CMA Incident in Rainbow Lake

[FlyingHi]

....?

[Airborne28]

When I worked at cma, the takeoff briefing was: ..... reject on captains command below 80, after 80 kts, only reject for eng fail, eng fire, loss of oil pressure or control problem. Have they added stall horn to the above 80 kts critical list?!?

Glad everyone's alive.

[rigpiggy]

.

However, this can be a very beneficial lesson. B1900 systems review 101:

The stall horn warning system is enabled via the landing gear squat switch. That's why when you're on the ground, and the stall tab is down (stalling position), you don't hear the horn. Once you takeoff, air lifts the tab, gear comes up, horn 'armed'.

A failure point to this system, if you're in bad weather, moisture can freeze the tab in the down/stalling position. Hence, once you begin rotation and the squat switch releases, you'll get a fault stall warning. (even with stall heat on).
.

Fail

Aerodynamic pressure on the lift transducer vane varies with the wing's angle of attack. When an angle of attack approaches that of an imminent stall, the vane changes position, and the sensor unit produces a signal which activates the stall warning horn in the cockpit. Rigging tolerances allow the vane to be in the up, "wing stalled", position or the down, "wing unstalled" position on the ground. In unstalled flight, dynamic air pressure holds the vane in the down, or "wing unstalled" position. The system is disabled on the ground by the operation of the landing gear safety switch, located on the left main landing gear.

from http://www.tsb.gc.ca/eng/rapports-repor ... 7c0229.asp

[Flybaby]

When I worked at cma, the takeoff briefing was: ..... reject on captains command below 80, after 80 kts, only reject for eng fail, eng fire, loss of oil pressure or control problem.

That's what most companies SOP's say, usually with a blurb about they may be other reasons, SOP's cannot cover all situations. I bring this up because at least for me the majority of rejects were due to possible collisions; animals, aircraft. Only once was because of an item on that list; loss of power.

[captainganush]

yikes, who would reject at V1 for a stall horn? 4500feet snow? maybe captain bob should rethink his career choice./ for the rest of you, keep on topic

[flyincanuck]

This has happened to me 3 times in that plane.

First: I know what the CADORS said, but was it really "V1", or did the reject just occur above 80kts? It's funny how there can be ambiguity over these two number. If I recall correctly, V1/VR are only a few knots apart, depending on weight.

It definitely gets the blood going.

Out of three occasions, we rejected once. On the other two occasions, the horn went off around 100kts but below V1 (and you're accelerating very quickly!). We continued the T/O. In one case, it immediately stopped (WOW issue); the second took a few hundred feet (plane was left outside overnight during a nasty nor-easter).

In a theoretical world, I suppose we wrong not to reject as we were slightly, albeit, below V1. Encompassing everything you know about your plane, and considering the degraded nature of the runway, flying seemed like a much safer decision those days.

Seems like a re-occurring issue in this plane. Glad no one was hurt.

[AuxBatOn]

I believe as a pilot, one of your responsabilities is to know your aircraft and its system as much as possible. It includes knowing the quirks of a model. Yes, it may mean research on your own and in your free time about your aircraft, reading accident reports, reviewing your aircraft manuals, etc...

It seems to me that it was a well known issue and there was no reason for the crew not to know about it. If they knew about it, there was no reason not to continue the take off and take it as a spurious warning. If they did not know about it, they did not do their homework and job as a pilot. Your ground training can only teach you so much. You will have to research on your own.

The pre-take off brief serves a purpose. It spring loads you to a situation that requires immediate action without thinking about it, and simplify the process in your mind by making it clear when you will do what. If you say that you will not abort above 80 kts for anything other than major emergencies, then don't. If you say that from V1/Vr, whatever speed you use, you will go flying, then do so. These SOPs have been written by far smarter people that most of us and have been tested for years, and some even paid the ultimate price.

[moreccsplease]

Am I reading this properly, or do some people on here not understand V1?

If you reject prior to V1, you will stay on the runway. That's why you take a penalty and reduce V1 on contaminated runways.

When the V1 call is made, your hands move off the power/thrust levers, and you're committed to flight, you're just waiting for the Vr call.

[flyincanuck]

hello there moreccsplease,

To be clear:

I've never had any difficulty with the definition.

Real-life, unfortunately, is not text-book. I'll give you a little more depth to my circumstance.

With this particular operation, the right seat pilot removed his hand from the power levers as the power was being set. Barring an incompacitation, the left seat pilot always rejected. I was never a fan of this, for obvious reasons.

The abort technique may have occurred well after V1 once the right-seat pilot called for abort, and left seat pilot actioned the call (include a time delay for the PM-who-is-to-be-the-PF-(surprise!!!) to process and action). The pilot flying should action a reject, and have his hands on the control upto V1 as you stated.

This particular SOP did a friggen good job of making things clear as mud. An old chief pilot once told me you can teach a person to fly anything, but you can't teach common sense.

[Flying Nutcracker]

I am sure there will be a report that has the accurate figures for when the reject was initiated, and whoever gets it first can share it with the rest of us and we can all celebrate the knowledge!

In the mean time... V1 is a fluctuating, but HARD number. Go-no-go number. The margins are sometimes tiny and any hesitation to reject prior to V1 will cost you a lot!!! Any decision to reject after V1 will put you into no-mans-land as far as your stopping distance goes.

This is why I don't understand why people get so revved up about using a shorter than the longest runway available. The numbers work. If you say they don't, you don't understand the context of V1. Yet, I have one reservation... I'll take the shorter runway only if it is not contaminated. If it is... I want all the stopping distance the airport has to offer, unless the wind is limiting... or I am climb restricted... or... if the longest one is not available... but then again... I could wait till it is available... but that would mean I don't have faith in my numbers... hmmm... stick with the numbers! If they work, it is safe! If you mess with the numbers...

AuxBatOn... couldn't agree more! I find the maintenance department is a great place to hang around after snagging an airplane and/or during the slow periods of the day... you learn alot. Actually, just talking to engineers will teach you a lot about the airplane you're flying!

FN

[turbo-prop]

At 2000ft elevation in the 1900D at
0C -15C
V1-115 V1-115
Vr-116 Vr-115
V2 123 V2-123

TOFL
4701ft 4359ft

17,120lbs

[Flying Nutcracker]

And with flaps 17?

[turbo-prop]

Flaps 0

[Caracrane]

It is 0 flaps cause 17 is 106,112,123. So you fly on long runways.

[Caracrane]

At 2000ft elevation in the 1900D at
0C -15C
V1-115 V1-115
Vr-116 Vr-115
V2 123 V2-123

TOFL
4701ft 4359ft

17,120lbs

V1/Vr 106, V2 112, V(enr) 123. V2 123? please explain, too lazy to look at the book. And so V(enr) is 128 ?

[splitpin]

Seems to me there is some terminology confusion going on here.

These speeds are defined in FAR 25 for transport category aircraft.

V1 is the takeoff decision speed - if an engine failure occurs below this speed you abort or reject the takeoff. If it occurs above this speed you continue the takeoff.

Vr is the rotation speed - where the nose gear is raised off the runway surface, but must allow the aircraft to accelerate to V2 before the aircraft reaches 35ft above the takeoff surface.

V2 is the takeoff safety speed - this minimum speed must be reached before the aircraft reaches 35ft above the takeoff surface with one engine inoperative. It guarantees a specific climb gradient up to 1500ft for obstacle clearance. From the time the landing gear is retracted until 400ft (second takeoff segment), it guarantees a 2.4%, 2.7%, and 3.0% climb gradient for 2-, 3-, and 4-engine airplanes. Above 400ft (final takeoff segment) to 1500ft the climb gradients are 1.2%, 1.5%, and 1.7% for 2-, 3-, and 4-engine airplanes.

Vfto - the minimum speed for the enroute climb above 1500ft until the aircraft reaches a cruise altitude.

Or, if you don't accept the above explanation, you can figure it out yourself here. http://www.mrelativity.net/AComp/AccelComp3.htm

[turbo-prop]

Venr- One-engine inoperative final segment speed
In this case Veener happens to be the same as V2 (123kts) and usually is within a knot of V2 at flaps 0. Just like V1 is usually within a knot. When you get to 3rd segment (level off altitude 400ft AGL) flaps are retracted to 0 once you have accelerated to Veener, then move into 4th segment and climb away at Veener to 1500ft.

[Caracrane]

so with a T/O at 0 flaps youre V2 is the same as V(enr) so more simple if runway lenght permits.

[jjj]

Splitpin,

I dare not debate the science of what you have to say, however I must debate the practical application of some of these concepts and how they are trained on small biz jets and the like.

Flightsafety will teach guys to fly a profile like what you describe and then at 400 feet AGL, fly a level segment to accelerate to Venr speed and then climb away at that speed.

Some mountainous airports come to mind where this procedure would smack you right into a hill. Airports like Kamloops come to mind. Many airports publish steep climb gradients to well above 400 to clear obstacles and they would not allow for a level segment.

Wouldn't a procedure to maintain V2 until clear if terrain be more prudent before accelerating?

Also, I would suggest that not enough pilots take a look at their single engine performance and a lot are not even aware of it's capabilities. Not usually a big deal in most of flat land Canada, but it sure as hell matters in BC.

Also, many pilots also never take into account nor can they tell you what the ramifications are of the effects of having engine anti ice on and how it affects second segment climb. Citation and Learjet provide this correction right on the performance tables. If memory serves the penalty for a Citation II is 3% and about 2 for 30 series Lears.

Therefore, out of Kelowna, if you are in a loaded Citation II and are taking off with engine anti ice on and you lose a burner - you will not climb away.

Thoughts?

[turbo-prop]

jjj

The 1900 covers all that as well with T/O charts that include bleed air on, engine anti ice on, flaps 0 and 17. Bleed air off, engine anti ice off, and flaps 0 and 17. Bleeed air off off, engine anti ice on, flaps 0 and 17. And bleed air on, engine anti ice off, flaps 0 and 17.

Level off altitude is not always a hard number like in your example you would want to climb to a higher altitude before leveling off. That would be one of the advantages of taking off flaps 0 as Venr and V2 would be the same speed.

[jjj]

Excellent,

It seems that you turbo prop guys have a lock on the situation.

There are a few out there that believe that by virtue of being in a jet that they don't have much of a single engine problem - you guys could show them a few moves.

Later.

JJJ

[planett]

Some aircraft have a 50+ knot differential between V2 and Venr. This requires an acceleration and clean up after a turn back towards the airport, or to flatter terrain, or in a shuttle before commencing the Venr climb. A level off of 1500' or even sector, or to the extended emergency time limit on the engine will always be safer than the ancient 400' level off. This is necessary planning anywhere now, towers will kill you just as easily in IMC as mountains, just less often. And there are lots of towers near airports now that are close to 400' tall.

[Caracrane]

Thank you guys, thumbs up!

[4930s]

I've had this stall horn many times (at rotation and during initial climb). In my experience it has been a stall vane contamination issue, or during times when i"ve used type 4 de-icing fluid. this fluid dosent shear until 100kt so sometimes if it was sprayed around the stall vane it could delay the vane from rising and when the wirght comes off the wheels you could get a temporary stall horn.

[rigpiggy]

It rises during the stall, think stagnation point people. grrrr