Lear Jet tire pressure
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Lear Jet tire pressure
Hi, my company tells me that we dont need to check tyre pressure on Lear 60XR is not required, I spoke to another captain who says that they have never got this exemption from the LBA, what is the rulling, how do you find out who the guy is at the LBA looking aftet the AOC?
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We check the tires on the lear 60 every 4 days , I am not sure if this is a regulation though, but I think it's a good way to monitor the condition of the tires! I am not sure if this is helpful, but I saw that nobody else had replied!
Happy landings!
Happy landings!
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As per the below you should find the answer to your question in the AFM, besides the Advisory Wire, an AD was issued:
EASA Airworthiness Directives Publishing Tool
Bombardier AW 32-047
Maintenance Manual changes:
1. Learjet maintains the Chapter 12 recommendation for preflight tire pressure checks and has moved this to the forefront of this chapter.
2. The Maintenance Manual now states tire pressure checks must be taken per the revised AFM limitations (96 hour check requirement prior to flight).
3. Tire pressure checks must be documented. A sample form to record tire pressures will be included in the Temporary Revision to the Maintenance Manual. It should be noted, an aircraft logbook entry is not required when recording this action.
4. The Temporary Revision will also include a Tire Pressure Check Procedure. Additionally, it is not required for an A&P Mechanic to perform this check or document the readings.
EASA Airworthiness Directives Publishing Tool
Bombardier AW 32-047
Maintenance Manual changes:
1. Learjet maintains the Chapter 12 recommendation for preflight tire pressure checks and has moved this to the forefront of this chapter.
2. The Maintenance Manual now states tire pressure checks must be taken per the revised AFM limitations (96 hour check requirement prior to flight).
3. Tire pressure checks must be documented. A sample form to record tire pressures will be included in the Temporary Revision to the Maintenance Manual. It should be noted, an aircraft logbook entry is not required when recording this action.
4. The Temporary Revision will also include a Tire Pressure Check Procedure. Additionally, it is not required for an A&P Mechanic to perform this check or document the readings.
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Imperial Jet tell us they dont need to do it as often becuase of an exemption and we get shoutedd at by the monkeys in the offices if wes ask for it, it is dangerous I hear and there should be a law about it now i am tell by a lear guy..
The requirement will be written in your own company Ops manual part B. The pre flight checks are defined by your company and published here. It is also in your maintenance programme, if there is a daily maintenance check which requires a tyre pressure check then do it. The simple answer is that you need to do what is written in your Part B ops manual.
Most companies do not like line pilots talking to the Ops inspector but you can find him by calling the authority, asking for the FOI department and asking for the inspector for your company.
Personally I do not like tyre pressure checks every day as you are effectively asking pilots to let down the tyres by degrees unless you have a nitrogen rig attached to the gauge. Regular maintenance checks with good visual guides will help you. I use a pen or other measuring stick on walk round to check both wheel on the same bogie rims are the same height when I do my walk round. I have found a large number of low pressure tyres on Lears, much more ethan any other type I have flown.
Low tyre pressures has been a hobby horse of mine for many years, you must satisfy yourself that the tyres are correctly inflated. If in doubt there is no doubt!
Stay safe
MM
Most companies do not like line pilots talking to the Ops inspector but you can find him by calling the authority, asking for the FOI department and asking for the inspector for your company.
Personally I do not like tyre pressure checks every day as you are effectively asking pilots to let down the tyres by degrees unless you have a nitrogen rig attached to the gauge. Regular maintenance checks with good visual guides will help you. I use a pen or other measuring stick on walk round to check both wheel on the same bogie rims are the same height when I do my walk round. I have found a large number of low pressure tyres on Lears, much more ethan any other type I have flown.
Low tyre pressures has been a hobby horse of mine for many years, you must satisfy yourself that the tyres are correctly inflated. If in doubt there is no doubt!
Stay safe
MM
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Mistaken I may be; but AFAIK the FAA exemption only allows
Pilots' to perform the tyre pressure checks ie it exempts the operator from having to call in the friendly neighbourhood A & P / Repair station
to certify the check each time it is performed.
Does not exempt the operator from the terms and conditions of the AD
Anyways; if you're worried about losing pressure each time you check 'em
get your boss to install Learjet SB.60-32-32 (electrickery 'smart' pressure caps)
ttfn
Pilots' to perform the tyre pressure checks ie it exempts the operator from having to call in the friendly neighbourhood A & P / Repair station
to certify the check each time it is performed.
Does not exempt the operator from the terms and conditions of the AD
Anyways; if you're worried about losing pressure each time you check 'em
get your boss to install Learjet SB.60-32-32 (electrickery 'smart' pressure caps)
ttfn
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oh my ...
Well Friends ,its out there since that accident in the US of A .
Lear 60 needs tire pressure checked approx ever 96 hours ,thats not Block hours !!!
Pilots need an Approved Mechanic to show them how to check tire pressure.
Refill not allowed ,only approved mechanic can do that .
Never heard of any written exemption.
In my eyes an excuse from Operators to save costs .
The one and only .....Fischmeister !!
Lear 60 needs tire pressure checked approx ever 96 hours ,thats not Block hours !!!
Pilots need an Approved Mechanic to show them how to check tire pressure.
Refill not allowed ,only approved mechanic can do that .
Never heard of any written exemption.
In my eyes an excuse from Operators to save costs .
The one and only .....Fischmeister !!
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Fuel Drains Jet aircraft.
Locust:
A word of advice about Fuel drains, If you do not do them, then you deserve anything that may happen to you, that is caused by Fuel contamination.
Tmb
A word of advice about Fuel drains, If you do not do them, then you deserve anything that may happen to you, that is caused by Fuel contamination.
Tmb
pbf. Checking the tyre pressure in accordance with the Bombardier AW 32-047 revision is an airworthiness directive FAA 2010-11-11 also mandated by EASA. It is a safety issue and your neck and all who travel in your aircraft depend on this being complied with as specified in the AD. If your operator says they have an exemption insist on them providing you with a copy.
If you operate the aircraft without complying with this AD the Certificate of Airworthiness is invalid.
If you operate the aircraft without complying with this AD the Certificate of Airworthiness is invalid.
The following applies to aircraft under the purview of the FAA. Any differences in interpretation by other countries regulatory authorities is beyond the scope my own knowledge. However I would not expect European agencies to differ by much.
In the USA, there is no exemption from compliance with ADs. SBs and STCs may provide alternate means of compliance, but the AD must be complied with. The "smart stem" is an example of incorporating an STC to comply with the AD by an acceptable alternate means.
There IS an exemption mentioned in a Bombardier training document, but it is NOT an exemption from compliance with the AD. It is an exemption from a requirement that part 135 operators must consider tire pressure checking to be a maintenance function pilots cannot perform. The exemption states that when properly trained, part 135 pilots may perform the AD required tire pressure check. Pilots operating under part 91 have never been precluded by regulation from performing the check. There is an FAA legal council finding that checking tires is a "preventative maintenance" activity and therefore may be performed by pilots under the provisions of part 91. The exemption simply extends the permissibility of this activity to part 135 pilots with the approval of the required training and procedures by the certificate holders FAA inspection team. (POI/PMI)
I suggest that any Lear 60 pilots who have not done so already take the time to review the Bombardier training document on the subject.
The actual causes of the accident which precipitated this mess involve more factors than just the underinflated tires, but that was indeed the first link in the accident chain. T/R and FADEC logic with a disconnected squat switch combined with crew response issues round out the major holes in the cheese.
Shortly after that accident while undergoing recurrent training at Bombardier, we had the opportunity to recreate several variations of the accident scenario. (extra sim time at Bombardier's expense) Failed tires or not, this outcome simply should not have occurred.
Happy flying in the 60! It's a real pleasure to fly in spite of it's shortcomings.
westhawk
In the USA, there is no exemption from compliance with ADs. SBs and STCs may provide alternate means of compliance, but the AD must be complied with. The "smart stem" is an example of incorporating an STC to comply with the AD by an acceptable alternate means.
There IS an exemption mentioned in a Bombardier training document, but it is NOT an exemption from compliance with the AD. It is an exemption from a requirement that part 135 operators must consider tire pressure checking to be a maintenance function pilots cannot perform. The exemption states that when properly trained, part 135 pilots may perform the AD required tire pressure check. Pilots operating under part 91 have never been precluded by regulation from performing the check. There is an FAA legal council finding that checking tires is a "preventative maintenance" activity and therefore may be performed by pilots under the provisions of part 91. The exemption simply extends the permissibility of this activity to part 135 pilots with the approval of the required training and procedures by the certificate holders FAA inspection team. (POI/PMI)
I suggest that any Lear 60 pilots who have not done so already take the time to review the Bombardier training document on the subject.
The actual causes of the accident which precipitated this mess involve more factors than just the underinflated tires, but that was indeed the first link in the accident chain. T/R and FADEC logic with a disconnected squat switch combined with crew response issues round out the major holes in the cheese.
Shortly after that accident while undergoing recurrent training at Bombardier, we had the opportunity to recreate several variations of the accident scenario. (extra sim time at Bombardier's expense) Failed tires or not, this outcome simply should not have occurred.
Happy flying in the 60! It's a real pleasure to fly in spite of it's shortcomings.
westhawk
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HI All,
Quote [I]"The actual causes of the accident which precipitated this mess involve more factors than just the underinflated tires, but that was indeed the first link in the accident chain. T/R and FADEC logic with a disconnected squat switch combined with crew response issues round out the major holes in the cheese".
The squat switch issues were brought about by the tires exploding and rupturing the wires to those switches, so directly attributed to the tire pressures.
As a 32 years Aircraft Engineer, I have always told aircrew, if they think the tires look low to them, they generally are well below spec.
This incident, tragic as it was, highlighted the short comings of the Lear 60, with those dinky wheels and brakes, so much so the an EASA AD was released, which is binding law in the European community, so WHY are you bitching about it, it is meant to save your lives at the end of the day.
£50/100 to top up tires is damn better than phoning your boss, [if you are still around] that you have mashed the airplane
Jetset41
Quote [I]"The actual causes of the accident which precipitated this mess involve more factors than just the underinflated tires, but that was indeed the first link in the accident chain. T/R and FADEC logic with a disconnected squat switch combined with crew response issues round out the major holes in the cheese".
The squat switch issues were brought about by the tires exploding and rupturing the wires to those switches, so directly attributed to the tire pressures.
As a 32 years Aircraft Engineer, I have always told aircrew, if they think the tires look low to them, they generally are well below spec.
This incident, tragic as it was, highlighted the short comings of the Lear 60, with those dinky wheels and brakes, so much so the an EASA AD was released, which is binding law in the European community, so WHY are you bitching about it, it is meant to save your lives at the end of the day.
£50/100 to top up tires is damn better than phoning your boss, [if you are still around] that you have mashed the airplane
Jetset41
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The following report is a very good example of why Lear tire pressures should be checked on a regular basis, regardless of what the "official" line may be. As one who has personal experience of a Lear tyre failure at V1 due to low pressure I cannot stress enought the importance of regular checks.
A tragic accident......
http://www.ntsb.gov/doclib/reports/2010/AAR1002.pdf
A tragic accident......
http://www.ntsb.gov/doclib/reports/2010/AAR1002.pdf
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Hi
@Jetset41
Good Morning ,
Noone was bitching or complaining,regulations are there to be followed.
Only thing you need to bare in mind is that sometimes Operators just think they can skip regulations .
The chap who wrote this article basically is screwed if company does not provide assistance concerning proper maintenance.
Then again is PIC decision to either comply or cancel flight .In these troubled days not an easy decision.
Safety or no Job,as we all know and have seen in the past (especially in eastern hemispheres) there can be a lot of pressure if u need to feed a family .
Closing i need to say :Regulations,Limits,Minima are there to be followed !I would not hesitate to bring in my veto if this would ever be questioned.
BRGDS
THE one and only ...Fischmeister !!
Good Morning ,
Noone was bitching or complaining,regulations are there to be followed.
Only thing you need to bare in mind is that sometimes Operators just think they can skip regulations .
The chap who wrote this article basically is screwed if company does not provide assistance concerning proper maintenance.
Then again is PIC decision to either comply or cancel flight .In these troubled days not an easy decision.
Safety or no Job,as we all know and have seen in the past (especially in eastern hemispheres) there can be a lot of pressure if u need to feed a family .
Closing i need to say :Regulations,Limits,Minima are there to be followed !I would not hesitate to bring in my veto if this would ever be questioned.
BRGDS
THE one and only ...Fischmeister !!
Reading and understanding
Jetset41:
I don't know where you got the idea that anyone was "bitching". Lear 60 pilots tend to be intimately familiar with the limitations imposed by the decidedly undersized MLG wheels, tires and brakes. Your decades of engineering experience aside, I think it's poor form for you take such a condescending tone with someone whose expertise you know nothing about. I for one fully understand the potential consequences of blown tires at high speed in a 60. Enough on that subject.
Now on to the matter of the squat switches and their relation to the T/R and FADEC operation logic. When the tire debris wiped out the squat switch, the T/Rs were already deployed, the sub levers unlocked and pulled up so as to increase engine N1s. T/Rs autostowed as a result of the change in air/ground status. Reversers now stowed, the engine N1s remained high, but now producing forward thrust. That is the relation of this accident to the T/R and FADEC logic. The Captain's decision to abort well above V1 is the primary crew action related to this accident. (other than missing the low tire(s) on pre-flight.)
I hope you can now see the logic behind my post. If not, I suggest reading the accident report so kindly linked by another poster to better understand. It was NOT just the tire failure alone which caused this accident. As I stated before, the underinflated tire(s) was just the first link in the accident chain.
I also pointed out that I had the opportunity to run through several variations on this accident in Bombardier's Lear 60 sim shortly after the accident occurred. Satisfactory outcomes were achieved by continuing the takeoff, leaving the gear down, burning off fuel and returning to land. Rejecting the takeoff at 140 KIAS and duplicating the failure mode experienced by the accident airplane, we consistently stopped the airplane on the available runway. The difference between what we did and what was done on the accident takeoff is that we knew the T/Rs had stowed, so we pushed the levers down to the stowed position which returned the engines to idle forward thrust. In air mode, the anti-skid must be switched off. Pneumatic braking is another option. Even with all tires and brakes fully serviceable, there is no hope of stopping a 60 at takeoff thrust from high speed. None. Without pushing the T/R levers down, they never had a chance.
It should be noted that a very similar failure had occurred some years prior in another 60 when a deer or some animal was struck on a runway during landing. In that case, the overrun was at low speed and nobody was hurt. If I remember right, the airplane belonged to the owner of the Dallas Cowboys. It was following that earlier occurrence that Learjet came up with a "fix" that failed to adequately address this design deficiency. This accident was quite instructive in many more ways than just proper tire care, important as that may be.
I apologize for the long rant, but I feel that these things need to be clarified for the benefit of Lear 60 pilots and passengers. Simply blaming a flat tire fails to address the totality of the safety issues involved.
Please read the full accident report linked in specialbrew's post above. Most illuminating.
Best regards,
westhawk
I don't know where you got the idea that anyone was "bitching". Lear 60 pilots tend to be intimately familiar with the limitations imposed by the decidedly undersized MLG wheels, tires and brakes. Your decades of engineering experience aside, I think it's poor form for you take such a condescending tone with someone whose expertise you know nothing about. I for one fully understand the potential consequences of blown tires at high speed in a 60. Enough on that subject.
Now on to the matter of the squat switches and their relation to the T/R and FADEC operation logic. When the tire debris wiped out the squat switch, the T/Rs were already deployed, the sub levers unlocked and pulled up so as to increase engine N1s. T/Rs autostowed as a result of the change in air/ground status. Reversers now stowed, the engine N1s remained high, but now producing forward thrust. That is the relation of this accident to the T/R and FADEC logic. The Captain's decision to abort well above V1 is the primary crew action related to this accident. (other than missing the low tire(s) on pre-flight.)
I hope you can now see the logic behind my post. If not, I suggest reading the accident report so kindly linked by another poster to better understand. It was NOT just the tire failure alone which caused this accident. As I stated before, the underinflated tire(s) was just the first link in the accident chain.
I also pointed out that I had the opportunity to run through several variations on this accident in Bombardier's Lear 60 sim shortly after the accident occurred. Satisfactory outcomes were achieved by continuing the takeoff, leaving the gear down, burning off fuel and returning to land. Rejecting the takeoff at 140 KIAS and duplicating the failure mode experienced by the accident airplane, we consistently stopped the airplane on the available runway. The difference between what we did and what was done on the accident takeoff is that we knew the T/Rs had stowed, so we pushed the levers down to the stowed position which returned the engines to idle forward thrust. In air mode, the anti-skid must be switched off. Pneumatic braking is another option. Even with all tires and brakes fully serviceable, there is no hope of stopping a 60 at takeoff thrust from high speed. None. Without pushing the T/R levers down, they never had a chance.
It should be noted that a very similar failure had occurred some years prior in another 60 when a deer or some animal was struck on a runway during landing. In that case, the overrun was at low speed and nobody was hurt. If I remember right, the airplane belonged to the owner of the Dallas Cowboys. It was following that earlier occurrence that Learjet came up with a "fix" that failed to adequately address this design deficiency. This accident was quite instructive in many more ways than just proper tire care, important as that may be.
I apologize for the long rant, but I feel that these things need to be clarified for the benefit of Lear 60 pilots and passengers. Simply blaming a flat tire fails to address the totality of the safety issues involved.
Please read the full accident report linked in specialbrew's post above. Most illuminating.
Best regards,
westhawk
Last edited by westhawk; 22nd Aug 2011 at 12:57.