GPS / FMS failure

오늘은 항법 시스템이 빠진 상황입니다. FMS나 GPS가 죽으면 *raw data(지상 항법시설)*로 되돌아가고, ATC 레이더 벡터의 도움을 받죠. 명사에 설명을 붙여 말하는 일이 많아, 문법은 관계절(which / that)로 갑니다. 동사도 switch, verify, navigate, tune 같은 새 표현 위주예요.

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1. Scenario

I was the First Officer of HL123, a twin-engine aircraft, in the cruise.

During the cruise, our FMS failed and we lost our GPS position, which meant we lost our area navigation. We could no longer follow the magenta line on the navigation display.

Our priority was to keep navigating safely, so we switched to raw data, which comes from ground-based navaids like VOR and DME. We tuned the navaids, cross-checked our position, and flew conventional navigation.

We told ATC about the FMS failure and requested radar vectors, which reduced our workload and made sure we stayed on a safe track. We also requested an ILS approach instead of an RNAV approach, because RNAV needs the systems that had failed.

The flight continued safely, and we landed using the ILS with radar vectors from ATC.

2. 상황 한눈에 (At a glance)

English — In the cruise, the FMS failed and we lost the GPS position, which meant we lost our area navigation. The fix is to go back to raw data — the VOR/DME signals from ground stations — tune the navaids, and cross-check the position. We told ATC, asked for radar vectors, and requested an ILS approach instead of an RNAV one, because RNAV needs the failed systems. It is manageable and not an emergency.

한국어 — 순항 중 FMS가 고장나고 GPS 위치를 잃어 area navigation을 상실했습니다. 해법은 raw data로 복귀 — 지상국의 VOR/DME 신호로 navaid를 맞추고 위치를 교차 확인하는 것. ATC에 알리고 레이더 벡터를 요청했고, RNAV 대신 ILS 접근을 요청했습니다(RNAV는 고장난 시스템이 필요하므로). 관리 가능하며 비상은 아닙니다.

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3. Key Verbs — 동사 + 예문

fail

뜻: 고장 나다

• Our FMS failed during the cruise.
• When the FMS fails, we go back to raw data.

switch (to)

뜻: 전환하다, 바꾸다

• We switched to raw data navigation.
• We switched to the ground-based navaids.

tune

뜻: (주파수를) 맞추다

• We tuned the VOR and DME.
• We tuned the navaids for our route.

verify

뜻: 검증하다, 확인하다

• We verified our position with raw data.
• We verified the track against the chart.

cross-check

뜻: 교차 확인하다

• We cross-checked our position using two navaids.
• The crew cross-checked the navigation carefully.

navigate

뜻: 항법하다

• We continued to navigate using raw data.
• We navigated with help from ATC vectors.

rely (on)

뜻: 의존하다

• We relied on ground-based navaids.
• We relied on radar vectors from ATC.

request

뜻: 요청하다

• We requested radar vectors.
• We requested an ILS approach instead of an RNAV approach.

confirm

뜻: 확인하다

• We confirmed our position with ATC.
• We confirmed the navaids were correct.

continue

뜻: 계속하다

• The flight continued safely.
• We continued using conventional navigation.

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4. 핵심 표현·콜로케이션

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5. 상황 어휘 Vocabulary

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6. ⭐ 말하기 좋은 문장 구조 (Sentence Frames)

빈칸만 갈아끼우면 다른 항법·시스템 상황에도 그대로 씁니다.

• Our ____ failed, which meant we lost ____. → Our FMS failed, which meant we lost our area navigation.
• We switched to ____, which comes from ____. → We switched to raw data, which comes from ground-based navaids.
• We tuned ____ and cross-checked ____. → We tuned the navaids and cross-checked our position.
• We requested ____, which ____. → We requested radar vectors, which reduced our workload.
• We requested ____ instead of ____, because ____. → We requested an ILS approach instead of RNAV, because RNAV needs the failed systems.

오늘의 표현 포인트 — "…, which meant / which comes from / which reduced…" 명사 뒤에 설명을 자연스럽게 덧붙이는 관계절. 길게 끊지 않고 정보를 잇기에 좋습니다.

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7. ❌ 흔한 실수 → ✅ 더 나은 표현

한국인이 자주 쓰는 틀리거나 약한 표현을, 시험에서 통하는 표현으로 바꿔 익히세요.

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8. 오늘의 문법 포인트 — 관계절: which / that

명사 뒤에 설명을 붙일 때 which / that을 씁니다. 문장을 잘게 끊지 않고 정보를 잇기에 좋아요.

• The FMS, which gives us our navigation, failed.
• We switched to raw data, which comes from ground stations.
• We requested radar vectors, which reduced our workload.

핵심: 사물 설명은 보통 which(또는 that). "…, which + 동사" = "그것은 ~한다/했다"를 자연스럽게 덧붙입니다. 콤마가 있으면 부가 설명, 없으면 한정.

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9. Model Answer — Q1

"What happened to your aircraft? Explain the nature of the incident."

틀은 자유 — 무슨 일 → 어떻게 대처 → 결과 흐름이면 됩니다.

During the cruise, our FMS failed and we lost our GPS position, which meant we lost our area navigation. We could no longer follow the magenta line on the navigation display.

Our priority was to keep navigating safely, so we switched to raw data, which comes from ground-based navaids like VOR and DME. We tuned the navaids, cross-checked our position, and flew conventional navigation.

We told ATC about the FMS failure and requested radar vectors, which reduced our workload and kept us on a safe track. We also asked for an ILS approach instead of an RNAV approach, because RNAV needs the systems that had failed.

The flight continued safely, and we landed using the ILS with vectors from ATC. The key was going back to raw data straight away and using ATC's radar to back us up.

10. Model Answer — Q2

"How do you think ATC handled the situation? Could it have been handled differently?"

Q2 = ATC 평가로 의견 표현을 익히는 자리. 아래는 한 예시 — 외워서 그대로 쓰지 말고, 시작·마무리 표현은 자유롭게 바꿔 보세요.

I was impressed by how quickly ATC adapted. As soon as we reported the FMS failure and asked for radar vectors, they took over our navigation with headings, which made our job much simpler while we set up raw data.

If anything, confirming the nearest airport with an ILS a little earlier would have helped our planning. But on the whole, their vectors and clear headings were exactly what we needed, and the approach went smoothly.

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11. Follow-up Q&A

1. What is raw data navigation? → It is navigation using the direct signals from ground-based navaids, like VOR and DME, instead of the FMS computed position.
2. Why did you ask for radar vectors? → ATC can give us headings from their radar, which reduces our workload and keeps us on a safe track while we navigate with raw data.
3. Why an ILS approach instead of RNAV? → An RNAV approach needs the FMS and GPS that had failed, so we chose an ILS, which works with ground-based signals.
4. Was this an emergency? → No. With raw data and radar vectors it is manageable. It would be more serious only if it happened with bad weather or no ground navaids available.

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12. Shadowing Sentences

각 문장을 3~5번 소리 내어 따라 하세요.

1. During the cruise, our FMS failed and we lost the GPS position.
2. That meant we lost our area navigation.
3. We switched to raw data, which comes from ground-based navaids.
4. We tuned the navaids and cross-checked our position.
5. We flew conventional navigation.
6. We told ATC and requested radar vectors.
7. The vectors reduced our workload and kept us on a safe track.
8. We requested an ILS approach instead of an RNAV approach.
9. RNAV needs the systems that had failed.
10. We landed using the ILS with vectors from ATC.

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다 읽었으면, 위 문장 구조 몇 개를 골라 30초만 직접 말해보세요. 화면에서 녹음하고 ICAO 6영역 채점을 받아보고 싶다면 EPTA Coach에서 1회차를 무료로 열어둡니다.