Dw747400 From United States of America, joined Aug 2001, 1252 posts, RR: 1 Posted (6 years 10 months 1 week 4 days 16 hours ago) and read 3439 times:
I was out at BWI today, and traffic was keeping the controllers very busy. A DL MD-80 was in position and holding, and was cleared on several occasions only to have its takeoff clearance revoked because it didn't get rolling fast enough.
After the third occurrence, the tower told him to clear the runway so the line of 737s behind him could get off. At this point he informed the tower that he needed 10 seconds to spool up his engines before beginning the takeoff roll because the temperature was just above freezing.
My question: why is this? No other aircraft seemed to have this issue, but this was the only DL flight, and only MD-80, I noticed. Thus, I'm guessing it is either DL operating procedures or something due to the MD-80's design (perhaps concern that ice off the fuselage could be ingested?) Anyone more informed than me on this one?
XFSUgimpLB41X From United States of America, joined Aug 2000, 4104 posts, RR: 38 Reply 4, posted (6 years 10 months 1 week 4 days 12 hours ago) and read 3369 times:
It has to do with clearing out the "vanes" from what I've been told. Which vanes, I don't know. I always assumed it had something to do with the bleeds. We used to have to do engine runups after deicing in the CRJ as well. Theres a decent likelihood Im going to be getting checked out on the 88 in the next few weeks... so I'll let you know once I learn (or 737 or 757/767- we shall see).
I personally can't tell the difference in the 80's... I just know the DL ones are 88's, haha. I'm sure I'll be able to if I get checked out on it.
TristarSteve From Sweden, joined Nov 2005, 3855 posts, RR: 34 Reply 5, posted (6 years 10 months 1 week 4 days 8 hours ago) and read 3334 times:
After the MD80 accident at ARN many years ago, when ice was shed of the fan blades just after take off, SAS now run up the engines on the runway before releasing the brakes in icing conditions. They always tell the tower on first contact that they are going to do this.
XXXX10 From United Kingdom, joined Jan 2000, 777 posts, RR: 0 Reply 6, posted (6 years 10 months 1 week 4 days 7 hours ago) and read 3311 times:
Out of interest, would it have been possible to throttle up the engines before getting the take-off clearance, assuming the pilot could judge more or less when the clearance would come, by the height of the previous a/c?
No,it has nothing to do with the Gottrøra accident.That one was caused by ice breaking off the top surface of the wings and entering the engines.
The engine run-up on the MD after de/anti-icing is to clear the engines of any de/anti-icing fluids that might enter the the air cycle machines/air condtion system and create a grey mist or smoke that will come out of the air condition outlets in the cabin.10-15 seconds of thrust at 70% will do the job.LHR did positively NOT like this procedure and we usually did the run up on the taxiway,having first positioned the plane so as not to blow exhaust on planes behind us.Other types of engines/planes have probably different layouts in these systems and do not require this runup to my knowledge.
United_Fan From United States of America, joined Nov 2000, 7282 posts, RR: 8 Reply 10, posted (6 years 10 months 1 week 3 days 19 hours ago) and read 3117 times:
Quoting Dw747400 (Thread starter): At this point he informed the tower that he needed 10 seconds to spool up his engines before beginning the takeoff roll because the temperature was just above freezing.
I heard the same request from a DL MD88 here in ROC last week,too.
'Empathy was yesterday...Today, you're wasting my Mother-F'ing time' - Heat.
FLY2HMO From , joined Dec 1969, posts, RR: Reply 11, posted (6 years 10 months 1 week 3 days 15 hours ago) and read 3036 times:
The engine's thrust rating (and model no. for that matter) does change slightly between -81/82/83 etc but externally there really is no way to differentiate amongst them (except for the -87, which is the shortest).
TrijetsRMissed From United States of America, joined Oct 2006, 2164 posts, RR: 7 Reply 12, posted (6 years 10 months 1 week 3 days 15 hours ago) and read 3029 times:
Quoting XFSUgimpLB41X (Reply 1): ...by the way.. its an MD-88. DL pilots will be quick to tell you its an 88 and not an 80, haha.
Yes the MD-88 is DL's plane. The airline had input in it's design. But for the record, they also operate a small fleet of MD-82's, and of course the MD-90's.
Quoting Dw747400 (Reply 2): Any major differences besides fuselage length in the MD80 series?
Besides what has already been said, the big differences are the engines, the range, and the avionics.
The MD-82 quickly became the standard when it was introduced with more powerful engines than the original MD-81. The MD-83 and -87 have the best range,(-83 same capacity as an -82). The MD-88 is an improvement over the MD-82 with the JT8D-219 engines, refurbished cabin, and EFIS glass cockpit.
The MD-90 had much improved engines with the V2500 engines. Better range and fuel efficiency. They also provide the quietest cabin in the industry, because of the rear engine design.
The MD-90 also offers additional pax capacity, IFE, refurbished cabin, and avionic improvements.
If you are unsure if you're spotting and MD-80 vs -90 at the airport, pay close attention to the engines while the aircraft lands. The the MD-80's have the distinctive clamp thrust reversers that fold over.
TrijetsRMissed From United States of America, joined Oct 2006, 2164 posts, RR: 7 Reply 15, posted (6 years 10 months 1 week 2 days 23 hours ago) and read 2881 times:
Quoting FLY2HMO (Reply 14): Quoting MidEx216 (Reply 13):
The big thing that helps me tell them apart is that MD-80s have the cone on the tail, while the MD-88s have the dove-tail (where it tapers flat).
Its a pretty unreliable method. Some airlines have switched the tail cone on several models. AA is going for an all screwdriver-tail on their fleet IIRC.
Indeed. I think the best way of differeniating MD-82/83/88's is to know which carrier flies what. It's very hard to judge from the outside, especially from a distance. A lot of later models were built with the same tailcone.