Ask The Pilot

[Boris spatsky]

If a plane is taken out of use due to a fault, do the maintenance teams ever require a "test flight" to make sure the issue is resolved like a car mechanic might? If so is this a job given to line pilots?

Surely there are some reported faults which can't be easily replicated on the ground (gear not retracting, or excessive engine vibration/noise reported at high power etc)? Obviously most faults are probably found easily, but there will always be those which are hard to diagnose that I am thinking of.

Last one we had was a test flight straight out of heavy maintenance. Flight was crewed by a check captain coupled with a line captain. Flight included test of autobrake system including high speed reject and max autobrake landing. Very rare to get to do those for real.

 

[anat0l]

Not sure if this has been mentioned or asked before, but are pilots conscious, or made to be / forced to be conscious, about fuel consumption?

When driving a car, we tend to drive it so as not to unnecessarily burn up fuel, at least most of the time. For example, avoid hard braking, drive in the appropriate gear, etc.. In addition, little or big things on a plane can affect the fuel consumption that it pays enough for it to be treated. This can include the cargo (freight and self-loading), an extra engine, or simply the dust and grime on the exterior of the aircraft (so wash it).

But when pilots are flying the plane, are they (or are they told / forced to be) particularly mindful of how to pilot the aircraft to conserve fuel? What kinds of guidelines are there? Or, you don't really think of the fuel consumption at all (unless it appears to be p***ing away at an alarming rate)?

 

[jb747]

Not sure if this has been mentioned or asked before, but are pilots conscious, or made to be / forced to be conscious, about fuel consumption?

When driving a car, we tend to drive it so as not to unnecessarily burn up fuel, at least most of the time. For example, avoid hard braking, drive in the appropriate gear, etc.. In addition, little or big things on a plane can affect the fuel consumption that it pays enough for it to be treated. This can include the cargo (freight and self-loading), an extra engine, or simply the dust and grime on the exterior of the aircraft (so wash it).

But when pilots are flying the plane, are they (or are they told / forced to be) particularly mindful of how to pilot the aircraft to conserve fuel? What kinds of guidelines are there? Or, you don't really think of the fuel consumption at all (unless it appears to be p***ing away at an alarming rate)?

Different companies play this game very differently. In many airlines, the crew don't order the fuel, but it's done by a dispatcher, with virtually no discretion on the part of the pilots. Others are more wary of the fact that the Captain actually has responsibility, and legal control, of the flight, and whilst they will recommend a loading, the crew can adjust it as they see fit.

There are countless competing costs. Going faster will reduce flight time related costs (most things in aircraft count the hours), whilst increasing the burn. Miss a curfew and the costs may dramatically exceed any fuel cost. Using maximum thrust settings (i.e. not derating take off or climb) reduces engine life, but burns LESS fuel.

During flight, you're always aware of both your projected arrival fuel and any calculated requirements. You're additionally very aware that it's your licence on the line, not someone in an office.

Overall though, fuel is just another factor in the whole aviation experience. Sometimes I try to save fuel. Sometimes I'm chasing time. And there are even occasions when neither is a priority (i.e. weather).

 

[JessicaTam]

Different companies play this game very differently. In many airlines, the crew don't order the fuel, but it's done by a dispatcher, with virtually no discretion on the part of the pilots. Others are more wary of the fact that the Captain actually has responsibility, and legal control, of the flight, and whilst they will recommend a loading, the crew can adjust it as they see fit.

There are countless competing costs. Going faster will reduce flight time related costs (most things in aircraft count the hours), whilst increasing the burn. Miss a curfew and the costs may dramatically exceed any fuel cost. Using maximum thrust settings (i.e. not derating take off or climb) reduces engine life, but burns LESS fuel.

During flight, you're always aware of both your projected arrival fuel and any calculated requirements. You're additionally very aware that it's your licence on the line, not someone in an office.

Overall though, fuel is just another factor in the whole aviation experience. Sometimes I try to save fuel. Sometimes I'm chasing time. And there are even occasions when neither is a priority (i.e. weather).

If the crew don't order the fuel are they absolved of any blame if there is a fuel related incident? Such as not enough for a diversion or extended holding pattern?

 

[Boris spatsky]

The PIC is always responsible for the safe arrival of the flight, especially regarding fuel loads.

JB has summed it up well. From short haul perspective, the company specifies a Cost Index to fly (lower cost index equals lower fuel burn but slower flight time in simple terms). Then we can modify that to make a schedule. If we are ahead of schedule then we will try to conserve fuel. We will also conserve fuel if there is bad weather at destination.

We are constantly aware of fuel burn etc and have to justify carrying more due to weather etc.

 

[jb747]

If the crew don't order the fuel are they absolved of any blame if there is a fuel related incident?

No.

When they depart, they don't legally need the fuel to go to destination. They just need the fuel to go somewhere. The argument will be that the crew chose to go past the various decision points. In any event, people who live in offices are never responsible for their actions.....

Such as not enough for a diversion or extended holding pattern?

That's more the norm than unusual....

 

[docjames]

In line with this thread (which may be better place to answer / discuss ??)

http://www.australianfrequentflyer....vel-in-aircraft-cabins-73541.html#post1382742


- Are there OH&S considerations regarding noise exposure?
- Is there regular testing (done at annual medical?)?

Without being too personal, have our "in residence pilots" noted any decline in their own hearing due to long term aircraft noise exposure?

 

[jb747]

In line with this thread (which may be better place to answer / discuss ??)

http://www.australianfrequentflyer....vel-in-aircraft-cabins-73541.html#post1382742


- Are there OH&S considerations regarding noise exposure?

Yes. 747 and 767 both had noise cancelling headsets in the coughpit for just this reason.

- Is there regular testing (done at annual medical?)?

It comes up every 5 years.

Without being too personal, have our "in residence pilots" noted any decline in their own hearing due to long term aircraft noise exposure?

I had it looked at last medical, just to see....and found that whilst still ok, there has been marked reduction in acuity at some frequencies.

 

[straitman]

Jb747, friend of mine in Colorado owns a single engine Cessna. He used to do flight tours in Alaska now living in DEN. He says he only flies VFR. His reasoning is that instrument flying requires 2 pilots to do it properly. What do you think?.

Some a/c are setup and equipped for single pilot IFR and others are not. The real issue with single pilot IFR is workload. In a simple a/c and with everything working it is not too difficult (after the appropriate training).
Things can go west very quickly though if you have something go astray during a period of high workload.

 

[mjt57]

I had it looked at last medical, just to see....and found that whilst still ok, there has been marked reduction in acuity at some frequencies.

Maybe the product of ancientness setting in, perhaps?

I work in heavy industry, exposed to noise levels approaching 140db. Whilst I wear the approved hearing protection, there is still a decline much like yours, I'd imagine.

Now, I can hear a pin drop in a quiet room, but if the TV is on, for example, or in the pub having an ale after work, I find it difficult to hear over the background noise.

 

[Boris spatsky]

Maybe the product of ancientness setting in, perhaps?

I work in heavy industry, exposed to noise levels approaching 140db. Whilst I wear the approved hearing protection, there is still a decline much like yours, I'd imagine.

Now, I can hear a pin drop in a quiet room, but if the TV is on, for example, or in the pub having an ale after work, I find it difficult to hear over the background noise.

My hearing has been affected by aircraft noise to the extent that i am subject to an annual CASA hearing test. Started noticing it in late 20s whilst in the RAAF. The decline is in only two frequencies but it is enough that CASA also make me do a speech test with a speech pathologist. All attributed to aircraft noise apparently according to the specialist.

 

[moa999]

Are military aircraft better or worse in terms of coughpit noise, and/or is the hearing protection used relative to the noise?

 

[tgh]

This is deeply disturbing information, and one wonders how long before a bean counter decision results in some bad news.
A thread with a list of airlines who habitually make computer generated fuel loading decisions and leave the pilots to carry the can or work elsewhere would be useful.
One assumes that the roo won't be on the list..

No.

When they depart, they don't legally need the fuel to go to destination. They just need the fuel to go somewhere. The argument will be that the crew chose to go past the various decision points. In any event, people who live in offices are never responsible for their actions.....



That's more the norm than unusual....

 

[jb747]

Are military aircraft better or worse in terms of coughpit noise, and/or is the hearing protection used relative to the noise?

In general...much, much, worse. I lifted my helmet in an A4 once, to hear how bad...it went straight back down.

 

[jb747]

This is deeply disturbing information, and one wonders how long before a bean counter decision results in some bad news.

Well, it was the only way that Concorde could get across the Atlantic. Without running a fuel course here, you won't understand how it's managed. Suffice it to say, that it isn't simple, and it's almost certainly not the way you think it's done.

A thread with a list of airlines who habitually make computer generated fuel loading decisions and leave the pilots to carry the can or work elsewhere would be useful.

Most would be obvious...and in any event such a list would offer you no useful information. You only think it would...sorry.

 

[knasty]

JB you mentioned max thrust uses less fuel. Normal train of thought is higher acceleration rate = lower fuel efficiency in a car for example. Can you add detail on the efficiency point please? Less time on the ground more than offsets the higher burn rate?

 

[Awesom Andy]

Most would be obvious...and in any event such a list would offer you no useful information. You only think it would...sorry.

The way I think of it is that no matter how much they have at take off, as long as they have enough at landing and that the pilots have no issues with diverting when it's called for, it's fine.

 

[torks]

I've just seen on the Sydney Atis the note "ELT operating vicinity of AD". After a bit of googling I think ELT means Emergency Locator Transmitter. Am I correct in this why would it be on and what effect, if any, does it have on other aircraft operating?

Thanks,

 

[jb747]

JB you mentioned max thrust uses less fuel. Normal train of thought is higher acceleration rate = lower fuel efficiency in a car for example. Can you add detail on the efficiency point please? Less time on the ground more than offsets the higher burn rate?

Jet engines are at their most efficient when at full thrust (or close to it). For metallurgical reasons this isn't a great idea. Like everything else in aviation, it's a trade off.

 

[jb747]

The way I think of it is that no matter how much they have at take off, as long as they have enough at landing and that the pilots have no issues with diverting when it's called for, it's fine.

Which basically sums up the concept under which they operate.

Do I have enough fuel to go somewhere right now, legally? The aim is to ensure the answer is yes for the entire flight.

It's doubly nice if the somewhere is the destination.