Can helicopters land in a poor visibility scenario?

Question

The Instrument Landing System and some others systems can provide to incoming aircraft guidance to the runway in poor visibility scenarios.

With that in mind, I have these questions:

Can helicopters fly in IMC?
Is there any system that can help the pilot land, just like ILS?

Keep in mind that light helicopters (such as, say, a R44) are not going to be equipped for IFR ops -- IFR helicopters not only must have the full complement of instruments and avionics + redundant power systems, but a stability augmentation system and its attendant hydraulics as well. (This is even true for the Kaman synchropters with their relative natural stability. I'm not sure if a coaxial-rotor design would be stable enough to be certified for unaugmented IFR flight or not...) — UnrecognizedFallingObject, Aug 13 '15 at 22:52
I clicked on this question because of the title, which I understood slightly differently to the text and existing answers. I'm guessing that a helicopter can land safely in poor visibility (without instruments), but not necessarily in the exact spot where it should land, and provided there are no other aircraft about it collide with. That's true, isn't it? — Level River St, Aug 14 '15 at 12:35
@UnrecognizedFallingObject I once flew an R22 kitted out as an instrument trainer which for the reasons you state, was not itself authorised to fly IFR! — Simon, Aug 14 '15 at 13:16
@steveverrill Not quite, and it depends on how you understand poor visibility. A helicopter without instruments cannot fly IFR. It must therefore be flying VFR and one of the requirements of VFR flight is that you remain in sight of the surface at all times. If your definition of poor visibility is that you cannot see the landing area, then you cannot fly without instruments. Thus, unless acting illegally, it is not possible for a helicopter to land, excluding emergencies and pilot error, without knowing precisely where it is. We don't leave not bumping into things to chance. — Simon, Aug 14 '15 at 13:19
@GabrielBrito - that's a whole new question, and I believe it's been asked/answered. Do a search before asking, but if you don't find it, go ahead and ask. — FreeMan, Aug 14 '15 at 19:38
@GabrielBrito VFR/IFR are the rules under which you fly. VMC/IMC are the conditions in which you fly. You can fly IFR in VMC or IMC but VFR can only fly in VMC. Visual Flight Rules. Instrument Flight Rules. Visual Meteorological Conditions. Instrument Meteorological Conditions. VMC is flown primarily with reference to the ground. IMC is flown primarily with reference to the instruments — Simon, Aug 15 '15 at 10:10
The swiss air force conducted some tests regarding flying in no-visibility conditions (whiteout in snow and brownout in dust) together with the US air force. They tested a solution that projects a digital image of the surrounding environment in the pilot's helmet visor. Here is an interesting video about it: Whiteout Tests - Degraded Visual Environment trials switzerland — jklingler, Mar 19 '18 at 18:30

Simon · Accepted Answer · 2015-08-14T06:50:54.390

8

Can helicopters fly IFR? Yes

Do they use ILS? Yes. The only tricky part of it is the need to be slow at the end of the glide slope.

An IFR helicopter can use any of the navigation and landing aids available to any other aircraft.

This PPRuNe discussion is interesting.

edited Aug 14 '15 at 06:50

answered Aug 13 '15 at 20:40

Simon

31,213
4
141
163

What's the issue with being slow on the glide slope? – rbp Aug 16 '15 at 20:31
1

@rbp Because you need to flare at the bottom. If the approach is busy, you may well be required to maintain high speed until close to the end. You will need quite an aggressive flare to lose that speed and that may put you above minimums or higher than the glideslope. Needs careful energy management. You also need to transition from instruments to visual cues which may be marginal. – Simon Aug 17 '15 at 07:28
@rbp, BTW, perfectly doable, just not straightforward. – Simon Aug 17 '15 at 21:15

score 7 · Answer 2 · answered Aug 13 '15 at 20:40

Helicopters can fly IFR and they fly the same approaches airplanes do. At certain airports there will be ILS (or other approach) procedures specific to helicopters.

The difference between the above procedure and the normal ILS 4L is that the copter approach has lower minimums, allowing the helicopters to land in lower visibility than airplanes. At airports without specific approaches for helicopters, they would fly the same procedures airplanes do.

score 1 · Answer 3 · answered Aug 16 '15 at 20:40

Not only do copters fly instrument approaches, they are allowed by regulation to halve both the ceiling and visibility minima for a non-Copter approach (but no less than 1200 and 1/4, or as otherwise restricted).

Also, copters often convert an instrument approach at the Missed Approach Point into a Special VFR clearance, which allows them to fly with 0 visibility (see and avoid) and clear of clouds. For example, this approach into JFK terminated in the middle of NY Harbor at 500 feet, and shows course lines to the various Manhattan helipads :

copter approach

How, exactly, does "see and avoid" work in zero visibility? – Vikki Jul 08 '21 at 23:40 — Vikki, Jul 08 '21 at 23:40

score 1 · Answer 4 · edited Mar 19 '18 at 17:46

I am flying AS 365 N3 Helicopter which is a twin engine machine and is approved for IFR operations. The helicopter is fitted with ILS and can fly a normal ILS approach like fixed wing aircrafts of CAT B.
The ILS system fitted on this helicopter takes the helicopter upto 50' above Threshold Touch Down Point and then makes the helicopter fly parallel to runway at 50'.
The approach speed for CAT B aircrafts is 120 kts which can be reduced as the helicopter descends closer to the TTDP. A fwd speed landing of speeds 70 kts and below can safely be executed to avoid a flare in poor visibility conditions. However this is not a standard landing procedure.
In normal conditions, pilot must flare the helicopter to reduce speed and land with zero fwd speed.

In my opinion, a RVR of at least 100 meters is necessary to execute a safe approach with flare at the end for touch down.

Can helicopters land in a poor visibility scenario?

4 Answers4