MikeTang

Good morning all! This is my first post here so please forgive me as I am learning your SOPs. I did a quick search and found a few things about v2 climbs, but nothing that addressed this question directly.

I fly a Lear 35 and my traditional climb profile goes something like this.

V1, Rotate, V2, Accelerate to flaps up speed around 400 feet. (I do not hold v2, but rather allow the aircraft to accelerate so I'm v2+30kts by 400' AGL.) Then, I continue to accelerate to 200kts where we get an ATC assigned level off at 2000' out of our local home base airport. I have always been comfortable having a combination of speed and altitude for safety in the event of an engine failure.

One of our captains however insists I fly at v2 all the way to 1,500 feet. This leads to a delay in retracting flaps, more than a 20 degree pitch up attitude, and a horrendous nose over at 1,500' to avoid busting the 2000' altitude restriction.

My question is: Should you always climb a jet at V2 even with all engine operating normally?

I am a pretty low time guy compared to him, but my argument against it is this:

If you are climbing at V2 at 1000' and you lose an engine, you will have one crazy pitch attitude that could end up in a stall when half your thrust is lost. Flaps are still deployed so it will be even more difficult to maintain a good airspeed. 20 degrees pitch up is not comfortable for me or our passengers.

I suppose my reasoning is I would take 200kts and 800' AGL over 130kts at 1,500' AGL for an engine failure all day. Also, climbing at V2 gives us a crazy pitch angle and sometimes triggers an RA because of the busy airspace.

This captain's reasoning behind climbing at V2 is because if you loose an engine at 1000' AGL, your pitch setting is already set up for v2 speed. I disagree with him because if you lose an engine, you will need to significantly lower the nose to maintain v2. An initial climb speed of 200kts is probably pretty close to the same pitch attitude of v2 when an engine fails.

Your thoughts?

Thanks!

1wrangler

Short answer: you're right, he's wrong. I've never seen anyone climb at V2 on a normal day, that'd just be way too excessive in a 35. As long as you're meeting all applicable climb gradients, he really has no reason to be trying to get you to climb at such a high rate of climb.

MikeTang

That's what I figured. I found a definition of V2 as follows: V2 is the speed at which the airplane will climb in the event of an engine failure. It is known as the takeoff safety speed.

V2 is a single engine climb speed. Not a normal departure speed.

Thanks for the reply.

680crewchief

Hawker 800 our profile was V2 with a limit of 20° pitch 2 engine. Soooooo....that usually ended up V2+10 or 15. Holding V2 without engine failure is just too much pitch and uncomfortable for the pax, resulting in a big pushover for quick level offs.

GrassLandings

You are correct. In fact most turbine airplanes dont have a specific FRA (flap retraction altitude), as it depends on weight, temp altitude and terrain clearance requirements etc. In flat terrain, in the E175 FRA is somewhere near 1,000 feet agl or higher. We climb at V2+10 to 20 until 1000, then lower the nose and speed up/continue climb/clean up.

"This captain's reasoning behind climbing at V2 is because if you loose an engine at 1000' AGL, your pitch setting is already set up for v2 speed."
How, just how does that make sense in his head? Its a basic thrust/drag equation. If pitch/thrust set for V2 with both engines, then that same pitch angle and half the thrust equals a speed less than V2 after you blow one up. Your captain must have missed aerodynamics 101... Im sorry man.

V2 +10 or V2+20 would actually be more appropriate, but it sounds like you already do that. Depends on the drag and flight characteristics of the plane you fly after an engine failure. But my understanding is thats why a 2 engine climb is V2+10 or 20 usually, until FRA/acceleration altitude. Your pitch would be nearly set for V2 on one engine(if that were to occur), if you are already V2+ plus a fudge factor like 10 or 20 with both engines operating.

BuddhaPilot73

I don't have the AFM in front of me, but I'm pretty sure it says something to the effect of once you hit 15 deg pitch attitude then allow the aircraft to continue to accelerate and maintain that. It says nothing about continuing to pitch to maintain V2 under 2 engine operating conditions. You're no where near a V2 pitch attitude or trim setting by flying the jet as he's asking you to. That condition is the specified takeoff trim and 35 ft AGL should an engine failure occur at V1 and takeoff be continued. At 35 ft single engine, your airspeed should be V2 and the takeoff trim setting helps you obtain that. Review what the AFM says about normal takeoff and climb technique and put that in front of him while asking him to explain why he is deviating from Lear's procedure.

rickair7777

Like others have said, and you said, if you climb at V2 and lose one the airplane will be trying to slide backwards on it's tail before you can get the pitch down. Dirty, you could easily mush out and stall or Vmc, maybe with some cross-control added for fun. Sounds very dangerous to me.

Look in your manual, it has to have a TO pitch limit published for these very reasons.

cubguy

You are exactly right. I've got a lot of time in both 20 and 30 series Lears. We would always let the speed build and at flap retraction reduce a LOT of thrust with a low altitude constraint keeping a comfortable pitch attitude. Either your way, (which everyone does) or his, (which nearly no one does) there WILL be a pitch adjustment with an engine failure. Lot safer to need an increase rather than a decrease. Also worth keeping in mind: If you lose an engine it's true that you have lost half of your thrust but you've also lost a hell of a lot more than half of your performance.
On another note, climbing at V2 on a ferry flight without pax to consider with both engines running is a lot of fun with no low altitude constraints!
CG

Skycakes

Miketang, I think you are absolutely correct. V2 in a 35 is just way too much with all systems go.
I too experienced this instruction from a pilot many years back, perhaps 4 or 3 years ago in a 35. Would this individuals initials be RK by any chance?

MikeTang

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