AS350 B3e course · Cockpit and equipment
Lighting, heating and ventilation
Lights, NVG cockpits, cabin heat and air conditioning
The essentials
Outside, the Astar carries position lights, an anti-collision light and one or more landing lights — often a searchlight too on utility aircraft. Inside, cockpit lighting can be modified for night vision goggles.
Cabin heat and windscreen demisting usually come from hot air bled from the engine, and air taken from the engine costs power. An optional air conditioner costs weight and power too.
Doors-off flying is approved for some doors on many aircraft, under its own limits.
External lights
Position lights show other pilots which way you are pointing; the anti-collision light — beacon or strobes — makes you visible. Landing lights let you see the ground; some utility Astars add a steerable searchlight.
Know which switch controls what, which lights are on a common breaker, and what happens to them on battery power after a generator failure.
Lights in cloud, snow and rain
A landing light or strobe in falling snow, rain or mist reflects back at you, and the glare can take away the horizon you are flying by. Strobes flashing on low cloud can also be disorientating.
Have a plan to turn them off quickly. A searchlight that shows you the ground in clear air may show you only a white wall in precipitation.
Cockpit lighting and NVIS
Goggles amplify the near-infrared that ordinary cockpit lights emit, so an unmodified panel washes them out. An NVIS-compatible cockpit replaces or filters the lighting so it is visible to the naked eye but not to the goggles.
For the AS350 this is done by STC — several firms hold approvals for the B3. Each modification comes with its own supplement, and a single unmodified light, such as a portable device, can undo it.
Cabin heat from bleed air
Turbine helicopters normally heat the cabin with hot air bled from the engine's compressor, mixed with outside air through a pilot-controlled valve. Your RFM or its supplement shows how your Astar's system works.
That air has been compressed by the gas generator but never reaches the turbines, so it does no work in them. For the same power, the engine has to run hotter. When you are near a turbine temperature or Ng limit — hot, high, heavy — the heater reduces the power available. Where the RFM gives a correction for heating on, use it.
Demisting
A cold windscreen and a cabin full of people fog up fast — in the hover, in rain, with the doors closed and the heater off. The demister blows heated air over the inside of the windscreen.
Fogging at the wrong moment takes away your outside reference as surely as cloud. Set the demister before a landing in cold or wet conditions, not when it's already needed, and know that heat delivered at low power is cooler and slower to work.
Air conditioning
Air conditioning is an option fitted under STC — vapour-cycle kits from several suppliers are approved for the AS350. It comfortably cools a cabin under a big canopy in the sun.
It costs weight, permanently, and power while it runs. A 2010 HeliHub report, quoting one supplier's engineer, warned operators to be sceptical of very low weight claims: use the weight in your aircraft's weight and balance record, not a brochure figure, and read the supplement for when it may run.
Doors-off flying
Photography, hoist, utility and some tour work fly with doors removed. The RFM or a supplement sets which doors may come off and the limits that follow, which usually include a lower airspeed limit.
Everything loose becomes a projectile that can leave through the door and into the tail rotor: headsets, papers, seat cushions, a camera strap. Secure the cabin as if it will be turned upside down.
Harnesses with the doors off
Doors-off passengers wear a harness and tether so they can move without falling out. The tether has a free end, and everything in the cabin is within its reach — including controls.
Check where every tether can swing, and that each passenger can release it themselves in seconds. A tether that holds someone in a helicopter that is upright can trap them in one that is not.
Source 12
East River, New York, 2018
An AS350 B2 on a doors-off photo flight lost engine power in cruise over New York. The NTSB found the fuel shutoff lever had been moved to off by the tail of the front passenger's tether, caught on it as he moved in his seat. The pilot restored the lever but was too low to relight in time and ditched in the East River.
The floats did not fully inflate; the helicopter rolled over and was submerged within seconds. The pilot escaped. The five passengers, held by harnesses they could not quickly release, drowned.
In a doors-off cabin, every loose end can reach something that matters. Brief the release before the flight, and check what each tether can touch.
Source 12
Why does cabin heating cost engine power?
Air leaves the compressor before the turbines. For the same power, the engine runs hotter — so near a limit, power available falls.
What is the first thing to secure before flying doors-off?
Loose items can leave the cabin into the tail rotor, and a tether can reach controls.
Your strobes are on and you enter falling snow at night. What may happen?
Light reflects off precipitation. Have a plan to switch it off quickly.
Where should the weight of an air-conditioning kit come from for your loading?
The installed weight as recorded for your aircraft, not a marketing figure.
Sources
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 12, Night Operations
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 4, Helicopter Components, Sections, and Systems
- Strong demand for Air Comm AS350 air conditioners; experts caution operators about weight claims · HeliHub · 16 February 2010
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 11, Helicopter Emergencies and Hazards
- NVG specialists reach STC milestone · AIN · 15 September 2006
- REBTECH provides NVG capability to HeliStream (AS350 B3) · HeliHub · 20 February 2013
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 7, Helicopter Performance
- Arriel 2D — Airbus H125 engine · Safran Helicopter Engines
- Aviation Investigation Report A98W0181 (AS350 B C-FSLF, Slave Lake, Alberta) · Transportation Safety Board of Canada
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 6, Weight and Balance
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 5, Rotorcraft Flight Manual
- Aircraft Accident Report AAR-19/04, Airbus AS350 B2 N350LH, East River, New York · NTSB · 11 March 2018
Educational only. Not approved training material, and never a substitute for the Rotorcraft Flight Manual, an instructor, or your operator's procedures. Figures marked as manufacturer data or test results are not limitations. This content is a draft and has not yet been reviewed by an instructor.