Things to keep in mind.
Summer is on its way and, in most parts of the northern hemisphere, that means warm weather will soon be upon us. Not every pilot is fortunate enough to fly a helicopter with air conditioning. When I lived and flew in Arizona, it was common for me to take all of the doors off my R44 in May and leave them off until September. It was that hot every single day. (And no, I don’t miss it one bit.)
Of course, pilots don’t need warm weather as a reason to take the doors off. Sometimes the mission you’re flying requires it. Aerial photography is a great example — there aren’t too many photographers who would be willing to pay hundreds of dollars an hour to fly with you and be forced to shoot photos through highly reflective, possibly scratched Plexiglas.
When you remove the doors from a helicopter, you add an element of risk to the flight. Fortunately, the risk can be controlled if you fully understand it and do what’s necessary to reduce or eliminate it. That’s what I want to touch upon in this post.
The most obvious risk is from loose objects blowing around the cockpit or, worse yet, exiting the aircraft. This is a real danger, especially if an object hits the tail rotor or someone/something on the ground.
Want some examples of how dangerous this can be?
- NTSB WPR14CA363
“While in cruise flight an unsecured jacket departed the helicopter through an open window. The tail rotor drive shaft sheared as a result of the jacket’s contact with the tail rotors. The pilot subsequently initiated a forced landing to an orchard where during landing, the main rotors struck and separated the tailboom.”
- NTSB WPR13CA071
“Prior to the flight, the doors were removed in order to make it easier for the passengers to board and exit the helicopter…. After the two passengers were transported to a work site location, the right rear passenger exited the helicopter and placed the headset on the hook located behind the front seats. After departing the site, about 3 to 5 minutes later while en route at an elevation of about 1,000 feet above ground level, the pilot felt something strike the helicopter. After landing and upon inspecting the helicopter, the pilot discovered that the right rear headset was missing and that the leading edge of the tail rotor had been damaged.”
- NTSB LAX03TA150
“While in cruise flight, the back door on the helicopter opened, and a flight jacket that had been unsecured in the back seat departed the helicopter and became entangled in the tail rotor assembly. The tail rotor assembly subsequently separated from the tail boom, and the pilot was unable to maintain control of the helicopter.”
- NTSB FTW86LA047
“The pilot failed to assure the cabin door was properly closed before flight, or the cabin door just popped open during flight, allowing an unsecured life vest to blow out the door and into the tail rotor blades. This resulted in the entire tail rotor assembly departing the helicopter.”
(As some of these examples show, you don’t need to have the doors removed to have an unsecured item depart the helicopter and get into the tail rotor.)
Robinson Helicopter warns about this in Safety Notice SN-30, “Loose Objects Can be Fatal.” It recommends that pilots firmly latch all doors and even goes so far to recommend that pilot never fly with a left door removed. (Remember, the tail rotor is on the left side in a Robinson and many other helicopter models.)
I know that my engine starting check list includes an item to assure that loose items are secure. Yours should, too. While this is always important, it’s vital for doors-off flight.
Be sure you warn passengers of the danger of an item exiting the aircraft. Even something as small as a lens cap or lens hood can do significant damage to the tail rotor in flight.
Never Exceed Speed
You might not realize this, but your helicopter’s never exceed speed might be reduced with the doors off. On a Robinson R44, for example, Vne is reduced to 100 knots with the doors off, even if other conditions such as altitude and temperature would allow a faster speed.
My understanding from the Robinson Factory Safety Course is that this reduction of Vne is for structural reasons. (If someone knows better, please correct me in the comments.) There’s more buffeting wind inside the cabin with one or more doors off than with all doors on.
Check the Pilot Operating Handbook for the aircraft you fly the next time you remove doors to make sure you don’t operate beyond doors-off Vne.
This might seem like a no-brainer, but if you’re going to remove doors, your passengers had better be secured in their seats with either seat belts or harnesses.
Because some of my aerial photography or video clients like a greater range of movement in their seats than seat belts allow, I have a mountain climbing harness with a suitable strap for securing it to the aircraft frame. I make this available to clients as an option if they don’t have their own. Under no circumstances do I allow my passengers to fly without being secured, especially when their doors are off.
Keep in mind that while a photographer might use a harness to secure himself in the aircraft, you must make sure he knows how to release the harness from the aircraft in the event of an emergency — just as your preflight briefing must tell passengers how to release their seat belts.
Dangling Seat Belts
Of course, it was my generous offering of a harness to a photographer that resulted in more than $2,000 of damage to my aircraft when he used the harness but failed to secure the seat belt at his seat. The seat belt buckle dangled outside the aircraft for the duration of our 90-minute video flight chasing racing trucks over desert terrain. On landing, the passenger side fuel tank and area just outside the door frame had at least 50 dings and paint chips in it. How he didn’t hear it repeatedly striking the aircraft near his head is something I’ll never figure out.
Of course, it was my fault for not catching this prior to starting up and taking off. Expensive lesson learned.
While I don’t think there’s anything wrong with taking the doors off a helicopter prior to flight, it does give the pilot more responsibilities to assure that everything is secure and all passengers are properly briefed.
Or isn’t that something we’re already supposed to be doing?