Supremely stupid question ...

pilot602

If specified, this will replace the title that
I've seen it mentioned a lot lately ... "the barber pole" what is it?

I'm pretty sure it's an airpseed limitation of some kind but what does it refer to exactly.



/removes:thestupidhat
 

Derg

Cap, Roci
Staff member
A "barber pole" is the red and white striped needle on your airspeed indicator that marks "Vmo/Mmo" (maximum operating speed [V=speed in knots/M=mach numer).

In a lot of transport category jets and some turboprops, it'll indicate Vmo until roughly FL 250 (25,000') and Mmo thereafter.

It kind of resembles a "barber pole":
[img]http://images.animfactory.com/animations/objects/barber_salon/barber_pole_md_wht.gif[/img]

 

Derg

Cap, Roci
Staff member
And there's no such thing as a stupid question.

If you think that's bad, I didn't know that the flight levels skip 2,000 feet about FL300 until my second year at Delta!


like FL310, FL330, FL350, FL370

We were flying from SEA to CVG when I was a 727 flight engineer. We hit an area of nasty turbulence, but if we went lower, we'd increase our fuel burn, but an extra 1000' would get us over the clouds.

"Captain - we're too heavy to go to FL350, but we'd have the 'margin' to make FL340"

co-pilot: "Can't get to 340"

me: "Yeah, we could make 340, and 350 after another 20 minutes of fuel burn"

captain: *laughs*

me: "huh?"

captain: "Dumass, there's no such 'thang' as FL 340, only 310, 330, 350, 370, etc."

me: "no, really?"

doh!
 

DE727UPS

Well-Known Member
If a Captain called me "Dumbass", I'd go essential power to external and make his Attitude Indicator go away.
 

Derg

Cap, Roci
Staff member
Nah, he's a cool guy! He was the original "The Military Route" author.

So Don, what was your biggest fuel imbalance on the 727?
 
Why can't you cruise at FL340? That doesn't make sense. Also, im kinda confused on just what exactly a flight engineer does. I mean, I know what a F/E is but what are his/her duties in the flight?
 

cointyro

New Member
The FE sits in the back very quietly and gets coffee for the CA/FO. Oh yeah he has to wash the plane on Saturday mornings.
 

cointyro

New Member
Here's another simple Q:

What is the official phraseology, as well as pilot slang, for the blue knob, the prop control?

Also isn't there a rule of thumb, keep your prop control forward / ahead of the throttles (forward being lower prop blade AoA / "flatter" prop disk)? Or have I got this confused?
 

I_Money

Moderator
You can not fly at FL340 because the want 2000 seperation between traffic. This is a safety procedure incase the pilots fall asleep.

The FE gets to look at dails and walk around with a flash light. He sits on the only sideways facing seat that does not flush, however I hear they are working on that.
 

Eagle

New Member
[ QUOTE ]
Why can't you cruise at FL340? That doesn't make sense.

[/ QUOTE ]

It is a seperation thing, when DVSR is up and running they "ahem" claim it will open up the Flt levels. but until that point.


And for those who want to know about Mmo, think of it as VNE, except in some swept wing aircraft, if you exceed Mmo, the center of lift moves far enough back that you lose the lift, and control, and the next thing you know the aircraft is pointing at the ground in an uncontrollable - nearly unrecoverable attitude. This is called Mach Tuck.

Think of it as moving the fulcrum on a lever back far enough to make one side unbalanced.

More than one Lear Jet has broken apart in flight, or crashed as a result of tucking the airplane.

And what reallllly sucks, is the Mmo is rather easy to make. (in the 35) as the profile is rather small and the thrust rather big...
 

I_Money

Moderator
I just call it the prop. I have never heard that rule of thumb, however it has been a while since I flew a complex aircraft, so it could be.
 

I_Money

Moderator
Dude no need to thank me, I am sure you can get much better answers then what I provided. I just really wanted the 'only non-flushing sideways facing seat' gag. The FE basically monitors systens like the hydraulics, fuel, and others, to ensure they are running properly. Now computers and pilots share the work of the FE.
 

DE727UPS

Well-Known Member
My worst fuel imbalance, outside the simulator, was when I forgot that the -200's (I mostly flew -100's) have override fuel pumps on tank two. I remembered something from -200 differences that was you were supposed to take off with all crossfeeds open on the -200's...so I did. Next thing I look at my fuel out of 10K or so and I see tank two is like 3K lbs less than one and three and getting rapidly worse. I had balanced fuel to start with, and therefore should have been tank to engine the whole time, but I just HAD to takeoff with all crossfeeds open on a -200. I told the captain, who didn't really seem to care much, and set up a crossfeed to run all engines out of 1 and 3. This procedue was not in the book but I saw no reason it wouldn't work, the captain shrugged at me when I asked him, and, in the end, it worked out fine. I think by the time we got to Ft. Wayne, everything was balanced.

In flight, the F/E looks for other planes, listens to the radio calls, and just generally makes sure the front seaters don't screw up. They also run their panel which includes the fuel, hydraulic, electrical, pneumatic, and pressurization systems. During an abnormal or emergency checklist they can get pretty busy but otherwise it's easy. They also do the landing data card and get the ATIS. At UPS, they serve the crew meals (box lunches), if contractually mandated, and will get you a water bottles from our contractually mandated on board refreshment center (ice chest). I won't even mention our fine, luxurious, restroom facilities (porta-potti)
 

Eagle

New Member
[ QUOTE ]
Also isn't there a rule of thumb, keep your prop control forward / ahead of the throttles (forward being lower prop blade AoA / "flatter" prop disk)? Or have I got this confused?

[/ QUOTE ]

The Throttle, controlling your MP, and the Prop controlling your RPM.

The Prop control goes to a small gizmo on the back of the engine case (on the Lyc-O-360, O-320, most cont and on the front on the Lyc 540s) this gizmo, the prop governor is what controls the amount of oil headed to the plunger in the Propeller, you are slowing the engine down by putting a bigger bite in the air, (pulling back) and speeding up by putting it forward, less of a bite.

The "old pilots tale" of keeping the RPM ahead of the MP is as stale and out of date as "shock cooling"

With the old radial engines this was an issue, so unless you are doing your flights in a T-6, I wouldn’t worry about it.

**UNLESS** your DE thinks it is important, then
Agree, Acknowledge, and Acquiesce

the fact of the matter is, as you get higher the MP drops as it is a measurement between the ambient air pressure and your manifold pressure. so if you are at 11,000 ft with a Lyc 0-360, you would nearly have to run your RPM at 1100 rpm to get "behind" the MP, so it really never comes up…
 

Eagle

New Member
[ QUOTE ]
set up a crossfeed to run all engines out of 1 and 3. This procedue was not in the book but I saw no reason it wouldn't work, the captain shrugged at me when I asked him, and, in the end, it worked out fine. I think by the time we got to Ft. Wayne, everything was balanced.

[/ QUOTE ]

Can't you just transfer from the heavy tank?
 

EatSleepFly

Well-Known Member
[ QUOTE ]
Also isn't there a rule of thumb, keep your prop control forward / ahead of the throttles (forward being lower prop blade AoA / "flatter" prop disk)? Or have I got this confused?


[/ QUOTE ]

"Props on top" is one.

Meaning: On a power reduction, props last. On a power increase, props first.
 

rausda27

Well-Known Member
Another is
"Climb to the left, Descend to the right", meaning if you are adding power (climbing) then go from left to right, prop first throttle second. If you are reducing power (descend) then throttle first, prop control second.
 
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