MCPILOT From Dominican Republic, joined Feb 2001, 16 posts, RR: 0 Posted (9 years 12 months 4 days 3 hours ago) and read 4119 times:
I Would Like to Know if you haven't had any problem making the 180 turn to Line-up on runway 35 in Las Americas International Airport (MDSD) at Night.
I am asking Because i would like to Know if the portable taxi way lights (Blue) Placed about 65 to 70 meters from the center of the runway 35 and Between E-7 and E-8 are safe enough for a heavy aircraft to make the 180 in order to line-up on runway 35.
Please this a very important information that i Would appreciate.
B747skipper From , joined Dec 1969, posts, RR: Reply 1, posted (9 years 12 months 2 days 21 hours ago) and read 3861 times:
I remember having done 180 degrees turns at the end of 17 and/or 35...
This with a 747-200... was no problem that I remember...
To do a 180 degrees turn, 153 feet-wide runway is required...
That is of course somewhat tight...
Note to all my friends on Tech.Ops -
I will be doing a charter to NRT next few days...
Then upon return, starting summer vacations, beach in Brasil...
You will not see much of me next 2 months...
Merry Xmas to all of you, and Happy New Year...
Happy contrails -
AJ From Australia, joined Nov 1999, 2380 posts, RR: 26 Reply 5, posted (9 years 12 months 2 days 16 hours ago) and read 3720 times:
Turn radius for a Boeing 747-400 is exactly as Skipper has stated, 46.6m/153', referring to the width of pavement required. The centre of the turn is just outside the inboard engine pylon and the outboard wingtip will prescibe a 45.1m/148.2' arc.
For the Boeing 767-200 the minimum required pavement width is 39.3m/129' with the turn centred mid chord in front of the high speed aileron. The wingtip will prescribe a 35.9m/117' arc.
The figures for the Boeing 767-300 are 44.6m/146' of pavement and a 37.6m/123' arc.
Minimum radius turns do apply a reasonable amount of stress on the gear, so they are treated with caution.
A main gear leg on a Qantas Boeing 747-338 was fractured conducting a 180 at Rome, using the Boeing turn procedure!
I understand that the large footprint A330/340 aircraft are very prone to undercarriage damage during tight turns. It's also very important when turning in the vicinity of obstacles to realise which part of the aircraft is prescribing the largest arc, as an Asiana Boeing 747-400 found out when it conducted a tight turn on the ramp at Anchorage and impaled an Aeroflot Il-62 on it's wingtip. On a Metroliner it is possible for the wingtip to clear the obstacle but the tail to strike it (seen it happen!).
MCPILOT, the distance you describe at the RW35 threshold sounds ample for a line up procedure.
AJ From Australia, joined Nov 1999, 2380 posts, RR: 26 Reply 9, posted (9 years 12 months 15 hours ago) and read 3311 times:
Differential thrust in tight turns can put side loadings on the gear and scrub the nose tires so is avoided if possible.
Mr Boeing describes a minimum radius turn in the 767 manual, starting by saying 'towing the aeroplane to the desired location may be the safest option'! It states to stop the aicraft, apply full tiller into the turn and add thrust on the outboard engine. Brake on the inboard gear can reduce the radius of turn. This type of turn is NASTY and should only be used when all other options are exhausted. If the airline was operating into an airport where this was required it's time to pay for some more pavement!
On a typical backtrack to line up type turn some differential thrust can be used to keep the aircraft moving, as stopping during the turn is not good for aircraft or ego!
Jjbiv From United States of America, joined Jan 2001, 1226 posts, RR: 5 Reply 10, posted (9 years 12 months 14 hours ago) and read 3300 times:
If making a minimum radius turn on pavement which is barely wide enough, how can you be assured that your outboard bogey is right on the edge of the pavement before beginning the turn in order to assure that you will clear the turn on the other side of the pavement?