C402b fuel system
Thread Starter
Join Date: Oct 2007
Location: Buenos Aires
Age: 39
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
C402b fuel system
Hello people. Can anyone help me with the fuel system of the cessna mentioned? I have some knowledge about it but not too much..
Thanks in advance...
Thanks in advance...
Join Date: May 2002
Location: Permanently lost
Posts: 1,785
Likes: 0
Received 0 Likes
on
0 Posts
Ditch the B model and get a C.
Cessna always take until the last model to get the details right. Why they ever thought the system they used on the 310 and early 402 models were acceptable, I do not know.
The POH will give you the fine detail but essentially, do not use the auxilliary tanks until you have burnt at least an hour out of the mains. The reason is that the engines draw more fuel than required from the tanks and return the excess to the main tank only. More than one person has got to top of climb in a 310 or early 402 and switched to the auxs only to wonder some time later why they are now seriously short on fuel.
The C model did away with the tip tanks and the auxs. Just a left and right tank to worry about.
I think the earlier system was probably designed by the "B Team" at Cessna.
Cessna always take until the last model to get the details right. Why they ever thought the system they used on the 310 and early 402 models were acceptable, I do not know.
The POH will give you the fine detail but essentially, do not use the auxilliary tanks until you have burnt at least an hour out of the mains. The reason is that the engines draw more fuel than required from the tanks and return the excess to the main tank only. More than one person has got to top of climb in a 310 or early 402 and switched to the auxs only to wonder some time later why they are now seriously short on fuel.
The C model did away with the tip tanks and the auxs. Just a left and right tank to worry about.
I think the earlier system was probably designed by the "B Team" at Cessna.
Join Date: Mar 2001
Location: Perth
Posts: 841
Likes: 0
Received 0 Likes
on
0 Posts
Perhaps a different explanation of what Plovett is talking about:
The C310 and C402 A and B have a fuel system that can allow pilots to vent fuel overboard accidently if they incorrectly manage their fuel burn.
Just think about one side of the aircraft, i.e. LH engine and tanks:
The fuel supplied to the engine is drawn from the fuel tank selected on the fuel taps ( either LH Mains, LH Auxilary and in some models of the aircraft, cross flow from the RH main ), roughly about two litres per minute is drawn from the selected tank.
Only about one litre per minute is consumed by the engine.
The other litre per minute is routed back directly to that engine main tank, i.e. LH main for the LH engine and RH main for the RH engine.
Irrespective of which tank you have selected , the LH engine will alway feed roughly one litre per minute back to the LH main tank ( and like wise for the RH side ).
So if you are flying an aircraft with the 118 litre aux tanks, when you select this tank, the engine will draw roughly 2 litres per minute from the Aux, burn one of those litres and route the other litre to the respective main tank.
So, if you burn 30 litres out of the main tank then select the 118 litre aux tank, the main tank will only be able to hold an additional 30 litres of the 59 ( 118 divided by 2 ) odd litres the engine will send its way, therefore, it will vent the remaining 29 odd litres overboard.
The Cross feed position only selects the opposite sides main tank.
So, if you have an engine failure inflight, say the RH engine, you will not be able to get the fuel from the RH aux fuel tank to the LH engine ( not technically correct, with a bit of rat cunning there is a way, but thats what the flight manual tells you and i do not think it my place to tell you something other than what the flight manual dictates ).
Enjoy, Cessna 310/402, delivering engineers to broken Chieftains all over the world, daily
.
The C310 and C402 A and B have a fuel system that can allow pilots to vent fuel overboard accidently if they incorrectly manage their fuel burn.
Just think about one side of the aircraft, i.e. LH engine and tanks:
The fuel supplied to the engine is drawn from the fuel tank selected on the fuel taps ( either LH Mains, LH Auxilary and in some models of the aircraft, cross flow from the RH main ), roughly about two litres per minute is drawn from the selected tank.
Only about one litre per minute is consumed by the engine.
The other litre per minute is routed back directly to that engine main tank, i.e. LH main for the LH engine and RH main for the RH engine.
Irrespective of which tank you have selected , the LH engine will alway feed roughly one litre per minute back to the LH main tank ( and like wise for the RH side ).
So if you are flying an aircraft with the 118 litre aux tanks, when you select this tank, the engine will draw roughly 2 litres per minute from the Aux, burn one of those litres and route the other litre to the respective main tank.
So, if you burn 30 litres out of the main tank then select the 118 litre aux tank, the main tank will only be able to hold an additional 30 litres of the 59 ( 118 divided by 2 ) odd litres the engine will send its way, therefore, it will vent the remaining 29 odd litres overboard.
The Cross feed position only selects the opposite sides main tank.
So, if you have an engine failure inflight, say the RH engine, you will not be able to get the fuel from the RH aux fuel tank to the LH engine ( not technically correct, with a bit of rat cunning there is a way, but thats what the flight manual tells you and i do not think it my place to tell you something other than what the flight manual dictates ).
Enjoy, Cessna 310/402, delivering engineers to broken Chieftains all over the world, daily
.
Last edited by Lefthanded_Rock_Thrower; 19th Jan 2008 at 05:01.
"do not use the auxilliary tanks until you have burnt at least an hour out of the mains"
That never seemed an issue to me! Perhaps because when I did the endorsement I was told "do not use the auxilliary tanks until you have burnt at least an hour out of the mains"!!
I do, however, seem to recall a process we went through on pre-flight to check the function of the fuel pumps, but I can't tell you the details without recourse to the POH. Does suggest an overly complex system.
Flying an executive configured C402B around outback Qld remains one of the highlights of my flying career. I just loved the thing. Two flights only in the C402C did not evoke the same feelings, and my one and only flight in the plain old C402 (ex Bushies VH-BPX) is probably best not recalled. Never flew the C402A.
For one memorable flight in from Mt Isa I was accompanied by an armed security guard and load of gold bullion - entertained myself the whole trip contemplating whacking the guard with my Maglight, turfing him out at some remote strip, and heading for the Solomons!
Dr
PS: "Cessna 310/402, delivering engineers to broken Chieftains all over the world, daily" - yeah, we used to deliver technicians to broken ATMs all over Qld.
That never seemed an issue to me! Perhaps because when I did the endorsement I was told "do not use the auxilliary tanks until you have burnt at least an hour out of the mains"!!
I do, however, seem to recall a process we went through on pre-flight to check the function of the fuel pumps, but I can't tell you the details without recourse to the POH. Does suggest an overly complex system.
Flying an executive configured C402B around outback Qld remains one of the highlights of my flying career. I just loved the thing. Two flights only in the C402C did not evoke the same feelings, and my one and only flight in the plain old C402 (ex Bushies VH-BPX) is probably best not recalled. Never flew the C402A.
For one memorable flight in from Mt Isa I was accompanied by an armed security guard and load of gold bullion - entertained myself the whole trip contemplating whacking the guard with my Maglight, turfing him out at some remote strip, and heading for the Solomons!
Dr
PS: "Cessna 310/402, delivering engineers to broken Chieftains all over the world, daily" - yeah, we used to deliver technicians to broken ATMs all over Qld.
Last edited by ForkTailedDrKiller; 19th Jan 2008 at 05:57.
Join Date: Mar 2001
Location: Perth
Posts: 841
Likes: 0
Received 0 Likes
on
0 Posts
One other issue i have had with the C402/C310 is hot starting.
The Left and Right Landing lights circuit breakers also power the ticker pumps ( these are located on the bottom side of the main fuel tank pods, turn the master on and you should hear them tick tick ticking ).
When priming a hot engine, i have had more sucess by opening the cct breaker during the start and priming the fuel system with the fuel pumps in the "HI" position.
Ensure the cct breakers are closed after start.
I have had little sucess using the "prime" function switch, surely someone else here would have some solid advice on how to best use the prime function.
The Left and Right Landing lights circuit breakers also power the ticker pumps ( these are located on the bottom side of the main fuel tank pods, turn the master on and you should hear them tick tick ticking ).
When priming a hot engine, i have had more sucess by opening the cct breaker during the start and priming the fuel system with the fuel pumps in the "HI" position.
Ensure the cct breakers are closed after start.
I have had little sucess using the "prime" function switch, surely someone else here would have some solid advice on how to best use the prime function.
Join Date: Aug 2003
Location: Sale, Australia
Age: 80
Posts: 3,833
Likes: 0
Received 0 Likes
on
0 Posts
Here is a 421B fuel diagram I got from the web some time ago. I suspect its not dissimilar to the 402. Sorry for the quality but may be enough to get an idea.
Join Date: May 2005
Location: Here and there.
Posts: 447
Likes: 0
Received 0 Likes
on
0 Posts
and my one and only flight in the plain old C402 (ex Bushies VH-BPX) is probably best not recalled.
Have many, many hours flogging around the outback in BPX and her sister ship RDZ. Wonderful old beasties. Have to agree that they were both a bit rough around the edges though.
Dare I complicate the issue further by adding that some of the earlier models had slipper tanks in the wing lockers as well (VH-RDZ....RIP)!!
The C310/402 fuel system is a little involved but by no means difficult to manage. Just requires a little FORTHOUGHT and fuel management should ALWAYS have some of that.
D
Join Date: Mar 2001
Location: Perth
Posts: 841
Likes: 0
Received 0 Likes
on
0 Posts
RDZ RIP ???
What happened, flew her in YBMA a few years ago, looks terrible, is the fastest C402 i've flown, lowest TAS I saw was 192 kts ( hot and heavy with four body bags onboard ).
Not very many have the nacelle tank/s fitted.
What happened, flew her in YBMA a few years ago, looks terrible, is the fastest C402 i've flown, lowest TAS I saw was 192 kts ( hot and heavy with four body bags onboard ).
Not very many have the nacelle tank/s fitted.
Join Date: May 2005
Location: Here and there.
Posts: 447
Likes: 0
Received 0 Likes
on
0 Posts
Different generation of RDZ LHRT. The original RDZ (c402) was a 402 straight model. Last I saw her she was looking very sad and sorry at Charters Towers in the late 90's early 00's. Think she ran out of airframe/spar life. Tough old plane thats for sure. I was one of many that cut their multi engine teeth with RDZ strapped to the back and a truckload of mail (or a Magistrate) just behind. Most fun you can have with your pants on.
I sure there are many reading this that will concur.
D
Edit: You've got me thinking now. Maybe it was BPX in the long grass at Charters Towers. I know one of the call signs got a new airframe some years ago. I'm sure someone will straighten me out.
I sure there are many reading this that will concur.
D
Edit: You've got me thinking now. Maybe it was BPX in the long grass at Charters Towers. I know one of the call signs got a new airframe some years ago. I'm sure someone will straighten me out.
Join Date: Mar 2001
Location: Perth
Posts: 841
Likes: 0
Received 0 Likes
on
0 Posts
I thought that was RDZ, there is an old C402 in some Transport/SES yard in YMBA, that i believe was once VH-RDZ ( decommisioned many years ago ), then the C402A might have gotten the RDZ rego when it changed from the P2 rego ?.
Join Date: May 2005
Location: Here and there.
Posts: 447
Likes: 0
Received 0 Likes
on
0 Posts
LHRT/Jamair,
RDZ and BPX were sister ships (ie consecutive production numbers) I think. Both born in '67. BPX first delivered to a company in PNG. Not sure about RDZ.
Flew RDZ (and BPX) for some time and remember that it was the mail plane mostly as it was nearing it's spar life and it could carry a little more gas if necessary. Pretty sure, but not positive, that it was 'retired' towards the turn of the century (fitting really) and was rebranded as an A model (only a slight improvement I'm told). That may be the one you you're thinking of.
Back to the thread for old mate.
Try http://www.esscoaircraft.com/Cessna_402B_POH_p/4808.htm and buy a copy for your own reference. A must have if you intend doing any flying in the machine. Although it will (at least should) come with it's own copy, having one of your own is not a bad idea.
D
RDZ and BPX were sister ships (ie consecutive production numbers) I think. Both born in '67. BPX first delivered to a company in PNG. Not sure about RDZ.
Flew RDZ (and BPX) for some time and remember that it was the mail plane mostly as it was nearing it's spar life and it could carry a little more gas if necessary. Pretty sure, but not positive, that it was 'retired' towards the turn of the century (fitting really
) and was rebranded as an A model (only a slight improvement I'm told). That may be the one you you're thinking of.Back to the thread for old mate.
Try http://www.esscoaircraft.com/Cessna_402B_POH_p/4808.htm and buy a copy for your own reference. A must have if you intend doing any flying in the machine. Although it will (at least should) come with it's own copy, having one of your own is not a bad idea.
D
Join Date: Sep 2006
Location: Melbourne
Posts: 1,569
Likes: 0
Received 0 Likes
on
0 Posts
what about the early C400 series avionics?.............tuneable ADF's (now that was an art!) & that A/P......if you had the C400B (& it was serviceable) you where flying high class !
Great old planes, did us Aussies well for learning the real art of flying!
CW
Great old planes, did us Aussies well for learning the real art of flying!
CW
PLovett, the Cessna C402A/B Fuel system is no worse than a lot of other aircraft fuel systems. Cessna's engineers designed it that way for a reason, there is plenty of good material published over the years on the design and and the reasoning on correct use.
Always interesting to watch people who been given a quickie endorsement on Cessna 300 or Cessna 400 series aircraft.
You state C402c is the only way to go, for starters how do you know how much fuel you actually on board unless you fill up the tanks? You really going to trust fuel gauges?
Always interesting to watch people who been given a quickie endorsement on Cessna 300 or Cessna 400 series aircraft.
You state C402c is the only way to go, for starters how do you know how much fuel you actually on board unless you fill up the tanks? You really going to trust fuel gauges?
You state C402c is the only way to go, for starters how do you know how much fuel you actually on board unless you fill up the tanks?
PS.. If I recall correctly, the bottom of the Fuel Nozzle Guard = 1000lbs!
Join Date: May 2002
Location: Permanently lost
Posts: 1,785
Likes: 0
Received 0 Likes
on
0 Posts
Stationair8
I happpen to be flying a 402C at the moment where the gauges have been proven to be accurate to within 5 to 10 litres and I am talking about the original gauges.
And Capt Wally, it has a 400b autopilot where it all works including being able to do a coupled approach.
Incidentally, if the early fuel system was designed that way for a reason they why did they change it? Had a better idea perhaps, which was my orginal point. My gripe with it primarily has to do with flying multiple short sectors when I needed more fuel than just the mains and no sector was more than an hour. The only way was to keep a very detailed fuel log involving the number of minutes spent on mains and then auxs to ensure I didn't "overfill" the mains. A pain in the proverbial.
For ease of use I still think the Aero Commander has them all beat. Five cells interconnected with both engines drawing from the same source.
I happpen to be flying a 402C at the moment where the gauges have been proven to be accurate to within 5 to 10 litres and I am talking about the original gauges.
And Capt Wally, it has a 400b autopilot where it all works including being able to do a coupled approach.
Incidentally, if the early fuel system was designed that way for a reason they why did they change it? Had a better idea perhaps, which was my orginal point. My gripe with it primarily has to do with flying multiple short sectors when I needed more fuel than just the mains and no sector was more than an hour. The only way was to keep a very detailed fuel log involving the number of minutes spent on mains and then auxs to ensure I didn't "overfill" the mains. A pain in the proverbial.
For ease of use I still think the Aero Commander has them all beat. Five cells interconnected with both engines drawing from the same source.