![\"\"](\"http:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2026\/06\/Question-about-engine-relight-in-flight_image_3.png\")
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\u6709\u4e09\u4e2a\u95ee\u9898\u3002<\/p>\n
\u95ee\u9898 1\uff1a\u5982\u679c\u53cc\u53d1\u5931\u6548\uff0c\u4ece\u9ad8\u9ad8\u5ea6\u4e0b\u964d\u5230 FL250 \u4e4b\u95f4\u5c31\u4e0d\u80fd\u5c1d\u8bd5\u91cd\u542f\u53d1\u52a8\u673a\uff0c\u53ea\u80fd\u98d8\u964d\u4e48\uff1f\u4e3a\u4ec0\u4e48\uff1f<\/p>\n
\u95ee\u9898 2\uff1a\u201cAPPROACHING OR BELOW\u201d\u4e2d\u7684 APPROACHING \u662f\u6307\u591a\u9ad8\uff1f<\/p>\n
\u95ee\u9898 3\uff1aFL250 \u4ee5\u4e0b\u90fd\u53ef\u4ee5\u7528 APU \u5f15\u6c14\u8f85\u52a9\u542f\u52a8\u4e86\uff0c\u4e3a\u4ec0\u4e48\u8fd8\u8981\u7528\u98ce\u8f6c\uff1f\u5982\u679c\u6709\u5fc5\u8981\u7528\uff0c\u90a3\u7528\u51e0\u6b21\u518d\u5207\u6362 APU \u8f85\u52a9\u542f\u52a8\uff1f<\/p>\n
\u7a7a\u5ba2\u89e3\u91ca\u8bf4\uff0c\u7a0b\u5e8f\u4e2d\u63d0\u5230\u7684\u6700\u5927\u4fdd\u8bc1\u9ad8\u5ea6\uff0c\u5bf9\u5e94\u7684\u662f\u5728\u8be5\u9ad8\u5ea6\u4ee5\u4e0b\uff0c\u91cd\u65b0\u70b9\u706b\u6210\u529f\u7387\u7ecf\u9a8c\u8bc1\u80fd\u591f\u6ee1\u8db3\u6cd5\u89c4\u8981\u6c42\u3002FL250 \u4ee5\u4e0a\uff0c\u968f\u7740\u6c14\u538b\u548c\u6e29\u5ea6\u4e0b\u964d\uff0c\u91cd\u65b0\u8d77\u52a8\u53d1\u52a8\u673a\u6240\u9700\u7684\u6761\u4ef6\u53d8\u5f97\u66f4\u52a0\u4e25\u82db\uff0c\u5e76\u4f1a\u5f71\u54cd\u91cd\u65b0\u70b9\u706b\u80fd\u529b\u3002<\/p>\n
\u5bf9\u4e8e\u5355\u53d1\u5931\u6548\u6765\u8bf4\uff0c\u5728 ENG RELIGHT IN FLT \u7a0b\u5e8f\u4e2d\uff0c\u5b9e\u9645\u4e0a\u5e76\u6ca1\u6709\u9650\u5236\u673a\u7ec4\u5728 FL250 \u4ee5\u4e0a\u5c1d\u8bd5\u53d1\u52a8\u673a\u91cd\u65b0\u70b9\u706b\uff0c\u524d\u63d0\u662f\u8be5\u64cd\u4f5c\u4e0d\u4f1a\u5e72\u6270\u673a\u7ec4\u5bf9\u6545\u969c\u6062\u590d\u7b56\u7565\u7684\u6267\u884c\u3002\u7136\u800c\uff0c\u5728 FL250 \u4ee5\u4e0a\u5c1d\u8bd5\u53d1\u52a8\u673a\u91cd\u65b0\u70b9\u706b\uff0c\u5e76\u4e0d\u4fdd\u8bc1\u53d1\u52a8\u673a\u4f1a\u91cd\u65b0\u8d77\u52a8\u3002\u56e0\u6b64\uff0c\u7a0b\u5e8f\u5efa\u8bae\u786e\u4fdd\u9075\u5b88\u6700\u5927\u9ad8\u5ea6\u9650\u5236\uff0c\u4ee5\u7ed9\u53d1\u52a8\u673a\u6700\u5927\u91cd\u65b0\u70b9\u706b\u673a\u4f1a\u3002<\/p>\n
\u800c\u5bf9\u4e8e\u53cc\u53d1\u5931\u6548\uff0cFADEC \u9996\u5148\u4f1a\u5c1d\u8bd5\u81ea\u52a8\u91cd\u65b0\u70b9\u706b\u53d1\u52a8\u673a\u3002\u5982\u679c\u81ea\u52a8\u91cd\u65b0\u70b9\u706b\u5931\u8d25\uff0cFADEC \u5c06\u7ee7\u7eed\u5c1d\u8bd5\u91cd\u65b0\u70b9\u706b\uff0c\u76f4\u5230\u8be5\u8fc7\u7a0b\u88ab\u4e2d\u65ad\u3002\u4e4b\u540e\uff0c\u5982\u679c FADEC \u6307\u793a\u81ea\u52a8\u91cd\u65b0\u70b9\u706b\u5e8f\u5217\u5931\u8d25\uff0c\u6216\u8005\u673a\u7ec4\u5c06\u4e3b\u7535\u95e8\u7f6e\u4e8e OFF \u4f4d\uff0cECAM \u4e0a\u5c06\u663e\u793a AS AUTO RELIGHT NOT SUCCESSFUL \u7a0b\u5e8f\u3002<\/p>\n
\u5bf9\u6b64\uff0c\u6211\u7684\u7406\u89e3\u662f\uff0cFL250 \u4ee5\u4e0a\u5982\u679c FADEC \u81ea\u52a8\u91cd\u542f\u90fd\u4e0d\u6210\u529f\uff0c\u4eba\u5de5\u518d\u53bb\u5c1d\u8bd5\u5927\u6982\u7387\u4e5f\u4e0d\u884c\u3002\u6240\u4ee5\u4e0d\u5982\u5148\u5e72\u70b9\u522b\u7684\uff0c\u6bd4\u5982\u627e\u5907\u964d\u573a\u3001\u8054\u7cfb ATC \u548c AOC\u3001\u4e0e\u5ba2\u8231\u505a\u597d\u6c9f\u901a\u7b49\u7b49\u3002\u53cd\u6b63\u8fd9\u4e9b\u4e8b\u513f\u603b\u5f97\u505a\uff0c\u4e0d\u5982\u5728\u53d1\u52a8\u673a\u542f\u52a8\u6982\u7387\u4f4e\u7684\u65f6\u5019\u505a\uff0c\u4f18\u5316\u5de5\u4f5c\u8d1f\u8377\u3002<\/p>\n
\u81f3\u4e8e\u201cAPPROACHING OR BELOW\u201d\u4e2d\u7684 APPROACHING \u662f\u6307\u591a\u9ad8\uff1f\u7a7a\u5ba2\u8ba4\u4e3a\u673a\u7ec4\u53ef\u4ee5\u8003\u8651\u5728 FL270 \u81f3 FL260 \u4e4b\u95f4\uff0c\u5c06\u53d1\u52a8\u673a\u4e3b\u7535\u95e8\u5faa\u73af\u81f3 OFF 30 \u79d2\uff0c\u4ee5\u4fbf\u5bf9\u53d1\u52a8\u673a\u71c3\u70e7\u5ba4\u8fdb\u884c\u901a\u98ce\u3002\u7136\u540e\uff0c\u5728 FL250\uff0c\u673a\u7ec4\u5c06\u4e24\u4e2a\u4e3b\u7535\u95e8\u7f6e\u4e8e ON\uff0c\u5e76\u5fc5\u987b\u76d1\u63a7 N3\u3001FF \u548c EGT \u53c2\u6570\uff0c\u4ee5\u68c0\u67e5\u91cd\u65b0\u70b9\u706b\u662f\u5426\u6210\u529f\u3002<\/p>\n
\u5173\u4e8e\u98ce\u8f6c\u542f\u52a8\u548c APU \u5f15\u6c14\u8f85\u52a9\u542f\u52a8\uff0c\u5e94\u4f18\u5148\u9009\u62e9\u98ce\u8f6c\u91cd\u65b0\u70b9\u706b\uff0c\u56e0\u4e3a\u53ef\u4ee5\u4e24\u53f0\u53d1\u52a8\u673a\u540c\u65f6\u8d77\u52a8\u3002Airbus \u5efa\u8bae\u5c1d\u8bd5\u4e0d\u6b62\u4e00\u6b21\u98ce\u8f6c\u8d77\u52a8\uff0c\u4f46\u662f\uff0c\u5230\u5e95\u5c1d\u8bd5\u51e0\u6b21\u7a7a\u5ba2\u4e00\u5982\u65e2\u5f80\u7684\u6ca1\u6709\u8bf4\u660e\uff0c\u53ea\u662f\u8bf4\u201c\u8fd9\u5e94\u57fa\u4e8e\u673a\u7ec4\u5224\u65ad\u4ee5\u53ca\u98de\u673a\u76f8\u5bf9\u4e8e\u5730\u5f62\u6216\u673a\u573a\u7684\u9ad8\u5ea6\u201d\u3002<\/p>\n
\n<\/strong><\/p>\nTR-81744468 \u539f\u6587<\/strong><\/p>\nQ1<\/strong><\/p>\nQ1<\/p>\n
In the procedure [ABN] ENG RELIGHT IN FLT, it states:<\/p>\n
MAX GUARANTEED ALTITUDE: 25000 FT<\/p><\/blockquote>\n
The procedure of ENG ALL ENGINES FAILURE also specifies:<\/p>\n
APPROACHING OR BELOW FL 250: WINDMILL START<\/p><\/blockquote>\n
Is this because the air density at high altitude is too low to achieve the required rotational speed for engine start?<\/p>\n
Q2<\/p>\n
In the event of ENG ALL ENGINES FAILURE, the engine will attempt an automatic restart.<\/p>\n
If the automatic restart fails due to insufficient air density at high altitude, what is the success probability?<\/p>\n
Is the restart attempted using the remaining high rotational speed during the short period after failure?<\/p>\n
And does this follow the same logic as the WINDMILLING QUICK RELIGHT FUNCTION described in DSC-70-10-80-20 D?<\/p>\n
Q3<\/p>\n
The ENG ALL ENGINES FAILURE procedure mentions:<\/p>\n
APPROACHING OR BELOW FL 250: WINDMILL START<\/p><\/blockquote>\n
What altitude range above FL 250 does the term APPROACHING cover?<\/p>\n
A1<\/strong><\/p>\nA1)<\/p>\n
Please be informed that the capability to relight the engine (as instructed in the ENG RELIGHT IN FLT procedure), was demonstrated during the A350\u2019s certification.<\/p>\n
The maximum guaranteed<\/span> altitude mentioned in the procedure corresponds to the altitude under which the rate of successful relight is acceptable in regards to the regulation requirements.<\/p>\nAbove this value (FL250), as the air pressure and temperature decrease, the effort required to restart the engine increases and affects the relight capability.<\/p>\n
In the ENG RELIGHT IN FLT procedure, there is actually no restriction to attempt<\/span> engine relight above FL250 (maximum guaranteed altitude) provided that it does not disturb<\/span> the flight crew from the failure recovery strategy. However, attempting an engine relight above FL250 does not guarantee<\/span> the engine will restart. It is then recommended by the procedure to ensure maximum altitude is respected in order to give the engine maximum chance<\/span> to relight.<\/p>\nA2)<\/p>\n
In case of ALL ENGINES FAILURE, first FADEC will try to autorelight the engine.<\/p>\n
If autorelight fails, the FADEC will continue to attempt<\/span> to relight the engine until interrupted<\/span>, then the procedure AS AUTO RELIGHT NOT SUCCESSFUL will be displayed on the ECAM if the FADEC indicates the autorelight sequence has failed or if the flight crew has set the master lever to OFF.<\/p>\nPlease be informed that the quick relight is effective if the rotary selector is on NORM position<\/span> and the master lever is cycled from On to Off to ON again.<\/p>\nIf the rotary selector is on IGN\/START position<\/span>, and the master lever is cycled from On to Off to ON again, an automatic start is commanded instead of a quick relight.<\/p>\nA3)<\/p>\n
In case of ALL ENGINES FAILURE, first FADEC will try to Autorelight the engine. If the Autorelight is not successful and if engine relight can be attempted, a windmilling start can be attempted (at adequate altitude for windmilling), refer to APPROACHING OR BELOW FL 250 : WINDMILL START in the FCOM.<\/p>\n
Therefore, we confirm that the flight crew can attempt a windmilling start at FL250 (certified altitude for windmilling start) or below FL 250. The term APPROACHING should be understood as \u201cat approaching FL 250\u201d.<\/span><\/p>\nQ2<\/strong><\/p>\nThank you for the explanation. However, the term APPROACHING OR BELOW FL 250 is still not specific enough. What I would like to know is the range or order of magnitude of \u201capproaching\u201d \u2014 does it refer to a few hundred feet, 1000 ft, 3000 ft, or 5000 ft, etc.? In other words, what is the highest altitude you would consider as APPROACHING FL 250?<\/p>\n
Additionally, you mentioned:<\/p>\n
In the ENG RELIGHT IN FLT procedure, there is actually no restriction to attempt engine relight above FL250 (maximum guaranteed altitude) provided that it does not disturb the flight crew from the failure recovery strategy.<\/p><\/blockquote>\n
Does this also apply to ALL ENGINES FAILURE? That is, after an automatic relight is unsuccessful (indicated as AS AUTO RELIGHT NOT SUCCESSFUL), the flight crew may still attempt engine relight even if not yet at FL 250, and this will not have any impact on the relight attempts after APPROACHING OR BELOW FL 250.<\/p>\n
A2<\/strong><\/p>\nA1) Refer to our answer in message \/003, a windmilling start can be attempted (at adequate altitude for windmilling), that being said, in case of ALL ENGINES FAILURE, the flight crew can attempt a windmilling start at FL250 (certified altitude for windmilling start) or below FL 250.<\/p>\n
However, in the ECAM line APPROACHING OR BELOW FL250: WINDMILL START, the flight crew can start with these first few actions before FL250:<\/p>\n
\n- ENG START SEL\u2026\u2026IGN START and<\/li>\n
- ALL ENG MASTERS OFF 30S then, the action to turn ON the ALL ENG MASTER needs to be below FL250<\/span> to ensure a successful start.<\/li>\n<\/ol>\n
As mentioned in the ALL ENGINE FAILURE procedure, the flight crew is required to adapt the speed to 250 kt which is the minimum speed for optimal relight on A350. Given a glide ratio of 2.5NM\/1000FT, the flight crew may consider cycling the engine master levers to OFF for 30 seconds between FL270 and FL260<\/span> to ventilate the combustion chamber of the engines.<\/p>\nDuring this 30-second period, expect an altitude loss of at least 2,000 ft<\/span>. Then, at FL250, the flight crew sets both master levers to ON, they must monitor the N3, the FF and the EGT parameters, to check if the relight is successful.<\/p>\nA2) No, as per A1, the flight crew can attempt a windmilling start at FL250 (certified altitude for windmilling start) or below FL 250 in case of ALL ENGINES FAILURE.<\/p>\n
Q3<\/strong><\/p>\nThank you for your explanation regarding \u201cAPPROACHING OR BELOW FL 250\u201d. However, this raises another question.<\/p>\n
According to the procedure, if an automatic restart is unsuccessful, a windmill start may be attempted when APPROACHING (between FL 270 and FL 260) OR BELOW FL 250, with repeated restart attempts until successful or until APU bleed is available.<\/p>\n
But APU bleed air becomes available below FL 250. Descending from FL 270 to FL 250 takes roughly only one minute, and all engine masters must be turned off for 30 seconds first.<\/p>\n
Does this mean that only one windmill start attempt at most can be made before switching to an APU\u2011assisted start? If so, is the value of this windmill start rather limited, making it better to perform an APU\u2011assisted start directly at FL 250?<\/p>\n
A3<\/strong><\/p>\nAs mentioned in the FCOM ENG ALL ENGINES FAILURE procedure, Airbus recommends performing windmill relight.<\/p>\n
Below FL 250, if the crew decides that engine relight can be attempted, priority should be given to windmill relight. This windmill start sequence allows trying both engine starts simultaneously<\/span>.<\/p>\nAirbus recommends attempting more than one<\/span> windmill start if APU bleed is still unavailable<\/span>. The crew should do this windmill start sequence regularly and as long as it is possible. This should be based on flight crew judgment and aircraft altitude above terrain\/airport.<\/p>\nIf windmill start is unsuccessful, the crew should decide to reduce speed down to green dot in order to save aircraft altitude.<\/p>\n
When flying at green dot, the crew still has the possibility to try to relight one engine at a time using APU bleed (Starter Assisted Relight).<\/p>\n
We recommend CSC refer to the FCTM All Engines Failure – ECAM procedure section for Airbus guidance on managing the all engines failure situation.<\/p>\n
Q4<\/strong><\/p>\nI agree that one advantage of windmill start is that both engines can be started simultaneously.<\/p>\n
If we attempt the first windmill start at FL270 and it is unsuccessful, and by the time we reach FL250 APU bleed becomes available, does Airbus recommend continuing with windmill start or switching to APU-assisted start?<\/p>\n
If windmill start is still recommended, how many attempts should be made before switching to APU-assisted start?<\/p>\n
A4<\/strong><\/p>\nWe remind CSC again that the flight crew can attempt a windmilling start at FL250 (certified altitude for windmilling start). We confirm that, at or below FL250, if the flight crew decides that engine relight can be attempted, it should give priority to windmill relight. This windmill start sequence allows both engines to start simultaneously. Airbus recommends<\/span> attempting more than one<\/span> windmill start.<\/p>\nThen, referring to the Engine Relight Envelope, the FADEC selects a start assisted<\/span> relight when N3 is below 6 % or the airspeed is below 250 kt.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"\u5728 [ABN] ENG RELIGHT IN FLT \u7a0b\u5e8f\u4e2d\u63d0\u5230\u6700\u5927\u6709\u4fdd\u8bc1\u7684\u9ad8\u5ea6\u662f 25000ft\uff1a \u540c\u65f6\u63d0\u4f9b … \u9605\u8bfb\u66f4\u591a<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[113],"tags":[],"ppma_author":[5],"class_list":["post-5462","post","type-post","status-publish","format-standard","hentry","category-fly"],"authors":[{"term_id":5,"user_id":2,"is_guest":0,"slug":"yaoguai","display_name":"\u5996\u602a","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/dfe71d09a1a83f49a02a4400c69ef2c361c2d967eae2ffeeb6318b73a0da763f?s=96&r=g","author_category":"","first_name":"","last_name":"","user_url":"http:\/\/laowudewo.com","job_title":"","description":""}],"_links":{"self":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/5462","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/comments?post=5462"}],"version-history":[{"count":5,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/5462\/revisions"}],"predecessor-version":[{"id":5470,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/5462\/revisions\/5470"}],"wp:attachment":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/media?parent=5462"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/categories?post=5462"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/tags?post=5462"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=5462"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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