I don't understand what happened to this Cessna 150. What does the C-130 have to do with the accident?

Question

http://www.ntsb.gov/ntsb/brief.asp?ev_id=16615&key=0

I see 180 degree answers to this one.

I am not knowledgeable enough to choose "the best answer". I'll let the forum pick the right answer on this one.

Answer 1

As I have pointed out before, if you dont have a copy of the FAA's "Pilots Handbook of Aeronautical Knowledge, get one! you NEED this among many publications in your study of becoming a Pilot. Many knowledge test questions are covered here.
For the question at hand, Wake turb is a Killer, you need to know how to avoid it. See chapter 12, specifically 12-12.
It is available on line in PDF, but I recommend a hard copy for student pilots, you will refer to it often!

Pilots Handbook of Aeronautical Knowledge is on line at:
http://www.faa.gov/pilots/training/handbook/

Chapters 10-12 is at:

http://www.faa.gov/library/manuals/aviation/pilot_handbook/media/faa-h-8083-25-3of4.pdf

Also in the AIM (you do have a copy of the FAR/AIM dont you ?
see 7-3-1 for info as well
http://www.faa.gov/airports_airtraffic/air_traffic/publications/atpubs/aim/Chap7/aim0703.html

Answer 2

The kid got into the wake of the departing 130. Aircraft destroyed, 1 fatality. So says the report. As soon as the 130 broke ground the wings started generating the familiar vortex pattern. On a still day such as you might find on the desert, that vortex can linger quite a while, as in several minutes. The report says he made an intersection take off. That could easily have put him smack in the middle of the turbulence. The vortex would have turned the little Cessna every way but loose. There is a prescribed method for dealing with vortex turbulence and includes a lot of factors. Obviously the kid didn't know about them.

Answer 3

The vortices coming off the wingtips of a heavy aircraft, especially in take-off configurations, with light wind conditions can hang on a runway for as long as 5 minutes, depending on the direction of the wind. These vortices are powerful enough, even two minutes later, to overturn a small aircraft like a Cessna 150. If I'm not mistaken, Mirana is a towered airport. I'm surprised they allowed a small plane to follow so quickly, although I'm sure they gave the standard warning of "beware wake turbulence".

I've been in wake turbulence a couple of times, but in aircraft large enough to not be flipped. It can still be a handfull.

Answer 4

Wake turb can get pretty bad. When we do a C-130 mass launch for a formation, they take off every 15 seconds. After the second one, you can see the aircraft tipping and dipping pretty good. We did a 12 aircraft launch in Italy, and the last 5 were all over the place.

Answer 5

They say a picture is worth 1000 words, go look at the graphic of "wake turbulence" from AOPA it is a really good depiction of disturbed air which follows an aircraft. The larger the aircraft the larger the disturbance!

http://www.aopa.org/asf/safety_alerts/waketurbulence.html

Now picture trying to fly into that in a Cessna (he couldn't see it but it was there!)

Answer 6

well

the C-130 is a larger aircraft. as it took off two minutes earlier, its body and wings spread off eddies of air (because of its size, actually pretty large eddies of air). the Cessna tried to take off in this disturbed air and actually was forced down due to it.

The fact that the C-130 was probably making the most of this disturbed air at the halfway point on the runway, and the fact the Cessna tried to take off at the halfway point intersection instead of going all the way to the end of the runway (where the air had probably settled down) were factors in the planes crash.

Answer 7

The C-130 probably had nothing to do with the accident. It was the last aircraft to use the runway about 2 minutes before the 150 took off.

Based on the report, it sounds like the Cessna tried to take off too quickly, probably exceeded it's climb rate and stalled. With no altitude to recover it probably nosed onto the tarmac. I've personally witnessed this twice with small private planes - once in Scott's Valley and once in Camarillo.

Small Cessna's need an easy climb-rate, all the airspeed and runway they can get to successfully launch, especially with two on board and if there is any crosswind at all - forget it. The report mentioned light wind.

Davis-Monthan AFB is the largest military boneyard in the nation with lots of derelict military planes in dry storage. The pilot was probably a military newbie trying to get his hours in. As a military facility the tower would've followed strict protocol and SOP's in clearing the smaller plane. I believe this was pilot error...