than in other types of buildings because they often contain equipment supporting maintenance operations, such as air compressors. Fire Protection Rooms in hangars are typically larger than in other types of buildings due to foam systems required to protect Aircraft Maintenance Bays. Provide a janitor closet near the restrooms.

Upper Level

The following spaces are typically provided on the upper level of a two story hangar.

Locate these rooms with consideration of the access requirements described in each Paragraph, regardless of the number of levels in the hangar.

2-2.2.1 Operational Administration

Unit administration offices, conference rooms and training rooms may be remote from the Aircraft Maintenance Bay and are typically located on the upper level. Spaces in this category are often grouped based on the level of security required for the use.

2-2.2.2 Personnel Support

Break rooms, restrooms, locker rooms should be located to support upper level personnel.

2-2.2.3 Building Support

These spaces are often satellite rooms associated with ground level mechanical, electrical and communication rooms. Provide a janitor closet near the restrooms.

Secure Spaces

Many hangars require some level of physical security for the protection of assets such as classified materials, Sensitive Compartmented Information (SCI) or Special Access Program (SAP) information. The requirements for the protection of assets is defined in DoD and Service regulatory guidance or policy. The security requirements must be coordinated with the supported command and their security representatives to ensure the configuration will meet their operational (compartmented) and the regulatory and policy based security requirements. When a hangar has more than one secure space, serious consideration should be given to consolidate multiple secure spaces. Any consolidation will reduce the initial and sustainment cost for infrastructure, electronic security systems and the associated accrediting requirements. When required, integrate the physical security protective measures into the site, building, room(s), or area(s) as applicable.

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MINIMUM AIRCRAFT MAINTENANCE BAY CLEARANCES

Provide the minimum required clearances between the aircraft and adjacent horizontal obstructions, vertical obstructions, and other aircraft in designing the Aircraft Maintenance Bay as indicated in Table 2-1: Minimum Aircraft Maintenance Bay Clearances and Figure 2-1: Minimum Aircraft Maintenance Bay Clearances, Figure 2-2:

Alternate Corner Configuration, Figure 2-3: Vertical Hangar Clearances, Figure 2-4: Vertical Hangar Clearances with Sloped Roofs. These clearances are essential to ensure aircraft are protected from structural damage as they are moving in and out of the hangar and to allow personnel and equipment to safely and efficiently maneuver around the aircraft during aircraft maintenance activities.

Horizontal Obstructions

The nearest horizontal fixed obstructions include but are not limited to the inside face of the wall, faces and jambs of hangar doors, structural columns or bracing, bollards, liner panels, mechanical equipment or ductwork, plumbing equipment, valves and pipes, electrical equipment such as power transformers or other permanent physical items.

Fixed obstructions do not include furniture, tables, desks, benches, cabinets, tools, parts, carts or other movable objects. Clearances from rotary blade aircraft are from rotor blade arcs, except where specifically noted otherwise in Table 2-1: Minimum Aircraft Maintenance Bay Clearances.

Vertical Obstructions

The nearest fixed or mobile overhead obstructions include but are not limited to structure, draft curtains, mechanical, electrical, and plumbing equipment such as lighting, fans, heaters, ductwork, and fire protection systems, crane rails and crane bridges. Crane hoists and hooks are excluded if they can be maneuvered around tall parts of the aircraft and can be stored out of the way during aircraft movement.

Additional Clearances

Specific airframe or Service requirements may increase the minimum clearances required by Table 2-1: Minimum Aircraft Maintenance Bay Clearances to allow performance of certain maintenance operations. Coordinate with the maintenance unit staff to determine if additional space is required to maintain the aircraft. Provide additional clearances where required by an approved document such as the design aircraft's Facility Requirements Document (FRD) or a Service-specific standard design, defined Service hangar type, or other approved criteria. For example, the FRD may require additional space aft of the aircraft to remove the engine, or additional space above an aircraft to provide the crane hook height to perform maintenance operations such as pulling the rotor shaft out of a helicopter or maintaining the radar dome on an Airborne Warning and Control System (AWACS) aircraft. Jacking the design aircraft will reduce the overhead clearance below requirements in this UFC. Confirm jacking the design aircraft in the parking position does not require additional height to avoid conflict with an overhead obstruction. Minimum hook height is to the saddle of the hook.

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Maximize the unobstructed space in Aircraft Maintenance Bays where designs allow for exceeding the minimum clearances determined from this section. Exceeding minimum requirements for bay widths and depths, door heights, clear heights or crane hook heights may provide the flexibility to accommodate a future aircraft type or a revised aircraft parking layout without violating required clearances. For example, if for some good reason the structure of an Aircraft Maintenance Bay roof is higher than necessary to meet the minimum vertical clearance requirements, locate MEP systems and cranes as high as possible rather than dropping them to the minimum clear height allowed.

Alternate Corner Configuration

The concept indicated in Figure 2-2: Alternate Corner Configuration is acceptable for Aircraft Maintenance Hangars of any size where it may be desirable to re-distribute large corner areas. The clearances indicated by Table 2-1: Minimum Aircraft Maintenance Bay Clearances apply to all hangars, even if using the alternate corner configuration. Where used in hangars with multiple aircraft parking positions the alternate corner configuration is only acceptable at the end bays. Do not reduce the square footage of the Aircraft Maintenance Bay. Distribute the area gained by the corner configuration within the Aircraft Maintenance Bay.

This UFC allows encroaching on the space in front of the wings of aircraft with walls and other fixed obstructions. However, it is the designer's responsibility to confirm operational clearance requirements around the aircraft if introducing obstructions in front of the wings of aircraft. Consult the users for any specific airframe or Service requirements that limit the location of an alternative sidewall configuration. Provide additional clearances where required by an approved document such as the design aircraft's Facility Requirements Document (FRD) or a Service-specific standard design, defined Service hangar type, or other approved criteria. For example, the FRD may require additional space in front of the wing of the aircraft to remove a wing-mounted engine. Allow for alternate aircraft layouts that could be used in the future such as tail-in parking. If future flexibility is a guiding concern, do not locate core spaces such as elevators, utility rooms, restrooms or showers in the high bay space. Refer to Appendix C-3.2: Considerations for Large Aircraft Maintenance Bays.

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Table 2-1: Minimum Aircraft Maintenance Bay Clearances

Notes:

1. Refer to 2-3: Minimum Aircraft Maintenance Bay Clearances.

2. Refer to Figure 2-1: Minimum Aircraft Maintenance Bay Clearances.

3. Minimum clearances A and C are to a vertical plane at the face of the fixed obstruction that extends furthest toward the aircraft.

4. The minimum clearance from the aircraft to the hangar door is to a vertical plane at the interior face of the innermost panel of a sliding door, or to the interior face of a vertical lift door panel or mullion. Fixed columns along the hangar door separating bays are considered hangar door jambs for the purpose of determining clearances.

5. Minimum clearance between aircraft is from any part of the aircraft. Depending on the hangar configuration, the minimum clearance between aircraft is wingtip to wingtip, nose to nose, tail to tail, nose to tail, or rotor blade arc to rotor blade arc. Do not assume wingtips or rotor blades are folded. Do not determine minimum clearances between aircraft based on specific stationary rotor blade positions.

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6. Minimum horizontal clearances at hangar door jambs are from wingtip or rotor blade to the edge of the clear width of the hangar door opening as the aircraft passes through the door opening. Rotor blades are assumed to be fixed in the narrowest configuration possible when entering and leaving the hangar. Do not assume wingtips or rotor blades are folded. Fixed columns along the hangar door separating bays are considered hangar door jambs for the purpose of determining clearances.

7. Refer to Figure 2-3: Vertical Hangar Clearances and Figure 2-4: Vertical Hangar Clearances with Sloped Roofs.

8. Minimum vertical clearances are from the top of the aircraft to the bottom of the nearest fixed or mobile overhead obstruction.

9. Minimum Hook height is to the saddle of the hook.

10. Refer to 7-3.1: Types of Hangars.

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Figure 2-1: Minimum Aircraft Maintenance Bay Clearances

Note: Refer to Table 2-1: Minimum Aircraft Maintenance Bay Clearances for dimensions A, B, C, D and E.

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Figure 2-2: Alternate Corner Configuration

Note: Refer to 2-3.4: Alternate Corner Configuration and Table 2-1: Minimum Aircraft Maintenance Bay Clearances for dimension A.

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Figure 2-3: Vertical Hangar Clearances dimensions F, G, and H.

Figure 2-4: Vertical Hangar Clearances with Sloped Roofs dimensions F and G.

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NET TO GROSS AREA IN AIRCRAFT MAINTENANCE HANGARS

Planning personnel are encouraged to allow sufficient net-to-gross area for specific spaces in Aircraft Maintenance Hangars. Aircraft Maintenance Bays require additional square footage outside of the safety lane where structure and other utilities create obstructions which cannot be specifically accounted for in paragraph 2-3: Minimum Aircraft Maintenance Bay Clearances. Hangars require large mechanical rooms to accommodate equipment such as air compressors. Hangar fire protection rooms are larger than in typical buildings due to the foam suppression system required for the Aircraft Maintenance Bay. Select Hangar doors based on the pros and cons of the different types of doors and by the users/installation preferences.

The area required for different types of hangar doors varies, but is not intended to govern the decision of the type of hangar door to use. Calculate the area inside the exterior face of hangar doors in the closed position at 100% square footage. Calculate the area inside the exterior face of door pockets at 100% square footage. Enclose all door pockets. Do not include the area under the roof, outside of the hangar doors. Refer to Figure 2-5: Space Requirements for Vertical Lift Fabric Doors and Figure 2-6: Space Requirements for Sliding Steel Hangar Doors for clarification on calculating gross square footage of different hangar doors.

Figure 2-5: Space Requirements for Vertical Lift Fabric Doors

Count the area inside the exterior face of the door as 100% square feet

Do not count the area under roof and outside the exterior face of the door

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Figure 2-6: Space Requirements for Sliding Steel Hangar Doors

Count the area inside the exterior face of the door as 100% Square Footage (SF)

Do not count the area under roof and outside the exterior face of the door

Count the area inside the exterior face of a door pocket as

100% SF

ACCESSIBILITY

It is the goal of the DoD to make its facilities accessible to persons with disabilities. In accordance with UFC 1-200-01, follow the Architectural Barriers Act (ABA) Accessibility Standard for Department of Defense Facilities.

SUSTAINABLE DESIGN

Design Aircraft Maintenance Hangars per the requirements of UFC 1-200-02. Refer to Appendix C - Best Practices for discussion on sustainability strategies applicable to Aircraft Maintenance Hangars.

HAZARDOUS MATERIALS

Background Information

The DoD, including the Department of the Navy, operates facilities which routinely utilize, or have utilized in the past, hazardous materials and chemicals that contain lead, cadmium and chromium, and other heavy metals. Operations and activities which can create an unsafe condition with regards to worker protection, include (but are not limited to): manual demolition, scraping, grinding, heat-gun applications, power tooling with dust collection, application of corrosion control materials, spray paint with lead/chromium (VI)/Cadmium-based paints, burning, power tooling without dust

Change 3, April 20, 2021 collection, rivet busting, cleanup activities with dry abrasives, movement/removal of enclosures, abrasive blasting, welding, cutting and burning on steel structures. When these operations occur, there are hazards associated with the generation of dust, debris and fumes. The hazards and the controls required are dependent on the materials used.

Additionally, these operations, and utilization of these hazardous materials and chemicals, are found in aviation facilities.

Facility Design Requirements

Comply with the Occupational Safety and Health Act (OSHA), American Conference of Governmental Industrial Hygienist (ACGIH), and DoD regulations and guidelines for facilities that will operate, or will continue to operate, utilizing hazardous materials and/or chemicals. The requirements found in the OSHA regulations and the DoD Instructions and Directives may affect facility design requirements, which may include (but are not limited to): separate toilets and washing/bathing areas for workers who are exposed to the hazard, change rooms, decontamination areas, break rooms, clothes washing facilities, areas for controlled disposal of contaminated waste and work clothes, both local and general high-efficiency particulate air (HEPA) ventilation systems and filters, eyewash stations and deluge showers. Areas of facilities utilizing these hazardous materials and/or chemicals must be designated as regulated areas whenever exposure can be expected to be in excess of the permissible exposure limit(s), and must be demarcated from the rest of the workplace in a manner that adequately establishes and alerts building occupants of the boundaries of the regulated area. Design facilities in a manner to allow the OSHA required air sampling and monitoring that are required for the specific hazardous material in use. Design facilities to control these hazards below the standards set in the stated regulations. Refer to Appendix D, Questionnaire, for a list of questions the planner and designer should ask the operators regarding their aircraft maintenance operations and activities.

Additionally, the DoD Instruction 6055.01, Appendix 4 lists additional requirements for facilities…