Post by golfhobo on Oct 1, 2005 0:09:35 GMT -4
This thread is mostly for Obviousman. Anyone can read or respond if they wish, but it is just a way to post this for him to read:
The boldface I used to distinguish my analysis from the excerpts from the NTSB report didn't come through. After a page or so, I quit putting GH in front of my comments. However, since you've read the Final Report, I believe you'll be able to distinguish MY analysis and comments from those of the NTSB. If you have any problems with that, just ask me.
Much has been made (mostly by Dr. Fetzer) about why they were off course before they crashed. This analysis was originally posted on the yahoo forum we were discussing this on, and was specifically intended to explain to him WHY they were on a heading of 269° when they stalled. I have since made a few minor changes and will someday delete this edition and replace it. But, for now this is how I see it.
Final Approach Analysis
Shortly after 1018:31, as the airplane approached the published EVM VOR
runway 27 final approach course from the south at about 164 KCAS and decreasing, ATC instructed the flight crew to turn left to a heading of 300° until established on the final approach course.
GH: At this point, the ATC controller, using the wrong range setting on his scope, thought the plane was still south of the 276° radial (which is the approx extension of the runway centerline) by about 1 mile, and assuming they would execute the turn immediately, as directed, they would intercept it from the south at a 25° angle and about 6 miles out, requiring only a slight left bank to line up.
However, the flight crew overshot the approach course almost immediately after being issued the turn, and the airplane ultimately traveled for almost 1 mile north of the course as it continued the turn toward the course until establishing a ground track of about 262°.
GH: The plane is now heading slightly southwest (west being 270°) and approaching the centerline from the north east at about the same 25° angle of attack, but now he’s almost 2 miles west of where he was earlier, and his point of intercept will now be at 5 miles out. Furthermore, he has to lose the same amount of altitude with 1 mile less to do it, increasing his rate of descent (steeper dive.)
The airplane began its descent from 3,500 feet, and the airspeed began increasing about 1019:20.
GH: Before he began his descent, he was just a few knots over max speed for landing gear extension, and had he still had that 2 extra miles, he could have extended gear and followed the glide slope with a gentle rate of descent. Note: it was at this time that ATC turned him loose and he flew the rest of the flight more or less on his own.
The airplane should have been at 130 knots at the start of the descent with flaps at the approach setting and the landing gear down.
Because the airplane was fast at this point in the approach, the flight crew had to lose a significant amount of airspeed and altitude in a short amount of time. As the airplane descended through 3,200 feet, its airspeed and vertical speed peaked at about 170 KCAS and 1,400 fpm, respectively.
GH: This would have looked something like a bird tucking its talons and wings and diving for a fish (although not quite as steep.)
At 1020:06, as the airplane descended through 2,700 feet about 5 miles east of the runway 27 threshold, a right turn was initiated and the airspeed began decreasing from about 170 KCAS.
GH: This is a critical point in the flight and the analysis. At the very moment of peak airspeed and descent rate (170 KCAS vs. 130, and 1400 fpm vs. the 1000 set by the company’s Maneuvers guide,) the plane was crossing the runway azimuth of 276° and only halfway through his rapid descent down to the MDA (and still well up in the clouds.)
It’s important to note here, that had he been where the ATC thought he was at 10:18:13, and had he IMMEDIATELY responded to the order to turn left to 300° and maintain 3500 ft until approach azimuth intercept, he would have intercepted the approach at 6 miles out, and at 1,000 fpm descent he could have fairly ‘glided’ down to the MDA of 1,840 ft in 2 minutes and be almost about to break through the cloud cover at approach speed of 130 Knots at the expected point of 2 miles out from the runway threshold.
Instead, he’s still screaming through the clouds, with another 1,000 feet to drop and too fast to even put down his gear. At this point, he apparently throttles back to get below 156 knots and probably extends flaps to the full 30° to help slow down and drop altitude. He accomplishes this within 30 seconds while also executing a right bank to 269°.
When the airplane was approximately 4 miles from the runway threshold, it was still at 2,300 feet and about 160 KCAS; however, at this point in the approach, the airplane still should have been at an airspeed of about 130 knots.
GH: Assuming (as I am) that flaps and gear were extended almost simultaneously at this 4 mile point, and he had already throttled back in the process, the plane would have wanted to drop like a rock, so he obviously pulled the nose up. This accounts for the ‘leveling out’ of his angle of attack shown in the vertical profile in the NTSB report.
As stated previously, the flight crew initiated a slight right turn at 1020:06, as the
airplane passed through the final approach course (this time flying from north to south) about 5 miles east of the runway 27 threshold.
The airplane continued its’ slight right turn until it established a ground track of 269°, which it maintained until the end of the radar data. At this point, the airplane was south of the published approach course (of 276°); therefore, this turn did not allow the airplane to intercept the course, and the flight crew never effectively maneuvered the airplane to remain near the approach course.
WHY?? Why would they not turn right far enough to regain the approach course? They were obviously still conscious and flying the plane at least 2 ½ minutes after Ongaro’s phone rang. After all, they stopped the right turn at 269° and maintained it. Why did they turn to a heading taking them to a point still west and south of the runway?
Because they didn’t KNOW they had crossed the 276° radial. They certainly couldn’t SEE the runway being still in the clouds and supposedly looking at the instruments. But, the instruments were lying to them. They THOUGHT they were still north of the runway approach azimuth and thus were making a slight right turn to ‘merge’ in with it like you would from a highway onramp. They knew (or thought) they had to go LEFT of 276° or they’d be paralleling it on the north side. Here’s the proof:
To further study the accuracy of the EVM VOR, the Safety Board requested that
the December 23rd demonstration flight be flown using an airplane capable of digitally storing the signal obtained by the on-board VOR receiver. The study also used data derived from the October 2002 flight checks.
.
The results of the study confirmed that the EVM VOR was misaligned to the north by about 2.3° in the area between 5 to 10 miles from the station, which caused the on-board VOR receiver to calculate that the airplane was at a radial position NORTH of its actual physical location with respect to the station. This is consistent with flight check radar data from the October 2002 flight test.
The EVM VOR was restricted per a December 4, 1996, notice to airmen (NOTAM), which was still in effect at the time of the accident. The NOTAM indicated that the EVM VOR was unusable in the area from the 204° radial through the 264° radial and in the area from the 264° radial through the
204° radial beyond 20 miles and below 4,000 feet.
[This last paragraph is a little confusing to me as it appears to be a misquote where I highlited it, and it may have no bearing on the accident. I only included it because the 262° radial MAY fall into this area, and mostly because it shows there were known problems with the beacon.]
Now, before Jim starts hitting me with facts from the report (that he dismisses) that might sound like the VOR works fine, I’ll post them. Notice the difference between GROUND checks and flight checks.
About 1530 on the day of the accident, technicians from the State of Minnesota
conducted a standard ground check of the EVM VOR and found it to be transmitting normally. [Does ‘normally’ mean to include the known deviations?]
On October 26 and 27, 2002, the FAA conducted a series of flight checks on the
EVM VOR using a King Air A100. On both days, the signal was found to be misaligned about 2.3° to the north, but within tolerance (a maximum variation of ±2.5° is permitted) in the region between 5 to 10 miles from the station.
However, the signal was found to be out of tolerance for bends (a maximum distortion of +4.1° was measured; a maximum distortion of ± 3.5° is allowed) in this same region.
On October 28th, a State of Minnesota technician conducted another, more comprehensive post-accident ground check of the EVM VOR under the supervision of the FAA ATSS. The EVM VOR was again found to be transmitting normally.
GH: So, apparently it works fine unless you’re trying to fly into the airport on instruments. Now, to be fair, the report also says that it worked well enough to bring you close enough to the end of the runway when using the autopilot. But, it’s my contention that according to the data concerning rate of descent and course deviation, and especially considering my explanation of the choice of a 269° heading, I don’t believe these pilots WERE using the autopilot, and unfortunately, the NTSB couldn’t tell us. Perhaps, Bill Rees might have an opinion on this.
So, to recap: At 1020:06, the plane is screaming toward earth with gear and flaps up and it passes through the approach azimuth. The pilots think they are at a point NORTH of the approach and start a right hand turn they THINK will merge them with it on a heading of 269°. Within the next 30 seconds or so (1020:36) they drop flaps and gear, throttle back, and pull up the nose to a point that they couldn’t see the ground if they WEREN’T still in the clouds and probably about now activate the runway lights. They are way behind the plane and very busy and blind.
At 1020:54, when the airplane was 3 miles from the runway threshold, it was descending through about 2,100 feet and slowing through about 130 KCAS. They are still in the clouds and still too high. But, I “believe” at this time, they think the runway is just ahead of them and slightly to the left, so they drop the flaps to a full 30% for landing.
For the next 50 seconds (1 mile) while again dropping altitude rapidly (another 300 ft) and excitedly anticipating the sudden breakout from the clouds, they are looking straight ahead (and slightly left) for the runway lights (which are almost 45° out the right corner of that slushy window I mentioned before, and about a mile north of them) and NOT watching the airspeed. It continues to drop while the CDI needle is rapidly approaching full deflection.
What happens next will probably forever remain unknown, but one thing is sure. They did NOT fly straight ahead and into the ground. [As Jim has suggested at times might be the case if a ‘decoy’ VOR was used to fool them]
They either WERE paying attention and realized they were too slow and had reached the MAP (missed approach point) and/or the CDI deflected, and they ATTEMPTED a left turn to go around (which raises the stall speed) but didn’t have enough speed to hold the turn or,
they WEREN’T and came out of the clouds and saw trees where a runway should have been and “yanked” up on the stick causing an immediate stall because they were too busy looking for the runway to monitor speed and CDI or,
More likely, they were indeed still looking for the runway and thinking they were approaching the threshold, and just failed to maintain airspeed or notice the CDI.
But, whichever or whatever, the radar data conclusively shows they entered a stall, “slipped” to the left (which turned them exactly 89° degrees out of phase with their last known heading,) and plummeted into the trees in a southerly direction – 180° --- yes, Jim heading AWAY from the airport.
If they WERE trying to execute a go around, the following info would further indicate they failed to ‘re-configure’ the plane fast enough to avoid a concurrent stall:
The flap actuators were recovered. (According to Raytheon documentation, the
measurements taken of the flap actuators were consistent with the flaps being in the approach position [about 30 percent] at the time of the accident.) Inspections of the nose and main landing gear found indications consistent with the gear having been down at the time of impact.
ADDITIONAL COMMENTS FROM THE REPORT
Aviation Charter’s chief pilot stated that the landing gear should be extended when the flight crew starts the descent to the MDA and that the power should simultaneously be reduced to get down to approach speed.
However, the maximum speed for landing gear extension is 156 knots. The airspeed exceeded 156 knots when the airplane started its descent to the MDA and during most of the descent.
The chief pilot and other Aviation Charter pilots indicated that it would have been difficult to exceed 156 knots with the gear extended. Therefore, it appears that the flight crew did not properly configure the airplane at the start of the approach (extending the landing gear or reducing power before descending from 3,500 feet). [They HAD to delay extension because they were LATE, FAST and too close to the airport, and had to dive like the devil to get down to the MDA.]
The last two radar returns indicate that the airplane was at approximately 1,800 feet [420 ft. agl] (just beneath the cloud ceiling and possibly STILL in a random cloud or two, probably frantically searching for the runway in light snow that hits your windshield like a blizzard,) and slowing through about 76 KCAS, which is the approximate stall speed for the configuration in which the airplane was found after the accident. The last radar return was about 2 miles southeast of the runway threshold.
Handheld tape measurements, survey data, and aerial observations indicated that the airplane descended through the trees wings level and upright on about a 26° downward flightpath angle on a ground track of about 180°.
Here, the ‘wings level’ might well indicate that the pilots were STILL trying to control the plane and keep it in a position to stay above the trees if they could get enough lift. Most planes that crash “out of control” as Jim has suggested, tumble in either tail over nose, or wing over wing like a cartwheel.
The compass card and both indicator needles were contained within the plate display and were damaged by heat; however, the numbers were legible. The compass card was positioned with the number 180 directly beneath the lubber line. Indicator needle No. 1 was pointing to approximately 335°, and needle No. 2 was pointing to approximately 332°.
Help me out here, Rees. Doesn’t this indicate that the instruments were still functioning right up until it crashed?
Computations showed that the airplane’s position relative to the VOR course would result in the CDI needle likely at full deflection approximately 2.6 miles from the VOR station.
On December 16, 2002, the pilots who conducted the October 2002 flight checks
told Safety Board investigators that the VOR runway 27 approach took them
approximately 1 mile south of the field when hand-flying the approach (which is exactly where the accident plane was when it crashed,) but that it took them to the correct aiming point (the position from which a normal transition to landing can be made) when flown coupled to the autopilot. [Like I said, I don’t believe they were using the autopilot although, again, I believe their manual tells them they should.]
Further, in a January 8, 2003, written statement concerning the October 26, 2002, flight check, the PIC of the flights indicated that during the first test, while hand-flying the approach,
“approximately 7 miles from the runway we noticed that the approach radial was leading us to the right of runway centerline extended. As we continued the approach, we remained to the right of runway centerline extended until about 4 miles out. Then the approach radial began to lead us to the left of centerline. We crossed centerline extended and continued left of centerline. We ended up between 1 to 2 miles to the left of the runway at the MAP [missed approach point. We completed the approach again and the results were close to the same as the first run. On our third run we coupled the autopilot to the flight director and let it fly the approach. For most of the approach the autopilot held us
approximately ½ dot left of course. The autopilot took us to the runway, just left of centerline; however, the approach radial was found to have an out of tolerance bend.”
FOOTNOTES:
Bends are fluctuations in the calculated VOR radial position that occur slowly enough to be followed by a pilot under normal conditions. [There was nothing ‘normal’ about the conditions of this attempted landing.]
For example, with a +4° error in the VOR signal, a pilot would need to fly the airplane inbound on the physical 100° radial from the station to center the CDI needle on an indicated 096° radial inbound. [i.e. Pay attention! There’s a lot of work to do here.]
Conclusion
In his book, Jim mentions 2 or 3 witnesses, all of whom confirm that the plane was too low, too slow and almost silent as it approached the airport. If anyone has ever been in their position or on such a plane, you know that there is usually an ‘increase’ in power just before landing. Also, the witnesses all said they heard the explosion of the crash before they saw indications of a fire.
Although, the NTSB cleared both the EVM VOR and the weather, I can’t help but believe that both were contributing factors in this accident. But, neither can really account for why the pilots failed to maintain airspeed and altitude causing a stall from which they might SHOULD have been able to recover, but on this day, did not.
I hope, however, that with this analysis of the final moments of the approach, I have in some way explained how all these factors combined to ‘rob’ the pilots of the attention to detail that was necessary to successfully execute such a difficult landing.
My sincerest sympathies are extended to all who lost their life that day.
GolfHobo
The boldface I used to distinguish my analysis from the excerpts from the NTSB report didn't come through. After a page or so, I quit putting GH in front of my comments. However, since you've read the Final Report, I believe you'll be able to distinguish MY analysis and comments from those of the NTSB. If you have any problems with that, just ask me.
Much has been made (mostly by Dr. Fetzer) about why they were off course before they crashed. This analysis was originally posted on the yahoo forum we were discussing this on, and was specifically intended to explain to him WHY they were on a heading of 269° when they stalled. I have since made a few minor changes and will someday delete this edition and replace it. But, for now this is how I see it.
Final Approach Analysis
Shortly after 1018:31, as the airplane approached the published EVM VOR
runway 27 final approach course from the south at about 164 KCAS and decreasing, ATC instructed the flight crew to turn left to a heading of 300° until established on the final approach course.
GH: At this point, the ATC controller, using the wrong range setting on his scope, thought the plane was still south of the 276° radial (which is the approx extension of the runway centerline) by about 1 mile, and assuming they would execute the turn immediately, as directed, they would intercept it from the south at a 25° angle and about 6 miles out, requiring only a slight left bank to line up.
However, the flight crew overshot the approach course almost immediately after being issued the turn, and the airplane ultimately traveled for almost 1 mile north of the course as it continued the turn toward the course until establishing a ground track of about 262°.
GH: The plane is now heading slightly southwest (west being 270°) and approaching the centerline from the north east at about the same 25° angle of attack, but now he’s almost 2 miles west of where he was earlier, and his point of intercept will now be at 5 miles out. Furthermore, he has to lose the same amount of altitude with 1 mile less to do it, increasing his rate of descent (steeper dive.)
The airplane began its descent from 3,500 feet, and the airspeed began increasing about 1019:20.
GH: Before he began his descent, he was just a few knots over max speed for landing gear extension, and had he still had that 2 extra miles, he could have extended gear and followed the glide slope with a gentle rate of descent. Note: it was at this time that ATC turned him loose and he flew the rest of the flight more or less on his own.
The airplane should have been at 130 knots at the start of the descent with flaps at the approach setting and the landing gear down.
Because the airplane was fast at this point in the approach, the flight crew had to lose a significant amount of airspeed and altitude in a short amount of time. As the airplane descended through 3,200 feet, its airspeed and vertical speed peaked at about 170 KCAS and 1,400 fpm, respectively.
GH: This would have looked something like a bird tucking its talons and wings and diving for a fish (although not quite as steep.)
At 1020:06, as the airplane descended through 2,700 feet about 5 miles east of the runway 27 threshold, a right turn was initiated and the airspeed began decreasing from about 170 KCAS.
GH: This is a critical point in the flight and the analysis. At the very moment of peak airspeed and descent rate (170 KCAS vs. 130, and 1400 fpm vs. the 1000 set by the company’s Maneuvers guide,) the plane was crossing the runway azimuth of 276° and only halfway through his rapid descent down to the MDA (and still well up in the clouds.)
It’s important to note here, that had he been where the ATC thought he was at 10:18:13, and had he IMMEDIATELY responded to the order to turn left to 300° and maintain 3500 ft until approach azimuth intercept, he would have intercepted the approach at 6 miles out, and at 1,000 fpm descent he could have fairly ‘glided’ down to the MDA of 1,840 ft in 2 minutes and be almost about to break through the cloud cover at approach speed of 130 Knots at the expected point of 2 miles out from the runway threshold.
Instead, he’s still screaming through the clouds, with another 1,000 feet to drop and too fast to even put down his gear. At this point, he apparently throttles back to get below 156 knots and probably extends flaps to the full 30° to help slow down and drop altitude. He accomplishes this within 30 seconds while also executing a right bank to 269°.
When the airplane was approximately 4 miles from the runway threshold, it was still at 2,300 feet and about 160 KCAS; however, at this point in the approach, the airplane still should have been at an airspeed of about 130 knots.
GH: Assuming (as I am) that flaps and gear were extended almost simultaneously at this 4 mile point, and he had already throttled back in the process, the plane would have wanted to drop like a rock, so he obviously pulled the nose up. This accounts for the ‘leveling out’ of his angle of attack shown in the vertical profile in the NTSB report.
As stated previously, the flight crew initiated a slight right turn at 1020:06, as the
airplane passed through the final approach course (this time flying from north to south) about 5 miles east of the runway 27 threshold.
The airplane continued its’ slight right turn until it established a ground track of 269°, which it maintained until the end of the radar data. At this point, the airplane was south of the published approach course (of 276°); therefore, this turn did not allow the airplane to intercept the course, and the flight crew never effectively maneuvered the airplane to remain near the approach course.
WHY?? Why would they not turn right far enough to regain the approach course? They were obviously still conscious and flying the plane at least 2 ½ minutes after Ongaro’s phone rang. After all, they stopped the right turn at 269° and maintained it. Why did they turn to a heading taking them to a point still west and south of the runway?
Because they didn’t KNOW they had crossed the 276° radial. They certainly couldn’t SEE the runway being still in the clouds and supposedly looking at the instruments. But, the instruments were lying to them. They THOUGHT they were still north of the runway approach azimuth and thus were making a slight right turn to ‘merge’ in with it like you would from a highway onramp. They knew (or thought) they had to go LEFT of 276° or they’d be paralleling it on the north side. Here’s the proof:
To further study the accuracy of the EVM VOR, the Safety Board requested that
the December 23rd demonstration flight be flown using an airplane capable of digitally storing the signal obtained by the on-board VOR receiver. The study also used data derived from the October 2002 flight checks.
.
The results of the study confirmed that the EVM VOR was misaligned to the north by about 2.3° in the area between 5 to 10 miles from the station, which caused the on-board VOR receiver to calculate that the airplane was at a radial position NORTH of its actual physical location with respect to the station. This is consistent with flight check radar data from the October 2002 flight test.
The EVM VOR was restricted per a December 4, 1996, notice to airmen (NOTAM), which was still in effect at the time of the accident. The NOTAM indicated that the EVM VOR was unusable in the area from the 204° radial through the 264° radial and in the area from the 264° radial through the
204° radial beyond 20 miles and below 4,000 feet.
[This last paragraph is a little confusing to me as it appears to be a misquote where I highlited it, and it may have no bearing on the accident. I only included it because the 262° radial MAY fall into this area, and mostly because it shows there were known problems with the beacon.]
Now, before Jim starts hitting me with facts from the report (that he dismisses) that might sound like the VOR works fine, I’ll post them. Notice the difference between GROUND checks and flight checks.
About 1530 on the day of the accident, technicians from the State of Minnesota
conducted a standard ground check of the EVM VOR and found it to be transmitting normally. [Does ‘normally’ mean to include the known deviations?]
On October 26 and 27, 2002, the FAA conducted a series of flight checks on the
EVM VOR using a King Air A100. On both days, the signal was found to be misaligned about 2.3° to the north, but within tolerance (a maximum variation of ±2.5° is permitted) in the region between 5 to 10 miles from the station.
However, the signal was found to be out of tolerance for bends (a maximum distortion of +4.1° was measured; a maximum distortion of ± 3.5° is allowed) in this same region.
On October 28th, a State of Minnesota technician conducted another, more comprehensive post-accident ground check of the EVM VOR under the supervision of the FAA ATSS. The EVM VOR was again found to be transmitting normally.
GH: So, apparently it works fine unless you’re trying to fly into the airport on instruments. Now, to be fair, the report also says that it worked well enough to bring you close enough to the end of the runway when using the autopilot. But, it’s my contention that according to the data concerning rate of descent and course deviation, and especially considering my explanation of the choice of a 269° heading, I don’t believe these pilots WERE using the autopilot, and unfortunately, the NTSB couldn’t tell us. Perhaps, Bill Rees might have an opinion on this.
So, to recap: At 1020:06, the plane is screaming toward earth with gear and flaps up and it passes through the approach azimuth. The pilots think they are at a point NORTH of the approach and start a right hand turn they THINK will merge them with it on a heading of 269°. Within the next 30 seconds or so (1020:36) they drop flaps and gear, throttle back, and pull up the nose to a point that they couldn’t see the ground if they WEREN’T still in the clouds and probably about now activate the runway lights. They are way behind the plane and very busy and blind.
At 1020:54, when the airplane was 3 miles from the runway threshold, it was descending through about 2,100 feet and slowing through about 130 KCAS. They are still in the clouds and still too high. But, I “believe” at this time, they think the runway is just ahead of them and slightly to the left, so they drop the flaps to a full 30% for landing.
For the next 50 seconds (1 mile) while again dropping altitude rapidly (another 300 ft) and excitedly anticipating the sudden breakout from the clouds, they are looking straight ahead (and slightly left) for the runway lights (which are almost 45° out the right corner of that slushy window I mentioned before, and about a mile north of them) and NOT watching the airspeed. It continues to drop while the CDI needle is rapidly approaching full deflection.
What happens next will probably forever remain unknown, but one thing is sure. They did NOT fly straight ahead and into the ground. [As Jim has suggested at times might be the case if a ‘decoy’ VOR was used to fool them]
They either WERE paying attention and realized they were too slow and had reached the MAP (missed approach point) and/or the CDI deflected, and they ATTEMPTED a left turn to go around (which raises the stall speed) but didn’t have enough speed to hold the turn or,
they WEREN’T and came out of the clouds and saw trees where a runway should have been and “yanked” up on the stick causing an immediate stall because they were too busy looking for the runway to monitor speed and CDI or,
More likely, they were indeed still looking for the runway and thinking they were approaching the threshold, and just failed to maintain airspeed or notice the CDI.
But, whichever or whatever, the radar data conclusively shows they entered a stall, “slipped” to the left (which turned them exactly 89° degrees out of phase with their last known heading,) and plummeted into the trees in a southerly direction – 180° --- yes, Jim heading AWAY from the airport.
If they WERE trying to execute a go around, the following info would further indicate they failed to ‘re-configure’ the plane fast enough to avoid a concurrent stall:
The flap actuators were recovered. (According to Raytheon documentation, the
measurements taken of the flap actuators were consistent with the flaps being in the approach position [about 30 percent] at the time of the accident.) Inspections of the nose and main landing gear found indications consistent with the gear having been down at the time of impact.
ADDITIONAL COMMENTS FROM THE REPORT
Aviation Charter’s chief pilot stated that the landing gear should be extended when the flight crew starts the descent to the MDA and that the power should simultaneously be reduced to get down to approach speed.
However, the maximum speed for landing gear extension is 156 knots. The airspeed exceeded 156 knots when the airplane started its descent to the MDA and during most of the descent.
The chief pilot and other Aviation Charter pilots indicated that it would have been difficult to exceed 156 knots with the gear extended. Therefore, it appears that the flight crew did not properly configure the airplane at the start of the approach (extending the landing gear or reducing power before descending from 3,500 feet). [They HAD to delay extension because they were LATE, FAST and too close to the airport, and had to dive like the devil to get down to the MDA.]
The last two radar returns indicate that the airplane was at approximately 1,800 feet [420 ft. agl] (just beneath the cloud ceiling and possibly STILL in a random cloud or two, probably frantically searching for the runway in light snow that hits your windshield like a blizzard,) and slowing through about 76 KCAS, which is the approximate stall speed for the configuration in which the airplane was found after the accident. The last radar return was about 2 miles southeast of the runway threshold.
Handheld tape measurements, survey data, and aerial observations indicated that the airplane descended through the trees wings level and upright on about a 26° downward flightpath angle on a ground track of about 180°.
Here, the ‘wings level’ might well indicate that the pilots were STILL trying to control the plane and keep it in a position to stay above the trees if they could get enough lift. Most planes that crash “out of control” as Jim has suggested, tumble in either tail over nose, or wing over wing like a cartwheel.
The compass card and both indicator needles were contained within the plate display and were damaged by heat; however, the numbers were legible. The compass card was positioned with the number 180 directly beneath the lubber line. Indicator needle No. 1 was pointing to approximately 335°, and needle No. 2 was pointing to approximately 332°.
Help me out here, Rees. Doesn’t this indicate that the instruments were still functioning right up until it crashed?
Computations showed that the airplane’s position relative to the VOR course would result in the CDI needle likely at full deflection approximately 2.6 miles from the VOR station.
On December 16, 2002, the pilots who conducted the October 2002 flight checks
told Safety Board investigators that the VOR runway 27 approach took them
approximately 1 mile south of the field when hand-flying the approach (which is exactly where the accident plane was when it crashed,) but that it took them to the correct aiming point (the position from which a normal transition to landing can be made) when flown coupled to the autopilot. [Like I said, I don’t believe they were using the autopilot although, again, I believe their manual tells them they should.]
Further, in a January 8, 2003, written statement concerning the October 26, 2002, flight check, the PIC of the flights indicated that during the first test, while hand-flying the approach,
“approximately 7 miles from the runway we noticed that the approach radial was leading us to the right of runway centerline extended. As we continued the approach, we remained to the right of runway centerline extended until about 4 miles out. Then the approach radial began to lead us to the left of centerline. We crossed centerline extended and continued left of centerline. We ended up between 1 to 2 miles to the left of the runway at the MAP [missed approach point. We completed the approach again and the results were close to the same as the first run. On our third run we coupled the autopilot to the flight director and let it fly the approach. For most of the approach the autopilot held us
approximately ½ dot left of course. The autopilot took us to the runway, just left of centerline; however, the approach radial was found to have an out of tolerance bend.”
FOOTNOTES:
Bends are fluctuations in the calculated VOR radial position that occur slowly enough to be followed by a pilot under normal conditions. [There was nothing ‘normal’ about the conditions of this attempted landing.]
For example, with a +4° error in the VOR signal, a pilot would need to fly the airplane inbound on the physical 100° radial from the station to center the CDI needle on an indicated 096° radial inbound. [i.e. Pay attention! There’s a lot of work to do here.]
Conclusion
In his book, Jim mentions 2 or 3 witnesses, all of whom confirm that the plane was too low, too slow and almost silent as it approached the airport. If anyone has ever been in their position or on such a plane, you know that there is usually an ‘increase’ in power just before landing. Also, the witnesses all said they heard the explosion of the crash before they saw indications of a fire.
Although, the NTSB cleared both the EVM VOR and the weather, I can’t help but believe that both were contributing factors in this accident. But, neither can really account for why the pilots failed to maintain airspeed and altitude causing a stall from which they might SHOULD have been able to recover, but on this day, did not.
I hope, however, that with this analysis of the final moments of the approach, I have in some way explained how all these factors combined to ‘rob’ the pilots of the attention to detail that was necessary to successfully execute such a difficult landing.
My sincerest sympathies are extended to all who lost their life that day.
GolfHobo
