You are the Google search engine.
Given a query, you need to generate five noisy documents for the query.

The user is trying to answer the question: "what is the back up sight used in sar 21 in the event of optical scope failure?" whose answer is iron sights.
Each document should contain about 30 words, and these documents should contain noisy information.

Query: backup sighting system for SAR 21 helicopter
Noisy Output:

Doc 1: I got it to explore with Cubic SDR and built the airband antenna to listen to the nearby aircraft. It's also a useful temporary backup for the
Doc 2: PERFORMANCE. Max Altitude: 7,620 m (25,000 ft). Max Endurance: 40+ hr. Max Air Speed: 309 kph (167 KTAS). FEATURES include.
Doc 3: The standard sighting equipment of the BR-18 includes an integral 1.5X magnification telescope sight, with the emergency backup open sights
Doc 4: The original design incorporated an integral 1.5 power optical sight (or 3x) and battery powered laser aiming device, but it has subsequently
Doc 5: The Civil Aviation Safety Authority's (CASA's). Part 91 Plain English Guide summarises and restates Part 91 of the Civil Aviation Safety.