Border face-off: China and India each deploy 3,000 troops

[Albany Rifles]

Shorter version

The plane capsizes because it got caught in the Black Hawks Wash. This has to be seen to be believed.

The part most people will not understand is that wash or wake by the rotor takes a good two minutes to clear. Had the plane arrived two minutes later it would have been fine.

Imagine being in a powerful helicopter at low altitude with limited visibility and being caught in your own down draft

Pilot increases thrust for more lift but there is no lift.

The increased turbulence causes a loss of lift which means your heli goes down in an uncontrolled manner.

The same happens in the wake or near any rotary wing aircraft or large jet aircraft. Being caught in jet/rotor wash is a real threat. It can cause loss of control or an engine to be cutout because it is cut off from air. Seeing that this is a small private aircraft with a fairly low power engine not surprised at all by the outcome.

[Double Edge]

Your average civilian pilot should never fly in bad weather but I would expect a trained military pilot to do better, much better.

A sane recommendation to make is if visibility is poor and the terrain is hilly then the best option is not to fly.

Good luck getting a military pilot to agree with that. They will no doubt say they are confident of their skills.

I've heard stories of pilots pushing their craft to the limits of their flight ceilings in the mountains in poor weather to rescue soldiers with altitude sickness or to deliver much needed supplies. That is how committed they are where they will ignore their instinct of self preservation in the service of others. They call these people good soldiers. Highly decorated.

With a daredevil background like that in the AF. These guys are just not going to listen.

The passenger(s) should just say no in that case.

[Double Edge]

Shorter version

The plane capsizes because it got caught in the Black Hawks Wash. This has to be seen to be believed.

The part most people will not understand is that wash or wake by the rotor takes a good two minutes to clear. Had the plane arrived two minutes later it would have been fine.

Imagine being in a powerful helicopter at low altitude with limited visibility and being caught in your own down draft

Pilot increases thrust for more lift but there is no lift.

The increased turbulence causes a loss of lift which means your heli goes down in an uncontrolled manner.

[Double Edge]

Pursuing this loss of control idea is finding some interesting results. Turns out there's numerous instances where this can arise leading to loss of control.

Rotor Wash and Wake Turbulence

In the first a blackhawk takes off and twenty seven seconds later a light plane coming into land flips over because of the rotor wash. Wow! Same deal with Wake turbulence.

A helicopter flying at low altitude, close to hills unseen due to fog, something as massive as a Mi-17 or the Taiwanese Black Hawk is going to create a great deal of turbulence that will affect its stability.

Now let's throw in a weather variable

https://flightsafety.org/asw-article/weather-impacts/

Another problem — one unique to flying helicopters — is loss of tail rotor effectiveness (LTE). The purpose of a tail rotor in a helicopter with one main rotor is to neutralize the torque created by the main rotor. If the tail rotor’s performance is impeded, it can lead to an uncontrollable spin (rotation of the fuselage). The magnitude of the LTE and difficulty of landing can be significantly affected by the speed and direction of the wind.

Wind direction also is important. For example, winds from approximately 60 degrees left of the nose (10 o’clock) can blow the main rotor vortex (swirling air generated by the helicopter downwash) into the tail rotor, greatly increasing the turbulence of the airflow. Any significant tail wind can decrease tail rotor effectiveness. This decrease may be due to a loss of translational lift, requiring more main rotor thrust and generating more torque than the tail rotor can counteract. The aircraft may also begin to weathervane with its nose into the relative wind. This can also cause an accelerating spin.

A typical LTE accident occurred on May 29, 2013, north of Fort McMurray, Alberta, Canada. The pilot of a Bell 206B was conducting wildlife survey work with two biologists aboard the helicopter. While slowing for an attempted landing, the helicopter began to spin to the right. The pilot lost control of the aircraft, and it crashed into the woods, killing the pilot and one passenger and seriously injuring the other passenger.

The Transportation Safety Board of Canada concluded, “The helicopter was operating in a flight regime where it was exposed to the left crosswind and tail wind, which would have placed the relative wind into the critical azimuth zone. The helicopter experienced LTE, causing a loss of directional control at a height above the trees that precluded an effective recovery

Wind interferes with the rotor down wash to further complicate turbulence (!)

Bingo!

Now I believe both Generals were victims of Rotor Downwash/LTE accidents.

There may be very little time to take counter measures once you realise you're in the danger zone or you realise it too late

The report said

The helicopter’s flight recorder was sent to the U.S. on Jan. 8 for investigation into the Jan. 2 incident. The Taiwan Transportation Safety Board (TTSB) had ruled out mechanical malfunction as the cause based on a preliminary reading of the data retrieved from the black box.

According to the report, rapidly changing weather conditions along with inadequate “situation awareness” contributed to the fatal crash. Defective cockpit resource management (CRM) could also have been involved, which is when the pilot and co-pilot fail to follow due procedures that compromise their response in an emergency, wrote UDN.

The chopper crashed into a hilltop under cloudy conditions in the mountains of northern Taiwan.

They got caught in either LTE or washout and could not respond in time. This is termed as 'inadequate situation awareness'. Harsh but true.

This is never going to appear in a news report because its too technical but now i have a better idea

Cheers AR

[Albany Rifles]

This must be a US only rule then. Taiwanese had a black box in the Black Hawk they lost. So did we in the Mi-17

There will be a military court of enquiry. This court is not obliged to release anything to the public.

But i'd imagine public pressure will demand they say something.

Hence why I said what I did about US aircraft and operations. It is also why helicopters use visual flight rules. If it is in inclement weather they respond to ATC guidance but not when they can see.

[Albany Rifles]

You were on to something when you said loss of control due to wind. This comes closest to explaining what might have happened.

But people will challenge it. They will ask how can a gust of wind disable a military grade helicopter.

One that is designed to hover, hug ridge lines, tree lines and do pop ups.

The controls on this aircraft dwarfs anything you can find in the civilian world.

And this is exactly what the issue was in the OH-58A...it was selected for production at a time when using like we did that day was not US doctrine. We were adapting a 1960s/early70s design to new 1980s doctrine. Hugging ridge lines, tree lines and do pop ups was not what the US Army was doing with light helicopters in Vietnam. The failure of control because of tailwinds was discovered in new doctrinal use...which is exactly why they came out with the OH-59C with a more powerful engine and improved tail rotor drive train. It was discovered during development of the Joint Air Attack Team work at Fort Hunter Liggett after the war.

[Double Edge]

Negative, they don't. Black boxes are a requirement for aircraft under FAA control. US Military helicopters fall under military ATC and operate under visual flight rules. No black boxes needed. Plus it removes one more avenue where an enemy could detect an aircraft.

This must be a US only rule then. Taiwanese had a black box in the Black Hawk they lost. So did we in the Mi-17

There will be a military court of enquiry. This court is not obliged to release anything to the public.

But i'd imagine public pressure will demand they say something.

[Double Edge]

Most of this is totally incorrect in my case.

You were on to something when you said loss of control due to wind. This comes closest to explaining what might have happened.

But people will challenge it. They will ask how can a gust of wind disable a military grade helicopter.

One that is designed to hover, hug ridge lines, tree lines and do pop ups.

The controls on this aircraft dwarfs anything you can find in the civilian world.

[Double Edge]

How do you train for bad weather? Let me rephrase that in a context you would understand. How do you lean to drive in a white out snow blizzard?

Since you mentioned it the Mi-17 is able to handle -30 -40 degrees C blizzards in Siberia. So going down in the picturesque if at the time foggy Nilgiris hills is unacceptable.

It has collision avoidance equipment.

That's the trouble with this topic, can't fault the aircraft, can't fault the pilots

White snow out blizzard. My one experience was getting to an office retreat in the French Alps. We just stopped the car and waited for the snow to recede. Hazard lights on. Too dangerous otherwise going up a mountain.

[Officer of Engineers]

The point is you cannot train for bad weather without bad weather present. And NOAA pilots do not train for hurricane. Newbies co-pilot with experienced pilots. In these cases of these helos, there is zero ways to train for sudden down drafts in a simulator, resulting in zero gs and your first instictive reaction is to control your bladder. You don't exactly have 1000s of feet of free fall to gain control of your helo. What's more, these bad weather scenarios don't happen that high. It's a lot closer to the ground where updraft and downdrafts caused by the terrain.

In short, I doubt very much any military pilot would have hands on training in controlling downdrafts and updrafts. To have such training, you need predictable updrafts and downdrafts with enough safety margin that allows pilots to make mistakes and recover. I cannot think of one single environment that would be such a case. The best you can do is book education and computer simulation but that does not replicate the full scale positive and negative g's that is inherant in these accidents.

[tbm3fan]

How do you train for bad weather? Let me rephrase that in a context you would understand. How do you lean to drive in a white out snow blizzard?

Well commercial airlines train their pilots to avoid bad weather if possible. OTOH civilian pilots when presented with bad weather along their course they can't avoid would probably be better off staying overnight in a hotel. However, NOAA does train their hurricane hunters to fly into bad weather that everyone else would automatically steer clear of.

As to me learning how to drive in a white out. I would need to know my car, my planned route, expected hazards on the road, my survival equipment, up to date weather forecast to start with after a few laps around a track to test my skills in driving straight. However, my natural tendency as a driver would make me avoid the inclement weather and instead sit by your warm fire place drinking a shot...

[Officer of Engineers]

Your average civilian pilot should never fly in bad weather but I would expect a trained military pilot to do better, much better.

Exactly. You have two instances, two years apart and both trained military pilots who could not do better.

How do you train for bad weather? Let me rephrase that in a context you would understand. How do you lean to drive in a white out snow blizzard?

[Albany Rifles]

That bolded bit could explain things.

Which is it was the tail rotor that hit a tree.

Taken in isolation that sentence makes no sense whatsoever.

But if the winds caused a loss of control of the aircraft then it does.

Is there no counter measure you can apply in such a case ? Requires you to be of sufficient altitude, right ? otherwise no.

Which begs the question why were they flying so low. So low as to be snapped by a smartphone. Should have been a dot in the sky.

Maybe they had already lost control by that point and were desperately trying to control the craft.

They were flying higher, lost control and then it was do whatever to make a controlled landing. Given the terrain that proved to be an impossible task.

Bodies burnt beyond recognition. This bit really had people upset

Just to be clear this was hills altitude. No where near any mountains. This happened in the southern most state of India.

Most of this is totally incorrect in my case.

1. We did not hit a tree...we were a treeline as a screen and popped up from behind it. We were hovering in an open field.

2. We were operating in a scouting mode. Scout aircraft hug close to the ground to minimize detection and engagement from air defense assets. Also a tank main gun can take down a helicopter as well...not to mention a .50 caliber machine gun.

3. The OH-58A was due to be turned in an upgraded to OH-59C status which corrected the low power issues for the tail rotor in the OH-58A aircraft. It was from the division cavalry squadron's air cavalry troop. The divisions attack and general aviation battalions were in the midst of their OH-58C conversion when this occurred.

4. The countermeasure was to apply power...which would likely have put us into the tree line. As it was we fell 15 feet and landed on its side. That is how I broke my ankle.

5. For the last 20 years US aviators have thought that helicopters need to fly at a high altitude to survive. That is because the threat was automatic weapons fire. And entire generation of our aviators believed fly high to survive. In large scale combat operations aircraft need to get back down to the deck to survive. This is a skill which needs to be relearned.

[Albany Rifles]

You would know this. Do military choppers have recording equipment on them like commercial aircraft and I am assuming military aircraft?

Negative, they don't. Black boxes are a requirement for aircraft under FAA control. US Military helicopters fall under military ATC and operate under visual flight rules. No black boxes needed. Plus it removes one more avenue where an enemy could detect an aircraft.

[Double Edge]

I never said it was a mechanical error nor a specific pilot error. I simply gave examples of such errors and could go on listing more of them if you want but felt that I had already got my point across without going overboard. Do I need to go overboard?

Any examples of losing control of the aircraft in the way AR described ? i think this is what likely happened.

I want to understand how you manage such a situation if at all possible.

There were no pilots present in the news shows i watched. Guess they could not find any at short notice. We never got a technical explanation. Also the news anchors were wary of speculating.

Granted these pilots no doubt had thousands of hours in the type and should be well trained in IFR flying and well aware of what losing situational awareness is. By the way do you understand how one can lose situational awareness in the fog? You have no horizon, you bank right, the hairs in your vestibular canals report to your brain that you are still flying straight, so you bank more to the right. On and on into a "death" spiral without you knowing. Kobe's pilot probably did that. JFK, Jr. no doubt did that. Your average civilian pilot should never fly in bad weather

Instruments ? if you're flying blind that's what you use isn't it. Your senses won't do and as you said would likely lead you astray easily.

The fog was thick enough not to be able to see more than four feet ahead. That's what a couple of guys having coffee near the crash site said. They could not see each other at that distance.

Couple of things to add here

- i don't know if I would call the weather bad. Yeah, it was dense fog but no storm. Not even raining. Eastern monsoons abated by this point.

- There was no pressure on the pilot. Pilot had the final say. The general did not countermand the pilot's better judgement. There have been instances in the past where that has happened and senior officer and heli both went down. Did not happen in this case. No urgency. The general was at the college only to deliver a talk.

but I would expect a trained military pilot to do better, much better.

Exactly. You have two instances, two years apart and both trained military pilots who could not do better.