ATR-72 engine failure after V1

[arman737ng]

Dear Pilots,
First of all, I thank you very much for taking time to check out the thread.

ATR-72
Engine flame out at take off(after V1) at what speed do you climb, after cleaning the aircraft? (consider full load)

Well, we remain at white Bug speed till level off/cruise level. Is it normal?
Is this really how it should be? or should it be higher?
I would even love to know different different operators standard, speed of climb? (plz dont mention the name)

One engine out, ceiling comes down to 20,000feet. I have even heard people saying it would stall at white bug speed if i have to climb 20,000 feet..

I would really appreciate if my fellow colleagues can put some light on it..

[rayfill]

Hi arman,

At acceleration altitude we increase the speed to white bug, and thats were we keep it during the climb. When you level off we increase the speed to 180 or higher, if it ever gets there:ugh:

Cheers,-

[Clandestino]

Engine flame out at take off(after V1) at what speed do you climb, after cleaning the aircraft?White bug in normal conditions. In icing condition white bug with flaps 15°. If circumstances warrant, we might clean up in level flight once past the red bug.


(consider full load)AUW considered in setting the bugs before startup.

Well, we remain at white Bug speed till level off/cruise level. Is it normal?Yes, given there are no icing conditions and only cruise that can take place is the one to take-off alternate.

I would even love to know different different operators standard, speed of climb? (plz dont mention the name)The way ATR wants it. It's the healthiest one - it comes with flight test team guarantee.

One engine out, ceiling comes down to 20,000feet.On 42-300 it could get below 11 000. Very entertaining when operating on routes with MEA around 13 000.

I have even heard people saying it would stall at white bug speed if i have to climb 20,000 feet..It might not climb to 20 000 ft at white bug but as long as wing is ice free and you are not practicing 45° banked turns, white bug keeps you out of stall.

EDIT:

This was the way we had flown in the days before PEC & EEC, I don't know whether 500s and 600s have dispensed with "climb with flaps 15" technique.

[Vc10Tail]

In cing conditions ...remain Flaps 15 (with MCT set).

About -600 series I would like to know.I believe this series resembles the A320 a little with its ECAM alerts and philosophy. It would be interesting to compare with Q400 and see which is superior in terms of systems and procedures.

[1jz]

its not gonna fall out of the sky at white bug speed Vmlb0, but one must maintain low bank config to avoid getting close to stall speeds at higher bank angles.. Atr42500 has the same procedure, at acceleration alt, one needs to accelerate to white bug n then maintain that till what ever u want to climb at.. white bug is also the best angle of climb speed so i think it would be the best to avoid any obstacles.
The drift down speed is also white bug n hence it proves its significance.

[Headinclouds]

For the 600, I believe, at VFTO (White bug), you select power management to MCT, which in turn automatically selects the FDAU for white bug speed. You climb at that speed.

In the Older models, there are two white bug speeds. These can differ by upto 10knots. In icing conditions, on single engine, you climb at the lower white bug speed. In Normal conditions, with two engines, you use the higher speed. Confusing? Yes that's ATR for you.......

For the emergency brief, always brief the two speeds, as you might need to know the difference....:D

[1jz]

theres a VMLB0 and VMLB15 speed.. or there is a white bug and a red bug.. i havent come through 2 white bugs untill now.. can u refer to which document guides you with 2 white bugs?

[bucks_raj]

The white bug speed corresponds to best L/D


Always climb at white bug icing or non icing

Icing- Flaps 15
Non icing - flaps 0

*rayfill said "Increase speed to whitebug"

That's incorrect .....

[rallye parachute]

How is it incorrect?
A/C climbs at V2+5 initially. At acc alt, ALT selected and allowed to accelerate to WB (normal or icing). Speed is increased to white bug on the ADU via the PTW.

WB speeds are at the back of the QRH.

[Mgggpilot]

For 72/42-500
Engine flame out at V1.... continue with take off (PNF checks Up-trim on live engine and autofeather on dead engine )
+ve rate of climb: Gear up, (up to this point you will be climbing with v2+5)
Acceleration altitude (500ft agl): Set alt....this meant to let speed increase
As speed reaches White bug.....set IAS on ADU, set MCT and flap to zero if normal conditions. If in icing conditions the flap will remain 15.

You note above that you will initially climb at v2+5 before climbing at White bug speed when you reach your acceleration altitude.

You had engine flame out at take off, why would you want climb to 20,000ft. You will basically climb to a safe altitude, hold somewhere for you to get some time to finish the checklist before initiating an approach. In a practical circumstance you will do a circuit if you are visual and land ASAP

[Frex]

@Mgggpilot

If I may, the procedure has changed recently :
Acc alt SET ALT, but At VFTO, P/L in the notch, PWR MGT on MCT and IAS WB.

It brings a mutual procedure with engine fire after T/O as it is exactly the same except that you perform those three steps at the Acc Alt (P/L, PWR MGT, IAS)

[JammedStab]

white bug is also the best angle of climb speed so i think it would be the best to avoid any obstacles.
The drift down speed is also white bug n hence it proves its significance.

Maybe then, it is not best angle of climb but a best rate of climb. Perhaps the best angle is V2+5.

Confirm anyone?

[1jz]

well white bug is the best angle of climb n best rate is actually bug+10.

[Mgggpilot]

C195, what 'bird' do you fly? Just curious

[1jz]

its complicated because ATR = Avions de transport regional.

[Stuck_in_an_ATR]

That's why we get paid big bucks on the ATR... :E

[JammedStab]

To expand a bit... I have never flown the the ATR but I met a friend recently who does and we were discussing the type and comparing it to the 340. The white bug/ red bug/ icing/ non-icing stuff seemed a little confusing at first.

For example (if I understood it correctly!), when using non-icing speeds you can select high bank at white bug if you keep the flaps at 15 degrees or you can retract the flaps at white bug and remain at low bank. But, you can't retract the flaps and select high bank at white bug.

Seemed reasonable. But, when using icing speeds you must wait until white bug+10 knots before you can select high bank (keeping the flaps at 15) or you can retract the flaps at white bug +10 knots but then you have to wait until red bug +10 knots until you select high bank. Did I understand it correctly? Anyway, whether I did or did not, it certainly seemed a bit complicated... green bug, yellow bug, white bug, red bug... + normal & icing conditions. The Saab was a bit simpler.

It is probably not that complicated. Just try to separate the icing conditions from non-icing conditions.

I wasn't on it very long but from what I can remember off the top of my head....

On all takeoffs, we set white bug and red bug speed. But depending on the environmental conditions, we ignore one of them for normal operations.

Usually we are in non-icing conditions. In this case, when accelerating through white bug speed, we can now retract the flaps(so it is your min clean speed). Because there were no icing conditions, you ignore the higher speed red bug even though it was set for departure.

But you are restricted to low bank(max 15°) until 10 knots higher at which time you can select high bank for the flight director and fly the aircraft at the higher bank angles. Therefore ATR came up with a complicated acronym calling this speed Vmlb0(V min for low bank for 0° flap). Many jets have some sort of restriction like this. Seem to remember a max 15° bank until V2+10 on the 737-200. 744 has similar to the ATR but only when heavy above 309,000 kg, so it is a common kind of thing, however they don't have a manual pushbutton for high bank/low bank on the flight director like the ATR.

In icing conditions, you can ignore the white bug for the most part and now use the normally ignored red bug for flap retraction speed. It sits about 10 or 15 knots above white bug speed depending on your weight. In this case, as you accelerate past white bug on takeoff, you continue and the at red bug do the same thing with the same type of bank restrictions.

Sort of similar for decelerating. White bug is normally your min clean speed unless in icing in which case it is the red bug. If I remember right, in severe icing, make it red bug+10.

That being said, white bug is your best lift to drag ratio(so therefore used for a driftdown target speed) and if you lose an engine on takeoff whether in icing conditions or not, you target white bug once above the acceleration altitude. But the red bug still applies for flap retraction purposes which may never be reached in some cases. That is why 4th segment can be more limiting than second segment on the ATR in some cases. Because of extended flaps.

There is a Vmhb0(high bank) as well in the ATR which is several knots above Vmlb0. This is retrieved from tables for reduced flap landing procedures.

The yellow bug, a target for a go-around speed. Green bug is V1 if different from VR which was an orange internal bug.

O.K., I went back to my notes. Vmhb0 is 1.3 times VS, Vmlb0 is 1.25 times Vs(maybe ATR did all this so they could certify with lower speeds and therefore better capabilities with some restrictions such as bank angle.) Vmlb for flaps 15 is V2.

But in icing conditions, the ratio is higher between Vs and min bank speeds as a precaution. Vmhb for flaps up or 15 is 1.5 times Vs, while it is 1.45 for Vmlb0. I see 3 different groups for flaps 15 with Vmlb15 ranging from 1.32 to 1.45 depending on what phase you are in(takeoff 2nd segment, normal climb, go-around). This is actually ATR-42 stuff by the way.

In the end, you don't really need to know this last portion, just follow the appropriate chart for takeoff and setting of bugs for approach and go-around and retract your flaps and limit your bank angles as appropriate, which is a limit of 15° until 10 knots above the white or red bug as appropriate for the conditions you are flying in.

Final approach speed is your orange internal bug which is at Vmhb 30 meaning proper protection is provided at 30° bank such as on your circling approach.

[JammedStab]

Great explanation, thank you! I still think it sounds complicated though, given it's just a small turboprop. I suppose you learn it quickly though.

Ok....instead of having the pilots memorize that there is an approximately 15 or so knots greater flaps up speed for icing conditions, a red bug is used on the airspeed indicator to display this info.

[bucks_raj]

At acc altitude when you SET ALT on ADU you get Alt Green, the ptw becomes inactive until VS or IAS is selected again.

so incase of engine failiure you set Alt at acc alt then accelerate to white bug and simply set IAS on adu once your at white bug, the speed captured by the ias mode will be the white bug speed (if IAS is pressed on reaching WB )

PS - Next time you have Alt green Try using the PTW