B206/TH-67, Tips Startup following cold night on mtn
 

Looking for tips in prepping and managing a B206 engine start when the machine has been siting overnite on a snowy mountian top. Say. -10c/14f, its -4 at start. Elevation, say .. 6,500 feet ASL

I have inlet covers, Honda 1000 (110v, 8amp/1000 watt) generator, concord battery minder, but no Tannis heating system. Anyone use an 110v heating pads, or other warming techniques prior to start out in the middle of nowhere? Priority on M/R Gear Box, Oil sump? Or it just a manner of watching and carefully managing temps.

Thoughts?

Steve

It's not that cold, just a normal start if your battery is good. Expect the N1 to only get to the lower range before light off. Let the oils warm before you go +70%.

Maybe crank to whatever N1 you can get, light it off and then quickly shut down if it looks like going hot. Let the heat work through the engine for 5 mins, try again.

As said, with a HEALTHY battery at those temps you should be fine. I’ve started cold soaked machines (BH07; we had a plane come in to the airport and unplug our extension cord but it wasn’t the customers problem…) at -35C off the battery and all was good. Oil pressure will go high but quickly come down. Just watch carefully.

I unplugged the fixed wings heaters before i left…jerk

Well if it has Jet A or A-1 On the first attempt it may not light off or light off then stagnate or quit. Close throttle immediately and monitor TOT motoring as necessary. Wait 5 or 10 minutes and try it again making sure TOT is below 150 before opening the throttle. It should start. Remember that if it does not light off on the first try you probably have fuel in the burner can so a “drying run” will be required, ignitor CB pulled, throttle closed , motor engine.
I miss Jet-B!
Be careful. Starts at the higher altitudes can be problematic but I assume your aircraft has been set up for this. Start/Acceleration and Start–Derichment Adjustments for example.
Long time since I flew a 206 but that’s what I remember. We used to operate down to -40 and even -45 sometimes but usually we had full covers and small electric heaters with fans in the engine ( which were sold in local hardware stores as “In Car Heaters” to keep the inside of your car warm ) and transmission compartments plus battery blankets running all night.
I assume also you have the snow deflectors installed if required.
I am sure asking other local pilots and engineers will be most helpful. -4C -15 C is not very cold really.

As a precaution you could always remove the battery and keep it warm overnight (take it to bed with you :p). Never actually experienced the conditions you describe.

I had someone do that to me and to add insult to injury he used our extension cords. A one sided, loud corrective interview took place. He was not departing until the late afternoon we would have happily loaned him our equipment and plugged in his aircraft once we started in the morning. Happily our Chief Pilot was very good friends with his Chief Pilot. Call it Karma if you will but it did not end well for him.

I would be more concerned about the ALT than the OAT wrt Start De-Rich setting.

Light it early rather than late as alluded to previous - as the RFM says. OAT versus Light Off N1 speed chart - 13% at those temps but never less than 12%.. You will want it to get hot otherwise it may stagnate.

Take some de-ice fluid as well. Was forced to leave a AW109E outside in -25C overnight once. Took me about 3 hours to get it going again.

Since you have a generator, get a ceramic heater (space heater, buddy heater..) and stick it in the engine compartment for half an hour while you clear the snow off the blades and critical surfaces. Throw a blanket over the top for better effectiveness as well. Either way as has been said, if the battery is good it should start just fine.


One thing to look for, since it was sitting there without covers, is the little vent hole on top of the bleed valve. If that gets plugged with ice or snow, funny things happen during a start up attempt.

What does the POH say?

Sounds like you need full covers for a start eg Air Covers. They will be at Heli-Expo, booth 10850

A long time ago, I used to fly a 206B-III for a certain 3-letter small-package carrier (not UPS). The ship, based at KJFK sat out on the ramp overnight for a time before it got moved to a hangar at an airport out in the suburbs. Now, New York City isn't known for its extremely harsh and frigid winters, but it often did get damn cold in January. And sometimes, from sitting out overnight, that little B-model would be well and truly cold-soaked by the time I got to it for the morning runs. Sometimes I'd give those glow-plugs a little extra time to get hot, and then I'd turn the key and the starter would groan as if trying to turn over my dad's old Packard-8 with the high-compression pistons. It would usually light off, but the TOT and N1 would just stagnate somewhere around 40%. I would let it sit there - briefly! - for a moment before shutting it back down. Then I'd simply wait a bit for the heat from turbine section to soak through (out?) to the FCU. Next attempt was always fine.

The next problem were the temps. Engine oil temperature would come up quickly as you'd expect, but the stupid transmission temp...man, with no load on the trans, you could sit at idle for a loooooooong time before the trans temp would even start to get warm. What I ended up doing was bumping the N1 up to 70% or so and then pulling some collective. Worked like a cham and the trans temp would get up into the green.

Sometimes the RFM's don't cover every situation and eventuality that we dumb pilots find ourselves in.

No problemo. If you have a red box or start stick that helps, though we use car batteries in serial too. Crank to max motoring on the external battery then flick the main battery on and give it fuel. If it hangs, shut her down and let it warm soak like everyone else says, then give it the beans again.

We never use an engine bay heater but usually throw a ceramic heater off a Honda 1000 in the cockpit. Sure sucks to have a frozen N1 or TOT gauge on start.

Is this a one-off requirement, or your normal daily operations?

Invest in a source of external power (start stick), and the rest of it becomes obvious - a single overtemp will cost you more than any practical investment you can ever make in the proper equipment for the conditions - and I'm not talking about just the cost of the overtemp, you need to include travel to your location, maintenance activities to remove and replace the turbine, rental module, and then changing it back out again. If you are consistently operating in these conditions, you will want to invest in a quality set of covers specifically for the 206. Removing the battery and bringing it inside and applying your trickle charge will make sure you also have a good battery to begin with.Heating the engine and transmission area will also assist in keeping everything functional. A start stick will also allow you to take your external power with you, having experienced a hot start on the top of a mountain after a brief shut-down one day, I can tell you that the logistics and expense of rescuing our crew and resolving that incident where the helicopter became entirely buried in snow and we were there replacing a module is not easily within the resources of a typical small operator. I had every kind of resource you could imagine, and in retrospect, I should have just slung it back to town!. Also, make sure you have appropriate survival equipment with the aircraft at all times.

There speaks the voice of experience! :) I would add that the official rotor blade covers are a royal pain to remove if they get frozen on to the blades - they are too long to get your arm up inside to loosen them. I found old parachutes over the blades and tailboom to be much more practical as a cover. Also, silly things like parking the nose to the East where the Sun comes up (if you can) helps to clear the windscreen.

Had a LongRanger with a sticky N1 gauge which didn't like working when it was very cold and would only come alive when things started spinning - 15% is when the blades start turning just on battery power.