12 questions on this topic, recalled by candidates after DGCA sittings between 2021 and 2026. Together they were asked 23 times; the most repeated come first. Pick a year to see only what was asked that year.
C. Streaks of cirrus
Long bands of cirrus lying along the flow, often sharp-edged on the cold (poleward) side, mark a jet stream - and the zone where clear-air turbulence may be found.
C. Westerly winds
In winter the subtropical westerly jet sits over north India at about 12 km, around 27 N, with westerlies of 80-100 kt or more.
B. Westerly winds
In winter the westerlies above about 10 000 ft spread south to the tip of the peninsula and strengthen with height, so at 12 km the wind is westerly even over south India.
B. Westerly winds
Until the monsoon sets in, the subtropical westerly jet still lies over north India, so the upper winds are strong westerlies - a tailwind towards Kolkata.
C. South-westerly winds
At low and medium levels the monsoon current over the west coast blows from the south-west off the Arabian Sea.
B. Easterly
The tropical easterly jet blows from the east at about 14-16 km over south India and Africa in the summer monsoon. The subtropical jet is westerly.
A. 60 kt
By WMO convention, a wind qualifies as a jet stream only when its core speed reaches at least 60 kt.
A. Fringes
Clear air turbulence near a jet stream is worst on its fringes - especially the cold (polar) side and near upper frontal zones - where the wind shear is strongest. The core itself is often smooth.
A. 15-16 km
The tropical easterly jet sits over India in the summer monsoon at about 15-16 km, close to the high tropical tropopause - well above the westerly jets of winter.
C. Not uniform
A jet stream is not a uniform tube of wind. The speed varies along its axis, with stronger segments (jet streaks) separated by weaker stretches.
B. A monsoon feature with its axis near 13 °N
The tropical easterly jet appears with the summer monsoon and is weak or absent in winter. Its axis runs near 13 °N - about the latitude of Chennai - at roughly 15 km, averaging 60-80 kt. It is found only over Asia and Africa, and the subtropical westerly jet takes over from it in winter.
B. Easterly
The name carries the answer: the tropical easterly jet blows from the east. It is a monsoon feature with its axis near 13 °N at about 15 km over India, and in winter it is replaced by the subtropical WESTERLY jet.
These are candidates' recollections, not official DGCA papers: wording can differ from the paper as set. Every answer was checked against the DGCA CARs, AIP India, ICAO documents or worked calculation (independent check completed 17 Oct 2026). Spotted a mistake? Tell us and we will check it against the source.