"Hot 5 assumtion"

[asolo]

I would like opionions on the "hot 5" I have been flying King Air 90's and 200's for a while now and occationally will have a 2 pilots on board. It seems as though a few people think the "hot 5" are pitot heat left, pitot heat right, Fuel vent heat left, fuel vent heat right, and stall warning. I always thought it was 1) pitot heat left and right, 2)fuel vent heat left and right 3) stall warning 4) winshield and 5) props.
The reason I bring this up is b/c a few people I fly with will turn on pitot L, R, Fuel vent L, R and stall and thats it. The reason these other pilots giver for this is either b/c they say the winshield costs $11,000 a side (or seomthing like that) or that it increases the load too much. My theory is that if you decide to put any anti/de-icing devices on is that it is all or nothing. If you are concerned about ice on the pitot, fuel vent, or stall warning you should also be concerned about props and the winshield. All the anti/de-icing devices are there for a reason and you should use them reguardless of cost replacement. And as far as load on the generators is concerned-the plane is designed to handle those loads!
My experience has taught me that if you turn on just a few of these items, it gives you a false sense of security. I was desending one day w/ out the winshield heat on (b/c I didn't want the extra load) and just b4 I went through a cloud layer I glanced at my icing switches and made the assumption that everthing was on. Low and behold, the winshield iced up quickly. No big deal, but like I said, a false sense of security.
What do you guys think?

 

[satpak77]

you should have King Air windshield heat on at all times above 10,000 to keep it pliable in cold altitudes. We had one crack (heat was not on) and the windshield manufacturer recommended that. Beech supposedly was coming out with an AFM supplement recommending it also.

there are no "load issues" associated with windshield heat. Prop heat should not be on unless in ice or visible moisture below 5+ C, per the AFM.

We are not talking a Cessna 172 at night with a questionable alternator, yeah, maybe kill the strobes and the moving map GPS...we are talking arguable the most capable turboprop twin family (the King Air line)....windshield heat ON ain't gonna hurt anything.

Every King Air pilot and FlightSafety recurrent session I have been to, the Hot Five is Fuel Vents L/R, Pitot L/R, Stall Warning. It is NOT windshield or Props.

In our climb checklist, we have a addition that says "Windshield Heat ON above 10,000"

 

[cvsfly]

Windshield heat distorts visibility slightly. I believe the POH suggests having it off by +10 C. I've been told windshield heat will not necessarily make it more pliable - as in some aircraft installations and offer some bird strike protection - but turning on windshield heat on early if there is any chance of needing it before it is cold soaked may prevent a thermal shock and hence a chance of cracking. 5 hots I can set and forget (on our Before Takeoff and After Landing). I can use my head for windshield heat (on our Above 10k and Descent) and props (as needed).

 

[satpak77]

hey, just telling you what the windshield manufacturer told us, which was also agreed to by the Beech factory and FlightSafety

 

[avbug]

Interesting. I never heard of "hot five" during any of my king air training, initial or recurrent.

I had to replace a forward windscreen in a BE20 once, for delamination. I used a refurbished unit (ppg, I think), and was told by a representative that within the previous few months, one crew had experienced two complete windsheield separations at altitude. The crew was flying straight and level, and the interior laminate fell into the lap of the first officer.

My theory is use what you need when you need it, and you'll never have to worry about cutsie word games. If you need it, turn it on. If you don't, turn it off. As a general rule of thumb, I think pitot heat & stall warning prior to takeoff every time, and windshield heat either prior to entering the runway for takeoff, or on a hot day, when at turning off air conditioning.

Everything else can wait until approaching visible moisture.

 

[Lopaka]

Hot 5 for us, taught by FSI & Simcom was always: L&R Pitot heat, L&R fuel vent heat, and stall warning. There was always the discussion about windshield heat, but we never had problems turning it on when it was needed like the prop heat of course.

 

[hyflyt560]

I agree with Satpak. All of the army C-12 pilots I've flown with say "Hot five" and mean the pitot, stall, and fuel vent. As a unit, we turn on the windshield at 10k, unless needed earlier. In the civilian 300 I fly, we say "Hot six" and this includes the probe heat. I asked our mechanic about it and he said because the probe heat gets hot enough without airflow it could be damaged. I asked the same question of the army contract maintainers and they said it doesn't get hot enough on the ground to worry about. It's never failed.

Our C-12 and the civ. 300 I fly have had a total of 4 windshield replacements in the last 4 years. We were told there was a rash of failures of King Air windshields from PPG from certain manufacture dates.

For what it's worth.

 

[TrafficInSight]

I'm curious as to why the left/right pitot and fuel vent heats are even separate, is it a load shedding thing?

 

[Cardinal]

For the life of me I can't figure out why Beech didn't wire the things like the annunciator dim funciton - if a generator is online, it's working. It is absolutely,totally, and completely retarded to be dicking with the stall heat in flows and checklist. Of course the same could be said for the EFIS power switches and a dozen other things I have to turn on after every start.

Just to muddy the waters, our FSDO let's us say "Standard Three" on approved checklists, meaning just the pitot tubes and the stall warning.

 

[FL420]

I'm curious as to why the left/right pitot and fuel vent heats are even separate, is it a load shedding thing?

I'm gonna take a WAG at this one. Since electrical heaters usually draw more juice than just about everything else, the designers wanted to give a pilot the ability to selectively load shed. If necessary a pilot could cut electric demand almost in half and still have one operating pitot static system and one vented fuel tank to draw from while crossfeeding from it if necessary.

 

[FN FAL]

I'm gonna take a WAG at this one. Since electrical heaters usually draw more juice than just about everything else, the designers wanted to give a pilot the ability to selectively load shed. If necessary a pilot could cut electric demand almost in half and still have one operating pitot static system and one vented fuel tank to draw from while crossfeeding from it if necessary.

Look at your buss, it's probably bussed seperately as well. No sense in losing it all, when half of it bites the dust.

Is the king air set up so that one fuel vent feeds the whole system as a redundancy? If not, at least the two separate fuel vent heats allow you the option of cross feeding the fuel tanks to the side where you still have fuel vent heat if that ever became an issue.

 

[minitour]

Is the king air set up so that one fuel vent feeds the whole system as a redundancy? If not, at least the two separate fuel vent heats allow you the option of cross feeding the fuel tanks to the side where you still have fuel vent heat if that ever became an issue.

If there wasn't a "cross vent" (like in the 172s...a vent from one tank to the other), when you went to crossfeed from the tank with the blocked vent, wouldn't the vacuum prevent the pump from sucking the fuel out of the blocked tank?

-mini

 

[asolo]

In the summer (CAVU), I don't turn on any heat items till 10K. I leave them on until decending through 10K. During the winter (even during CAVU), I turn everything on when I get cleared for T/O. I turn them off when I get off the runway or if when decending, I note that it is ~+10 C or above and there isn't a temp inversion.

 

[FN FAL]

If there wasn't a "cross vent" (like in the 172s...a vent from one tank to the other), when you went to crossfeed from the tank with the blocked vent, wouldn't the vacuum prevent the pump from sucking the fuel out of the blocked tank?

-mini

Why would you cross feed FROM the blocked tank?

 

[flint4xx]

There is a difference between a technique and a procedure. The before takeoff section of the POH says "Anti Icing-As Required". Saying "hot 5" and turning on whatever you want is a technique, and maybe be a good one at times. I've seen enough techniques turn into "procedure" without any real thought going into it. And there is always the "that's the way we've always done it" mentality that may factor into this. If you default to the POH, "as required" notation, then just do what is right for that flight. I wouldn't turn on any of it for a local flight around pattern in Cancun for example.

Personally, I wouldn't use window heat unless it was required for visibility. it provides no impact protection, and will only cause premature wear and tear. There are over 6000 KingAirs out there, and every now and then a windshield fails just like every other component. You would see an AD to use window heat if that was a real problem in the fleet.