Caravan in YMM

[rigpiggy]

News of a Caravan Accident in YMM today any news

[ohoh]

http://www.cbc.ca/news/canada/edmonton/ ... -1.3914327

[J31]

That is a McMurray Aviation Grand Caravan C-GHLI. Was Wade flying?

I'm glad they are all ok.

[Mick G]

I wonder what the fuel situation was ?

[Independence]

Unusual that there is no flap deployed.

[rigpiggy]

if your trying to stretch the glide, why would you put out flaps

[godsrcrazy]

That is a McMurray Aviation Grand Caravan C-GHLI. Was Wade flying?

I'm glad they are all ok.

The new article says it was a privately operated Caravan.

[B-rad]

Putting out flaps doesn't stretch the glide but it stretches the flare. Putting them down at the right time could be helpful when short of a runway by 500 metres.
He's a very experienced pilot and everyone is ok so it looks to me like he made good decicions in getting to the ground safely regardless of where his flaps ended up.

[TintinaHR]

if your trying to stretch the glide, why would you put out flaps

Deploying the flaps in a Caravan at the very end will typically get you a couple of hundred more feet (and lower impact speed) but it could have been that something very solid was located a couple of hundred feet further on

[Redneck_pilot86]

It's been awhile, do the spoilers only activate with flaps deployed, or was it with a certain amount of aileron deflection?

[Rookie50]

Question -- is this an old wives tale or true:

How much distance could one gain in that scenario diving for the deck and trying to glide it farther in ground effect?

Would the inefficient dive lower wipe out ground effect gains?

Sounds like something cool to try in a Sim.

[J31]

if your trying to stretch the glide, why would you put out flaps

Deploying the flaps in a Caravan at the very end will typically get you a couple of hundred more feet (and lower impact speed) but it could have been that something very solid was located a couple of hundred feet further on

This happened about 530 pm and there might not been much to see in the dark given the sun set about 355 pm.

[J31]

That is a McMurray Aviation Grand Caravan C-GHLI. Was Wade flying?

I'm glad they are all ok.

The new article says it was a privately operated Caravan.

Ok, privately operated commercially registered Grand Caravan.

[Jean-Pierre]

Where did you guys hear flaps will stretch your glide? Seem it would to the opposite to me. Thank you.

[Boreas]

It's been awhile, do the spoilers only activate with flaps deployed, or was it with a certain amount of aileron deflection?

From what I remember, they deploy with an offside aileron deflection of 5deg... or was it 8deg. They're independent of flap position.

[Boreas]

Where did you guys hear flaps will stretch your glide? Seem it would to the opposite to me. Thank you.

If you deploy flaps at the very end you'll 'balloon' and delay your touchdown a little, thereby 'stretching' your glide.

Just a last minute method of gaining a couple of hundred feet.

[goingnowherefast]

Question -- is this an old wives tale or true:

How much distance could one gain in that scenario diving for the deck and trying to glide it farther in ground effect?

Would the inefficient dive lower wipe out ground effect gains?

Sounds like something cool to try in a Sim.

How far did you dive down, how much speed did you gain. Remember, the faster you are going, the less ground effect affects you. Also, you need to be really close to the ground to make any difference, especially in a high wing. If the terrain is smooth enough to be that close, just land on it, no need to extend the glide. Only exception being water I suppose.

You do see it as a tactic in sailplane racing. Except those guys carry enough kinetic energy to complete a small circuit and are doing it to win a race, not extend a glide.

[ThatArmyGuy]

Where did you guys hear flaps will stretch your glide? Seem it would to the opposite to me. Thank you.

If you deploy flaps at the very end you'll 'balloon' and delay your touchdown a little, thereby 'stretching' your glide.

Just a last minute method of gaining a couple of hundred feet.

This is a very effective method in a Twin Otter when going from 0 to 37.5 to gain that last 500 feet of ground distance. It's an exercise that is completed every time at flight safety in the event of dual engine failure - really neat to do and I thoroughly enjoyed it when it was the difference between with the side of an island, or hitting the runway

As for deploying flaps to increase your glide ratio, it's a matter of looking at the coefficients of lift versus drag because all else is equal for both the Lift and Drag equations- air density, velocity, and wing surface area. The maximum CL over CD will give you optimum glide. Almost always, flaps will increase the CD more than the CL and therefore lower your glide ratio.

In short, keep the flaps up until landing is assured.

[bodyflyer2]

Question -- is this an old wives tale or true:
How much distance could one gain in that scenario diving for the deck and trying to glide it farther in ground effect?
Would the inefficient dive lower wipe out ground effect gains?
Sounds like something cool to try in a Sim.

This isn't more of an aside for the thread in general but I'll answer it.

Sounds like one of those things where theoretically one could improve the distance covered, if one knew the exact characteristics of the aircraft, the exact headwind at different altitudes, and were able to fly the ideal profile exactly --- but in practice it probably isn't worth it to try, and likely becomes less applicable to something other than a sailplane that can make relatively good use of ground effect.

Has anyone studied this? Yes, there was a master's thesis report, "Glider Ground Effect Investigation" by a US military pilot in 1989 that both tested and simulated these choices for a Blanik glider at Edwards AFB. Not exactly a high performance sailplane these days. One of the project pilots was that Chris Hadfield guy, presumably when he was doing test pilot school.

I did manage to find the 132 page report online:
http://www.dtic.mil/dtic/tr/fulltext/u2/a209152.pdf

They did conclude that yes one can eke out a little more distance if done just right .... however, that in practice it just isn't worth it. Including in many situations the safety aspect of trying to skim along low in ground effect.

(After all, just getting the best glide speed for best range is already complex, depending on knowing the aircraft and the winds, although the sort of thing advanced glider avionics with GPS, airspeed, and an accurate built in polar can help predict and measure.)

Peter Chapman

[pelmet]

C-GHLI, a privately operated Cessna 208B Grand Caravan aircraft, was on a VFR flight from Camrose, AB (CEQ3) to Fort McMurray, AB (CYMM). During the descent through 3 000 feet ASL approximately 6 nautical miles South of CYMM, the RESERVOIR FUEL LOW warning light illuminated. The pilot completed the checklist for this emergency and informed ATC that the aircraft had an engine issue, however without declaring an emergency. The pilot continued to join the base leg for Runway 25 at CYMM. During the turn from base leg to final approach, the engine (Pratt & Whitney-Canada, PT6A-114A) lost power approximately 1 nautical mile from the runway. The pilot determined that the aircraft would not make the runway and elected to land on a service road east of the airport. ATC was notified and ARFF was dispatched to the area along with local Fire and EMS units. The aircraft landed in a field off airport property, approximately 1 400 feet South West
of the threshold of Runway 25. The pilot and the three passengers exited the aircraft with no injuries. The aircraft sustained substantial damage, however there was no post-crash fire.

[ditar]

If I recall correctly from my Caravan days, when that light comes on you have 90 seconds of fuel left.

[nine sixteenths]

From the maintenance manual, which sometimes disagrees with the POH and reality, the low fuel lights for the wings come on with 20-30 gallons per side left, and the reservoir low light with 1.95-2.20 gallons of fuel, which the manual equates to up to 3 minutes at full power or 12 minutes of partial power (not very realistic!)