O2 delivery systems

[Kent Wyatt]

I am considering moving into a B36TC (currently fly a F33A).  I have the precise flight O2 system, which I don't use frequently because it requires frequent refills and my plane is normally aspirated and doesn't like to fly up there anyway.  I am considering the mountain high EDS unit.  I understand there is a regulator that can be mounted between the plane O2 system and the EDS to ensure proper function.  This should give a very generous man hour duration of O2 (approx 170 hrs at 10K).  Does this seem like a good option?  What do the rest of the TC or TN members do for O2?

Thanks,

Kent

[Michael Brooker]

I purchased a B36TC about 4 years ago for those few times I must reach high MEA's.  Getting the O2 tanks filled can be pricey, plus they have to be inspected regularly.  So I purchased the Precise flight system with the Oxymiser flow controls and have been pretty happy with the endurance for 2 people.  The fill, at a medical or welding supply place costs me only $20-$25.  I believe if you use the system by EDS, you will certainly get a lot of use from the O2 tank in the aircraft.

Mike.

[John Rohrer]

I have a B36TC that I purchased 3 years ago. I generally cruise between 11,000 and 13,000, so I use the built-in O2 system regularly. Most recently was a 3 hour flight from Missoula, MT at 14,500 to clear clouds. With three passengers wearing masks, and me on a cannula, I used up one tank plus half of the other (a tank in each wing). I wear a SkyOx cannula with their A3 flowmeter so that I can adjust down the ships pressure to work with the cannula. I found that I needed to install a hose clamp where the tubing connects to the scott connector (before the flowmeter) or the tubing pops off the scott connector. The flowmeter is $49.95 from SkyOx.

I recently bought a mask with microphone ($385) and A5 flowmeter ($70) from Precise Flight. They also make a oxygen conserving system that you can use with their mask and the ship's system, but they are out of stock -- one of their suppliers folded, and the tooling was seized! They need to qual a new vendor. Maybe they will be back in production end of 2009.

The tanks need to be hydrostatic tested every 3-5 years (depending on the tank), and replaced at approx. 25 yrs (don't remember the exact number). The hydro test isn't a big deal, but keeping the system running can be. I've had several leaks and a cracked fitting. Still, I prefer the built-in system over hauling a tank around! My kids know how to use it.

I've never had problems getting the O2 system filled. There's a fitting and gauge right under a wing panel, and most shops can deal with it. My regular shop charges me $37 to fill the entire system (two tanks). Considering the gas the TSIO-520UB gobbles up in 3 hrs, O2 is a minimal expense!

John

[Clint Davies]

I have a 1984 B36TC with a 76 cubic foot built in oxygen system.  I use the built in O2 often - usually above 10,000 feet or above 5,000 at night.  I use an Aerox oxygen saver cannulas and flowmeters for up to about 16,000 feet and then use a mask with a built in microphone above that.  

I use a fingertip oxymeter to check my oxygen levels periodically in flight, plus I to pay close attention for any signs of hypoxia.  For me that's tunnel vision and reduced performance - difficulty tuning radio frequencies for example.  The mask keeps my oxygen level right up at 96%, which is close to sea level oxygen level.

The system works great, and if I only have one or two people on high altitude flights the oxygen lasts me quite a while.  I usually top off the oxygen at each oil change - and rarely is it near empty.  We replaced the single bottle last year (at 25 years) and the cost for a bottle from Aerox and shop labor was about $1,400.  

With the TC, you will find the big advantage of going up high is getting a tailwind and leaning the engine out to get longer range.  The teens and low flight levels also enable topping some weather and most haze, and makes it easier to see and avoid storms.

A few weeks ago at 69% power I burned about 16 gph (100 rich of peak)at 21,000 with a TAS about 180 kts.  With a 20 kt tailwind for the first two hours and neutral winds after that I flew an 860 nm leg and landed with 1:20 min reserve.  I had good weather at my destination so the likelihood of diverting to my alternate was low.  

The B36TC climbs nicely - typically close to 1000 fpm up to the flight levels at middle weights - which makes it easy to fly in the teens on most flights. I typically plan 24 gallons for the first hour, and then 16 to 19 gph hour after that depending on power setting.  

Hope this is helpful, let me know if you have any additional questions.

Clint

[Nick DeMarco]

I run my B36TC lean of peak mixture. I have a JPI EDM-830 engine monitor and spent time, money and effort to balance the cylinder mixtures. The work was methodical, starting with baffles, fuel system, engine monitor, injectors, refine injectors, re-refine injectors.

I now run 15.5 GPH, 34", 2320 RPM, 175 KTAS at 10-12,000 ft MSL fully loaded. This setting is about 60 deg lean.

What a wonderful airplane.

Nick