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EK380
20th Sep 2005, 15:30
Hi guys,


Have a question for you A330-340 (and maybe 320) drivers...

Here I go;

The VOL2 special OPS 2.04.25 explains what the procedure is for dispatching with a landing gear that will not retract. One of the limitations on 2.04.25 p1 is the max altitude of 35000ft i.s.o. 21000ft.

The text in the 1st paragraph says;

This chapter applies to dispatch with landing gear down However the limitations and inflight performance also apply in case of an inflight landing gear retraction failure....

Question;

Does this mean that if you take off and the gear doesn't retract due to e.g. a microswitch problem, one can climb to e.g. FL240 i.s.o. the VOL3 21000ft limitation.....?


It might be another problem if the gear can't retract after a gravity gear extension since the landing gear doors remain open after a case like this.


If seems pretty straightforward to me, but people seem to have different opinions on the above....


Any thoughts please....?



Regards


:confused:

jayalion
20th Sep 2005, 15:42
I think the 21000 ft is only a inflight squat switch operation limitation. When dispatching this limit does not apply. You could fly at 24000 ft without limitations other than gear down operation speed.
Doors opened is a different agenda all together!!!!

Zeke
20th Sep 2005, 16:43
Does this mean that if you take off and the gear doesn't retract due to e.g. a microswitch problem, one can climb to e.g. FL240 i.s.o. the VOL3 21000ft limitation.....?

Vol 3 - GENERAL LIMITATIONS


Maximum altitude at which the landing gear may be extended . . . . . . . . . . . . . . . .21,000 FT

Vol 2 - FLIGHT WITH GEAR DOWN LIMITATIONS

— The maximum altitude is 35,000 FT.
— Do not fly into expected icing conditions
— Ditching with landing gear down has not been demonstrated.
— Do not use managed speed (except in approach), and CLB and DES autopilot modes.
— Disregard FM fuel predictions. Other predictions should also be disregarded (altitude, speed and time), except time predictions at waypoints when in cruise.



MEL - Landing Gear

Retracting System

A 1 0 *(o) May be inoperative for a maximum of three flights provided the aircraft is operated in accordance with the Flight Manual supplement for the flight with landing gear down.

Does this mean that if you take off and the gear doesn't retract due to e.g. a microswitch problem, one can climb to e.g. FL240 i.s.o. the VOL3 21000ft limitation.....?


Yes, Vol 3 is for the action of extending the gear, Vol 2 for the gear already extended condition.

Gear door position is only applicable to the ferry flight condition, must be closed on takeoff, takeoff performance consideration.

340 differances - Revenue flight is permitted with the L/G down, and the gear doors closed in the conditions stated below. The aft doors of the center landing gear must be removed.

EK380
21st Sep 2005, 09:06
Guys,

Thanks for the replies so far

I understand the MEL considerations etc...

Lets only talk A330 for now.

Briefly 2 more questions to make it 100% clear :

1/ The gear does not move at all after t/o ( gear doors still closed), retraction failure. What is my max altitude... 21000ft or 35000ft ?


2/ The gear is stuck down after a gravity extension, no HYD G press and the gear doors remain open. What is my max altitude... 21000ft or 35000ft ?


Thanks and regards:D

Zeke
21st Sep 2005, 10:44
EK380,

My understanding is 35,000 ft for both questions, the limit is for when the gear is extended.

Referance question 2, I am aware of no altitude restriction with gear doors open and gear retracted, just a speed restriction 250/.55, see VOL 3 L/G DOORS NOT CLOSED.

Only provision for a takeoff is that gear doors must be closed.

FlexibleResponse
21st Sep 2005, 13:29
Hmmm….

Gear Extended Max Operating limits
IAS = 250 kts
Mach No = 0.55
Pressure Alt = 21,000 ft

What could be the common factor? We try these numbers on the pilots CR4 magic wheel…

Sacre Bleu, they all line up!

Voila! The maximum dynamic pressure, Mach No and Pressure altitude are coincident for these particular values. Those Froggie aircraft designers are very smart cookies indeed!

Therefore, may I fly above 21,000ft with gear extended? Yes provided you stay below M0.55.
But what will be my IAS? Something less than 250 kts.
If I had to plan a flight with gear extended, what would be the maximum practical altitude to fly without exceeding the IAS and Mach No limits and yet maintain sufficient buffer above stall speed (green dot or above for the initiated)? Maybe about 220-240 kts at 21,000 ft should keep everyone happy.

PS. M0.55 = 183 kts at 35,000 ft. You won’t be at that altitude for long with flaps retracted…and you shouldn’t be there with flaps extended!

EK380
22nd Sep 2005, 09:21
Thanks guys....


Please feel free to post them, if more or other views on the above. ..:D

Marcellus Wallace
22nd Sep 2005, 09:50
IMHO the 21,000 foot limit will keep you out of trouble when you get airborne and suddenly cannot retract the gear - i.e. fly at maximum of 21,000 feet - 250kts IAS/M.55 whichever lower.

I would fathom that you would either return to base or divert if weather or airfield conditions were unsuitable for a turnback - maximum altitude 21,000 feet and maximum speeds as above...better make a PA coz I am guessing it'll get pretty noisy and lot's of vibration in the cabin at that altitude and speed.

The 35,000 feet limit is for DISPATCH with the gear down due to some fault which is known etc. - you can plan the TOW and the most suitable altitude/FL plus you must already account for the Takeoff performance with the gear down - should the engine fail on you.

Nonetheless if the former happens to you and you decide to divert - it would be prudent to have a look at the VOL 2 notes to decide on routing (within 50nm of land) and the planned fuel burn with the gear down. It also has all the other nice bits of information you will most likely need to use.

As the table in VOL 2 suggests - you will be nearly empty at DOW to fly at FL350 - so that your Vls will be at least 20 knots below the 250/M.55 limit.

Take note as well this information is in "Special Operations" of Vol 2 - i.e. it's not for abnormal situations generally but definitely for a PLANNED flight - i.e. dispatching with the known fault - having considered the fuel burn, takeoff performance, enroute requirements - MEA, descent and approach plus landing requirements - with "gear down".:ok:

Sorry with reference to your questions:

1) IMHO 21,000 feet - as FlexResponse has mentioned - you CANNOT climb to FL350 or practically you would not have been able to climb above 21,000 feet unless you had departed on a short flight from DXB-SHJ - your TOW would not permit you to get up so high and still respect all the limits - Above 20000 - Flaps up , weight 200t(A332) Vls - about 230kts(FL350) - definitely above M.55!

2) Gravity extension - 200knots recommended to avoid vibrations but Limitation of 250/M.55 - same reasons as given in response above as to what altitude if you needed to divert - highly unlikely as you would have ascertained the weather conditions for a successful approach before deciding on a Gravity Extension.

Preparing for an upgrade are we?:ok:

EK380
22nd Sep 2005, 10:25
Marcellus Wallace:

Thanks for your advice.... I fully understand what you're saying.

No way, that I was thinking to climb FL350, just confused why they had, " I quote":

"This chapter applies to dispatch with landing gear down however the limitations and inflight performance also apply in case of an inflight landing gear retraction failure...."

I know that climbing to, FL240 with a 22000ft MEA would be bloody stupid, if an engine fails (... and it will in the sim).

More pratical, I understand that being more than 50NM from the shore, would infringe with the above VOL2 chapter, and would be a no go. Even if one experiences a landing gear retraction failure in flight...


Briefly, I've concluded that the VOL2 Special OPS chapter is probably the only time, one will use VOL2 in flight....

Upgrading.... yes, getting there
:confused:


Brgds

Marcellus Wallace
22nd Sep 2005, 10:36
I guess the VOL 2 says to use "in case of an inflight landing gear retraction failure" - it would be the case of gear down - unable to retract after takeoff - need to divert - need to know fuel burn etc. - that's probably when you would look at it.

All the best!

LEM
23rd Sep 2005, 10:37
Hi Airbus Drivers, I understand you can be despatched with the gear down for a revenue flight? :confused:

Do you have performance tables for a gear down takeoff?

I'm intersted because we don't...

Zeke
23rd Sep 2005, 10:51
LEM,

"Revenue flight" is the wording the MEL for the A340, not the A330. A330 ferry flight only.

EK380
23rd Sep 2005, 14:18
Zeke:

My company MEL does not say "ferry flight" for the A330.... the MEL ops procedure only sends you to the VOL 2, where it states:

"Revenue flight is permitted, with the landing gear in the down position and the gear doors closed, provided the conditions stated below are observed."


I know it shouldn't, but maybe the MMEL has something different.


Brgds

Zeke
23rd Sep 2005, 15:07
EK380,

My mistake, should have said FCOM 2, not MEL.

A330This Chapter applies to dispatch with landing gear down. However, the limitations and inflight performance also apply in case of an inflight landing gear retraction failure. Ferry flight is permitted with the landing gear in the down position and the gear doors closed in the conditions stated below. However each airline has to get approval from its national authorities to perform such a flight.

A340This Chapter applies to dispatch with landing gear down. However, the limitations and inflight performance also apply in case of an inflight L/G retraction failure. Revenue flight is permitted with the L/G down, and the gear doors closed in the conditions stated below.

You may have of course have a different engine/airframe combination to this, most CAA's as far as I know will not allow pax on the flights.

:ok:

Marcellus Wallace
23rd Sep 2005, 15:46
FCOM Vol 2(A332) for the Airline I work for - does allow revenue flight with the gear down. MEL for the airplane also allows revenue flights - maximum 3 before the defect needs to be rectified.

You would need to dispatch according to the Flight Manual - in this case our AFM performance figures have been translated into data on an onboard laptop or in Airbus speak - FOVE-LPC.

We would need to make sure to select from the list of defects for "gear down" - thus taking care of the Takeoff with gear down followed by engine failure.

I am guessing the figure will be pretty restictive and may likely result in a non-revenue flight for practical purposes on the A332.

The charts for takeoff with gear down can be found in the AFM.