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此份維護提示包含以下提示內容：
1、不同構型位置燈件號互換性；
2、位置燈罩出現裂紋後的航線放行標準及臨時處理措施；
3、常見故障處理提示。
一、關於帶小翼位置燈及位置燈罩件號及互換性的問題
根據SL描述，帶小翼的飛機位置燈可以安裝滷素燈，也可以安裝LED燈。並且不同構型的位置燈或者頻閃燈可混用。如同一架飛機，左側位置燈裝滷素燈，右側可以裝LED燈。下表列出小翼翼尖位置燈及頻閃燈相關件號，便於反查。
注意：（1）部分飛機改裝小翼後，原適用於無小翼的位置燈在IPC有效性沒有修改。（2）在更換不同構型燈組件燈罩或者燈泡時，必須與對應構型的燈組件相匹配。
二、關於位置燈罩出現裂紋後的航線放行標準及臨時處理措施
1. 關於翼尖燈罩，AMM57-21-22有檢查標準。經諮詢波音，燈罩裂紋可臨時處理放行。位置燈罩出現裂紋後在完成以下工作後，白天可以放行飛機飛行5個航段：
a) 用金屬膠帶做臨時修理：在裂紋方向用金屬膠帶以1英寸或更多的間隔重疊覆蓋；每次飛行前檢查確定裂紋沒有進一步擴展或有水氣進入燈罩內部。
b)拔出相關系統跳開關，按MEL33-11保留，每次飛行前檢查確認膠帶完好。
2. 不允許夜航；
3. 作為臨時修理措施，在5個飛行循環內儘快更換新的燈罩。
三、常見故障處理建議
1、位置燈單個燈泡不亮。一般是燈泡的問題，如果不確定是滷素燈還是LED燈，準備航材時建議準備滷素燈組件或者LED組件一套，組件已包含燈泡。如果準備燈泡，兩種構型的燈泡都準備，手冊要求兩個燈泡同時更換。另外滷素位置燈底座氧化腐蝕的現象比較常見，更換時注意檢查。我們多次遇到更換燈泡過幾天又不亮的情況，最後發現底座腐蝕，更換了燈組件。
2、如果位置燈燈罩有裂紋，可以單獨更換燈罩，但更換燈罩可能比更換整個燈組件還麻煩。建議有燈組件的話直接更換燈組件。
3、如果翼尖頻閃燈不亮，排故時注意嚴格按手冊先隔離轉換組件（Stepdown Converter），不可貿然將轉換組件串至別的飛機測試，以免故障件燒壞燈組件。已經遇到過好幾次燒壞燈組件的案例了。
參考資料：
1、737-SL-33-065
2、AP737-33-007
3、MT-2017- 02 737NG飛機位置燈的維護提示
4、SR4-3697189086
相關文章：帶小翼B737NG飛機位置燈罩腐蝕開裂可靠性分析及建議
附件：波音SR(GUN)
DESCRIPTION:
China Southern found the Left Position Light Lens was cracked on datum airplane, please refer to the ref /A/ attached pictures for the damage. In order to find out the dispatch relief for this circumstance among their 737NG fleet, China Southern Guangxi Maintenance team requests Boeing/APB to address their technical questions below:
1/ Whether the crack damage on lens of position light upon the winglet is dispatchable during day/night operations?
2/ If such damage is dispatchable, please advise the penalty or precaution during airplane night operations.
3/ If such damage is not dispatchable, whether China Southern can apply the speed tape on the crack damage area as temporary solution?
Note: The attachment contains the ref /A/ damage pictures, ref /B/ MEL/DDG for 737NG, ref /C/ CDL from APB, which intends for Boeing reference.
RESPONSE AND/OR REQUIRED ACTION :
Please advise the dispatch relief for the position light at the leading edge on the winglet.
Note: This questions above are associated with fleet wide technical questions in China Southern 737 fleet.
RESPONSE:
Boeing has reviewed your request and provides the following:
1/ The cracked lens of position light on the winglet is dispatchable for day operations (no night operations allowed) for 5 Flight cycles with the following provisions:
a) Apply speed tape for temporary repair. Cover the crack damage with speed tape to overlap the cracks 1 inch or more in each direction. Inspect the crack prior to each flight to verify the crack has not grown or allowed moisture ingress into the lens.
b) Remove power from the system by opening the system circuit breaker, apply MEL item 33-11 (no night dispatch allowed), and inspect the speed tape integrity prior to each flight.
2/ No night operations allowed.
3/ It is acceptable to cover the cracked area with speed tape as a temporary repair mentioned in 1/.
Install a new light lens as soon as available, no later than 5 flight cycles.