Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
queb
Topic Author
Posts: 1030
Joined: Tue Jun 01, 2010 3:10 am

Gulfstream Engine Spool-up Time Question

Sun Oct 03, 2010 11:08 pm

On page 19 of this document, it is mentioned that some Gulfstream aircraft have an engine “spool-up” time longer than most transport category jet aircraft. Between 8 and 30 seconds. Here is the text (p. 19):

Quote:
The JOEB found only one Special Flight Characteristic; the engine “spool-up” time is longer than most transport category jet aircraft. It can range from 8 seconds at sea level to 30 seconds at altitude to move from idle thrust to maximum continuous thrust. At low altitude e.g. circling, the spool-up time will be considerably longer than 8 seconds if Flaps are -flight briefing, highlighting engine spool-up times, is accomplished prior to conducting training or checking in the following areas: stalls, touch-and-go landings and simulated one-engine inoperative manoeuvres.

Flight crew must be made aware of the risks during a go-around from an LNAV/VNAV approach. The danger is related to the requirement to set an altitude below actual aircraft altitude during the final approach. Until such time as modifications are made so that the altitude selector setting procedures are similar to procedures used during an ILS approach, LNAV/VNAV approaches to a go-around must stress FMA awareness and the requirement to reset the altitude selector, after the go-around has been initiated, to the go-around altitude.


https://www.easa.europa.eu/ws_prod/c/doc/final%20reports/Gulfstream/GV,GV-SP,GIV-X%20JOEB%20Report.pdf

Is this an engine issue ?

[Edited 2010-10-03 16:10:48]

[Edited 2010-10-03 16:11:05]
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: Gulfstream Engine Spool-up Time Question

Mon Oct 04, 2010 2:41 am

Limited to the RR Spey powered models, as these engines are not of the turbofan variety.
Having said this, the Spey spools up much faster than the 'ole JT4A did on the 707.
 
2H4
Posts: 7960
Joined: Tue Oct 19, 2004 11:11 pm

RE: Gulfstream Engine Spool-up Time Question

Mon Oct 04, 2010 2:49 am

Quoting 411A (Reply 1):
the Spey spools up much faster than the 'ole JT4A did on the 707.

About how long did it take the JT4A to get from flight idle to go-around thrust?
 
bohica
Posts: 2462
Joined: Tue Feb 10, 2004 3:21 pm

RE: Gulfstream Engine Spool-up Time Question

Mon Oct 04, 2010 2:55 am

Quoting 411A (Reply 1):
Limited to the RR Spey powered models

The RR Spey was also on the Trident, BAC-111, and the F-28. Did these planes experience the same spool-up issues?
 
DashTrash
Posts: 1337
Joined: Mon Aug 21, 2006 8:44 am

RE: Gulfstream Engine Spool-up Time Question

Mon Oct 04, 2010 3:21 am

Quoting 411A (Reply 1):
Limited to the RR Spey powered models, as these engines are not of the turbofan variety.

Speys are turbofans, just VERY low bypass.
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: Gulfstream Engine Spool-up Time Question

Mon Oct 04, 2010 4:04 am

Quoting 2H4 (Reply 2):
About how long did it take the JT4A to get from flight idle to go-around thrust?

16 to 18 seconds.
This is why the airplane needed to be flown carefully so as to not un-spool the engines whilst on approach for landing.
So-called 'slam-dunk' approaches were simply not possibe, to be done safely.
This changed with the fan-powered varients, especially the advanced cowl models.
 
2H4
Posts: 7960
Joined: Tue Oct 19, 2004 11:11 pm

RE: Gulfstream Engine Spool-up Time Question

Mon Oct 04, 2010 4:19 am

Quoting 411A (Reply 5):

Interesting, thanks.
 
queb
Topic Author
Posts: 1030
Joined: Tue Jun 01, 2010 3:10 am

RE: Gulfstream Engine Spool-up Time Question

Wed Oct 06, 2010 2:49 am

thanks for your responses

Who is online

Users browsing this forum: System07 and 17 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos