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V2 to MSA or Accelerate to VFS????

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LegacyDriver

Moving Target
Joined
Mar 7, 2004
Posts
1,691
Once again this argument rears its ugly head. Falcon has their way. Boeing has theirs. Cessna another. 121 Airline says do this but same equipment in 135 charter says do that.

So....

What's the rule folks? What is going to keep you from hitting that cumulus granite? After a V1 Engine Failure..........

V2 to MSA then accelerate?

V2 to 500'/1000'/1500'/APG Accel Height then accelerate and clean up to VFS - Final Segment (EMBRAER) / VNER (Cessna) / fill-in-the-blank (Boeing, Falcon, etc.)?

I swear Part 25 and TERPS do not talk to one another and every time I go to recurrent I find some new reason to question whatever method I'm using that six months...
 
Fly it how the sim instructor wants you to :beer:
 
Last edited:
Standard Legacy Engine Failure at V1 Profile, non-APG:

V1 - Engine Failure

Vr - Rotate

V2 to Acceleration height (400-1500' AGL, unless otherwise standardized for your ops)

At Acceleration height

Call "ALT Hold"

V2+15 call "Flaps Up"

At Vfs call "SPD Hold Vfs"

Climb to initial altitude at Vfs

Avoid obstacles visually. If unable to maintain visual conditions, incorporate APG. Procedures will vary from DP to DP and must be individually briefed.
 
Really depends upon the DP and your aircraft's performance limitations.
CAVU companies used to have an excellent tutorial on their website which may be of interest.
 
I used the above EMB profile for years in the ERJ and Legacy. Then our sop changed to V2 until MSA.I seem to recall in recurrent seeing the numbers run for Dassault... Not cleaning up and accelerating made you hit the obstacle if it was a very tall one (net climb gradient at V2 was less than cleanup and fly final segment).So Cessna has numbers for V2 to 1500' but I'm led to believe I should cleanup after that. Instructor says hold V2. Yes I will do it his way for the ride but I want to know if that's truly the safest bet considering I'm a Cessna noob.
 
Maybe I'm misreading what y'all are suggesting here...

But taking a wag like "In the event of an engine failure at V1, I think I'll climb at V2 to X altitude today" is misguided. You really have to work the data. The sooner you can get the airplane cleaned up and accelerate to Vfs (or Venr), the better net climb gradient you will have. If you can't find an acceleration segment that allows you to briefly level, clean up then climb then the obstacles you're trying to avoid are either a) too high / close in; b) it's too hot; or c) you're too heavy. In these situations you really need to have other analysis data such as APG or similar.
 
I agree w you. But the perf data says, "1500 or clear of obstacles."I read that as a close-in obstacle not a mountain several miles away.Venr would give a better climb gradient than V2 I would think.
 
If VMC or under radar contact, 1500 and accelerate. IMC / Night no controller to keep me out of terrain - MSA

V2 is best angle i.e. terrain consids - most altitude per mile down range
getting clean and accelerating gets you closer to a best rate airspeed - most altitude per minute
 
The only correct answer is the one written in the performance charts. Use that.

Remember V2 is a safety speed, not a best climb speed. Best climb speeds are Vx (angle) and Vy (rate). No doubt some aircraft have V2 and Vx very near or identical.
 
The only correct answer is the one written in the performance charts. Use that.

Remember V2 is a safety speed, not a best climb speed. Best climb speeds are Vx (angle) and Vy (rate). No doubt some aircraft have V2 and Vx very near or identical.




But when the manufacturer says stuff like, "V2 to 1500' or until clear of obstacles" that can lead you down a road you shouldn't follow.

At 14K' with flaps and V2 this Citation have a negative climb gradient depending on temperature and weight. As a previous poster said, if you can't accelerate and clean up without hitting a rock then you shouldn't be flying the airplane under those conditions.


I just don't think we have thought this through thoroughly as an industry. There should be an answer--one answer--that is correct (safe) and unequivocal. I don't feel I have it.

By design I am a believer in cleaning up and flying out at final segment speed. But that's how I was taught in my first jet and I could be wrong in this belief.
 
But when the manufacturer says stuff like, "V2 to 1500' or until clear of obstacles" that can lead you down a road you shouldn't follow.

At 14K' with flaps and V2 this Citation have a negative climb gradient depending on temperature and weight. As a previous poster said, if you can't accelerate and clean up without hitting a rock then you shouldn't be flying the airplane under those conditions.


I just don't think we have thought this through thoroughly as an industry. There should be an answer--one answer--that is correct (safe) and unequivocal. I don't feel I have it.

By design I am a believer in cleaning up and flying out at final segment speed. But that's how I was taught in my first jet and I could be wrong in this belief.

My main point was that the procedure has to be aircraft specific. Just because a Citation does this doesn't mean a Lear should or vice versa.

As for departing, you are right...you should never depart an airport that you can't avoid terrain single engine. If that means you tell your boss he has to fly into Denver and drive to Aspen...so be it.
 
Its always clear as mud.

Dassaults idea of V2 to TOSA (say 1500ft+) is downright comical....The deck angle enough could be enough to get you fired! - lol. We go along the lines of comfort.

Most often by the time one rotates and gets the gear up you are well past V2 in any plane with performance.

As per FOM we also dont operate into nasty terrain places (Aspen etc) unless very VFR. If we did we would possibly need to re-look at things.

Just play the game in the sim and fly like you always have once you leave, the OEMs dont always use common sense to make their numbers.
 
If you are single engine flying at V2 I assure you that deck angle will not be an issue- in any aircraft.

Not only would it not be an issue, it should be the absolute least of your worries.

If you are climbing out at V2 with both engines operating, you would be..........strange
 
...Well spilling coffee on the citation circuit panels makes an engine out even worse sometimes :)
 
Simuflite teaches V2 to MSA, and that is just plain wrong. All performance data is based on a climb at Vfs or Venr. You're taking your life and that of your passengers into your own hands when listen to that crap. Fly the profiles like the manufacturer says to.
 
All I'll say on this subject is, that if you are above V-2 after takeoff and lose an engine, do not go back to V-2, keep what you have and climb.
 
I swear Part 25 and TERPS do not talk to one another and every time I go to recurrent I find some new reason to question whatever method I'm using that six months...

How can you possibly be an experienced pilot and not know or understand this?

Part 25 has nothing to do with TERPS. TERPS has nothing to do with Part 25.

Part 25 contains certification standards for transport category aircraft.

TERPS contains design standards for instrument procedures, routes, etc.

When planning a departure, it's up to you to look at the aircraft performance, given the existing conditions, and determine if you can meet climb criteria for a departure procedure or obstacle departure. Part 25 has nothing to do with TERPS. Part 25 doesn't presume to account for any particular procedure. TERPS has no bearing on segmented climb gradients.

For departure, you have either to meet diverse climb gradient criteria at 200'/nm, or whatever the DP/obstacle departure prescribes. You need to determine what is required, then compare the aircraft data to see if you can do it. If you can't, then you need to refuse the departure, make other plans, or accept that on departure you're not going to make it with an engine failure. It's all you.

Your comments seem to make an assumption that if you follow the manufacturer procedures, then you'll automatically clear terrain. This is NOT the case, as there is no correlation between flying the engine-out procedure for your aircraft, and clearing terrain. It may very well be that your aircraft isn't capable of clearing terrain or obstacles with an engine failure. This isn't up to Part 25, the manufacturer, or TERPS. It's up to you to determine, period.

Whether you should maintain V2 or not is up to you to determine.

Our policy is to maintain V2 to V2 + 10 after departure. With an engine failure, it's V2, unless a speed over V2 has been obtained, in which case We'll maintain that speed up to 10 knots over V2. Normally, we set climb thrust at a thousand feet, but with an engine failure we will level at a nominal 800', and begin the cleanup process before setting max continuous thrust, and then continuing the climb at the flaps-up speed, or flaps-up speed plus 20 knots if we intend to bank in excess of 15 degrees.

That speed is normally maintained until 10,000', at which point we accelerate on schedule. If a return to landing is in order, then it's done at V2 plus 100, or with flaps at V2 plus 60. That's for our airplane. Yours, of course, is different.

None of those numbers guarantee terrain separation or obstacle clearance. Each departure must be tempered with the specific data for the departure runway, and is assessed as a runway analysis. With the runway analysis done, taking into account close-in obstacles plus the departure area, terrain, etc, we can plan for a departure, and brief the departure accordingly.

One should know before starting engines what one will do with respect to to an engine failure, terrain, MSA, MEA, etc. This is why a departure procedure is published, or obstacle departure information is given. You need to look at your climb gradient performance relative to an engine failure/power loss and determine if you can make those values or not.

If you are single engine flying at V2 I assure you that deck angle will not be an issue- in any aircraft.

It very well could be an issue; again, this is aircraft-specific. Some aircraft have minimum pitch angles for minimum fuel, for example, and this is just as important as maintaining an airspeed, if one is to keep the remaining powerplant running.

In my airplane, we use a maximum pitch attitude of 18 degrees, and if that gives a speed higher than V2+10, we take whatever speed it gives. However, if we have a fuel situation in progress (a missed approach at an alternate after a 4500 mile trip, for example, in a remote location), then we're restricted to 9 degrees nose up.

If you are climbing out at V2 with both engines operating, you would be..........strange

Again, we do V2 to V2+10 to 3,000' on a normal departure before cleaning up, which is a requirement at some locations as part of the noise abatement departure procedure. In some cases, we will hold that to a higher altitude, depending on the conditions and locations.

Look at your specific airplane, your departure conditions, your procedures, and the obstacle and climb criteria required. Such planning is a basic part of every departure.

I don't believe I've ever been asked to maintain V2 to MSA at any simuflite course I've attended. In fact, at each course, the training has been tailored to company procedure and requirements, including the departure.

I've never been to a FSI course or Simuflite course that's taught other than manufacturer procedures, with specific simulator training tailored to the client's needs.
 
I don't believe I've ever been asked to maintain V2 to MSA at any simuflite course I've attended. In fact, at each course, the training has been tailored to company procedure and requirements, including the departure.

I've never been to a FSI course or Simuflite course that's taught other than manufacturer procedures, with specific simulator training tailored to the client's needs.

Well I have. Talk to any instructor in the Challenger program at Dallas CAE and they all teach (preach) V2 until MSA. It's complete BS. This subject is an argument point every year at recurrent. CAE's teaching methods are why we are changing to FSI. We will see if they are any better....
 

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