"Practice" Emergency Descent

Vector4Food

Vector4Food

This job would be easier without all the airplanes
Tonight we had a 767 that was on an empty ferry flight from FL410, requested a "Practice" Emergency descent to their arrival airport, traffic was light at the time and it was approved with all sorts of co-ordination of course with the various sectors.

The question I have is, is this sort of thing acceptable to the companies you work for? If it is, is it common?

that being said, it was interesting to see a 767 descending at almost 9000FPM...
 
Interesting. I've heard that sort of descent profile saves a bunch of fuel, but is very uncomfortable for passengers (I'm thinking specifically a continuous descent to landing). I've also heard that's how airnet rolls for the same reason. I've got no first hand knowledge of this, but I'd love to hear some commentary on the subject.
 
OhioStatePilot said:
Interesting. I've heard that sort of descent profile saves a bunch of fuel, but is very uncomfortable for passengers (I'm thinking specifically a continuous descent to landing). I've also heard that's how airnet rolls for the same reason. I've got no first hand knowledge of this, but I'd love to hear some commentary on the subject.
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Well this was an empty ferry flight also...
 
OhioStatePilot said:
Interesting. I've heard that sort of descent profile saves a bunch of fuel, but is very uncomfortable for passengers (I'm thinking specifically a continuous descent to landing). I've also heard that's how airnet rolls for the same reason. I've got no first hand knowledge of this, but I'd love to hear some commentary on the subject.
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Normally use a 2/1 descent at the 'net = ~4000 fpm depending on winds. That Lear will come down in a hurry on an emergency descent though.

PS - From what I hear, you can be just outside the marker at 10,000' and land on the fixed distance markers. ;)
 
averyrm said:
Normally use a 2/1 descent at the 'net = ~4000 fpm depending on winds. That Lear will come down in a hurry on an emergency descent though.

PS - From what I hear, you can be just outside the marker at 10,000' and land on the fixed distance markers. ;)
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Interesting, is that at flight idle (mind you, I don't know squat about turbine power settings)?

As to the second statement... :eek::rawk:
 
OhioStatePilot said:
Interesting. I've heard that sort of descent profile saves a bunch of fuel.
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From a fuel savings point of view, the optimum descent profile would have you stay at cruise up until the time you could pull all throttles to idle and then glide all the way to touchdown without touching them again, staying as clean as possible for as long as possible. Of course, nobody does it that efficiently. I'm thinking an "emergency descent" would be less fuel efficient than what I described since there's a penalty involved in using drag devices such as spoilers or thrust reversers.

Most reputable companies would frown upon unnecessary "practice" like this in the jet. Of course, it would be fun as hell! :D
 
In a Lear 35 the emergency descent profile (thrust at idle, spoilers extended, landing gear down) gives you -6,000fpm. Any faster descent rate would exceed Vle, which probably isn't a good idea.
 
canadian_atc said:
Tonight we had a 767 that was on an empty ferry flight from FL410, requested a "Practice" Emergency descent to their arrival airport, traffic was light at the time and it was approved with all sorts of co-ordination of course with the various sectors.

The question I have is, is this sort of thing acceptable to the companies you work for? If it is, is it common?

that being said, it was interesting to see a 767 descending at almost 9000FPM...
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Is it acceptable? Depends. Being empty and on a ferry flight helps. Is it common? Well, ferry flights are very uncommon and I have never heard of anyone doing a "practice" emergency decent.

BTW, the way we do them in the 767 is Spin, Pull, Spin, Push. Spin the altitude down to 10000 or lowest possible, Pull the speedbrakes, Spin up the speed and, Push the Flight Level Change button.
 
germb747 said:
I'm thinking an "emergency descent" would be less fuel efficient than what I described since there's a penalty involved in using drag devices such as spoilers or thrust reversers.
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Am I reading that right? Are there even jets or companies that allow the use of thrust reversers in-flight?
 
I have seen a c-17 doing the tactical descent into kchs and the thing looks like it's nose down. We had a Fdx guy in the Jumpseat who flys them in the reserves and he said they put out reversers and pitch about 20 degrees nose down- well in excess of 10k/min down. Looks like fun!
 
higney85 said:
I have seen a c-17 doing the tactical descent into kchs and the thing looks like it's nose down. We had a Fdx guy in the Jumpseat who flys them in the reserves and he said they put out reversers and pitch about 20 degrees nose down- well in excess of 10k/min down. Looks like fun!
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Wow, sounds like fun. I can see the military doing this for tactical reasons but I have never heard of a civilian carrier allowing this. Just curious...
 
It has been done at a few my previous carriers on ferry flights with ATC approval. Depending on the plane it really isn't that big of a deal. I've seen it done several time in TP's and once in an empty CRJ.

I wouldn't do it just for in some of the older cargo birds though as it is just hard on the aicraft. There is no really need to do it and take the plane to VMO/MMO in a descent with the boards out. Besides you get to see it enough in the sim.
 
Most TR's are squat switch inhibited in flight. So unless you had a switch failure, I doubt you could manually deploy the TRs.
 
Crockrocket94 said:
Most TR's are squat switch inhibited in flight. So unless you had a switch failure, I doubt you could manually deploy the TRs.
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The only two planes that I know of that can use TR's in flight are the DC-8 and a modified Gulfstream that NASA uses for Shuttle Pilot Training. All the planes I have flow have the TR's locked out in flight.
 
Crockrocket94 said:
Most TR's are squat switch inhibited in flight. So unless you had a switch failure, I doubt you could manually deploy the TRs.
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In the SAAB, going into reverse (or was it ground-idle?) in-flight was prohibited after an accident occured due to a pilot doing this. They even installed a lock on the power lever to prevent moving the control to reverse (ground-idle?) until weight-on-wheels was detected.
 
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