{"id":15491,"date":"2026-05-09T15:26:42","date_gmt":"2026-05-09T09:56:42","guid":{"rendered":"https:\/\/ibexaviation.com\/pilot-training\/?p=15491"},"modified":"2026-07-25T13:35:03","modified_gmt":"2026-07-25T08:05:03","slug":"aerodrome-limitations","status":"publish","type":"post","link":"https:\/\/ibexaviation.com\/pilot-training\/aerodrome-limitations\/","title":{"rendered":"Aerodrome Limitations"},"content":{"rendered":"<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-1.jpg\" alt=\"\"\/><\/p>\n<h2>Aerodrome Limitations restricting Operational Capability<\/h2>\n<p>Aerodrome limits are the physical, operational and regulatory constraints that determine the types of aircraft and flight operations an aerodrome can safely accommodate. They are based on factors such as runway dimensions and strength, obstacle clearance, weather conditions and available facilities. These limits ensure safe aircraft operations during take-off, landing and ground movement.<\/p>\n<h2>Aerodrome Requirements for Take-off<\/h2>\n<h3>Take-off Segment<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-2.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Take-off is the distance from the Brake Release Point (BRP) to screen height.<\/li>\n<li>BRP is the point where the pilot releases the brakes to commence the take-off roll.<\/li>\n<li>Screen height is the safe height that must be achieved during the take-off phase.<\/li>\n<li>The aircraft must reach screen height before leaving the airport environment.<\/li>\n<li>Screen height is a predefined value for each aircraft category.<\/li>\n<li>Class A aircraft have a screen height of <strong>35 ft<\/strong>.<\/li>\n<li>Class B aircraft have a screen height of <strong>50 ft<\/strong>.<\/li>\n<\/ul>\n<h3>Take-off Run Available (TORA)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-3.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Take-off Run Available (TORA) is the available length of runway for the take-off roll.<\/li>\n<li>TORA begins where the aircraft can commence the take-off run.<\/li>\n<li>TORA ends at the nearest point unsuitable for continuing the take-off roll.<\/li>\n<li>The runway may become unsuitable due to insufficient load-bearing capability.<\/li>\n<li>For larger aircraft, TORA may be less than the total runway length.<\/li>\n<li>Large aircraft may line up ahead of the threshold, reducing available TORA.<\/li>\n<li>Reduced TORA values are published in aerodrome information and flight manuals.<\/li>\n<\/ul>\n<h3>Reduced Take-off Run Available<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-4.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>TORA may be reduced for several operational reasons.<\/li>\n<li>Line-up ahead of the threshold due to obstacles or nearby roads.<\/li>\n<li>Variations in runway surface strength.<\/li>\n<li>Temporary runway closures due to maintenance work.<\/li>\n<li>Temporary changes are published through NOTAMs.<\/li>\n<li>Permanent changes are reflected in aerodrome charts.<\/li>\n<\/ul>\n<h3>Stop-way<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-5.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>A stop-way is a defined rectangular area beyond the end of TORA.<\/li>\n<li>It is prepared for safely stopping an aircraft following a rejected take-off.<\/li>\n<li>Stop-way are intended only for abandoned take-off<\/li>\n<li>They do not normally have the structural strength for routine aircraft operations.<\/li>\n<li>A stop-way cannot be counted as take-off run or landing distance available.<\/li>\n<\/ul>\n<h3>Usable Stop-way<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-6.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Seasonal conditions may reduce the usable stop-way length.<\/li>\n<li>Heavy rainfall may make portions of the stop-way marshy or unsuitable.<\/li>\n<li>A stop-way with runway markings may be used for the initial take-off roll.<\/li>\n<li>Unusable stop-way are marked with yellow chevrons beyond the runway threshold markings.<\/li>\n<\/ul>\n<h3>Clearway<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-7.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>A clearway is a defined rectangular area beyond the end of TORA.<\/li>\n<li>It is kept free from tall or hazardous obstacles.<\/li>\n<li>High-rise structures are not permitted within the clearway.<\/li>\n<li>Clearways are provided to enhance safety during the initial climb.<\/li>\n<li>The initial phase of flight includes take-off and initial climb.<\/li>\n<li>Clearways cannot be used for landing or stopping the aircraft.<\/li>\n<li>A stop-way is normally located within the clearway area.<\/li>\n<\/ul>\n<h3>Maximum Clearway Length<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-8.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>The maximum clearway length is limited by the lesser of the following:<\/li>\n<li>Distance to the first upstanding or non-frangible obstacle.<\/li>\n<li>Distance to any frangible obstacle 0.9 m (3 ft) or more in height.<\/li>\n<li>Fifty percent (50%) of TORA.<\/li>\n<li>The maximum permitted clearway is 50% of the Take-off Run Available.<\/li>\n<li>Even if the area beyond is obstacle-free, it cannot be included in performance calculations beyond the permitted limit.<\/li>\n<\/ul>\n<h3>Accelerate-Stop Distance Available (ASDA)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-9.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Accelerate-Stop Distance Available (ASDA) is the emergency stopping distance available.<\/li>\n<li>It is used if a take-off is rejected.<\/li>\n<li>ASDA represents the total distance available to accelerate and then safely stop.<\/li>\n<li><strong>ASDA = TORA + Stop-way<\/strong><\/li>\n<\/ul>\n<h3>Take-off Distance Available (TODA)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-10.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Take-off Distance Available (TODA) is the distance available for the complete take-off segment.<\/li>\n<li>TODA begins where the aircraft starts its take-off roll.<\/li>\n<li>It ends where the aircraft is clear of obstacles.<\/li>\n<li>Obstacles are objects projecting above the ground in the take-off path.<\/li>\n<li>Obstacle clearance directly affects aircraft safety.<\/li>\n<li>TODA depends upon TORA and the available clearway.<\/li>\n<li>If no clearway exists, <strong>TODA = TORA<\/strong>.<\/li>\n<li>If a clearway exists, <strong>TODA = TORA + Clearway<\/strong>.<\/li>\n<\/ul>\n<h3>Balanced Field Length (BFL)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-11.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>An airfield has a balanced field length when take-off distance equals rejected take-off stopping distance.<\/li>\n<li>In practical terms, the clearway is matched by an equal stop-way.<\/li>\n<li>Balanced Field Length exists only when <strong>Stop-way = Clearway<\/strong>.<\/li>\n<li>Unbalanced airfields have different TODA and ASDA values.<\/li>\n<li>The available distance for take-off differs from the available distance for a rejected take-off.<\/li>\n<li>For a balanced field:\n<ul>\n<li><strong>ASDA = TODA<\/strong><\/li>\n<li><strong>TORA + Stop-way = TORA + Clearway<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>Aerodrome Limitations for Landing<\/h2>\n<h3>Landing Distance Available (LDA)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-12.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Landing Distance Available (LDA) is the runway length available for landing.<\/li>\n<li>LDA begins at the designated touchdown point.<\/li>\n<li>It ends where the pavement can no longer safely support the aircraft.<\/li>\n<li>LDA calculations assume normal operating conditions.<\/li>\n<\/ul>\n<h3>Airfield Strength<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-13.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Aircraft may operate only from airfields capable of supporting their weight.<\/li>\n<li>Suitability depends on two factors:<\/li>\n<li>Pavement strength, expressed as the Pavement Classification Number (PCN).<\/li>\n<li>Aircraft loading, expressed as the Aircraft Classification Number (ACN).<\/li>\n<\/ul>\n<h3>Pavement Classification (PCN)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-14.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>A pavement strength report is expressed in the format: <strong>70 \/ R \/ A \/ W \/ T<\/strong>.<\/li>\n<li>The first number is the Pavement Classification Number (PCN).<\/li>\n<li>Pavement type may be:\n<ul>\n<li>R \u2013 Rigid<\/li>\n<li>F \u2013 Flexible<\/li>\n<\/ul>\n<\/li>\n<li>Sub-grade strength:\n<ul>\n<li>A \u2013 High<\/li>\n<li>B \u2013 Medium<\/li>\n<li>C \u2013 Low<\/li>\n<li>D \u2013 Ultra Low<\/li>\n<\/ul>\n<\/li>\n<li>The fourth character indicates the maximum allowable tyre pressure.<\/li>\n<li>The final character indicates the pavement evaluation method:\n<ul>\n<li>T \u2013 Technical Evaluation<\/li>\n<li>U \u2013 User Evaluation<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Aircraft Classification (ACN)<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aircraft-performance\/p2-aerodrome-limitations-15.jpg\" alt=\"\"\/><\/p>\n<ul>\n<li>Each aircraft is assigned an Aircraft Classification Number (ACN).<\/li>\n<li>ACN represents the minimum pavement strength required for aircraft operations.<\/li>\n<li>The ACN value for each aircraft is published in the Aircraft Flight Manual.<\/li>\n<li>Example:\n<ul>\n<li>PCN = <strong>30 \/ F \/ C \/ X \/ T<\/strong><\/li>\n<li>ACN = <strong>42<\/strong><\/li>\n<\/ul>\n<\/li>\n<li>If <strong>ACN exceeds PCN<\/strong>, the aircraft cannot normally operate from that airfield.<\/li>\n<li>PCN includes a built-in safety margin.<\/li>\n<li>Therefore, a variation of approximately <strong>10%<\/strong> between ACN and PCN may be acceptable under certain circumstances.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Aerodrome Limitations restricting Operational Capability Aerodrome limits are the physical, operational and regulatory constraints that determine the types of aircraft and flight operations an aerodrome can safely accommodate. They are based on factors such as runway dimensions and strength, obstacle clearance, weather conditions and available facilities. These limits ensure safe aircraft operations during take-off, landing and ground movement. Aerodrome Requirements for Take-off Take-off Segment Take-off is the distance from the Brake Release Point (BRP) to screen height. BRP is the point where the pilot releases the brakes to commence the&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"disable_featured_image":false,"footnotes":""},"categories":[355],"tags":[],"class_list":["post-15491","post","type-post","status-publish","format-standard","hentry","category-aircraft-performance"],"_links":{"self":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/15491","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/comments?post=15491"}],"version-history":[{"count":1,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/15491\/revisions"}],"predecessor-version":[{"id":16574,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/15491\/revisions\/16574"}],"wp:attachment":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/media?parent=15491"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/categories?post=15491"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/tags?post=15491"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}