Traffic pattern different to flight manual

[Wyverex]

I wonder why the traffic pattern in this campaign is different from the one in the manual (200m vs. 600m, short vs. long approach). What are the advantages or disadvantages of either one or are there situations where I would prefer one pattern over the other?

[Ramsay]

There is an initial altitude you join a traffic pattern (perhaps +500ft) and the pattern altitude itself. Exact altitude/height depends on the terrain, etc. and local instructions.

 

Typical pattern altitudes for piston aircraft are:

 

... traffic pattern altitudes for propeller-driven aircraft generally extend from 600 feet to as high as 1,500 feet above the ground

 

so 200m (650 ft) AGL is within that margin, AFAIK 300m (1000 ft) AGL is recommended for piston aircraft, with a jets at perhaps 500-600m (1,500 ft) ("Cat. C" depends on approach speed).

 

If Kursant's training is based off a real syllabus - it's possible, the lower pattern altitude is to avoid conflicting with a 'jet' lane i.e. breaking a 300m ATC ceiling, etc. but there numerous factors IRL, OTOH they may have used a pattern for piston aircraft.

 

The L-39 pattern altitude in DCS's manual reflects the manufactures recommendation (500-600m, 1500-2000ft, depending on the manual, imperial/metric, etc.). RSBN/PRGM's electronic glide slope is programmed to level-off at 500m.

Edited February 2, 2019 by Ramsay

[Ramsay]

What are the advantages or disadvantages of either one or are there situations where I would prefer one pattern over the other?

The long (600m AGL) approach is typical of an instrument approach or where you need to fit in with other traffic.

 

The short (200m) approach is typical of a visual pattern, however it's very low to my taste and I'd only fly it to avoid low cloud cover, etc.

 

As we don't need to take other traffic into account - I fly a visual pattern, descending in the base turn to pass over the outer marker at 150-200m (500ft) @ 250 km/h (135 KIAS).

 

Approach and Landing

Initial: 250 KIAS / 1,500 ft AGL (450 km/h, 500m)

Break: Throttle 70%, Speedbrakes as Req'ed

Speed: Decrease to traffic pattern 190 KIAS (350 km/h)

 

Downwind:

Gear - DOWN below Max 180 KIAS (330 km/h)

Speedbrakes - Retract if extended

Flaps Dn (half) - TAKEOFF below 160 KIAS (300km/h)

Throttle 95-100% - As Req'ed to maintain 150 KIAS (280km/h)

 

Base/Final Turn:

Flaps Dn (full) - LANDING

Throttle - As Req'ed to maintain 135-140 KIAS (250-260km/h)

 

Final:

135 KIAS (250 km/h), 500ft (150m)

(+10 KIAS for half flap/crosswind, +15 KIAS with full drop tanks)

Landing Light as Req'ed

(Throttle 70% min recommeded for abort/go around, 9-12s idle response lag)

Reducing to:

Threshold speed 120 KIAS (220 km/h)

Touchdown speed 95-100 KIAS (185-200 km/h)

 

While training, you should follow Kursant's "local instructions".

Edited February 2, 2019 by Ramsay