PPRuNe Forums - View Single Post - Why is the t/o climb gradient requirement higher for quads than twins?
Old 27th Apr 2012, 14:25
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aterpster
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bubbers44:

JT, not as risky as climbing straight out with no performance data. We had no engine out performance procedure for Reno. Our speeds were compatible with the 727 so knowing we could outclimb that by .3% we were golden. We had a private jet so didn't have data for Reno. We used Western Airlines procedures. We had airport altitude and field length data but no procedure. I think we did the only thing we could for a safe operation.
So, taking off to the south if you had an engine failure just above V1 you would do a right 180 (more or less) over town? I recall that is what WAL did many years ago.

As to the 727, the option for the biggest engines would seem to make a difference.

War story: When TWA first planned to operate into Reno in the early 1980s they planned to use only 727-100s and only fly to KLAS. They told our ALPA safety committee with OEI that would permit a straight out climb to a fix in the Carson Valley where a climb in hold would occur. I got the FAA form for the fix and advised them they would enter the hold 1,800 feet below MRA for the fix. Lots of red faces on the company side of that table.

Of course, they also asserted all TWA airplanes could climb straight-out everywhere with OEI. Our ALPA safety committee convinced a senior VP to get us the altitude each mile for a 727-231 at max structural takeoff on KLAS Runway 25 at the critical temperature for that weight. It took 31 miles to get to 1,500 agl. The airplane would have hit the first ridge of mountains west of town. That changed TWA's OEI procedures, big time.

I found this incredible from an airline that sold performance data to other airlines, etc.

Since then, I generally do not trust performance engineering, except JT of course.


I think a couple of these for-hire performance engineering departments often "cook the books" so to speak.

P.S. I think more likely than not, with an engine failure just above V1 in IMC or at night, more likely in those days there would have been CFIT into Rattlesnake Peak regardless of airline.
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