Business jets & APU on landing.

[Chris24]

I was told that the smell of aviation fuel near airports is because business jets power up their auxiliary power units (apu’s) when landing.

sounds like nonsense to me when they have 2 engines already spinning and are close to the ground.

is this a thing that businesses jet pilots actually do? Do commercial jets do the same?

is there not enough battery power to run the systems and move flight controls in the final approach and landing phases?

the smell is unbearable at times and worse the closer you get to the airport perimeter.

[john_tullamarine]

I was told that the smell of aviation fuel near airports is because business jets power up their auxiliary power units (apu’s) when landing. Probably in the realm of fairy tales.

sounds like nonsense to me when they have 2 engines already spinning and are close to the ground. Indeed

is this a thing that businesses jet pilots actually do? Do commercial jets do the same? Type and operation specific but I think not at all common.

is there not enough battery power to run the systems and move flight controls in the final approach and landing phases? Not a concern. There are certification battery power requirements which provide for a reasonable spare capacity.

the smell is unbearable at times and worse the closer you get to the airport perimeter. True. Something to do with all those turbine engines operating and the density of products of combustion reducing as you get further away ?

[OutsideCAS]

the smell is unbearable at times and worse the closer you get to the airport perimeter

Answer is to stay away from airports.

Business Jets in most places don't have access to ground power units (GPU) and will use (APU) for all air conditioning and electrical needs on the ground when required - batteries alone are not viable for extended periods.

[TheAirMission]

I was told that the smell of aviation fuel near airports is because business jets power up their auxiliary power units (apu’s) when landing.

sounds like nonsense to me when they have 2 engines already spinning and are close to the ground.

is this a thing that businesses jet pilots actually do? Do commercial jets do the same?

is there not enough battery power to run the systems and move flight controls in the final approach and landing phases?

the smell is unbearable at times and worse the closer you get to the airport perimeter.
Standard operating procedure for airbus aircraft is to start the apu after landing, I assume the same for Boeings. I work for the largest bizjet company in world and on my AC type we do not start the APU on landing, and I think that is normal across the fleet. Unless we need it for technical issues or have a rare short turn around on the ground.

[Chris24]

Answer is to stay away from airports.

Business Jets in most places don't have access to ground power units (GPU) and will use (APU) for all air conditioning and electrical needs on the ground when required - batteries alone are not viable for extended periods.


sadly I live near an airport.

I think I could have been clearer in my question.

I was told that in preparation for landing, business jets have their APU’s running as an extra precaution in case of an engine issue during the landing sequence.

this is not them running whilst on the ground but running in flight as part of their preparation for landing.

I hope that is clearer.

[Chris24]

Some clarity to my question

I think I could have been clearer in my question.

I was told that in preparation for landing, business jets have their APU’s running as an extra precaution in case of an engine issue during the landing sequence.

this is not them running whilst on the ground but running in flight as part of their preparation for landing.

I hope that is clearer.

[Check Airman]

Do you mean to ask if they have the APU on while flying? The answer is almost certainly negative. After they’ve landed, it may be necessary though.

[Chris24]

Do you mean to ask if they have the APU on while flying? The answer is almost certainly negative. After they’ve landed, it may be necessary though.


no I was specifically told that they turn their APU’s on for landing

as in part of the landing procedure is to have the apu running as a precaution in case of some issue with the engines during the landing phase of the flight.

my impression was that they’d turn on the apu before contacting the tower for landing so it’s running and producing power while the aircraft is still in normal flight in preparation for the landing phase.

I hope that makes sense.

seems everyone is used to running the apu on the ground, not during flight.

[Speed_Trim_Fail]

no I was specifically told that they turn their APU’s on for landing

as in part of the landing procedure is to have the apu running as a precaution in case of some issue with the engines during the landing phase of the flight.

my impression was that they’d turn on the apu before contacting the tower for landing so it’s running and producing power while the aircraft is still in normal flight in preparation for the landing phase.

I hope that makes sense.

seems everyone is used to running the apu on the ground, not during flight.

I can tell you now that (on the business jets I am familiar with) this is most definitely not the SOP and isn’t in the AFM either. None of my colleagues have come across it; the term “biz jet” covers a huge raft of aircraft types and operators so it may be an SOP at some but I can assure you across the types my colleagues and I have flown it isn’t an SOP. No idea where the idea it has come from.

[Chris24]

I can tell you now that (on the business jets I am familiar with) this is most definitely not the SOP and isn’t in the AFM either. None of my colleagues have come across it; the term “biz jet” covers a huge raft of aircraft types and operators so it may be an SOP at some but I can assure you across the types my colleagues and I have flown it isn’t an SOP. No idea where the idea it has come from.

thanks

I had assumed I was being told nonsense.

the airport is FAB, and that is what I was told at recent presentation they did in their bid to secure extra landing slots.

I asked if they monitored for the smell of aviation fuel and the guy told me the smell was because of the apu’s the planes power on before landing.

I queried why they need the apu on during for landing and he said they use it in case of an issue with the engines during landing & the apu gives them the power needed to control the aircraft, he was suggesting it was a safety thing.

I don’t see why they’d need the apu at the airfield either.

I can understand using the apu during an emergency but not as a normal operating procedure for landing.

[TheAirMission]

I queried why they need the apu on during for landing and he said they use it in case of an issue with the engines during landing & the apu gives them the power needed to control the aircraft, he was suggesting it was a safety thing.

I don’t see why they’d need the apu at the airfield either.

I can understand using the apu during an emergency but not as a normal operating procedure for landing.
He has told you absolute nonsense!

[ATOguy]

On some types it is normal to start the APU for the approach as there are some occasions when it is necessary.
On the Challengers I fly it is needed when it is cold, as with anti-ice on it is prohibited to have the engines supplying bleed air to the pressurisation during takeoff or landing.
It is also desirable when it is very hot as the bleed air struggles to keep the cabin cooled at low power settings, but that is not normally an issue at Farnborough!
However, as a result a lot of operators routinely start it for landing since it is so common for it to be required.
On the other hand, the fuel usage and efficiency of the APU is such that it can’t possibly be adding a smell of jet fuel that would be noticeable above what is produced by engines.
But certainly what you have reported the guy as saying is nonsense.

[605carsten]

On the 600 series Challengers its normal ops to have APU running on landings and takeoffs and swap bleed sources in the air. But the exhaust coming from a small apu is non-existant compared to having the engines running. So saying its only APU causing the smell is BS..

Are you talking about raw fuel fumes or the smell of burnt jetfuel?

if its a smell of raw jet fuel, then maybe TAG has an issue with their fuel farm and how its vented.

[PDR1]

If you were listening to the audience at the Farnborough events it's worth considering that at least one of the more vocal opponents on the FCC has been given an ASBO for his sustained, truth-free personal campaigns against people and companies involved. Most of the opposition is deliciously unconstrained by and great respect for facts.

PDR

[Harry Grout]

The smell you are getting at FAB is a consequence of the inferior chemtrail systems installed in biz jets when compared to airliners. The cooling turbines are too heavy to install in smaller aircraft, so you are smelling the hot "burn off" after the system has been shut down. It is usually present for between 30-45 minutes depending on how long the system had been activated in flight. Hope that helps.

[Speed_Trim_Fail]

The smell you are getting at FAB is a consequence of the inferior chemtrail systems installed in biz jets when compared to airliners. The cooling turbines are too heavy to install in smaller aircraft, so you are smelling the hot "burn off" after the system has been shut down. It is usually present for between 30-45 minutes depending on how long the system had been activated in flight. Hope that helps.

Does the lack of cooling turbines impact the mind control qualities of the CTX?