Flight testing still serves as a prerequisite for learning about the qualities and performance of the F-16, even after years of flying service. With an extensive modification like the Mid-Life Update, flight testing the now more capable F-16 is even more a prerequisite. Improved core avionics, new generic systems, and associated weapons that take the F-16 to new operational levels make the need for a prolonged flight testing program apparent. Testing those levels is the domain of the F-16 flight test office of the Royal Netherlands Air Force.

As a long-time user of the F-16, RNLAF maintains a separate unit for flight testing the F-16. Kantoor Testvliegen, or KTV, at Leeuwarden Air Base is the official home of the F-16 flight test office. At Leeuwarden, one of RNLAF’s three F-16 main operating bases, the unit uses a specially instrumented F-16B MLU aircraft for its testing purposes. “We have been here at Leeuwarden since we changed to MLU in 1999,” says Maj. Tjebbe “Speedy” Haringa, F-16 test pilot and head of the KTV. He, together with a flight test engineer and an electronics specialist, forms the KTV team that operates the RNLAF’s MLU test jet. Haringa, a graduate of the Empire Test Pilot School at Boscombe Down in England, has been flying F-16s since 1981 and has amassed well over 2,000 hours in the Fighting Falcon.

KTV had operated out of Volkel Air Base with a specially instrumented Block 15 OCU F-16B as a test aircraft. “When we received our MLU test aircraft in June 1999,” explains Haringa, “it was obvious that Volkel would have difficulties supporting us because it was still fully equipped with Block 15 OCU jets.” With the Leeuwarden squadrons already converting to MLU aircraft, relocation was obvious. “Besides,” continues Haringa, “we are sitting right next to our test air space here, which enables us to reduce our flying time without cutting back on our testing activities. We can make more efficient use of our test sorties from here.” Considering that the KTV is a single-aircraft unit, this proximity to airspace constitutes a major factor in the move as well.

323 Squadron at Leeuwarden, also known as the Tactical Training, Evaluation, and Standardization Squadron, or TACTESS, accommodates this small test unit. The KTV relies on 323 for logistical support but does not report to it for operational control. Instead, the KTV reports to the RNLAF Chief of Staff through the operational research and evaluation section at the Air Staff in The Hague. This high level of reporting underlines the special position of the test unit.

Nonetheless, 323 Squadron is a close associate of the KTV because it services the MLU test jet. The crew chief and assistant crew chief of the test aircraft are part of 323 Squadron rather than of the KTV. For testing activities that do not require special instrumentation, the squadron borrows one of its own F-16 two-seaters when the test aircraft is not available. “We put a strain on the 323 every now and then,” Haringa admits. “Some of our test flights require support from 323 on short notice, but the squadron never lets us down. The guys are a great help to us.”

Orange Jumper

The MLU test aircraft is a one-of-a-kind F-16. The RNLAF developed the requirements and specification, but the NLR, the national aerospace laboratory in the Netherlands, developed the modifications. The aircraft called Orange Jumper, a nod to the orange test wiring installed in the aircraft, was modified at Woensdrecht Air Base when it went through the MLU program. A key RNLAF requirement was that the modifications not affect the aircraft’s operational capabilities. (Modifications to the previous F-16 test aircraft made it unsuitable for operational use.) To meet that requirement, the aircraft’s special instrumentation is compact size with some detachable systems. More importantly, the MLU test aircraft retains its gun. As a result, only a few external features on the F-16 test jet distinguish it as a test aircraft. In addition to the Orange Jumper markings on the tail, the most catching feature on the aircraft is an extended pitot tube with sideslip meters.

The inside of the Orange Jumper looks like a test jet for sure, particularly the backseat cockpit. This realm be-longs to Capt. Hielke Bosma, the unit’s flight test engineer, who like Haringa is an ETPS graduate. “We installed a separate computer in the rear cockpit to control the instrumentation,” he explains. “The computer’s display atop the front panel can be repeated on the right multifunction display in the front cockpit.” The aircraft features an onboard telemetry system that allows the flight test engineer to monitor test results in-flight and in real-time. “This system allows us to assess test results immediately, which gives us the opportunity to redo the test if we want while we’re still airborne,” Bosma notes. All flight data can be stored on a test data recorder located in the left side panel. The front cockpit features a few minor modifications as well. Repetition of the real-time data in the front cockpit, such as AOA and sideslip, assists the pilot in applying control inputs during certain test profiles. The aircraft can also be fitted with cameras in the chaff/flare launchers, on the wingtip stations, and in a small blister just aft of the cockpit. The camera is used to record wing flutter and separation tests.

Test Activities

The KTV is primarily involved in development test and evaluation, DT&E, to certify and verify tests for the RNLAF material directorate. The ensuing operational test and evaluation, OT&E, is performed by 323/TACTESS, specifically by the weapons instructors. “DT&E and OT&E are strictly separated,” points out Haringa. “OT&E is an entirely different game as it deals with tactics. 323/TACTESS is quite apt for this game.”

Part of the testing the KTV performs includes determining the handling qualities of the F-16 in certain weapons configurations that include the Pylon Integrated Dispenser System, or PIDS, in combination with the AMRAAM missile and the MK-84 bomb. The KTV recently tested a new anti-g suit, performed ammunition tests, and did flare trials for the NLR. “We sometimes do tests for contractors,” says Bosma. “Last year, we test flew a new composite drag brace made for the F-16 main landing gear by SP.”

Once the MLU was introduced into the RNLAF, the KTV became involved in certifying new weapon systems for the MLU F-16s. Its most important project was to determine the handling qualities of the MLU F-16 with intake stores. “We performed directional stability tests with the GEC-Marconi Falcon Owl navigation pod as part of the certification process for the RNLAF,” explains Haringa. Recently, the unit tested the laser spot locator of the navigation pod. The pod has since been selected by the RNLAF for its F-16 MLU fleet.

Targeting Pod

Falcon Owl is used with the AN/AAQ-14 targeting pod of the LANTIRN system. The KTV played a key role in the 1999 debut of the targeting pod into RNLAF operation after NATO planners required an increased capability for delivering precision-guided munitions during Operation Allied Force. Since the RNLAF was planning to receive its first pods later that year, the delivery and acceptance process was hastened to field the pod sooner.

The software to use the pod on an MLU platform had already been tested at Edwards AFB, California. “Through our representative at the F-16 SPO, we were cleared by USAF to use the software,” recalls Haringa. What remained was for RNLAF to certify the pod on the MLU F-16. USAF agreed to deliver three pods to the RNLAF, and the RNLAF compressed a hectic testing program to a few weeks to certify the pod temporarily. Haringa flew most of the test sorties. “On average, we flew three sorties a day to test the pod for handling qualities with all kinds of weapon loads,” continues Haringa. “We also tested the pod in combination with AMRAAM and PIDS pylon.” As a result of this joint effort between the RNLAF and the KTV, the RNLAF was able to field the pod at the F-16 detachment in Amendola, Italy, and NATO received a precision guided attack capability to support Operation Allied Force, both in short order.

International Contacts

In addition to testing for the RNLAF, the KTV flight tests systems for foreign operators. It performed radar trials for the European Participating Air Force partners. It evaluated the handling qualities of the aircraft carrying the Danish Modular Reconnaissance Pod from Terma. It has currently been flight testing a PIDS-3 pylon instrumented to record vibration levels. Haringa knows why the list is growing. “Our biggest strength lies in our flexibility. The fact that we are such a small team reporting directly to the air staff allows us to respond to requests swiftly. Besides, we have a full envelope jet available here for testing. It’s state of the art,” he stresses.

The USAF Seek Eagle office from Eglin AFB and Lockheed Martin are combining forces with the KTV for the PIDS-3 Pylon and stores flight test program. (The Seek Eagle office, located at Eglin AFB, Florida, certifies stores for carriage on combat aircraft.) “We started building our test schedule months ago,” says Don Wages, a flight test engineer from Lockheed Martin on assignment at Leeuwarden on the joint USAF Seek Eagle/Lockheed Martin test project with the KTV. “I am surprised to see how quickly everything came together.” According to Terry Lester, a structural dynamics engineer from Lockheed Martin, the cooperation has been very rewarding so far. “The unit here is responsive to our needs. Our combined talent has resulted in a good team effort.”

From a professional viewpoint, such a joint testing project offers distinct advantages. “It’s good experience for us to share data and knowledge,” says Capt. Brett Barton, a Canadian exchange officer representing the Seek Eagle office during the PIDS-3 and stores flight testing at Leeuwarden. “Joint testing is not that common. The operations community does it all the time. But to us in the test community, a joint project is rather novel. It is an excellent opportunity for us to make ourselves known a bit more. It is good to establish our own contacts with occasions like these.” Adds Bosma, “We have established relations with the F-16 Combined Test Force at Edwards, but most of our contacts go through the SPO. We seldom have face-to-face exchanges.”

Test projects, such as these, illustrate a continued need for F-16 flight testing as long as the Fighting Falcon is around. New systems will emerge; new requirements will arise. Evidently, the KTV will continue to have a busy calendar.

Eric Stijger is an aviation journalist based in the Netherlands.