Blackhawk Landing technique

[18greens]

Hi,

I've just been watching the Thunderstuck video of miltary helicopters doing stuff, great for combating the mid morning office ennui.

Anyway in the video the Blackhawks appear to land fairly severely tail first. They do it more than once so I'm guessing its for a reason. Is it a standard low viz landing technique?

Thunderstruck (http://www.grouchymedia.com/other_videos/helo_thunder/index.cfm)

Also what connects the pilots helmet in the Apache to the position of the gun?

[teeteringhead]

Several connected reasons ... primarily because the Blackhawk, like its grandaddy the S-58, has a tail wheel stressed for a landing, rather than a skid/stinger/frange which isn't, and which in any case may dig into the ground and provide no protection to the tail rotor.

Moreover, like most helos, it sits tail down in the hover (and in the case of the Blackhawk, right wheel low on account of the rotor's direction of rotation), so any landing will be tailwheel first - tail, right, left for the precise sequence.

Can also be useful in potential low vis situations, eg loose dust/sand/snow. That then requires a rapid-decleration-get-it-on the-ground-quickly manoeuvre, which of course emphasises the tail down attitude.

You can certainly get a Blackhawk on the ground more quickly than a Huey, primarily (IMHO, having flown both) because of the tailwheel, and of course, if you land with forward speed, because wheels means brakes.

[helmet fire]

teetering is right. In bits I think! Doesn't the Black Hawk hang left wheel low?

The Black Hawk is significantly tail low in the hover due to the built in forward mast tilt for better forward flight attitudes. Interestingly, the tail rotor is tilted 20 degrees or so, and subsequently provides just under 2.5% of the lift in the hover! (memory is a shakey thing, so please call these figures if I missed them)

In the Thunderstruck video, the "severe" landing is a very poorly executed low viz style landing used for dust ops. Landing on the tailwheel is for aerodynamic braking which uses the tail wheel on the ground as a pivot point and the rearward tilted rotor thrust to rapidly slow the aircraft. That is why it's good for dust landings, and good for tactical landings to slow quickly.

teetering: A huey almost gets to the ground quicker because it is slowing from such an enourmous forward speed in the first place!!!!:}

[teeteringhead]

teetering is right. In bits I think! Doesn't the Black Hawk hang left wheel low? OOps - too much time more recently flying French rather than Sikorski!:O :O

[SASless]

Right wheel...left wheel....just keep the collective coming down....the aircraft will sort it out for you.

Dusty LZ's can be fun....just imagine a Chinook or Sea Stallion....in talcum powder like dust.....that is a thrill particularly with the cockpit height.

[ShyTorque]

The Blackhawk also has a very hefty main undercarriage. As I recall (but it's a few years since I was current) it can withstand about 500 feet /minute landing without damage; which equates to the rate of descent for an instrument approach without flaring at the bottom.

One of Mr. Sikorsky's best ever products, if not THE best one, imho. :ok:

"Also what connects the pilots helmet in the Apache to the position of the gun?"

Er... The pilot? :p

[18greens]

Shyt...

You know what I mean. They spin their heads and the gun moves where they look, is it string, fancy lights, a helmet proximity system. In the video the man is waggling his head from side to side and the gun is waggling in turn (very impressive) Perhaps I should say 'How does the man in the apache aim the gatling gun under the cockpit at the target?. Another thought , how does the marshaller know the gun is not armed when the Apache lands, or do they just wheel out another one?

[Sabre Zero 1]

The helmet used for the Apache has an IHADS (Integrated Helmet-mounted Aquisition & Data System). Three sensors situated around the cockpit pick up the helmets relative position by sensing the movement of pencil lazers attatched to the helmet. All the pilot has to do is look through the monacle mounted on his helmet (target sighting and flight information are projected on to the monacle), look at a target and (hopefully) the cannon will follow. (please excuse any inaccuracies!):8

[SASless]

Inaccuracies....think about the gunner finger on trigger...pumping HE rounds at the bad guys....something catches his attention to the side and he turns his head to look at it.....forgets to take his finger of the rock and roll switch. To discover he is looking at some Friendly forces! That could be some sad "inaccuracy"...not the kind you had mind I know.:E

[Sabre Zero 1]

Blue-on-blue......say no more!:ouch:

[Lu Zuckerman]

On most if not all Sikorsky designs the mast is tilted three degrees forward. In a hover the blades will align themselves with the local horizon which makes the helicopter hover with the tail down by three degrees. On most Sikorsky helicopters there is a built in rigging change when the pilot goes into a hover. The disc will tip down about 7-degrees to the left to compensate for tail rotor translation. So when coming to a hover the helicopter will hang down at the tail and be tilted to the left so the tail wheel hits first and the left wheel makes contact before the right wheel. On those helicopters equipped with an autopilot or a SCAS this tilting must be taken into consideration when rigging the autopilot or SCAS to the flight control system. On those helicopters equipped for SONAR dipping the SONAR operator has the capability to null out autopilot or SCAS inputs so the helicopter can remain directly over the SONAR ball.

As far as the Apache pilot aiming the Chain Gun ® that has been pretty well explained. There is an urban myth that states that on one occasion there was a disconnect between the pilots helmet and the gun. The gun was pointing to the left and the pilot was aiming in another direction. When the trigger was depressed the pilots’ wingman was shot out of the air.


:E :E

[teeteringhead]

withstand about 500 feet /minute landing without damage ...much more than that I think Shy Torque , ISTR the S-58/Wessex was allegedly stressed for 1200 fpm (for deck landings!), I would have thought the 'Hawks would be no less....

Any authoritative answers out there??

[flygunz]

Please excuse me if I fall into the trap but Sabre Zero 1 has clearly misread the instructions on his model kit! I'm still trying to work out what a pencil lazer is?

However, the Apache Pilot has a system called the IHADSS (Integrated helmet and Display Sighting System) which once the Helmet is boresighted to the Ac, can then act as a sight. The Gun when actioned is then slaved to the Pilots helmet and follows head movements within it's available limits.
This is achieved through IR connectivity and algorithm calculation of head movement and positional timing.

So to answer the original question 'what connects the Apache Pilot to the gun?',.. Black box technology.

There is always the possibility of the Pilot forgetting he has the gun actioned and causing a blue on blue and I believe there are recorded instances. Good drills and training discipline help to negate fratracide but the human interface is usually the weak link!

[Sabre Zero 1]

Damn those Airfix kits!!!

Sorry, getting mixed up between IHADSS and TADS (Target Aquisition & Data System)

[ShyTorque]

Teeteringhead,

You may be correct; as I said, it's a few years since I was current and the definitive answer is in the RFM as I recall - perhaps a current pilot might care to check it out for us. The u/c IS certainly capable of handling a lot more, but it is a staged system (3 stages?) and I think certain replaceable components need checking and possibly replacing if the ROD at touchdown exceed certain limits.

Anyway, I was always SO gentle, I never needed it ;)

[212man]

"Are we down yet?" :ok:

[SASless]

212man....remember some of us have seen you land a helicopter....I know you were only trying to make sure the squat switches got squashed!