Vertical Surface Aircraft Orientation and Altitude 

In the Helicopter Altitude and Heading Considerations During a Hoist post, we stated, “Ideal positioning during a hoist is an exercise in dynamic risk management. Optimization relies on astute judgment, clear communication, and shared situational awareness across the entire crew. Pre-hoist considerations and disciplined execution enable safe, effective hoisting under challenging SAR [search and rescue] conditions.” Although this statement also pertains to vertical surface hoists, due to the unique nature of the hoist, there are additional factors to consider which are addressed below.  

The main factors influencing the optimal altitude for a vertical surface hoist are:  

Visual References – Higher precision hoists can be more demanding due to the lack of visual cue acuity. However, high hoists offer other operational advantages.  

Wind – Avoiding turbulence makes for a more stable platform with wider power margins. If winds are strong and terrain is varied, hoist in clean air above the line of demarcation or below the turbulent and down draft zones in the null area.  

Terrain and Obstacles – Obstacle separation is paramount. Adjusting altitude and heading can provide increased clearance or improve the crew’s ability to visually monitor the helicopter’s position relative to the obstacle.  

Rotor Wash – In many vertical surface hoists, the survivor is clinging to an object in danger of falling. Moreover, rocks and debris above the survivor can be loosened by rotor wash and fall on the survivor. As such, the impact of rotor wash needs to be emphasized.  

Survivor Location and Security – The greater the degree of stability in the survivor’s perch, the lower the helicopter can be. 

Fly Out – The greater the altitude between the helicopter and obstacles, the more feasible a fly out will be in the event of a power loss, loss of tail rotor effectiveness, or if power required exceeds power available. 

Helicopter orientation to the vertical surface also depends on several factors, the most influential of which is wind and helicopter performance, followed by visual cues for the pilot and the flight mechanic’s ability to see the swimmer and survivor, the ability to clear the helicopter from obstacles, the ability to keep the hoist cable from rubbing or snagging on the helicopter once positive contact is established and fly out or an escape. Below is a chart delineating the considerations unique to each of the four 90° helicopter orientations in relation to a vertical surface assuming that the hoist and door are on the right side of the helicopter.  

Helicopter Orientation	Considerations Unique to Helicopter Orientation
	FM Visuals	Pilot Visuals	Cable Rub/Snag	Escape
Door to Vertical Surface	On approach to the vertical surface the FM has good situational awareness and can clear the tail throughout the hoist. However, once the swimmer has positive contact and the helicopter position imparts an angle in the cable, the FM must look under the helicopter to see the swimmer and survivor.	The right seat pilot should have solid visuals out the right window.	(Depends on hoist boom length from helicopter fuselage and configuration of the aircraft) – as the cable is angled under the helicopter duringpositive contact, it can hit the bottom of the cabin door creating a risk of cable damage.	Excellent escape or fly out for helicopters with a clockwise rotation (European helicopters). It is suboptimal for helicopters with a counterclockwise rotation (American helicopters).
Door Away from Helicopter	Sliding left on approach to the vertical surface, the FM will have to look out the left side of the aircraftto clear the helicopter with the left seat pilot. Once over the top of the hoist area, it is difficult to clear the tail. However, when positive contact is established, the FM has an excellent view of swimmer and survivor down and in front of him.	The left seat pilot likely has the best cues and is probably in the best position to hover the helicopter during the hoist.	Mitigates aircraftrub and snag concerns because establishingpositive contact pulls the cable away from the helicopter.	Excellent escape or fly out for helicopters with a counterclockwise rotation (American helicopters). It is suboptimal for helicopters with a clockwise rotation (European helicopters).
Nose to Vertical Surface	Provides adequate visual and likely keeps the tail away from terrain and obstacles.	Ideal for pilot visuals. Both pilots will likely have excellent visual references.	Keeps the cable away from the bottom of the door but may introduce some aircraft snag hazards at the front of the helicopter.	Most difficult orientation to affect a fly out from.
Tail to Vertical Surface	Adequate visuals however, the tail will be the closest part of the helicopter to the vertical surface and if clearance is tight, keeping the tail free of obstacles expendssignificant FM bandwidth.	Facing away from the vertical surface can create a situation where the helicopter is well above the pilot’s hover references. If this is the case, it is the worse orientation for pilot visual references (outer space).	Keeps the cable away from the bottom of the door but may introduce some aircraft snag hazards in the aft section of the helicopter.	Excellent escape or fly out.

Wind/performance permitting in the American helicopter I fly, door away is the optimal mix of visuals, cable clearance and fly out capability. However, in this orientation, extra vigilance must be given to tail clearance, and the left seat pilot will likely be the flying pilot due to having superior hover references. The left seat hoist can be a paradigm shift for some helicopter crews.