Technical Specific · DA-42 NG (Austro Engine)

Chapter 7 — Operating Limitations & V-Speeds

DGCA CPL Technical Specific notes — Capt. Pankaj Pahil

This is the chapter the paper is built on. Nearly every type-specific question is, at heart, a limitation question — a speed, a mass, an RPM, a marking. Learn these tables until you can write them from memory. I've laid them out the way I'd want a cadet to rote-learn them.

7.1 The V-speeds

All speeds are indicated (KIAS).

Speed	Value	What it means
V_NE	188	Never exceed — in any operation.
V_NO	151	Max structural cruising — above it only in smooth air, with caution.
V_O (manoeuvring)	122 / 119 / 112	122 above 1800 kg; 119 from 1700–1800 kg; 112 up to 1700 kg. No full or abrupt control inputs above it.
V_FE	133 (APP) / 113 (LDG)	Max flaps-extended speed for each setting.
V_LE	188	Max speed with the gear extended.
V_LO extend	188	Max speed to extend the gear.
V_LO retract	152	Max speed to retract the gear.
V_MCA	76 (UP) / 73 (APP)	Minimum control speed airborne, one engine inoperative.
V_YSE (blue line)	85	Best rate of climb, one engine inoperative.

Why the blue-line / red-line gap matters V_YSE 85 sits above V_MCA 76 — a 9-knot cushion. On one engine you fly the blue line: it gives you both directional control and the best climb the aeroplane has. Let the speed sag towards the red line and you're trading away the control that keeps the aeroplane pointing straight. That gap is the single most important idea in multi-engine flying.

7.2 Airspeed indicator markings

Marking	Range / value	Meaning
White arc	62 – 113 KIAS	Full-flap operating range (V_S0 to V_FE LDG).
Green arc	69 – 151 KIAS	Normal operating range.
Yellow arc	151 – 188 KIAS	Caution — smooth air only.
Blue radial	85 KIAS	Best single-engine rate of climb (V_YSE).
Red radial	76 KIAS	Minimum control speed (V_MCA).
Red radial	188 KIAS	Never-exceed (V_NE).

7.3 Power-plant limits

Item	Limit
Engines	2 × Austro Engine E4-B
Max take-off RPM	2300 (propeller), 5 min max
Max continuous RPM	2100 (propeller)
Max overspeed	2500 RPM, 20 sec max
Max take-off power	100% (≈ 123.5 kW), 5 min max
Max continuous power	92% (≈ 114 kW)
Max fuel temperature	60 °C

7.4 Mass limits

Mass	Standard limit
Maximum take-off mass	1900 kg (4189 lb)
Maximum landing mass	1805 kg (3979 lb)
Maximum zero-fuel mass	1765 kg (3891 lb)

A word on the higher figures You will meet 1999 kg and 2001 kg quoted for this type. Those apply only to aircraft carrying a specific approved weight-increase modification. For the standard aeroplane — and in the exam unless told otherwise — work to 1900 kg.

7.5 Centre of gravity, load factors, altitude and crew

The datum plane is 2.196 m forward of the most forward point of the wing root rib. The permitted CG for flight lies between a forward limit that moves aft as mass increases (about 2.350 m at light weight to about 2.418 m at maximum take-off mass) and an aft limit of about 2.480 m. In practice you confirm this with the loading chart in the mass-and-balance chapter — but know that the envelope narrows at the front as you get heavier.

Structural load factors	Positive	Negative
Flaps up (at V_O / V_NE)	+3.8 g	−1.52 g
Flaps in APP or LDG	+2.0 g	0.0 g

Intentional negative-g manoeuvres are not permitted. The maximum operating altitude is 18,000 ft pressure altitude. Minimum crew is one; maximum occupancy is four.

The must-know shortlist V_NE 188 · V_NO 151 · V_YSE (blue) 85 · V_MCA (red) 76 · V_FE 133/113 · gear retract 152, extend 188 · take-off 2300 RPM (5 min) / continuous 2100 · MTOM 1900 kg · load +3.8/−1.52 clean · ceiling 18,000 ft · crew 1, occupants 4.