B737 Break-away thrust?

[OhNoCB]

De facto -

Our lot also gives no info, so "That looks about right" is what is used.

[Capt. Inop]

Break-away thrust?

I have recently seen them up in the mid 60's N1. B737, no chocks in place.

[TypeIV]

35 n1 won't get you very far on some rural Russian fields

[Groucho]

Ask Airbus about the level for the AB340?

http://www.pprune.org/rumours-news/3...ounded-26.html

[ACMS]

We had a 777 stuck in the Tarmac after pushback in Dubai 7 years ago. Had to give up and de-plane the pax......

Ever been to VTBS? The new aprons are notorious for needing TOGA thrust to move...

[Manicured garden]

Thanks for all your answers guys. But here I'd like to say that despite many ideas; still missing the correct amount. Some ppl says it depends on weight, temperature etc. Of course, but it's meaningless to say that as we are all airliners. I do not want to extend the question but you should get it that what I was gonna ask was for normal Standard conditions.

So the some ppl says 35%N1 is normal limit but any source for that amount of thrust?

And here comes the second question; what should be the minimum distance to get closer to another aircraft? Same problem we had; what I ve been told is that it should be 50 m. minimum. (could depend on the types but I ask for same types) And when I ask the source, he told me that's an Air Law rule but I checked for that on Jeppesen Air Law book, not found.

Any idea?

[TypeIV]

An instructor I've flown with uses half of the take off as a guideline maximum limit without obtaining a clearence from the tower. I haven't encountered this anywhere in the manuals.

[FlyingStone]

normal Standard conditions

Define "normal standard conditions". What I would suggest is that you show your captain the following excerpt from the FCTM - granted, it's not a precise value, but it comes from Boeing itself.

Idle thrust is adequate for taxiing under most conditions. A slightly higher thrust setting is required to begin taxiing.

An instructor I've flown with uses half of the take off as a guideline maximum limit without obtaining a clearence from the tower.

Half of what? N1 is not a linear indication and 50% N1 will not give you one half of thrust at 100% N2.

[TypeIV]

N1 of course, more convenient than calculating kilo newtons when taxying on the apron

I've yet to find where it's written if there is such a thing at all, apparently a small piston aircraft was damaged due to the jet blast a while ago and the company were hold nonresponsible since they could prove that less than half of the take off thrust N1 was used, according to him. While the subject is up for discussion, I would like to ask if anyone has heard anything similiar?

[RAT 5]

And here comes the second question; what should be the minimum distance to get closer to another aircraft? Same problem we had; what I ve been told is that it should be 50 m. minimum

And much depends on what you are and what they are. A PA-31 behind a B747 is >50m. You'd get airborne if they went 40% break away. I was very nervous when I was in front of a B747 and I felt his shadow cover me like a shark over a scuba diver. I doubt he could even see me, so I reminded him I was first and still there. I once heard (rumour) of some guys in a DC-9 type a/c, who were getting close to their hold-over time during a lengthy taxi in USA, and it started to snow again, that "maybe we should get it close to the B747 jet blast and clean the wings a bit?" An A319 or EMB135 behind an A380 might be shaken not stirred if too close.
It's not an exact science, more common sense.

[Skyjob]

Originally Posted by Manicured garden

what should be the minimum distance to get closer to another aircraft?

The answer is the distance should be at least the length of the preceding aircraft, except (in EU) in Germany when operating a less than Heavy behind a Heavy which is defined at 200m.

So 737 behind 737 need to be able to fit 737 between tail and nose, 737 behind 777 need be able to fit 777 between tail and nose... except Germany where 737 behind 777 requires 200m.

This distance (preceding aircraft length) prevents the trailing aircraft being damaged by engine jet blast from the preceding aircraft, which generally speaking would have more jet blast the bigger the aircraft...

[Qwerti]

More than 40% is not uncommon at all on a hot day with a bit of slope, just make sure is clear behind you or theres jet blast fence.

[framer]

I think a pilot got blown over while doing a walk around in Brisbane and broke a bone a year or two ago so injuries do happen.

[JeroenC]

Skyjob, can you please provide reference? Never g'heard of it. Based in Germany...

[Skyjob]

Used to be contained in Jeppesen supplement, ATC section - Germany variations.
Will need to look up where they got their reference from

Jeppesen Airway Manual
STATE RULES AND PROCEDURES - EUROPE
GERMANY
RULES AND PROCEDURES
AVOIDANCE OF WAKE TURBULENCE
f) When taxiing behind an aircraft of higher wake turbulence category a minimum distance of 200m should be kept whenever possible.

[Dynamite1]

ACMS ...needed a minimum of 50 on the 738 past two days; to break out after push back at BKK....just started going there...

[OverRun]

ACMS - I knew the DXB problem you refer to, and the asphalt rutting was fixed shortly afterwards. I also know the BKK/VTBS rutting problems but don't anticipate any early resolution.