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707 Holding Brakes On Take Off  
User currently offlineJackbr From Australia, joined Dec 2009, 666 posts, RR: 0
Posted (2 years 7 months 4 weeks 19 hours ago) and read 7387 times:

I've seen a lot of videos of 707s taking off - many show the aircraft having its brakes held until the engines seem to reach full take off power before being released. I've only seen one video (a 1989 video of a private 707-123B) making a rolling take off.

Were rolling take offs rare on the 707 (and DC-8, CV-880 etc)?

[Edited 2012-01-26 00:13:05]

16 replies: All unread, jump to last
 
User currently offlinesimairlinenet From United States of America, joined Oct 2005, 917 posts, RR: 2
Reply 1, posted (2 years 7 months 4 weeks 18 hours ago) and read 7364 times:

Not knowing for certain, my initial suspicion is that runway lengths in that era were in many cases not sufficiently extended to allow for rolling or idle stop takeoffs.

User currently offlinenonfirm From United States of America, joined Sep 2005, 434 posts, RR: 0
Reply 2, posted (2 years 7 months 4 weeks 17 hours ago) and read 7350 times:

Check this link here. This is for a Virtual Airline but it has a takeoff procedure in it.Here is part of the section.Again I do not know how accurate the info is. http://www.vpiaheritage.com/707procedures.pdf

Standard Takeoff Procedures
Standard takeoff procedures include the following:
• The captain will use nosewheel steering to 80 knots.
• The first officer will hold the nosewheel on the runway and keep the wings level to 80 knots.
• The pilot not making the takeoff will call out “Airspeed, 80 knots, V1, Vr, V2, Positive climb,
and 800 feet.”
• The engineer will automatically switch to an operating generator if essential power is lost.
• The pilot making the takeoff will advance the throttles to about 0.10 below the target
takeoff EPR value. The engineer will trim the engines to takeoff thrust and monitor the
power throughout the takeoff regime. Once set, the captain will position his hand on the
throttles until V1.
• The captain will make any decision to discontinue the takeoff and will execute the RTO
procedures.
• The captain will remove his hand from the throttles at V1.
Takeoff Positioning
Takeoff performance calculations presume the use of all available runway. Good judgment
dictates that a minimum amount of runway be used in positioning for takeoff, especially when
TOGW is runway-limited.
Applying Takeoff Thrust
On all airplanes, set the chart rolling-takeoff EPR values, with appropriate turbocompressor
corrections, on the EPR gauges. When aligned with the runway:
• Advance throttles smoothly.
• Pause until all engines have accelerated and are stabilized at 60% to 65% N1.
• If using brakes, ease them off.
• Smoothly advance the throttles to about 0.10 below target takeoff EPR-bug value. Call for
takeoff thrust.
• Between 40 and 80 knots, adjust the thrust to bug value. Do not readjust EPR after 80 knots
except to stay within EGT or N1-N1 limits. During the takeoff roll, the ERP may drop as
much as 0.03 by Vr. Do not adjust or recover for this drop since engine over-boost will
occur. Also, be alert for N1 over-speed on hot weather takeoffs.
This technique of applying thrust permits even heating and expansion of the engines, reduces peak
temperatures and avoids controllability problems associated with asymmetric engine acceleration.
Takeoffs made from a static condition may be made as required. Set static takeoff EPR before
releasing the brakes. Ease the brakes off. All other procedures remain the same. 5
Advancing the number 3 throttle to the takeoff setting will cause an intermittent horn to sound for
any of the following reasons:
• Speedbrake lever out of the zero detent.
• Stabilizer index out of the green band.
• Flaps not in a takeoff position.


User currently offlineNorthwest727 From United States of America, joined Jul 2005, 491 posts, RR: 0
Reply 3, posted (2 years 7 months 4 weeks 13 hours ago) and read 7241 times:

My guess is that early turbine engines spooled up rather slow, maybe by holding the brakes they allowed the thrust from the engines to stabilize, but that is a guess. 411A would answer this question perfectly as soon as he signed on, if he was still with us, unfortunately...

User currently offlineFabo From Slovakia, joined Aug 2005, 1219 posts, RR: 1
Reply 4, posted (2 years 7 months 4 weeks 2 hours ago) and read 6957 times:

This was actually briefly discussed in a 727 thread nearby.


The light at the end of tunnel turn out to be a lighted sing saying NO EXIT
User currently offlineclydenairways From Ireland, joined Jan 2007, 1234 posts, RR: 0
Reply 5, posted (2 years 7 months 3 weeks 6 days 15 hours ago) and read 6804 times:

Quoting Jackbr (Thread starter):
I've seen a lot of videos of 707s taking off - many show the aircraft having its brakes held until the engines seem to reach full take off power before being released. I've only seen one video (a 1989 video of a private 707-123B) making a rolling take off.

For any aircraft that is performance limited off a particular runway, you may see that happening. But it was much a much more common practice with older aircraft, especialy when they were heavy. 707,DC8,747-100,IL62 etc

But i've also seen 737,EJets,Airbus do this off very short runways.


User currently offlinecedarjet From United Kingdom, joined May 1999, 8114 posts, RR: 53
Reply 6, posted (2 years 7 months 3 weeks 3 days 3 hours ago) and read 6315 times:

Quoting Jackbr (Thread starter):
I've seen a lot of videos of 707s taking off

I think you've seen a lot of Saha Air 707 clips, who do hold the brakes on most takeoffs. It was never standard 707 practise, and Saha do it because those engines are just so old, and have so many locally-made parts inside them, it just gives them a decent few seconds, and sometimes quite a few seconds, to spool everything way up and really watch the indications and totally establish that all four are stable before committing to a roll. Once the aircraft is moving, there are other things to look for, so it does make sense.

Also makes for a very thrilling takeoff!



fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
User currently offlinegr8circle From Canada, joined Dec 2005, 3107 posts, RR: 4
Reply 7, posted (2 years 7 months 3 weeks 23 hours ago) and read 5980 times:

I did a lot of flying on the B707 back in the 70's when I was small......AI 707's, both RR and P&W powered......takeoffs were always with power building up with brakes on and then commencing TO roll....don't ever remember a rolling takeoff.....that's something I only encountered when I started flying on more modern planes in the 80's.....

User currently offlineBAe146QT From United Kingdom, joined Sep 2006, 996 posts, RR: 0
Reply 8, posted (2 years 7 months 2 weeks 3 days 7 hours ago) and read 5566 times:

Obligatory on-topic bit:

I've always assumed, judging by the movement of the aircraft, that brakes weren't applied during the final run-up at take-off, since the aircraft is rolling at the time. Clearly that's based on adult observations where I had any idea what might be going on up front. I can't say I remember what my 747 experiences were like in the mid-70s.

Quoting Northwest727 (Reply 3):
411A would answer this question perfectly as soon as he signed on, if he was still with us, unfortunately...

Apologies for being off-topic, but what happened to him please? I've been away from the site for a while and so don't know who has left and why.

On a related note, it's good to see you, Hawk21M.



Todos mis dominós son totalmente pegajosos
User currently offlineFabo From Slovakia, joined Aug 2005, 1219 posts, RR: 1
Reply 9, posted (2 years 7 months 2 weeks 2 days 4 hours ago) and read 5418 times:

Quoting BAe146QT (Reply 8):
Apologies for being off-topic, but what happened to him please? I've been away from the site for a while and so don't know who has left and why.

He left, as they say, for the Western skies



The light at the end of tunnel turn out to be a lighted sing saying NO EXIT
User currently offlineHumanitarian From United States of America, joined Jan 2012, 106 posts, RR: 0
Reply 10, posted (2 years 7 months 1 week 6 days 1 hour ago) and read 5150 times:

I was once told it was because the pilots on the aircraft were ex-military. Holding brakes was a standard take-off procedure for them.

User currently offlineB777LRF From Luxembourg, joined Nov 2008, 1360 posts, RR: 3
Reply 11, posted (2 years 7 months 1 week 5 days 9 hours ago) and read 5088 times:

Been many, many, years since the last time I was onboard a 707 (well, a 720 actually) and rolling take-offs were common operating from homebase (long runway) whereas standing the engines up while holding the brakes were common when departing from down route (short runway, usually very warm too).

I've been onboard MD80s that were held on the brakes while the engines were spooled up, and I've done rolling take-offs as well.

On the B757s I used to fly we were initially not allowed to do rolling take-offs, but can only recall a few instances where the engines were spooled up while holding her on the brakes. Later on we got a new CP who didn't have a problem with rolling take-offs, and the SOP were changed accordingly. After that rolling take-offs were not unusual if the Captain was PF (no tiller on FO side, so the Skipper did all the taxying), whereas FO take-offs were usually from a stand still. But even that wasn't cut in stone; as a FO I did rolling take-offs as well.

I guess the answer is, as is very often the case in aviation: It depends .....



From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
User currently offlinemusang From United Kingdom, joined Apr 2001, 864 posts, RR: 7
Reply 12, posted (2 years 7 months 1 week 4 days 4 hours ago) and read 4904 times:

Interesting.

We fly Classic 737s and a few years ago one crew set t/o thrust while stationary. It blew chunks out of the asphalt runway which impacted the tailplane (stabiliser) leading edge and belly. A subsequent enquiry to Boeing by our Management provoked the response that the manufacturer saw negligible t/o roll reduction from brakes on t/o thrust launches when compared to setting thrust with the brakes off. We are now advised not to set t/o thrust on the brakes, but having said that we don't serve any really short runways.

The other consideration for under-wing engines is of course FOD.

However, advice on the 146 was that on short runways, setting t/o thrust on the brakes was what the performance was predicated on. On short, slippery runways (e.g. compacted snow) we had to increase to t/o thrust, and if it started to skid, just release the brakes and let her rip.

Regards - musang


User currently offlineimiakhtar From , joined Dec 1969, posts, RR:
Reply 13, posted (2 years 7 months 1 week 4 days 4 hours ago) and read 4890 times:

Quoting musang (Reply 12):
It blew chunks out of the asphalt runway which impacted the tailplane (stabiliser) leading edge and belly.

Did a fair bit of damage to the elevator too. Relevant pics in the report below:

http://www.aaib.gov.uk/cms_resources...ng%20737-436,%20G-DOCT%2006-07.pdf


User currently offlineBAe146QT From United Kingdom, joined Sep 2006, 996 posts, RR: 0
Reply 14, posted (2 years 7 months 6 days 8 hours ago) and read 4513 times:

Quoting Fabo (Reply 9):
He left, as they say, for the Western skies

Please tell me this means he just had better things to do and hasn't passed away.

Also: Thank you for your post, musang.



Todos mis dominós son totalmente pegajosos
User currently offlineQantas744ER From United States of America, joined Jun 2005, 1286 posts, RR: 4
Reply 15, posted (2 years 7 months 18 hours ago) and read 4058 times:

Quoting BAe146QT (Reply 14):
Please tell me this means he just had better things to do and hasn't passed away.

Also: Thank you for your post, musang.

"He died of a massive coronary heart attack talking about the L-1011 with drink in one hand, cuban cigar in the other."

You can read all about it here.

http://www.pprune.org/where-they-now/449191-411a-has-flown-west.html


Godspeed Bob



Happiness is V1 in Lagos
User currently offlineBAe146QT From United Kingdom, joined Sep 2006, 996 posts, RR: 0
Reply 16, posted (2 years 6 months 4 weeks 1 day 7 hours ago) and read 3798 times:

Oh hell. Thank you for the link, Bob.


Todos mis dominós son totalmente pegajosos
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