engine temperature

[Daffers 0]

I am having trouble maintaning decent engine temperatures. T5 gauge is going in red fast and i can only generate 20 torque pressure and have a safe engine temperature. Did a 4 hour flight at 16000 feet trying everything to get it down, rpm higher and lower, ice protection off, bleed air off. But nothing seemed to work.

I must be missing something but what?

Because now my cruising airspeed is not higher then 100 knots.

Can anyone help me out?

[LeadingEdge 4]

16000 feet? You realize this aircraft is not pressurized and you really should be operating below 10000 feet. You can operate slightly higher for mountainous crossings. But you need supplemental oxygen. 12500 max ceiling without, but not advisable.

[Emi 5161]

16000 feet? You realize this aircraft is not pressurized and you really should be operating below 10000 feet. You can operate slightly higher for mountainous crossings. But you need supplemental oxygen. 12500 max ceiling without, but not advisable.

The Twin Otter can go up to FL267, so 16.000ft is not a problem. In a Cargo aircraft you might even do this because it saves fuel of cause. And I'm almost sure that on a 4 hour flight a portable oxygen mask is cheaper than the additional fuel required.

We even use those masks in gliders in real world because we sometimes fly that high and even higher. And the last thing a glider has is a pressurised cabin

I am having trouble maintaning decent engine temperatures. T5 gauge is going in red fast and i can only generate 20 torque pressure and have a safe engine temperature. Did a 4 hour flight at 16000 feet trying everything to get it down, rpm higher and lower, ice protection off, bleed air off. But nothing seemed to work.

I must be missing something but what?

Because now my cruising airspeed is not higher then 100 knots.

Can anyone help me out?

Can you show us some screenshots please? Most propably something is wrong with your configurations and with a screenshot we can figure it out as fast as possible.

[Daffers 0]

I cannot recreate the situation now it is flying at good speed, i red somewhere that engines overheat faster with loads of fuel which i was carrying. Maybe also because i was flying higher than usual ( thinner air, less cooling).

Btw i was flying over the rockies so i needed to be high.

But it seems the otter operates better at lower altitude.

Can someone maybe tell me if my assumptions are aomewhat right or just downright bulls**t?

[LeadingEdge 4]

The Otter gets very little benefit from high altitude flight because of its fixed landing gear, lots of drag, much more work for the engines. Remember, the altitudes of 12500 without pressurization and 25000 ft ceilings with pressurization, are only to show what the aircraft can do at its upper most operational limits. Carrying commercial passengers and utilizing supplemental oxygen= Possible Hypoxia nightmare issues. You only fly with supplemental oxygen because, generally for the most part, there are situations where you have no other choice. This aircraft's climb rate to 25000 feet goes down to a mere 100 FPM! This aircraft is a superstar though, at lower flight levels and is capable of feats that no other twin can perform. There's a reason for it not being pressurized though.

Sec. 91.211 — Supplemental oxygen.

(a) General. No person may operate civil aircraft of U.S. registry—

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration.

[Finn 873]

What was the OAT ?

Note that above appr. 17.000 ft the Pt6 engine is more prone to overheat than overtorque.

Finn

[Daffers 0]

OAT was -20 Celcius, you are right it was engine overheat impossible to overtorque at that altitude.

Decided not to do long flights anymore and stay lower.

Haven't had troubles with an overheated engine anymore.

[Al G. 0]

LeadingEdge is right. There is a big difference between mx design limits and actual operational limits/use. I leave in TwinOtter country and I can tell you they rarely fly above 5000 feet around here. In fact when we cross over the island with a single engine aircraft, I climb to at least 4500 in case of engine failure so I can make it either back to point Roberts or somewhere around Active Pass. And then here you are: TwinOtters everywhere, crossing to and from Vancouver Island. The stick to lower altitude cuz that's what they actually designed for. That said they can (obviously) operate much higher if need be, Lukla being a perfect exemple, but you need to watch them EGT's. You have to pull power and expect to fly a much slower cruise speed, say 110kts.

Oh and look at this guy who showed up yesterday while I was on the taxiway at the south terminal. But i'm not envious...maybe.

[Daffers 0]

K i will stay lower, i am flying at orcas island (orbx) so i am sort of flying in the same region, i like to do some bush flying to the mountains so you need al ittle bit of altitude though ;

[Eric Bakker 736]

Daffers, you can fly higher as well, you only need to monitor your engine temperature. Power down a bit when it gets in the red