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707 Engine Starts

Posted: Sun Mar 20, 2011 7:05 am
by Jackbr
Seeing as the 707s lacked an APU, would an engine be started at the gate prior to pushback after the ground power unit was disconnected?

RE: 707 Engine Starts

Posted: Sun Mar 20, 2011 8:30 am
by zainmax
Here when PK had B707s, we used start carts or high-pressure pneumatic bottles (3000psi) for emergency purpose to start the engine on ramp.
During push back other engines were started with the help of #1 Engine bleed.

P.S I have heard that the Royal fleet of SV was equipped with APU located in the wheel well.

Its exhaust is located in the flaps flit area.
This link picture shows the APU exhaust on a B707.

http://www.flickr.com/photos/peteredin/3175328390/

[Edited 2011-03-20 01:36:25]

RE: 707 Engine Starts

Posted: Sun Mar 20, 2011 3:04 pm
by 411A
In most normal situations, all four engines were started at the gate, then pushback and taxi commenced.
IF it was desired to use a cross-bleed start procedure, normally number three engine was started first.
However, many airport authorities did not permit cross-bleed engine starts with the 707 (except under exceptional circumstances), because...that one engine started first, had to be accelerated considerably, to allow its associated turbocompressor to supply sufficient bleed air to start the second engine.
Airport authorities were concerned about jet blast damage, using this procedure.

And yes, I've actually flown the 707 in Command, for about five thousand hours...not just read about it in some magazine or book.

RE: 707 Engine Starts

Posted: Sun Mar 20, 2011 3:46 pm
by n901wa
Hi. Yes the Eng would be started at the gate, and when the Engine came up to idle the power would be trasfered to the eng and the ground power removed ( can't remember if the Gen had to be sync'd like the 727 but I guess they did ). Now I have seen both, all four started at the gate, and 2 started at the gate and crossbleeded. The reason I liked starting all four at the gate, was if they push and had a problem we would have to drag them back to the gate. You start all 4 at the gate and you saved your self a headace. I know Western sold some 720B's that were modified after it left with the APU. It was in the fwd side of the aft cargo pit. I would think the 707 mods were the same due to the size of the APU would take up. BTW the eng start was the same with the DC-8 with out APU's. HAL use to gate start the 8 next door to us in HNL. HTH

[Edited 2011-03-20 08:48:50]

RE: 707 Engine Starts

Posted: Mon Mar 21, 2011 3:51 am
by Viscount724
Quoting Jackbr (Thread starter):
Seeing as the 707s lacked an APU, would an engine be started at the gate prior to pushback after the ground power unit was disconnected?

I can't recall any of my 707 and DC-8 flights where all 4 engines weren't started at the gate.

RE: 707 Engine Starts

Posted: Tue Apr 05, 2011 5:27 pm
by Venus6971
Quoting N901WA (Reply 3):
Hi. Yes the Eng would be started at the gate, and when the Engine came up to idle the power would be trasfered to the eng and the ground power removed ( can't remember if the Gen had to be sync'd like the 727 but I guess they did ). Now I have seen both, all four started at the gate, and 2 started at the gate and crossbleeded. The reason I liked starting all four at the gate, was if they push and had a problem we would have to drag them back to the gate. You start all 4 at the gate and you saved your self a headace. I know Western sold some 720B's that were modified after it left with the APU. It was in the fwd side of the aft cargo pit. I would think the 707 mods were the same due to the size of the APU would take up. BTW the eng start was the same with the DC-8 with out APU's. HAL use to gate start the 8 next door to us in HNL. HTH

Yes 707 generators had to be sync'd, I once played around to see if I could start a 707 for a quick emergency get out Dodge moment. I started both inboards with the 3000 psi start bottles and once they reached idle 55% N2 I opened up the bleed and not the turbocompressors to start both outboards with a cross start, the one time I did it it took less than 2 minutes and that was the generators on line with no APU. Not recommended for a novice.

RE: 707 Engine Starts

Posted: Tue Apr 12, 2011 12:56 pm
by CALTUS67
Back in the 60s Continental had 707-124s on which they used airstart trucks, a GMC panel truck with a gas turbine in the back which had a connecting hose in a rack where the front bumper would be. The truck was parked a short distance from the aircraft and the hose was attached to a port low on the plane's right wing root. With the turbine fired up the number three engine was started and at a signal from the cockpit the hose was detached and the truck removed. Number four was then started with bleed air followed by two and one. All four were started at the gate I would assume in case the bleed air process failed. That process, however, greatly facilitated the quick and orderly removal of equipment, which also included GPU, A/C truck and mobile stairs, to accomodate the 22-25 minute TUS ground times! Those were the days!!

RE: 707 Engine Starts

Posted: Tue Apr 12, 2011 2:48 pm
by Moose135
Quoting Venus6971 (Reply 5):
I once played around to see if I could start a 707 for a quick emergency get out Dodge moment.

Sounds like an alert start on a KC-135, except we used cartridges instead of the air bottles.

RE: 707 Engine Starts

Posted: Tue Apr 12, 2011 4:35 pm
by Thrust
Were the operations for engine starts any different for the early 707s that were powered by the turbojets than for the turbofan ones?