Kobi Bryant Helicopter Crash N72EX

Maoraigh wrote:

My very limited experience of low cloud and "just better than minimum " visibility in flatlands leads me to the opposite opinion.
In valleys, you have an indication of cloudbase ahead which you don’t get in flatland. I have more experience in that environment.
See what at 5 km? A white cottage against brown moor, or a fogbank against grey cloud?

I’m talking about a suitably qualified pilot flying VFR, not a pilot without instrument experience using visual navigation.

Formula for 45deg bank is Radius(ft) = V(kts)*V(kts)/11, at 40kts that would be along 150ft radius turns, probably safer 120kts vs terrain/weather but makes VIP transport 2h instead of 40min…

The laws of physics apply to helicopters in the same way as to fixed wing aircraft. The formula relating speed, bank angle, turn radius and rate of turn is exactly the same. If I could remember it, I’d write it here, but Google will find it quickly enough.

Helicopters don’t stall at some minimum speed. They can be safely and comfortably flown at anything from 0 (hover) to Vne (if they have enough power). But there is a speed (which doesn’t have a name) where Effective Translational Lift (ETL) happens, somewhere around 25-30 KIAS. Above that you need significantly less power (around 25%). Also airflow over the minimal fixed control surfaces helps with stability. I’ve never flown an IFR-capable heli (most IR training is done in Robbies which have a full IFR instrument set but can’t legally be flown in IMC), though I do have several hours of heli hood time (needed for the CPL-H even without an IR-H).

It’s my understanding that IFR capable helis do have a “minimum recommended speed in IMC” which is somewhere around 40 KIAS.

A helicopter manouvers just fine at any permissible speed, from 0 upwards. Although sideways cyclic at very low speed results in going sideways rather than turning, until you get some significant airflow over the tail. But you can always use the pedals to turn, so it’s not important.

I understand in cuise, heli turn physics on bank angle/speed/g-load are basically the same as fixed wing? but I have no clue on their stall or min maneuver speeds? nor how good maneuvering at 110kts?

Peter wrote:

I think that very few people fly into terrain which they can see.

Fast touring SEPs (60kts stall) have pity maneuvering performance at best power cruise, they literally don’t fly very high for SVFR scud running (or even 500ft agl tight flying near terrain in sunny days)

Fast SEP “best maneuverability” sits around 80kts: 1000fpm climb (800ft/nm), 600ft radius turn (45deg at 1.4G), +/-10deg vs horizon and some available power, it still very tight for SVFR scud running near terrain (500ft ceiling, 1nm visibility, 500ft bellow terrain peak)

At 150kts cruise: 300ft/1nm climb, 6000ft rate1 turn radius, 2000ft 2G turn radius, +/-5 deg vs horizon with no available power, this surely get anyone killed in SVFR near terrain: just pure maths that has less to do with “being able to see”

Of course there is “extra maneuverability” from pulling stick to stall but you can’t do [instrument+mountain+aerobatic] all at once (assuming you already have an aircraft, maybe one with an afterburner?)

I had to turn back from terrain/weather as I was a bit optimistic to clear nasty clouds/peaks that were 20deg above horizon
My subconscious still blame it on engine problems and density altitude…

ASN report

airways wrote:

Back in the student pilot days, I was taught: when inadvertently entering IMC, make a 180 and go back to the VMC.

For an IR-rated going VFR in IMC (which is an emergency), I would expect climb above MSA and let ATC know before doing anything else?

Back in the student pilot days, I was taught: when inadvertently entering IMC, make a 180 and go back to the VMC.
By the looks of Flightradar24, that’s exactly what this guy did, and what led him to colliding with a hill.