Issue Number 208
October 1996
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System
P.O. Box 189, Moffett Field, CA 94035-0189

Avoiding "SAR" While IFR

Most pilots may believe that the meaning of "clearance void time" is pretty obvious--the time after which a given IFR clearance is not longer valid. But there is more to know about the phrase, as this flight instructor learned:

  • I told my student to file an IFR flight plan, [then] had him amend it when he called back for clearance pickup. The student was issued a release time and a void time... The void time was only 10 minutes after the phone call, and I didn't see that we would make it off in time. We departed [on a local flight] 5-8 minutes after our void time, and assumed the plan was canceled. [I thought] if you were not off the ground by the void time, and no phone call was made [to ATC]...the flight plan was canceled. Not so, as I learned when we returned. The Controller had made numerous phone calls, looking for us.

Section 5-2-4 (Departure Procedures) of the Aeronautical Information Manual (AIM) offers this clarification: "A pilot who does not depart prior to the clearance void time must advise ATC as soon as possible of their intentions... This time cannot exceed 30 minutes. Failure of an aircraft to contact ATC within 30 minutes after the clearance void time will result in the aircraft being considered overdue and search-and-rescue [SAR] procedures initiated."

Another instance when search-and-rescue procedures may be initiated is described by our next reporter, who mistakenly believed that a VFR flight plan could be "converted" to an IFR flight plan en route without first closing the VFR flight plan segment:

  • I filed a VFR flight plan... The flight departed VFR normally and [soon] I was on top, VFR, with a solid undercast... The sky cover became broken with building cumulus due to a developing line of thunderstorms. Being IFR rated, both pilot and airplane, I obtained an IFR flight plan from Center by converting my VFR plan. I was cleared IFR to destination by Center. However, I decided to land...and was cleared to the ABC airport by Center and handed off to the Tower (a non -federal tower) and landed.

    After the weather had passed and [we] had some food, we departed for destination VFR. I called FSS to obtain a weather briefing and to file a VFR flight plan and was advised...that a search-and-rescue had been initiated for us because I neglected to close my VFR flight plan. I assumed that because I had converted to an IFR plan and landed at a tower-controlled airport, that my plan was automatically closed. The FSS told me that...I should have closed my VFR plan personally and separately.

    After talking to other pilots later, I realized they also would have assumed the original VFR plan would automatically have been closed and would not have closed it separately...

Section 6-2-7 of the AIM offers these cautions in filing VFR flight plans: "If you land at a location other than the intended destination, report the landing to the nearest FAA FSS and advise them of your original destination... The pilot is responsible for closure of a VFR...flight plan; they are not closed automatically."

See-and-Avoid While IFRF-14 Fighter Aircraft and  Boeing 747 NMAC

Whenever the pilot of one aircraft can see another aircraft, the see-and-avoid-concept applies. FAR 91.113(b) explains: "...When weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules [ASRS emphasis], vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft." One reason for this regulation is that ATC radar coverage has limitations, and may fail to display ("paint") some VFR traffic. These radar limitations may make it impossible for the controller to issue timely traffic advisories.

An ASRS report from an air carrier flight crew provides a vivid example of how important the see-and-avoid concept is, even under instrument flight rules:

  • Flight in cruise at 15,000 feet. Center advised traffic...opposite direction, 14,500 feet, about 5 miles. No TCAS return until 3 miles. First TCAS return was a Resolution Advisory (RA), "Climb, Climb now!" We had not established visual at this point so I disconnected the autopilot and immediately began climb to comply with the RA. At 15,300 feet in the climb, the First Officer (FO) stated, "There's two! One above us!" I immediately stopped climb to avoid second aircraft visually. They were gone as fast as they appeared--two F-15s, one transponder, at different altitudes, right on the departure transition and Victor airway [route]. The FO stated the F-15s appeared to be in afterburner. In any case, they were so fast we were lucky to see and avoid the non-transponder aircraft.

    Center was advised of the situation and compliance with RA. They apologized for not giving a vector, but said the aircraft just "popped up" fast moving and that [Center] was not talking to them..."

Kudos to the First Officer for see-and-avoid vigilance during the TCAS evasive maneuver.

Customs North and South

A fly-it-yourself trip across the Canadian or Mexican border can be a pleasant expedition, if the pilot is knowledgeable about all the details for clearing U.S. Customs both going and coming back. Some ASRS reporters share their Customs confusion--and their misfortunes.

  • On a business flight returning from Canada to [Pennsylvania airport], we had to stop at [New York airport] to clear U.S. Customs... Approach cleared us for an intercept to minimize exposure to the ice. Nevertheless, we picked up about one-quarter inch--enough to obscure the windshield. After an uneventful landing, we cleared Customs. Prudence dictated we not attempt to climb back out in the drizzle, so we rented a car and drove to our destination.

    The next day, I drove back to [New York airport], and flew out, after $168 worth of glycol to get rid of the one-half inch of ice. [Later], I called Customs to see if this had been truly necessary... It turns out that the "clear Customs at the first [designated airport] after border crossing" rule only applies to the Southern border, not the Canadian border. I had never seen anything about a distinction between the Mexican/Caribbean and Canadian borders.

    I got myself in a potentially dangerous situation because I believed that I was obliged to deal with Customs at [New York airport]. In fact, I could have gone to Pennsylvania [airport], where it was VFR. This obviously isn't in the "narrowly averted disaster" category...but it's something folks should know about that's not easily obtainable info.

Pilots who file their flight plans from Canada may proceed to the first U.S. airport of intended landing--as long as the airport has Customs services, and the required Customs notifications are made. However, pilots arriving from south of the Mexican border or the Pacific, Gulf of Mexico, or Atlantic coastlines must adhere to special reporting requirements, which specify Customs notification at the "nearest designated airport" to U.S. border crossing. The U.S. Customs Service offers a pamphlet with additional information, U. S. Customs Guide for Private Flyers. It may be mail-ordered from the U.S. Government Printing Office, Superintendent of Documents, Mail Stop: SSOP, Washington, DC, 20402 -9328. The GPO Internet site for ordering documents is: http:/

Our next reporter, en route to the U.S. from Mexico, encountered stronger headwinds than expected over the Gulf of Mexico, and was forced to land short of the originally filed point-of-entry. In this incident, the pilot's "notification" to Customs didn't meet the requirements specified above.

  • I informed [U.S.] Center of a fuel emergency...and got a clearance to land [at an alternate airport]... I hoped that our emergency declaration sufficed as notice for penetrating the ADIZ and for the one-hour notice to Customs. My total attention was taken up with trying to fly the airplane... Customs did show up at the strip...and thoroughly searched the plane with the use of narcotics-sniffing dogs.

ADCUS Not Fail-Safe

  • Departed Mexico on an IFR flight plan. Upon landing and parking at U.S. Customs, I was asked if I had called ahead to let them know I was coming. I replied that I had an IFR flight plan, with them as my first stop. I was informed that they had not received it... After a check was made by Customs, it was found that the IFR flight plan was not passed to the U.S. side of the border.

Although a pilot may include an "Advise Customs" (ADCUS) message in the remarks section of the pre-departure flight plan, this method may not be as timely or reliable as direct communications by telephone or radio. Since it is ultimately the pilot's responsibility to ensure proper notification, it is advisable that pilots contact Customs directly.

"Creature Feature" in a Cobweb

Last year about this time, we reported an incident involving mud daubers, wasplike insects with a penchant for building nests in generally inaccessible places in aircraft. A recent report to ASRS provides an even more dramatic mud-dauber horror story.

  • We were being vectored, approximately 10 miles from the airport, when we heard a loud bang and the aircraft jolted. We looked for the cause and saw that the top of the right wing was caved in and badly distorted. I realized that aileron movement was very restricted or impeded. We decided to declare an emergency. After landing and inspecting the aircraft, we found that the bottom of the wing was also caved in.

An ASRS analyst's callback conversation with the reporter revealed that a mud-dauber nest was found in the fuel tank vent, too far into the vent to be visible during preflight. This problem was exacerbated by a recent paint job, which had left a small amount of paint covering the fuel cap vent. With no air entering the fuel tank from either vent, the tank imploded, damaging the wing.

Another reporter ascribed a delay in bringing a local Automated Surface Observation System (ASOS) online to the construction genius of an eight-legged architect:

  • A spider built a web on a sensor and the ASOS was reporting snow with the temperature in the 90s. This problem was supposedly solved with insect repellent paint. It remains to be seen how long that will be effective...

 ASRS Recently Issued Alerts On.

 ATC radar "dead spots" near a North Carolina VORTAC
 Hazardous position of an arresting cable at a NY airport
 Abrupt pitch-up and roll in a B-747A attributed to failed INS
 Altitude deviation attributed to SA227 runaway stabilizer trim
 False airspeed indication caused by A-300 pitot heat failure

 July 1996 Report Intake

 Air Carrier Pilots


 General Aviation Pilots